An adaptive control scheme is presented,which can simultaneously realize vibration suppression and compliance control for flexible joint robot(FJR).The proposed control scheme provides a unified formulation for both v...An adaptive control scheme is presented,which can simultaneously realize vibration suppression and compliance control for flexible joint robot(FJR).The proposed control scheme provides a unified formulation for both vibration suppression mode,where FJR tracks the desired position with little vibration,and compliance mode,in which FJR presents passive.Instead of designing multiple controllers and switching between them,both modes are integrated into a single controller,and the transition between two modes is smooth and stable.The stability of the closed-loop system is theoretically proven via the Lyapunov method,with the considering the dynamics uncertainties in both link side and motor side.Simulation results are presented to illustrate good performances of the proposed control scheme.展开更多
Autonomous planning is a significant development direction of the space manipulator,and learning from demonstrations(LfD)is a potential strategy for complex tasks in the field.However,separating control from planning ...Autonomous planning is a significant development direction of the space manipulator,and learning from demonstrations(LfD)is a potential strategy for complex tasks in the field.However,separating control from planning may cause large torque fluctuations and energy consumptions,even instability or danger in control of space manipulators,especially for the planning based on the human demonstrations.Therefore,we present an autonomous planning and control strategy for space manipulators based on LfD and focus on the dynamics uncertainty problem,a common problem of actual manipulators.The process can be divided into three stages:firstly,we reproduced the stochastic directed trajectory based on the Gaussian process-based LfD;secondly,we built the model of the stochastic dynamics of the actual manipulator with Gaussian process;thirdly,we designed an optimal controller based on the dynamics model to obtain the improved commanded torques and trajectory,and used the separation theorem to deal with stochastic characteristics during control.We evaluated the strategy with locating pre-screwed bolts experiment by Tiangong-2 manipulator system on the ground.The result showed that,compared with other strategies,the strategy proposed in this paper could significantly reduce torque fluctuations and energy consumptions,and its precision can meet the task requirements.展开更多
基金supported by the National Key R&D Program of China(No.2017YFB1300400)the National Natural Science Foundation of China(No. 51805107)
文摘An adaptive control scheme is presented,which can simultaneously realize vibration suppression and compliance control for flexible joint robot(FJR).The proposed control scheme provides a unified formulation for both vibration suppression mode,where FJR tracks the desired position with little vibration,and compliance mode,in which FJR presents passive.Instead of designing multiple controllers and switching between them,both modes are integrated into a single controller,and the transition between two modes is smooth and stable.The stability of the closed-loop system is theoretically proven via the Lyapunov method,with the considering the dynamics uncertainties in both link side and motor side.Simulation results are presented to illustrate good performances of the proposed control scheme.
基金the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.51521003)the National Natural Science Foundation of China(Grant No.61803124)the Post-doctor Research Startup Foundation of Heilongjiang Province。
文摘Autonomous planning is a significant development direction of the space manipulator,and learning from demonstrations(LfD)is a potential strategy for complex tasks in the field.However,separating control from planning may cause large torque fluctuations and energy consumptions,even instability or danger in control of space manipulators,especially for the planning based on the human demonstrations.Therefore,we present an autonomous planning and control strategy for space manipulators based on LfD and focus on the dynamics uncertainty problem,a common problem of actual manipulators.The process can be divided into three stages:firstly,we reproduced the stochastic directed trajectory based on the Gaussian process-based LfD;secondly,we built the model of the stochastic dynamics of the actual manipulator with Gaussian process;thirdly,we designed an optimal controller based on the dynamics model to obtain the improved commanded torques and trajectory,and used the separation theorem to deal with stochastic characteristics during control.We evaluated the strategy with locating pre-screwed bolts experiment by Tiangong-2 manipulator system on the ground.The result showed that,compared with other strategies,the strategy proposed in this paper could significantly reduce torque fluctuations and energy consumptions,and its precision can meet the task requirements.
