ABSTRACT
Abstract
A robot controller for controlling a robot arm includes a first space shaping module configured to provide a shaped first space target motion by convolving a first space target motion with an impulse train, where the first space target motion defines a target motion in a first reference space; a second space shaping module configured to provide a shaped second space target motion by convolving a second target motion with the impulse train; where the second target motion defines the target motion in a second reference space; and a motor controller module to generate motor control signals to the joint motors based on the shaped first space target motion and the shaped second space target motion.
Description
This application is a U.S. national stage entry of PCT application no. PCT/DK2021/050155 which was filed on May 14, 2021. PCT application no. PCT/DK2021/050155 claims priority to Denmark application no. PA202070318 which was filed on May 14, 2020. This application claims priority to both PCT application no. PCT/DK2021/050155 and to Denmark application no. PA202070318. Both PCT application no. PCT/DK2021/050155 and Denmark application no. PA202070318 are incorporated into this this application by reference.
FIELD OF THE INVENTION
The present invention relates to control of a robot arm, where vibrations of the robot arm are suppressed by utilizing input shaping. The robot arm comprises a plurality of robot joints connecting a robot base and a robot tool flange and a part of the robot arm (e.g. the tool flange) is controlled with reference to a cartesian space.
BACKGROUND OF THE INVENTION
Robot arms comprising a plurality of robot joints and links where motors or actuators can move parts of the robot arm in relation to each other are known in the field of robotics. Typically, the robot arm comprises a robot base which serves as a mounting base for the robot arm; and a robot tool flange where to various tools can be attached. A robot controller is configured to control the robot joints in order to move the robot tool flange in relation to the base. For instance, in order to instruct the robot arm to carry out a number of working instructions. The robot joints may be rotational robot joints configured to rotate parts of the robot arm in relation to each other, prismatic joints configured to translate parts of the robot arm in relation to each other and/or any other kind of robot joints configured to move parts of the robot arm in relation to each other.
Typically, the robot controller is configured to control the robot joints based on a dynamic model of the robot arm, where the dynamic model defines a relationship between the forces acting on the robot arm and the resulting accelerations of the robot arm. Often, the dynamic model comprises a kinematic model of the robot arm, knowledge about inertia of the robot arm and other parameters influencing the movements of the robot arm. The kinematic model defines a relationship between the different parts of the robot arm and may comprise information of the robot arm such as, length, size of the joints and links and can for instance be described by Denavit-Hartenberg parameters or like. The dynamic model makes it possible for the controller to determine which torques and/or forces the joint motors or actuators shall provide in order to move the robot joints for instance at specified velocity, acceleration or in order to hold the robot arm in a static posture.
Robot arms need to be programmed by a user or a robot integrator which defines various instructions for the robot arm, such as predefined moving patterns and working instructions such as gripping, waiting, releasing, screwing instructions. The instruction can be based on various sensors or input signals which typically provide a triggering signal used to stop or start at a given instruction. The triggering signals can be provided by various indicators, such as safety curtains, vision systems, position indicators, etc.
Typically, it is possible to attach various end effectors to the robot tool flange or other parts of the robot arm, such as grippers, vacuum grippers, magnetic grippers, screwing machines, welding equipment, dispensing systems, visual systems etc.
A collaborative robot is a robot designed for direct interaction with a human. Light-weight design is one of the main concerns, when a robot is designed to be collaborative. This is to reduce the impact in a potential collision with a human or an obstacle. Thus the design will be a compromise between low mass and high rigidity. Light-weight design is a major goal in current development of robots, cranes, and automotive industry, just to name a few. A light-weight design is motivated by for example increased performance, increased safety, reduced environmental footprint, reduced energy consumption, and reduced price. A light-weight design will feature an increased amount of mechanical flexibility, compared to the traditional heavy and rigid industrial robots, which are often based on a cast iron design.
A robot arm motion can move its end-effector from one position two another in infinitely many ways. The most common motions are described in either joint space or Cartesian space. In robot arms with rotational robot joints the joint space motion is most natural for the robot actuators and is the fastest motion. The end-effector motion will in joint space motions follow a curved profile. The linear Cartesian motion leads to a linear end-effector motion, and a corresponding joint space motion, which can include high accelerations in different joint directions.
Robots with mechanical flexibility pose a challenge in terms of performance. For example, when rapid point-to-point motions are desired, and mechanical vibrations are not acceptable. Therefore, it is desired to suppress mechanical vibrations in robot arms. This can for instance be achieved by utilizing input shaping methods, which slightly modify the target motion of the robot arm, by intelligently adding a time-delay. The modified(shaped) trajectory will reduce the amount of vibrations at the critical natural frequencies of the system.
Input shaping for industrial robots has been implemented in both joint space and Cartesian space. Most implementations are in joint space, which is the natural control space of the robot, e.g. {iii.}-{iv.}-{v.}-{vi.}{vii.} Multiple researchers noticed Cartesian trajectory deviations related to joint space input shaping. Cartesian space input shaping for robots has been suggested and compared to joint space input shaping in order to reduce the path deviation {viii.} {ix.}{x.}.
WO19012040A1 and corresponding scientific articles {i.} {ii.} disclose a method for generating inputs to a physical system with varying dynamic properties, which can be used to suppress the mechanical vibrations of a robot arm. The control signals to the robot arm are generated based on the dynamic properties of the physical system which for instance can be obtained based on dynamic modeling of the physical system, lookup tables containing dynamic properties of the physical system, measurements of parts of the physical system, or a combination of the aforementioned. WO19012040A1, {i.} and {ii.} utilizes a Time-Varying input Shaping method in joint space. Time-Varying Input Shaping has never been presented in Cartesian space. The existing research on Cartesian input shaping for robot arms relies on a trajectory generator, which outputs Cartesian reference position instead of joint angles.
Vibration suppression can be effective in either filtering space. However, a joint space filter will cause deviations of a Cartesian path. Likewise, a Cartesian filter on a joint space motion undermines the benefits of linear joint space motions, such as short duration without exceeding actuator limits. In general, joint space motions will benefit from joint space filtering, and Cartesian motions will benefit from Cartesian space filtering.
It is possible to switch between the two methods when the robot is at a standstill. However, programming of robots, such as the UR robots UR3, UR5, UR10, UR3e, UR5e, UR10e and UR16e provided by Universal Robots A/S, allow a so-called blend between joint space motions and Cartesian space motions. A blend is a soft transition between the trajectories, which eliminates the need for a standstill and increase productivity. Utilizing input shaping either joint space or Cartesian space during blend between joint space motions and causes space motion causes significant deviations from the intended path of motion of the robot arm.
REFERENCES
{i.} D. K. Thomsen, R. Soe-Knudsen, D. Brandt, X. Zhang, Experimental implementation of time-varying input shaping on ur robots, in: Proceedings of the 16th International Conference on Informatics in Control, Automation and Robotics (ICINCO 2019), Vol. 1, 2019, pp. 488-498; doi:10.5220/0007834504880498
{ii.} D. K. Thomsen, R. Soe-Knudsen, D. Brandt, O. Balling, X. Zhang, Smooth online time-varying input shaping with fractional delay {FIR} filtering, Control Engineering Practice 88 (2019) 21-37; doi:10.1016/j.conengprac.2019.04.003
{iii.} P. H. Chang, H.-S. Park, Time-varying input shaping technique applied to vibration reduction of an industrial robot, Control Engineering Practice Volume 13, Issue 1, January 2005, pages 121-130; doi:10.1016/j.conengprac.2004.02.009
{iv.} W. Chatlatanagulchai, V. M. Beazel, and P. H. Meckl. Command shaping applied to a flexible robot with configuration-dependent resonance. In 2006 American Control Conference, June 2006; doi:10.1109/ACC.2006.1656475
{v.} Y. Qiang, F. Jing, Z. Hou, and P. Jia. Residual vibration suppression using off-line learning input shaping method for a flexible joint robot. In Intelligent Control and Automation (WCICA), 2012 10th World Congress on, pages 3858-3863, July 2012; doi:10.1109/WCICA.2012.6359116.
{vi.} Arto Kivila. Modeling, estimation and control for serial flexible robot arms. PhD thesis, Georgia Institute of Technology, 2017; URL: http://hdl.handle.net/1853/58644
{vii.} T. Solatges, S. Rubrecht, M. Rognant, and P. Bidaud. Adaptive input shaper design for flexible robot manipulators. In 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages 444-449, September 2017. doi:10.1109/IROS.2017.8202191
{viii.} Y. Liu, Y. Cao, L. Sun, and X. Zheng. Vibration suppression for wafer transfer robot during trajectory tracking. In 2010 IEEE International Conference on Mechatronics and Automation, pages 741-746, 2010. doi:10.1109/ICMA.2010.5589042
{ix.} Yu Zhao, W. Chen, Te Tang, and M. Tomizuka. Zero time delay input shaping for smooth settling of industrial robots. In 2016 IEEE International Conference on Automation Science and Engineering (CASE), pages 620-625, August 2016. doi:10.1109/COASE.2016.7743459
{x.} Joonyoung Kim and Elizabeth A. Croft. Preshaping input trajectories of industrial robots for vibration suppression. Robotics and Computer-Integrated Manufacturing, 54: 35-44, 2018 doi:10.1016/j.rcim.2018.05.009.
SUMMARY OF THE INVENTION
The objective of the present invention is to address the above described limitations with the prior art or other problems of the prior art. This is achieved by a robot controller for controlling a robot arm where the robot controller comprises:
a first space shaping module configured to provide a shaped first space target motion by convolving a first space target motion with an impulse train, where the first space target motion defines a target motion in a first reference space; a second space shaping module configured to provide a shaped second space target motion by convolving a second space target motion with the impulse train; where the second target motion defines the target motion in a second reference space; and a motor controller module is configured to generate motor control signals to the joint motors based on at least one of the shaped first space target motion and the shaped second space target motion.
Further, the objective of the present invention is addressed by a method of controlling a robot arm where the method comprises the steps of:
generating a shaped first space target motion by convolving a first space target motion with an impulse train; where the first space target motion defines a target motion in a first reference space; generating a shaped second space target motion by convolving a second space target motion with the impulse train; where the second space target motion defines the target motion in a second reference space; and
generating motor control signals for the joint motors of the robot arm based on at least one of the shaped first space target motion and the shaped second space target motion.
The robot controller and method according to the present invention makes it possible to dynamically adjust in which reference space the input shaping shall be performed whereby deviations in position in another reference space can be reduced. Further it is possible to dynamically provide input shaping in two different reference spaces and gradually change from one reference space to another reference space. For instance this makes it possible to preserve the core feature of blending between joint space motions and cartesian space motions, as a new implementation strategy for Cartesian Input Shaping is presented. The proposed implementation enables the filtering space to be changed during motion, and is further extended, such that filtering can be completely enabled or disabled during motion, which is also a new feature within input shaping. Further advantages and benefits are described in the detailed description of the invention.
The dependent claims describe possible embodiments of the method according to the present invention. The advantages and benefits of the present invention are described in the detailed description of the invention
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a robot arm configured according to the present invention;
FIG. 2 illustrates a simplified structural diagram of the robot arm of FIG. 1 ;
FIG. 3 illustrates a flow chart of a method of controlling a robot arm according to the present invention;
FIG. 4 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention;
FIG. 5 illustrates a flow chart of an embodiment of a method of controlling a robot arm according to the present invention;
FIG. 6 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention;
FIG. 7 illustrates a flow chart of an embodiment of a method of controlling a robot arm according to the present invention;
FIG. 8 illustrates the concept of blending between way points of a linear movement of a robot arm;
FIG. 9 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention;
FIG. 10 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention;
FIG. 11 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in view of exemplary embodiments only intended to illustrate the principles of the present invention. The skilled person will be able to provide several embodiments within the scope of the claims. Throughout the description, the reference numbers of similar elements providing similar effects have been given the same last two digits. Further it is
This application is a U.S. national stage entry of PCT application no. PCT/DK2021/050155 which was filed on May 14, 2021. PCT application no. PCT/DK2021/050155 claims priority to Denmark application no. PA202070318 which was filed on May 14, 2020. This application claims priority to both PCT application no. PCT/DK2021/050155 and to Denmark application no. PA202070318. Both PCT application no. PCT/DK2021/050155 and Denmark application no. PA202070318 are incorporated into this this application by reference.
FIELD OF THE INVENTION
The present invention relates to control of a robot arm, where vibrations of the robot arm are suppressed by utilizing input shaping. The robot arm comprises a plurality of robot joints connecting a robot base and a robot tool flange and a part of the robot arm (e.g. the tool flange) is controlled with reference to a cartesian space.
BACKGROUND OF THE INVENTION
Robot arms comprising a plurality of robot joints and links where motors or actuators can move parts of the robot arm in relation to each other are known in the field of robotics. Typically, the robot arm comprises a robot base which serves as a mounting base for the robot arm; and a robot tool flange where to various tools can be attached. A robot controller is configured to control the robot joints in order to move the robot tool flange in relation to the base. For instance, in order to instruct the robot arm to carry out a number of working instructions. The robot joints may be rotational robot joints configured to rotate parts of the robot arm in relation to each other, prismatic joints configured to translate parts of the robot arm in relation to each other and/or any other kind of robot joints configured to move parts of the robot arm in relation to each other.
Typically, the robot controller is configured to control the robot joints based on a dynamic model of the robot arm, where the dynamic model defines a relationship between the forces acting on the robot arm and the resulting accelerations of the robot arm. Often, the dynamic model comprises a kinematic model of the robot arm, knowledge about inertia of the robot arm and other parameters influencing the movements of the robot arm. The kinematic model defines a relationship between the different parts of the robot arm and may comprise information of the robot arm such as, length, size of the joints and links and can for instance be described by Denavit-Hartenberg parameters or like. The dynamic model makes it possible for the controller to determine which torques and/or forces the joint motors or actuators shall provide in order to move the robot joints for instance at specified velocity, acceleration or in order to hold the robot arm in a static posture.
Robot arms need to be programmed by a user or a robot integrator which defines various instructions for the robot arm, such as predefined moving patterns and working instructions such as gripping, waiting, releasing, screwing instructions. The instruction can be based on various sensors or input signals which typically provide a triggering signal used to stop or start at a given instruction. The triggering signals can be provided by various indicators, such as safety curtains, vision systems, position indicators, etc.
Typically, it is possible to attach various end effectors to the robot tool flange or other parts of the robot arm, such as grippers, vacuum grippers, magnetic grippers, screwing machines, welding equipment, dispensing systems, visual systems etc.
A collaborative robot is a robot designed for direct interaction with a human. Light-weight design is one of the main concerns, when a robot is designed to be collaborative. This is to reduce the impact in a potential collision with a human or an obstacle. Thus the design will be a compromise between low mass and high rigidity. Light-weight design is a major goal in current development of robots, cranes, and automotive industry, just to name a few. A light-weight design is motivated by for example increased performance, increased safety, reduced environmental footprint, reduced energy consumption, and reduced price. A light-weight design will feature an increased amount of mechanical flexibility, compared to the traditional heavy and rigid industrial robots, which are often based on a cast iron design.
A robot arm motion can move its end-effector from one position two another in infinitely many ways. The most common motions are described in either joint space or Cartesian space. In robot arms with rotational robot joints the joint space motion is most natural for the robot actuators and is the fastest motion. The end-effector motion will in joint space motions follow a curved profile. The linear Cartesian motion leads to a linear end-effector motion, and a corresponding joint space motion, which can include high accelerations in different joint directions.
Robots with mechanical flexibility pose a challenge in terms of performance. For example, when rapid point-to-point motions are desired, and mechanical vibrations are not acceptable. Therefore, it is desired to suppress mechanical vibrations in robot arms. This can for instance be achieved by utilizing input shaping methods, which slightly modify the target motion of the robot arm, by intelligently adding a time-delay. The modified(shaped) trajectory will reduce the amount of vibrations at the critical natural frequencies of the system.
Input shaping for industrial robots has been implemented in both joint space and Cartesian space. Most implementations are in joint space, which is the natural control space of the robot, e.g. {iii.}-{iv.}-{v.}-{vi.}{vii.} Multiple researchers noticed Cartesian trajectory deviations related to joint space input shaping. Cartesian space input shaping for robots has been suggested and compared to joint space input shaping in order to reduce the path deviation {viii.} {ix.}{x.}.
WO19012040A1 and corresponding scientific articles {i.} {ii.} disclose a method for generating inputs to a physical system with varying dynamic properties, which can be used to suppress the mechanical vibrations of a robot arm. The control signals to the robot arm are generated based on the dynamic properties of the physical system which for instance can be obtained based on dynamic modeling of the physical system, lookup tables containing dynamic properties of the physical system, measurements of parts of the physical system, or a combination of the aforementioned. WO19012040A1, {i.} and {ii.} utilizes a Time-Varying input Shaping method in joint space. Time-Varying Input Shaping has never been presented in Cartesian space. The existing research on Cartesian input shaping for robot arms relies on a trajectory generator, which outputs Cartesian reference position instead of joint angles.
Vibration suppression can be effective in either filtering space. However, a joint space filter will cause deviations of a Cartesian path. Likewise, a Cartesian filter on a joint space motion undermines the benefits of linear joint space motions, such as short duration without exceeding actuator limits. In general, joint space motions will benefit from joint space filtering, and Cartesian motions will benefit from Cartesian space filtering.
It is possible to switch between the two methods when the robot is at a standstill. However, programming of robots, such as the UR robots UR3, UR5, UR10, UR3e, UR5e, UR10e and UR16e provided by Universal Robots A/S, allow a so-called blend between joint space motions and Cartesian space motions. A blend is a soft transition between the trajectories, which eliminates the need for a standstill and increase productivity. Utilizing input shaping either joint space or Cartesian space during blend between joint space motions and causes space motion causes significant deviations from the intended path of motion of the robot arm.
REFERENCES
{i.} D. K. Thomsen, R. Soe-Knudsen, D. Brandt, X. Zhang, Experimental implementation of time-varying input shaping on ur robots, in: Proceedings of the 16th International Conference on Informatics in Control, Automation and Robotics (ICINCO 2019), Vol. 1, 2019, pp. 488-498; doi:10.5220/0007834504880498
{ii.} D. K. Thomsen, R. Soe-Knudsen, D. Brandt, O. Balling, X. Zhang, Smooth online time-varying input shaping with fractional delay {FIR} filtering, Control Engineering Practice 88 (2019) 21-37; doi:10.1016/j.conengprac.2019.04.003
{iii.} P. H. Chang, H.-S. Park, Time-varying input shaping technique applied to vibration reduction of an industrial robot, Control Engineering Practice Volume 13, Issue 1, January 2005, pages 121-130; doi:10.1016/j.conengprac.2004.02.009
{iv.} W. Chatlatanagulchai, V. M. Beazel, and P. H. Meckl. Command shaping applied to a flexible robot with configuration-dependent resonance. In 2006 American Control Conference, June 2006; doi:10.1109/ACC.2006.1656475
{v.} Y. Qiang, F. Jing, Z. Hou, and P. Jia. Residual vibration suppression using off-line learning input shaping method for a flexible joint robot. In Intelligent Control and Automation (WCICA), 2012 10th World Congress on, pages 3858-3863, July 2012; doi:10.1109/WCICA.2012.6359116.
{vi.} Arto Kivila. Modeling, estimation and control for serial flexible robot arms. PhD thesis, Georgia Institute of Technology, 2017; URL: http://hdl.handle.net/1853/58644
{vii.} T. Solatges, S. Rubrecht, M. Rognant, and P. Bidaud. Adaptive input shaper design for flexible robot manipulators. In 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), pages 444-449, September 2017. doi:10.1109/IROS.2017.8202191
{viii.} Y. Liu, Y. Cao, L. Sun, and X. Zheng. Vibration suppression for wafer transfer robot during trajectory tracking. In 2010 IEEE International Conference on Mechatronics and Automation, pages 741-746, 2010. doi:10.1109/ICMA.2010.5589042
{ix.} Yu Zhao, W. Chen, Te Tang, and M. Tomizuka. Zero time delay input shaping for smooth settling of industrial robots. In 2016 IEEE International Conference on Automation Science and Engineering (CASE), pages 620-625, August 2016. doi:10.1109/COASE.2016.7743459
{x.} Joonyoung Kim and Elizabeth A. Croft. Preshaping input trajectories of industrial robots for vibration suppression. Robotics and Computer-Integrated Manufacturing, 54: 35-44, 2018 doi:10.1016/j.rcim.2018.05.009.
SUMMARY OF THE INVENTION
The objective of the present invention is to address the above described limitations with the prior art or other problems of the prior art. This is achieved by a robot controller for controlling a robot arm where the robot controller comprises:
a first space shaping module configured to provide a shaped first space target motion by convolving a first space target motion with an impulse train, where the first space target motion defines a target motion in a first reference space; a second space shaping module configured to provide a shaped second space target motion by convolving a second space target motion with the impulse train; where the second target motion defines the target motion in a second reference space; and a motor controller module is configured to generate motor control signals to the joint motors based on at least one of the shaped first space target motion and the shaped second space target motion.
Further, the objective of the present invention is addressed by a method of controlling a robot arm where the method comprises the steps of:
generating a shaped first space target motion by convolving a first space target motion with an impulse train; where the first space target motion defines a target motion in a first reference space; generating a shaped second space target motion by convolving a second space target motion with the impulse train; where the second space target motion defines the target motion in a second reference space; and
generating motor control signals for the joint motors of the robot arm based on at least one of the shaped first space target motion and the shaped second space target motion.
The robot controller and method according to the present invention makes it possible to dynamically adjust in which reference space the input shaping shall be performed whereby deviations in position in another reference space can be reduced. Further it is possible to dynamically provide input shaping in two different reference spaces and gradually change from one reference space to another reference space. For instance this makes it possible to preserve the core feature of blending between joint space motions and cartesian space motions, as a new implementation strategy for Cartesian Input Shaping is presented. The proposed implementation enables the filtering space to be changed during motion, and is further extended, such that filtering can be completely enabled or disabled during motion, which is also a new feature within input shaping. Further advantages and benefits are described in the detailed description of the invention.
The dependent claims describe possible embodiments of the method according to the present invention. The advantages and benefits of the present invention are described in the detailed description of the invention
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a robot arm configured according to the present invention;
FIG. 2 illustrates a simplified structural diagram of the robot arm of FIG. 1 ;
FIG. 3 illustrates a flow chart of a method of controlling a robot arm according to the present invention;
FIG. 4 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention;
FIG. 5 illustrates a flow chart of an embodiment of a method of controlling a robot arm according to the present invention;
FIG. 6 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention;
FIG. 7 illustrates a flow chart of an embodiment of a method of controlling a robot arm according to the present invention;
FIG. 8 illustrates the concept of blending between way points of a linear movement of a robot arm;
FIG. 9 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention;
FIG. 10 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention;
FIG. 11 illustrates a simplified structural diagram of an embodiment of a robot controller for a robot arm configured according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is described in view of exemplary embodiments only intended to illustrate the principles of the present invention. The skilled person will be able to provide several embodiments within the scope of the claims. Throughout the description, the reference numbers of similar elements providing similar effects have been given the same last two digits. Further it is to be understood that in the case that an embodiment comprises a plurality of the same features then only some of the features may be labeled by a reference number.
FIG. 1 illustrates a robot system 100 according to the present invention, where the robot system comprises at least one robot arm 101 and at least one robot controller 110 configured to control the robot arm.
The robot arm 101 comprises a plurality of
robot joints
102 a , 102 b , 102 c , 102 d , 102 e , 102 f connecting a robot base 103 and a robot tool flange 104 . A base joint 102 a is configured to rotate the robot arm around a base axis 105 a (illustrated by a dashed dotted line) as illustrated by rotation arrow 106 a ; a shoulder joint 102 b is configured to rotate the robot arm around a shoulder axis 105 b (illustrated by a cross indicating the axis) as illustrated by rotation arrow 106 b ; an elbow joint 102 c is configured to rotate the robot arm around an elbow axis 105 c (illustrated by a cross indicating the axis) as illustrated by rotation arrow 106 c ; a first wrist joint 102 d is configured to rotate the robot arm around a first wrist axis 105 d (illustrated by a cross indicating the axis) as illustrated by rotation arrow 106 d and a second wrist joint 102 e is configured to rotate the robot arm around a second wrist axis 105 e (illustrated by a dashed dotted line) as illustrated by rotation arrow 106 e . Robot joint 102 f is a robot tool joint comprising the robot tool flange 104 , which is rotatable around a tool axis 105 f (illustrated by a dashed dotted line) as illustrated by rotation arrow 106 f . The illustrated robot arm is thus a six-axis robot arm with six degrees of freedom with six rotational robot joints, however it is noticed that the present invention can be provided in robot arms comprising less or more robot joints and also other types of robot joints such as prismatic robot joints providing a translation of parts of the robot arm for instance a linear translation.
The robot joints may comprise a robot joint body and an output flange rotatable or translatable in relation to the robot joint body and the output flange is connected to a neighbor robot joint either directly or via an arm section as known in the art. The robot joint comprises a joint motor configured to rotate or translate the output flange in relation to the robot joint body, for instance via a gearing or directly connected to the motor shaft. The robot joint body can for instance be formed as a joint housing and the joint motor can be arranged inside the joint housing and the output flange can extend out of the joint housing. Additionally, the robot joints can comprise at least one joint sensor providing a sensor signal for instance indicative of at least one of the following parameters: an angular and/or linear position of the output flange, an angular and/or linear position of the motor shaft of the joint motor, a motor current of the joint motor or an external force and/or torque trying to rotate the output flange or motor shaft. For instance, the angular position of the output flange can be indicated by an output encoder such as optical encoders, magnetic encoders which can indicate the angular position of the output flange in relation to the robot joint. Similarly, the angular position of the joint motor shaft can be provided by an input encoder such as optical encoders, magnetic encoders which can indicate the angular position of the motor shaft in relation to the robot joint. It is noted that both output encoders indicating the angular position of the output flange and input encoders indicating the angular position of the motor shaft can be provided, which in embodiments where a gearing have been provided makes it possible to determine a relationship between the input and output side of the gearing. The joint sensor can also be provided as a current sensor indicating the current through the joint motor and thus be used to obtain the torque provided by the motor. For instance, in connection with a multiphase motor, a plurality of current sensors can be provided in order to obtain the current through each of the phases of the multiphase motor. It is also noted that some of the robot joints may comprise a plurality of output flanges rotatable and/or translatable by joint actuators, for instance one of the robot joints may comprise a first output flange rotating/translating a first part of the robot arm in relation to the robot joint and a second output flange rotating/translating a second part of the robot arm in relation to the robot joint. The joint sensor can also be provided as a force-torque sensor or an acceleration sensor. For instance, a force and/or torque sensor may be provided at the tool joint and configured to indicate force and/or torque provided to the tool flange and an acceleration sensor may also be provided at the tool joint and configured to indicate the acceleration of the tool joint. However, the other parts of the robot arm may also comprise force-torque sensors or acceleration sensors.
A robot tool flange reference point 107 also known as a TCP (Tool Center Point) is indicated at the robot tool flange and defines the origin of a tool flange coordinate system defining three coordinate axes x flange , y flange , z flange . In the illustrated embodiment the origin of the robot tool flange coordinate system has been arrange on the tool flange axis 105 f with one axis (z flange ) parallel with the tool flange axis and with the other axes x flange , y flange parallel with the outer surface of the robot tool flange 104 . Further a base reference point 108 is coincident with the origin of a robot base coordinate system defining three coordinate axes x base , y base , z base . In the illustrated embodiment the origin of the robot base coordinate system has been arrange on the base axis 105 a with one axis (z base ) parallel with the base axis 105 a axis and with the other axes x base , y base parallel with at the bottom surface of the robot base. The direction of gravity 109 in relation to the robot arm is also indicated by an arrow and it is to be understood that the robot arm can be arrange at any position and orientation in relation to gravity.
The robot system comprises at least one robot controller 110 configured to control the robot arm 101 . The robot controller is configured to control the motions of the parts of the robot arm and the robot joints for instance by controlling the motor torque provided to the joint motors based on a dynamic model of the robot arm, the direction of gravity acting and the joint sensor signal. Further the robot controller may control the motions of the robot arm based on a robot program stored in a memory of the robot controller. The controller can be provided as an external device as illustrated in FIG. 1 or as a device integrated into the robot arm or as a combination thereof.
The robot controller can comprise an interface device 111 enabling a user to control and program the robot arm. The interface device can for instance be provided as a teach pendent as known from the field of industrial robots which can communicate with the controller via wired or wireless communication protocols. The interface device can for instanced comprise a display 112 and a number of input devices 113 such as buttons, sliders, touchpads, joysticks, track balls, gesture recognition devices, keyboards, microphones etc. The display may be provided as a touch screen acting both as display and input device. The interface device can also be provided as an external device configured to communicate with the robot controller, for instance in form of smart phones, tablets, PCs, laptops etc.
The robot system may also comprise an end effector 126 (illustrated in dotted lines) attached to the robot tool flange and is illustrated in form of a gripper, however it is to be understood that the end effector can be any kind of end effector such as grippers, vacuum grippers, magnetic grippers, screwing machines, welding equipment, gluing equipment, dispensing systems, painting equipment, visual systems, cameras etc.
FIG. 2 illustrates a simplified structural diagram of the robot arm illustrated in FIG. 1 . The robot joints 102 a , 102 b and 102 f have been illustrated in structural form and the robot joints 102 c , 102 d , 102 e and the robot links connecting the robot joints have been omitted for the sake of simplicity of the drawing. Further the robot joints are illustrated as separate elements however it is to be understood that they are interconnected either directly or via a robot link as illustrated in FIG. 1 . The robot joints comprise an
output flange
216 a , 216 b , 216 f and a
joint motor
217 a , 217 b , 217 f or another kind of actuator, where the
output flange
216 a , 216 b , 216 f is rotatable in relation to the robot joint body. The
joint motors
217 a , 217 b , 217 f are respectively configured to rotate the
output flanges
216 a , 216 b , 216 f via an
output axle
218 a , 218 b , 218 f . It is to be understood that the joint motor or joint actuator may be configured to rotate the output flange via a transmission system such as a gear (not shown). In this embodiment the output flange 216 f of the tool joint 102 f constitutes the tool flange 104 . The robot joints may optionally comprise at least one
joint sensor
219 a , 219 b , 219 f providing a
sensor signal
220 a , 220 b , 220 f indicative of at least one joint sensor parameter J sensor,a , J sensor,b , J sensor,f of the respective joint. The joint sensor parameter can for instance indicate a pose parameter indicating the position and orientation of the output flange in relation to the robot joint body, an angular position of the output flange, an angular position of a shaft of the joint motor, a motor current of the joint motor. The joint sensor parameter can for instance be selected from the list comprising: speed, acceleration, torque, motor torque, force and position. The joint sensor parameters can be measures obtained from sensors or values derived from such sensor values. For instance, the angular position of the output flange can be indicated by an output encoder such as optical encoders, magnetic encoders which can indicate the angular position of the output flange in relation to the robot joint. Similarly, the angular position of the joint motor shaft can be provided by an input encoder such as optical encoders, magnetic encoders which can indicate the angular position of the motor shaft in relation to the robot joint. The motor currents can be obtained and indicated by current sensors. The motor torque can for instance be obtained based on motor currents or via torque sensors provided in the robot joints.
The end effector 126 connected to the robot tool flange 104 may be connected to the robot controller and the robot controller may be configured to control the end effector via an end effector control signal 228 . Further the end effector may provide an effector feedback signal 229 to the robot controller for instance in order to indicate the status of the end effector, status of various end effector sensors etc.
The robot controller 110 comprises a processer 221 , memory 222 and communication interfaces for communicating with external devices such as the user interface, the robot joints, the end effector etc. The processor comprises a motion planner module 230 , a shaping module 231 , an impulse generation module 237 , a combining module 238 and a motor controller module 232 . The motion planner module 230 , the shaping module 231 , the impulse generation module 237 , the combining module 238 and the motor controller module 232 can for instance be provided as processes executed by the processor 221 , however it is noted that they also can be provided and executed on separate processor units.
The motion planner module 230 is configured to provide target motions of the robot arm, for instance by generating trajectories of parts of the robot arm. The trajectories can for instance be generated based on a robot program stored in a memory 222 , based on an external control signal 224 and/or user inputs provided via an interface device 111 . In the illustrated embodiment the motion planner module provides a target motion M t of parts of the robot arm. The target motion may indicate the kinematics of at least at part of the robot arm, for instance a path along which a part of the robot arm shall move, the speed of a part of the robot arm, the acceleration of a part of the robot arm, a waypoint to which a part of the robot arm shall move, or a force/torque to be generated by part of the robot arm. The target motion can for instance be indicated in a target reference space, such as a cartesian space in reference to the robot base coordinate system, the tool flange coordinate system or any other reference coordinate systems, such as a polar coordinate system. Also, the target motion can be indicated in joint space where the kinematics of the robot joints are indicated; e.g. as angular position q t of output axles of the joint transmissions, a desired angular velocity {dot over (q)} t of output axles of the joint transmissions, a desired angular acceleration {umlaut over (q)} t of the robot transmission.
The shaping module 231 is configured to provide at least one shaped target motion based on the target motion M t and the impulse train A, S, in order to utilize input shaping reducing the vibrations of the robot arm. The impulse train comprises a number of impulses {right arrow over (A)} separated by a time distance {right arrow over (Î)}. In the illustrated embodiment the impulse train is generated by the impulse generation module 237 which is configured to generate the impulse train based on the vibrational properties of the robot arm as known in the art of input shaping, for instance based on the configuration/pose of the robot arm. For instance, the configuration/pose of the robot arm can be obtained based on the target motion or the joint sensor parameters, such as the angular position of the output flanges of the robot joints. The impulse train can also be obtained from memory 222 .
According to the present invention, the shaping module 231 comprises a first space shaping module 233 and a second space shaping module 234 . The first space shaping module 233 is configured to provide a shaped first space target motion Q t * by convolving a first space target motion Q t with the impulse train ({right arrow over (A)},{right arrow over (Î)}), where the first space target motion Q t defines the target motion in a first reference space. The second space shaping module 234 is configured to provide a shaped second space target motion X t * by convolving a second space target motion X t with the impulse train ({right arrow over (A)},{right arrow over (Î)}), where the second space target motion defines the target motion in a second reference space.
The shaping module may optionally comprise a target space to first space transformation module 235 configured to transform the target motion M t into the first space target motion in the first reference space Q t . This can be achieved by utilizing a mapping functions transforming the target motion into the first reference space, for instance the target motion M t may define the kinematics of a part of the robot in relation to a reference point in a coordinate space and the target space to first space transformation module 235 can be configured to utilize inverse kinematics as known from the field of robotics to transform the target motion into for instance a joint reference space, where the kinematics of at least a part of the robot arm is indicated based on robot joint parameters such as the kinematics of joint motors or the kinematics of the output flanges. It is to be understood that the target space to first space conversion module 235 may be omitted in embodiments where the first target motion M t indicates the target motion of the robot arm in the first reference space, as consequently the first space shaping module 233 can provide the shaped first space target motion by convolving the target motion M t with the impulse train.
The shaping module may optionally comprise a target space to second space transformation module 236 configured to transform the target motion M t into the second space target motion in the second reference space X t . This can be achieved by utilizing a mapping functions transforming the target motion into the second reference space. For instance, the target motion M t may define the kinematics of a part of the robot arm in a joint reference space, where the kinematics of at least a part of the robot arm is indicated based on robot joint parameters such as the kinematics of joint motors or the kinematics of the output flanges, and the target space to second space transformation module 236 can be configured to utilize forward kinematics as known from the field of robotics to transform the target motion into for a coordinate space where the kinematics of the robot arm is indicated in relation to a reference point. It is to be understood that the target second space transformation module 236 may be omitted in embodiments where the second target motion M t indicates the target motion of the robot arm in the second reference space, as consequently the second space shaping module 234 can provide the shaped second space target motion by convolving the target motion M t with the impulse train.
The combining module 238 is configured to combine the shaped first space target motion Q t * and the shaped second space target motion X t * into a combined shaped target motion M t *, based on which the motor controller module generates the motor control signals. Consequently, the motor controller module can be provided as known in the art of robot control as the motor controller module receives a shaped target motion which is of the same kind as an ordinary target motion. The combination module can for instance be configured to transform the shaped first space target motion Q t * and the shaped second space target motion X t * into the reference space of the target motion M t and then adding the two shaped target motions. In one embodiment the two shaped target motions can be scaled in relation to each other.
The motor controller module 232 is configured to generate the at least one motor control signal 223 a - 223 f to the joint motors based on at least one of the shaped first space target motion Q t * and the shaped second space target X t * which in the illustrated embodiment is provided as the combined shaped target motion M t * provided by the combining module. The motor controller module 232 is configured to generate at least one motor control signal to the joint motors, for instance in form of motor control signals 223 a , 223 b , 223 f indicating control parameters for the joint motors, which can be used to control the joint motors as desired. For instance the control parameters can indicate the motor torque T motor,a , T motor,b , and T motor,f that each joint motor shall provide to the output flanges and the robot controller is configured to determine the motor torque based on a dynamic model of the robot arm as known in the prior art. The motor controller module 232 is configured to generate the motor control signals 223 a , 223 b , 223 f based on the combined shaped target motion M t * and a dynamic model of the robot arm D robot . The dynamic model of the robot arm D robot can for instance be stored in a memory 222 . The dynamic model makes it possible for the controller to calculate which torque the joint motors shall provide to each of the joint motors to make the robot arm perform a target motion, where a target motion indicate a motion of at least a part of the robot arm. The motor controller module may additionally also as illustrated by dotted line be configured to generate the motor control signal 223 a , 223 b , 223 f based on at least one
sensor signal
220 a , 220 b , 220 f indicative of at least one joint sensor parameter J sensor,a , J sensor,b , J sensor,f and/or other sensor signals indicating other robot parameters. The sensor signal can for instance indicate the angular position q of the output flange; the angular position θ of the motor axle; the motor torque T motor provided to the motor axle by the joint motor. For instance, the joint motors can be provided as multiphase electromotors and the robot controller can be configured to adjust the motor torque provided by the joint motors by regulating the current through the phases of the multiphase motors as known in the art of motor regulation.
It is noted that the motor controller module 232 also can be configured to generate the at least one motor control signal 223 a - 223 f to the joint motors directly based on at least one of the shaped first space target motion Q t * and the shaped second space target X t *. The shaped first space target motion Q t * and the shaped second space target X t * can thus be directly provided to the <figure-callout i
CLAIMS
Claims ( 26 )
The invention claimed is:
1. A robot controller for controlling a robotic arm, where the robotic arm comprises joints connecting a base of the robotic arm and a tool flange, and where at least one of the joints comprises an output flange that is movable relative to a body of a joint, the robotic arm comprising a motor configured to move the output flange relative to the body, the robot controller comprising:
a shaping module configured to shape a target motion of the robotic arm; and
a motor controller module configured to generate at least one motor control signal for the motor;
wherein the shaping module comprises:
a first space shaping module configured to produce a shaped first space target motion by convolving a first space target motion with an impulse train, where the first space target motion defines the target motion in a first reference space; and
a second space shaping module configured to produce a shaped second space target motion by convolving a second space target motion with an impulse train, where the second space target motion defines the target motion in a second reference space; and
wherein the motor controller module is configured to generate the at least one motor control signal based on both the shaped first space target motion and the shaped second space target motion.
2. The robot controller of claim 1 , wherein the target motion comprises a continuous motion of at least a part of the robotic arm.
3. The robot controller of claim 1 , wherein the target motion comprises a continuous motion of at least a part of the robotic arm; and
wherein the robot controller is configured to perform operations comprising:
for a first part of the target motion, generating the at least one motor control signal based on the shaped first space target motion and not based on the shaped second space target motion; and
for a second part of the target motion, generating the at least one motor control signal based on the shaped second space target motion and not based on the shaped first space target motion.
4. The robot controller of claim 1 , further comprising:
a combining module configured to combine the shaped first space target motion and the shaped second space target motion into a combined shaped target motion;
wherein the motor controller module is configured to generate the at least one motor control signal based on the combined shaped target motion.
5. The robot controller of claim 1 , wherein the motor controller module comprises:
a first space motor control module configured to generate a first motor control signal based on the shaped first space target motion and a first dynamic model of the robotic arm, where the first dynamic model is defined in the first reference space;
a second space motor control module configured to generate a second motor control signal based on the shaped second space target motion and a second dynamic model of the robotic arm, where the second dynamic model is defined in the second reference space; and
a motor control signal combining module configured to generate the at least one motor control signal based on the first motor control signal and the second motor control signal.
6. The robot controller of claim 1 , wherein the first reference space and the second reference space are different.
7. The robot controller of claim 1 , wherein the first reference space is a joint reference space in which kinematics of at least a part of the robotic arm are based on joint parameters, where the joint parameters are based on kinematics of at least one joint motor and at least one output flange.
8. The robot controller of claim 1 , wherein the second reference space is a coordinate space in which kinematics of at least a part of the robotic arm are defined relative to te a reference point.
9. The robot controller of claim 1 , further comprising:
at least one space transformation module configured to transform the target motion into at least one of the first space target motion in the first reference space or the second space target motion in the second reference space.
10. The robot controller of claim 1 , further comprising:
at least one space transformation module configured to transform at least one of:
the shaped first space target motion into a shaped first target motion in at least one of a target reference space of the target motion or the second reference space; and
the shaped second space target motion into a shaped second target motion in at least one of a target reference space of the target motion or the first reference space.
11. The robot controller of claim 1 , further comprising:
at least one scaling module configured to scale at least one of:
the shaped first space target motion according to a first space scaling parameter to produce a scaled shaped first space target motion; or and
the shaped second space target motion according to a second space scaling parameter to produce a scaled shaped second space target motion.
12. The robot controller of claim 11 , further comprising:
a shaped target motion combining module configured to combine the scaled shaped first space target motion and the scaled shaped second space target motion into a combined shaped target motion on which the at least one motor control signal is based.
13. The robot controller of claim 1 , further comprising:
at least one target motion scaling module configured to scale the target motion prior to convolving based on a target motion scaling parameter.
14. A method of controlling a robotic arm, where the robotic arm comprises joints connecting a base of the robotic arm and a tool flange, and where at least one of the joints comprises an output flange that is movable relative to a body of a joint, the robotic arm comprising a motor configured to move the output flange relative to the body, the method comprising:
generating a target motion of the robotic arm;
generating a shaped first space target motion by convolving a first space target motion with an impulse train, where the first space target motion defines the target motion of the robotic arm in a first reference space;
generating a shaped second space target motion by convolving a second space target motion with an impulse train, where the second space target motion defines the target motion of the robotic arm in a second reference space; and
generating at least one motor control signal for at least one joint motor of the robotic arm based on both the shaped first space target motion and the shaped second space target motion.
15. The method of claim 14 , wherein the target motion comprises a continuous motion of at least a part of the robotic arm.
16. The method of claim 14 , wherein the target motion comprises a continuous motion of at least a part of the robotic arm; and
wherein the method comprises:
for a first part of the target motion, generating the at least one motor control signal based on the shaped first space target motion and not based on the shaped second space target motion; and
for a second part of the target motion, generating the at least one motor control signal based on the shaped second space target motion and not based on the shaped first space target motion.
17. The method of claim 14 , further comprising:
combining the shaped first space target motion and the shaped second space target motion into a combined shaped target motion, where generating the at least one motor control signal is based on the combined shaped target motion of both the shaped first space target motion and the shaped second space target motion.
18. The method of claim 14 , further comprising:
generating a first motor control signal based on the shaped first space target motion and a first dynamic model of the robotic arm, where the first dynamic model is defined in the first reference space;
generating a second motor control signal based on the shaped second space target motion and a second dynamic model of the robotic arm, where the second dynamic model is defined in the second reference space; and
combining the first motor control signal and the second motor control signal to generate the at least one motor control signal.
19. The method of claim 14 , wherein the first reference space and the second reference space are different.
20. The method of claim 14 , wherein the first reference space is a joint reference space in which kinematics of at least a part of the robotic arm are based on robot joint parameters, where the robot joint parameters correspond to kinematics of at least one joint motor and kinematics of at least one output flange.
21. The method of claim 14 , wherein the second reference space is a coordinate space in which kinematics of at least a part of the robotic arm are relative to a reference point.
22. The method of claim 14 , further comprising:
transforming the target motion into the first space target motion in the first reference space; and
transforming the target motion into the second space target motion in the second reference space.
23. The method of claim 14 , further comprising:
transforming the shaped first space target motion into a shaped target motion in at least one of a target reference space of the target motion or the second reference space; and
transforming the shaped second space target motion into a shaped target motion in at least one of a target reference space of the target motion or the first reference space.
24. The method of claim 14 , further comprising:
scaling the shaped first space target motion based on a first space scaling parameter to produce a scaled shaped first space target motion; or scaling the shaped second space target motion based on a second space scaling parameter to produce a scaled shaped second space target motion.
25. The method of claim 24 , further comprising:
combining the scaled shaped first space target motion and the scaled shaped second space target motion to produce a combined shaped target motion.
26. The method of claim 14 , further comprising:
scaling the target motion prior to convolving.
US17/924,715
2020-05-14
2021-05-14
Input shaping control of a robot arm in different reference spaces
Active
2041-09-17
US12350838B2
( en )
Applications Claiming Priority (3)
Application Number
Priority Date
Filing Date
Title
DKPA202070318
2020-05-14
DKPA202070318
2020-05-14
PCT/DK2021/050155
WO2021228347A1
( en )
2020-05-14
2021-05-14
Input shaping control of a robot arm in different reference spaces
Publications (2)
Publication Number
Publication Date
US20230191603A1
US20230191603A1 ( en )
2023-06-22
US12350838B2
true
US12350838B2 ( en )
2025-07-08
Family
ID=76502643
Family Applications (1)
Application Number
Title
Priority Date
Filing Date
US17/924,715
Active
2041-09-17
US12350838B2
( en )
2020-05-14
2021-05-14
Input shaping control of a robot arm in different reference spaces
Country Status (4)
Country
Link
US
( 1 )
US12350838B2
( en )
EP
( 1 )
EP4149730A1
( en )
CN
( 1 )
CN115605325B
( en )
WO
( 1 )
WO2021228347A1
( en )
Cited By (2)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US20240238970A1
( en )
*
2021-04-21
2024-07-18
Kuka Deutschland Gmbh
Generating a robot program and operating a robot
US20240375274A1
( en )
*
2023-05-10
2024-11-14
Southwest Research Institute
Coordinated motion of a manipulator and mobile base
Families Citing this family (13)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
WO2020211914A1
( en )
2019-04-17
2020-10-22
Universal Robots A/S
Method of controlling a robot arm based on adaptive friction
US12384030B2
( en )
2019-05-29
2025-08-12
Universal Robots A/S
Detection of change in contact between robot arm and an object
WO2021078344A1
( en )
2019-10-22
2021-04-29
Universal Robots A/S
Safe activation of free-drive mode of robot arm
US12296485B2
( en )
2019-10-22
2025-05-13
Universal Robots A/S
Robot arm with adaptive three-dimensional boundary in free-drive
DK180508B1
( en )
2019-10-22
2021-06-03
Universal Robots As
Maintaining free-drive mode of robot arm for period of time
DK180673B1
( en )
2019-12-29
2021-11-25
Universal Robots As
Method of obtaining vibrational properties of robot arm
WO2021228347A1
( en )
2020-05-14
2021-11-18
Universal Robots A/S
Input shaping control of a robot arm in different reference spaces
CN115943019B
( en )
*
2020-08-21
2025-10-31
åé£ç§æ ªå¼ä¼ç¤¾
Robot control device
EP4240565A1
( en )
2020-11-06
2023-09-13
Universal Robots A/S
A robot system and a method for monitoring a robot system
US12576530B2
( en )
2021-08-13
2026-03-17
Universal Robots A/S
Robot system for anomaly detection
USD1082878S1
( en )
2022-01-14
2025-07-08
Universal Robots A/S
Robot joint
USD1099187S1
( en )
2022-01-14
2025-10-21
Universal Robots A/S
Robot joint
CN114218718B
( en )
*
2022-02-22
2022-05-06
æ²³åå·¥ä¸å¤§å¦
A Reliability Analysis Method for S-shaped Trajectory Flexible Vibration Suppression
Citations (39)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US5638267A
( en )
*
1994-06-15
1997-06-10
Convolve, Inc.
Method and apparatus for minimizing unwanted dynamics in a physical system
US5917300A
( en )
1997-03-10
1999-06-29
Convolve, Inc.
Method and apparatus for the control of gantry machines
US5988411A
( en )
1996-04-05
1999-11-23
Convolve, Inc.
Method and apparatus for reduced vibration of human operated machines
US6314473B1
( en )
1998-03-05
2001-11-06
Convolve, Inc.
System for removing selected unwanted frequenices in accordance with altered settings in a user interface of a data storage device
US6560658B2
( en )
1999-03-04
2003-05-06
Convolve, Inc.
Data storage device with quick and quiet modes
US6829207B1
( en )
1999-12-08
2004-12-07
Convolve, Inc.
Method for reconstruction of phonograph records from physical measurement
US7791758B2
( en )
2000-05-02
2010-09-07
Convolve, Inc.
Vibration control technology and interface for computer printers and scanners
US20130079928A1
( en )
2011-09-28
2013-03-28
Universal Robots A/S
Calibration and Programming of Robots
US20130231778A1
( en )
2010-11-16
2013-09-05
Universal Robots Aps
Method and Means for Controlling a Robot
US20130255426A1
( en )
2006-03-03
2013-10-03
Universal Robots Aps
Programmable robot and user interface
CN104589304A
( en )
2013-10-31
2015-05-06
精工ç±æ®çæ ªå¼ä¼ç¤¾
Robot control device and robot
WO2019012040A1
( en )
2017-07-13
2019-01-17
Universal Robots A/S
Vibration control of systems with configuration dependent dynamics
CN109664297A
( en )
2018-12-14
2019-04-23
æ·±å³å¸æ±å·ææ¯è¡ä»½æéå ¬å¸
Vibration suppressing method, system, device and the computer-readable memory of robot
WO2019094794A2
( en )
2017-11-10
2019-05-16
Intuitive Surgical Operations, Inc.
Systems and methods for controlling a robotic manipulator or associated tool
CN110026987A
( en )
2019-05-28
2019-07-19
广ä¸å·¥ä¸å¤§å¦
Generation method, device, equipment and the storage medium of a kind of mechanical arm crawl track
US10399232B2
( en )
2014-03-04
2019-09-03
Universal Robots A/S
Safety system for industrial robot
US10850393B2
( en )
2015-07-08
2020-12-01
Universal Robots A/S
Method for extending end user programming of an industrial robot with third party contributions
US20210086374A1
( en )
2017-12-14
2021-03-25
Universal Robots A/S
Robot comprising safety system ensuring stopping time and distance
WO2021228347A1
( en )
2020-05-14
2021-11-18
Universal Robots A/S
Input shaping control of a robot arm in different reference spaces
US11260543B2
( en )
2017-01-13
2022-03-01
Universal Robots A/S
Clamped flange joint
US20220161433A1
( en )
2019-04-02
2022-05-26
Universal Robots A/S
Extendable safety system for robot system
US20220175472A1
( en )
*
2019-03-29
2022-06-09
Intuitive Surgical Operations, Inc.
Reducing energy buildup in servo-controlled mechanisms
US20220184810A1
( en )
2019-04-02
2022-06-16
Universal Robots A/S
Robot arm safety system with runtime adaptable safety limits
US20220226993A1
( en )
2019-04-17
2022-07-21
Universal Robots A/S
Method of controlling a robot arm based on adaptive friction
US11474510B2
( en )
2016-04-12
2022-10-18
Universal Robots A/S
Programming a robot by demonstration
US20220379468A1
( en )
2019-10-22
2022-12-01
Universal Robots A/S
Robot arm with adaptive three-dimensional boundary in free-drive
US20220379463A1
( en )
2019-10-22
2022-12-01
Universal Robots A/S
Safe activation of free-drive mode of robot arm
US20220388156A1
( en )
2019-10-22
2022-12-08
Universal Robots A/S
Maintaining free-drive mode of robot arm for period of time
US20230035296A1
( en )
2019-12-29
2023-02-02
Universal Robots A/S
Method of suppressing vibrations of a robot arm with external objects
US20230052996A1
( en )
2019-12-29
2023-02-16
Universal Robots A/S
Method of obtaining vibrational properties of robot arm
US20230098877A1
( en )
*
2020-02-06
2023-03-30
Exonetik Inc.
Low-impedance actuation device usingmagnetorheological fluid clutch apparatuses
US11796045B2
( en )
2021-03-25
2023-10-24
Universal Robots A/S
Strain wave gear with encoder integration
US11839979B2
( en )
2018-06-15
2023-12-12
Universal Robots A/S
Dual mode free-drive of robot arm
US20230405822A1
( en )
2020-11-06
2023-12-21
Universal Robots A/S
A robot system and a method for monitoring a robot system
US20230405819A1
( en )
2020-11-06
2023-12-21
Universal Robots A/S
A robot controller with integrated logic functionality
US20230418258A1
( en )
2020-10-09
2023-12-28
Universal Robots A/S
Multifunctional input device for a robot arm
US11964389B2
( en )
2017-11-15
2024-04-23
Universal Robots A/S
Strain wave gear with output flange and integrated encoder
US12011824B2
( en )
2018-05-18
2024-06-18
Universal Robots A/S
Robot joint comprising brake assembly
US20240351209A1
( en )
2021-08-13
2024-10-24
Universal Robots A/S
A robot system for anomaly detection
2021
2021-05-14
WO
PCT/DK2021/050155
patent/WO2021228347A1/en
not_active
Ceased
2021-05-14
US
US17/924,715
patent/US12350838B2/en
active
Active
2021-05-14
EP
EP21733054.7A
patent/EP4149730A1/en
active
Pending
2021-05-14
CN
CN202180035014.5A
patent/CN115605325B/en
active
Active
Patent Citations (51)
* Cited by examiner, â Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
US5638267A
( en )
*
1994-06-15
1997-06-10
Convolve, Inc.
Method and apparatus for minimizing unwanted dynamics in a physical system
US5988411A
( en )
1996-04-05
1999-11-23
Convolve, Inc.
Method and apparatus for reduced vibration of human operated machines
US5917300A
( en )
1997-03-10
1999-06-29
Convolve, Inc.
Method and apparatus for the control of gantry machines
US6163116A
( en )
1997-03-10
2000-12-19
Convolve, Inc.
Method and apparatus for the control of gantry machines
US6314473B1
( en )
1998-03-05
2001-11-06
Convolve, Inc.
System for removing selected unwanted frequenices in accordance with altered settings in a user interface of a data storage device
US7483232B2
( en )
1999-03-04
2009-01-27
Convolve, Inc.
Dynamic system control method
US7433144B2
( en )
1999-03-04
2008-10-07
Convolve, Inc.
Dynamic system control method
US8144417B2
( en )
1999-03-04
2012-03-27
Convolve, Inc.
Dynamic system control method
US20090154001A1
( en )
1999-03-04
2009-06-18
Convolve, Inc.
Dynamic system control method
US7620739B2
( en )
1999-03-04
2009-11-17
Convolve, Inc.
Dynamic system control method
US6560658B2
( en )
1999-03-04
2003-05-06
Convolve, Inc.
Data storage device with quick and quiet modes
US20120176875A1
( en )
1999-03-04
2012-07-12
Convolve, Inc.
Dynamic system control method
US6829207B1
( en )
1999-12-08
2004-12-07
Convolve, Inc.
Method for reconstruction of phonograph records from physical measurement
US7330414B2
( en )
1999-12-08
2008-02-12
Convolve Incorporated
Method for reconstruction of phonograph records from physical measurement
US7791758B2
( en )
2000-05-02
2010-09-07
Convolve, Inc.
Vibration control technology and interface for computer printers and scanners
US20100309490A1
( en )
2000-05-02
2010-12-09
Convolve, Inc.
Vibration control technology and interface for computer printers and scanners
US20130255426A1
( en )
2006-03-03
2013-10-03
Universal Robots Aps
Programmable robot and user interface
US20130231778A1
( en )
2010-11-16
2013-09-05
Universal Robots Aps
Method and Means for Controlling a Robot
US20130079928A1
( en )
2011-09-28
2013-03-28
Universal Robots A/S
Calibration and Programming of Robots
CN104589304A
( en )
2013-10-31
2015-05-06
精工ç±æ®çæ ªå¼ä¼ç¤¾
Robot control device and robot
US20160318183A1
( en )
*
2013-10-31
2016-11-03
Seiko Epson Corporation
Robot control device and robot
US10399232B2
( en )
2014-03-04
2019-09-03
Universal Robots A/S
Safety system for industrial robot
US10850393B2
( en )
2015-07-08
2020-12-01
Universal Robots A/S
Method for extending end user programming of an industrial robot with third party contributions
US11474510B2
( en )
2016-04-12
2022-10-18
Universal Robots A/S
Programming a robot by demonstration
US11260543B2
( en )
2017-01-13
2022-03-01
Universal Robots A/S
Clamped flange joint
WO2019012040A1
( en )
2017-07-13
2019-01-17
Universal Robots A/S
Vibration control of systems with configuration dependent dynamics
US20200171658A1
( en )
2017-07-13
2020-06-04
Universal Robots A/S
Vibration control of systems with configuration dependent dynamics
WO2019094794A2
( en )
2017-11-10
2019-05-16
Intuitive Surgical Operations, Inc.
Systems and methods for controlling a robotic manipulator or associated tool
US20200261169A1
( en )
*
2017-11-10
2020-08-20
Intuitive Surgical Operations, Inc,
Systems and methods for controlling a robotic manipulator or associated tool
US11964389B2
( en )
2017-11-15
2024-04-23
Universal Robots A/S
Strain wave gear with output flange and integrated encoder
US20210086374A1
( en )
2017-12-14
2021-03-25
Universal Robots A/S
Robot comprising safety system ensuring stopping time and distance
US12011824B2
( en )
2018-05-18
2024-06-18
Universal Robots A/S
Robot joint comprising brake assembly
US11839979B2
( en )
2018-06-15
2023-12-12
Universal Robots A/S
Dual mode free-drive of robot arm
CN109664297A
( en )
2018-12-14
2019-04-23
æ·±å³å¸æ±å·ææ¯è¡ä»½æéå ¬å¸
Vibration suppressing method, system, device and the computer-readable memory of robot
US20220175472A1
( en )
*
2019-03-29
2022-06-09
Intuitive Surgical Operations, Inc.
Reducing energy buildup in servo-controlled mechanisms
US20220161433A1
( en )
2019-04-02
2022-05-26
Universal Robots A/S
Extendable safety system for robot system
US20220184810A1
( en )
2019-04-02
2022-06-16
Universal Robots A/S
Robot arm safety system with runtime adaptable safety limits
US20220226993A1
( en )
2019-04-17
2022-07-21
Universal Robots A/S
Method of controlling a robot arm based on adaptive friction
CN110026987A
( en )
2019-05-28
2019-07-19
广ä¸å·¥ä¸å¤§å¦
Generation method, device, equipment and the storage medium of a kind of mechanical arm crawl track
US20220379463A1
( en )
2019-10-22
2022-12-01
Universal Robots A/S
Safe activation of free-drive mode of robot arm
US20220388156A1
( en )
2019-10-22
2022-12-08
Universal Robots A/S
Maintaining free-drive mode of robot arm for period of time
US20220379468A1
( en )
2019-10-22
2022-12-01
Universal Robots A/S
Robot arm with adaptive three-dimensional boundary in free-drive
US20230035296A1
( en )
2019-12-29
2023-02-02
Universal Robots A/S
Method of suppressing vibrations of a robot arm with external objects
US20230052996A1
( en )
2019-12-29
2023-02-16
Universal Robots A/S
Method of obtaining vibrational properties of robot arm
US20230098877A1
( en )
*
2020-02-06
2023-03-30
Exonetik Inc.
Low-impedance actuation device usingmagnetorheological fluid clutch apparatuses
WO2021228347A1
( en )
2020-05-14
2021-11-18
Universal Robots A/S
Input shaping control of a robot arm in different reference spaces
US20230418258A1
( en )
2020-10-09
2023-12-28
Universal Robots A/S
Multifunctional input device for a robot arm
US20230405822A1
( en )
2020-11-06
2023-12-21
Universal Robots A/S
A robot system and a method for monitoring a robot system
US20230405819A1
( en )
2020-11-06
2023-12-21
Universal Robots A/S
A robot controller with integrated logic functionality
US11796045B2
( en )
2021-03-25
2023-10-24
Universal Robots A/S
Strain wave gear with encoder integration
US20240351209A1
( en )
2021-08-13
2024-10-24
Universal Robots A/S
A robot system for anomaly detection
Non-Patent Citations (25)
* Cited by examiner, â Cited by third party
Title
Chang et al., " Time-varying input shaping technique applied to vibration reduction of an industrial robot, " Control Engineering Practice vol. 13, Issue 1, pp. 121-130, DOI:10.1016/j.conengprac.2004.02.009 (Jan. 2005), 10 pages.
Chatlatanagulchai et al., " Command shaping applied to a flexible robot with configuration-dependent resonance, " In 2006 American Control Conference, DOI:10.1109/ACC.2006.1656475 (Jun. 2006), 6 pages.
Chatlatanagulchai et al., " Switching ZVDk input shaper for flexible closed-loop system with saturation ", In 2017 American Control Conference (ACC), 2017, pp. 4492-4497.
File History received for European Patent Application No. 21733054.7, downloaded on Dec. 12, 2024, 252 pages.
Freese et al., " Endpoint Vibration Control of a Mobile Mine-Detecting Robotic Manipulator, " American Control Conference, ACC'07, IEEE, Piscataway, NJ, USA, pp. 7-12, (Jul. 1, 2007), 6 pages.
International Preliminary Report on Patentability in Application No. PCT/DK2021/050155 dated Nov. 15, 2022, 9 pages.
International Search Report and Written Opinion in Application No. PCT/DK2021/050155, dated Sep. 3, 2021, 12 pages.
Kim et al., " Preshaping input trajectories of industrial robots for vibration suppression, " Robotics and Computer Integrated Manufacturing, 54: 35-44, DOI:10.1016/j.rcim.2018.05.009 (2018), 20 pages.
Kivila, A., " Modeling, estimation and control for serial flexible robot arms, " PHD thesis, Georgia Institute of Technology, URL: http://hdl .handle.net/ 1853/58644 (2017), 236 pages.
Liu et al, " Vibration Suppression for Wafer Transfer Robot During Trajectory Tracking ", 2010, (Year: 2010).
*
Liu et al., " Vibration Suppression for a Class of Flexible Manipulator Control with Input Shaping Technique, " 2006 International Conference on Machine Learning and Cybernetics, IEEE, Piscataway, NJ, USA, pp. 835-839, (Aug. 13, 2006), 5 pages.
Liu et al., " Vibration suppression for wafer transfer robot during trajectory tracking, " 2010 IEEE International Conference on Mechatronics and Automation, pp. 741-746, DOI:10.1109/ICMA.2010.5589042 (2010), 6 pages.
Office Action received for Chinese Patent Application No. 202180035014.5, mailed on Mar. 6, 2025, (9 pages), with English machine translation (10 pages).
Office Action received for European Patent Application No. 21733054.7, Mailed on Sep. 16, 2024, 5 Pages.
Qiang et al., " Residual vibration suppression using off-line learning input shaping method for a flexible joint robot, " Intelligent Control and Automation (WCICA), 2012 10th World Congress on, pp. 3858-3863, (Jul. 2012); DOI:10.1109/WCICA.2012.6359116, 6 pages.
Ramli et al., " Control strategies for crane systems: A comprehensive review ", In: Mechanical Systems and Signal Processing, Elsevier, Amsterdam, NL, vol. 95, 2017, pp. 1-23.