A grasping force control strategy is proposed in order to complete various free manipulations by using anthropomorphic prosthetic hand. The position-based impedance control and force-tracking impedance control are use...A grasping force control strategy is proposed in order to complete various free manipulations by using anthropomorphic prosthetic hand. The position-based impedance control and force-tracking impedance control are used in free and constraint spaces, respectively. The fuzzy observer is adopted in transition in order to switch control mode. Two control modes use one position-based impedance controller. In order to achieve grasping force track, reference force is added to the impedance controller in the constraint space. Trajectory tracking in free space and torque tracking in constrained space are realized, and reliability of mode switch and stability of system are achieved. An adaptive sliding mode friction compensation method is proposed. This method makes use of terminal sliding mode idea to design sliding mode function, which makes the tracking error converge to zero in finite time and avoids the problem of conventional sliding surface that tracking error cannot converge to zero. Based on the characteristic of the exponential form friction, the sliding mode control law including the estimation of friction parameter is obtained through terminal sliding mode idea, and the online parameter update laws are obtained based on Lyapunov stability theorem. The experiments on the HIT Prosthetic Hand IV are carried out to evaluate the grasping force control strategy, and the experiment results verify the effectiveness of this control strategy.展开更多
In order to improve the force tracking performance of hydraulic quadruped robots in uncertain and unstructured environments,an impedance-based adaptive reference trajectory generation scheme is used.Secondly,in order ...In order to improve the force tracking performance of hydraulic quadruped robots in uncertain and unstructured environments,an impedance-based adaptive reference trajectory generation scheme is used.Secondly,in order to improve the robustness to environmental changes and reduce the contact force errors caused by trajectory tracking errors,the backstepping sliding mode controller is combined with the adaptive reference trajectory generator.Finally,a virtual damping control based on velocity and pressure feedback is proposed to solve the problem of contact force disappearance and stall caused by sudden environmental change.The simulation results show that the proposed scheme has higher contact force tracking accuracy when the environment is unchanged;the contact force error can always be guaranteed within an acceptable range when the environment is reasonably changed;when the environment suddenly changes,the drive unit can move slowly until the robot re-contacts the environment.展开更多
针对高端制造过程中机械臂与工件之间应具有接触力感知与控制要求的问题,设计一种具有接触力感知反馈的2R机械臂(a 2R manipulator with contact force perception feedback,2RM-CFPF)。首先,利用堆叠式压电陶瓷传感器设计一种具有接触...针对高端制造过程中机械臂与工件之间应具有接触力感知与控制要求的问题,设计一种具有接触力感知反馈的2R机械臂(a 2R manipulator with contact force perception feedback,2RM-CFPF)。首先,利用堆叠式压电陶瓷传感器设计一种具有接触力感知反馈的机械臂关节,建立关节3D模型并阐述关节结构。然后,基于所设计的关节搭建2RM-CFPF机械臂模型,探究其工作机理并推导出数学模型;结合2RM-CFPF机械臂自身特性,采用基于阻抗滑模控制的运动位置/接触力控制方法,实现2RM-CFPF机械臂的力-位混合控制。最后,进行2RM-CFPF机械臂运动控制仿真实验,仿真实验结果表明阻抗滑模控制法能够有效实现2RM-CFPF机械臂的力-位混合控制,满足高端制造中的接触力感知控制要求。展开更多
基金Project(2009AA043803) supported by the National High Technology Research and Development Program of China Project (SKLRS200901B) supported by Self-Planned Task of State Key Laboratory of Robotics and System (Harbin Institute of Technology),ChinaProject (NCET-09-0056) supported by Program for New Century Excellent Talents in Universities of China
文摘A grasping force control strategy is proposed in order to complete various free manipulations by using anthropomorphic prosthetic hand. The position-based impedance control and force-tracking impedance control are used in free and constraint spaces, respectively. The fuzzy observer is adopted in transition in order to switch control mode. Two control modes use one position-based impedance controller. In order to achieve grasping force track, reference force is added to the impedance controller in the constraint space. Trajectory tracking in free space and torque tracking in constrained space are realized, and reliability of mode switch and stability of system are achieved. An adaptive sliding mode friction compensation method is proposed. This method makes use of terminal sliding mode idea to design sliding mode function, which makes the tracking error converge to zero in finite time and avoids the problem of conventional sliding surface that tracking error cannot converge to zero. Based on the characteristic of the exponential form friction, the sliding mode control law including the estimation of friction parameter is obtained through terminal sliding mode idea, and the online parameter update laws are obtained based on Lyapunov stability theorem. The experiments on the HIT Prosthetic Hand IV are carried out to evaluate the grasping force control strategy, and the experiment results verify the effectiveness of this control strategy.
基金Projects(51975376,51505289)supported by the National Natural Science Foundation of ChinaProject(19ZR1435400)supported by the Natural Science Foundation of Shanghai,China。
文摘In order to improve the force tracking performance of hydraulic quadruped robots in uncertain and unstructured environments,an impedance-based adaptive reference trajectory generation scheme is used.Secondly,in order to improve the robustness to environmental changes and reduce the contact force errors caused by trajectory tracking errors,the backstepping sliding mode controller is combined with the adaptive reference trajectory generator.Finally,a virtual damping control based on velocity and pressure feedback is proposed to solve the problem of contact force disappearance and stall caused by sudden environmental change.The simulation results show that the proposed scheme has higher contact force tracking accuracy when the environment is unchanged;the contact force error can always be guaranteed within an acceptable range when the environment is reasonably changed;when the environment suddenly changes,the drive unit can move slowly until the robot re-contacts the environment.
文摘针对高端制造过程中机械臂与工件之间应具有接触力感知与控制要求的问题,设计一种具有接触力感知反馈的2R机械臂(a 2R manipulator with contact force perception feedback,2RM-CFPF)。首先,利用堆叠式压电陶瓷传感器设计一种具有接触力感知反馈的机械臂关节,建立关节3D模型并阐述关节结构。然后,基于所设计的关节搭建2RM-CFPF机械臂模型,探究其工作机理并推导出数学模型;结合2RM-CFPF机械臂自身特性,采用基于阻抗滑模控制的运动位置/接触力控制方法,实现2RM-CFPF机械臂的力-位混合控制。最后,进行2RM-CFPF机械臂运动控制仿真实验,仿真实验结果表明阻抗滑模控制法能够有效实现2RM-CFPF机械臂的力-位混合控制,满足高端制造中的接触力感知控制要求。
