It is crucial for serial robots with redundant degrees-of-freedom to accomplish complex tasks with high pose pre-cision of the end-effector.However,due to the cumulative errors in each joint actuator,it is always chal...It is crucial for serial robots with redundant degrees-of-freedom to accomplish complex tasks with high pose pre-cision of the end-effector.However,due to the cumulative errors in each joint actuator,it is always challenging to guarantee high pose precision of the end-effector.To address this issue,this study proposes a virtual-constraints-based end-effector pose compensator.The actual angles of specific joints are treated as known variables,which are called virtual constraints.The virtual constraints,combined with the expected pose of the end-effector,yield compensation angles for the other joints.The compensation angles are applied to the expected angles of other joints,eliminating the end-effector pose errors caused by the joints treated as virtual constraints.Finally,a typ-ical planar 3-degree-of-freedom serial robot(the leg hydraulic drive system for legged robots)is utilized for experimental validation.The experimental results demonstrate that,with the application of the compensator,the maximum reduction in position error of the foot end exceeds 75%.The compensation strategy further im-proves the end-effector pose precision based on various high-precision position control methods for the joint actuators.In addition,this study introduces a novel idea and provides experimental evidence for compensating the end-effector pose error of redundant serial robots.展开更多
基金supported by the National Excellent Natural Science Foundation of China(52122503)the Yanzhao’s Young Scientist Project(2023203258)+4 种基金the National Natural Science Foundation of China(51975506)the Hebei Natural Science Foundation(E2022203002,and E2024203067)the Science and Technology Plan of Hebei Provincial Department of Education(BJK2022060)the Shijiazhuang Science and Technology Planning Project(241790727A)the Postgraduate In-novation Fund Project of Hebei Province(CXZZBS2023052).
文摘It is crucial for serial robots with redundant degrees-of-freedom to accomplish complex tasks with high pose pre-cision of the end-effector.However,due to the cumulative errors in each joint actuator,it is always challenging to guarantee high pose precision of the end-effector.To address this issue,this study proposes a virtual-constraints-based end-effector pose compensator.The actual angles of specific joints are treated as known variables,which are called virtual constraints.The virtual constraints,combined with the expected pose of the end-effector,yield compensation angles for the other joints.The compensation angles are applied to the expected angles of other joints,eliminating the end-effector pose errors caused by the joints treated as virtual constraints.Finally,a typ-ical planar 3-degree-of-freedom serial robot(the leg hydraulic drive system for legged robots)is utilized for experimental validation.The experimental results demonstrate that,with the application of the compensator,the maximum reduction in position error of the foot end exceeds 75%.The compensation strategy further im-proves the end-effector pose precision based on various high-precision position control methods for the joint actuators.In addition,this study introduces a novel idea and provides experimental evidence for compensating the end-effector pose error of redundant serial robots.
