In this paper, coordinated control of multiple robot manipulators holding a rigid object is discussed. In consideration of inaccuracy of the dynamic model of a multiple manipulator system, the error equations on obje...In this paper, coordinated control of multiple robot manipulators holding a rigid object is discussed. In consideration of inaccuracy of the dynamic model of a multiple manipulator system, the error equations on object position and internal force are derived. Then a hybrid position/force coordinated learning control scheme is presented and its convergence is proved. The scheme can improve the system performance by modifying the control input of the system after each iterative learning. Simulation results of two planar robot manipulators holding an object show the effectiveness of this control scheme.展开更多
In this paper,the leader-follower consensus problem for a multiple flexible manipulator network with actuator failures,parameter uncertainties,and unknown time-varying boundary disturbances is addressed.The purpose of...In this paper,the leader-follower consensus problem for a multiple flexible manipulator network with actuator failures,parameter uncertainties,and unknown time-varying boundary disturbances is addressed.The purpose of this study is to develop distributed controllers utilizing local interactive protocols that not only suppress the vibration of each flexible manipulator but also achieve consensus on joint angle position between actual followers and the virtual leader.Following the accomplishment of the reconstruction of the fault terms and parameter uncertainties,the adaptive neural network method and parameter estimation technique are employed to compensate for unknown items and bounded disturbances.Furthermore,the Lyapunov stability theory is used to demonstrate that followers’angle consensus errors and vibration deflections in closed-loop systems are uniformly ultimately bounded.Finally,the numerical simulation results confirm the efficacy of the proposed controllers.展开更多
In order to overcome the shortcomings of the previous obstacle avoidance algorithms,an obstacle avoidance algorithm applicable to multiple mobile obstacles was proposed.The minimum prediction distance between obstacle...In order to overcome the shortcomings of the previous obstacle avoidance algorithms,an obstacle avoidance algorithm applicable to multiple mobile obstacles was proposed.The minimum prediction distance between obstacles and a manipulator was obtained according to the states of obstacles and transformed to escape velocity of the corresponding link of the manipulator.The escape velocity was introduced to the gradient projection method to obtain the joint velocity of the manipulator so as to complete the obstacle avoidance trajectory planning.A7-DOF manipulator was used in the simulation,and the results verified the effectiveness of the algorithm.展开更多
For the situation of multiple cooperating manipulators handling a single object,an equilibrium equation is presented in which the manipulator dynamics and control forces/torques are taken into account,and a expression...For the situation of multiple cooperating manipulators handling a single object,an equilibrium equation is presented in which the manipulator dynamics and control forces/torques are taken into account,and a expression is derived to allow the optimal dynamic load distribution of the combined system can be made.展开更多
The characteristic that multiple limb manipulation systems can resist disturbance external forces without relying on the feedback control of joint torques, called the robustness, has been addressed by several resear...The characteristic that multiple limb manipulation systems can resist disturbance external forces without relying on the feedback control of joint torques, called the robustness, has been addressed by several researchers. Based on their results, a further study of robustness is presented in this paper. By decomposing the space of external forces into two subspaces, the necessary and sufficient condition for a system to have robustness is given and a definition of robustness which is applicable to any multiple limb systems is also proposed. For the purpose of the evaluation of robustness, a new quality measure — critical disturbance external force and its algorithm are put forward. Finally, two examples of robustness analysis are presented.展开更多
Automated parallel manipulation of multiple micro-objects with optoelectronic tweezers(OET)has brought significant research interests recently.However,the parallel manipulation of multiple objects in complex obstacle-...Automated parallel manipulation of multiple micro-objects with optoelectronic tweezers(OET)has brought significant research interests recently.However,the parallel manipulation of multiple objects in complex obstacle-dense microenvironment using OET technology based on negative dielectrophoresis(nDEP)remain a big technical challenge.In this work,we proposed an adaptive light pattern design strategy to achieve automated parallel OET manipulation of multiple micro-objects and navigate them through obstacles to target positions with high precision and no collision.We first developed a multi-micro-object parallel manipulation OET system,capable of simultaneous image processing and microparticles path planning.To overcome microparticle collisions caused by overlapping light patterns,we employed a novel adaptive light pattern design that can dynamically adjust the layout of overlapping light patterns according to surrounding environment,ensuring enough space for each microparticle and preventing unintended escapes from the OET trap.The efficacy of this approach has been verified through systematic simulations and experiments.Utilizing this strategy,multiple polystyrene microparticles were autonomously navigated through obstacles and microchannels to their intended destinations,demonstrating the strategy’s effectiveness and potential for automated parallel micromanipulation of multiple microparticles in complex and confined microenvironments.展开更多
文摘In this paper, coordinated control of multiple robot manipulators holding a rigid object is discussed. In consideration of inaccuracy of the dynamic model of a multiple manipulator system, the error equations on object position and internal force are derived. Then a hybrid position/force coordinated learning control scheme is presented and its convergence is proved. The scheme can improve the system performance by modifying the control input of the system after each iterative learning. Simulation results of two planar robot manipulators holding an object show the effectiveness of this control scheme.
基金This work was supported in part by the National Key Research and Development Program of China(2021YFB3202200)Guangdong Basic and Applied Basic Research Foundation(2020B1515120071,2021B1515120017).
文摘In this paper,the leader-follower consensus problem for a multiple flexible manipulator network with actuator failures,parameter uncertainties,and unknown time-varying boundary disturbances is addressed.The purpose of this study is to develop distributed controllers utilizing local interactive protocols that not only suppress the vibration of each flexible manipulator but also achieve consensus on joint angle position between actual followers and the virtual leader.Following the accomplishment of the reconstruction of the fault terms and parameter uncertainties,the adaptive neural network method and parameter estimation technique are employed to compensate for unknown items and bounded disturbances.Furthermore,the Lyapunov stability theory is used to demonstrate that followers’angle consensus errors and vibration deflections in closed-loop systems are uniformly ultimately bounded.Finally,the numerical simulation results confirm the efficacy of the proposed controllers.
基金Supported by Ministeral Level Advanced Research Foundation(65822576)Beijing Municipal Education Commission(KM201310858004,KM201310858001)
文摘In order to overcome the shortcomings of the previous obstacle avoidance algorithms,an obstacle avoidance algorithm applicable to multiple mobile obstacles was proposed.The minimum prediction distance between obstacles and a manipulator was obtained according to the states of obstacles and transformed to escape velocity of the corresponding link of the manipulator.The escape velocity was introduced to the gradient projection method to obtain the joint velocity of the manipulator so as to complete the obstacle avoidance trajectory planning.A7-DOF manipulator was used in the simulation,and the results verified the effectiveness of the algorithm.
文摘For the situation of multiple cooperating manipulators handling a single object,an equilibrium equation is presented in which the manipulator dynamics and control forces/torques are taken into account,and a expression is derived to allow the optimal dynamic load distribution of the combined system can be made.
文摘The characteristic that multiple limb manipulation systems can resist disturbance external forces without relying on the feedback control of joint torques, called the robustness, has been addressed by several researchers. Based on their results, a further study of robustness is presented in this paper. By decomposing the space of external forces into two subspaces, the necessary and sufficient condition for a system to have robustness is given and a definition of robustness which is applicable to any multiple limb systems is also proposed. For the purpose of the evaluation of robustness, a new quality measure — critical disturbance external force and its algorithm are put forward. Finally, two examples of robustness analysis are presented.
基金the support from Optoseeker Biotechnology(Shenzhen)Co.,Ltd.to help build the OET system and provide Optobot 500 to carry out the experiment shown in supplementary Movie S4.National Key R&D Program of China(2023YFE0112400,2022YFA1207100,2024YFC3406900)National Natural Science Foundation of China(62103050,62473245,61933008)+6 种基金Beijing Municipal Natural Science Foundation(4242060,L246030)the Chongqing Municipal Natural Science Foundation(Grant No.2024NSCQJQX0192,CSTB2024NSCQ-JQX0034)the BIT Research and Innovation Promoting Project(Grant No.2023CX01002)Innovation Program of Shanghai Municipal Education Commission(2021-01-07-00-09-E0013)Shanghai Science and Technology plan project(23ZR1422300)Shenzhen Science and Technology Program(KJZD20240903101359020)Open Research Fund of Guangdong Provincial Key Laboratory of Advanced Biomaterials(Southern University of Science and Technology,Grant No.KLAB202404002).
文摘Automated parallel manipulation of multiple micro-objects with optoelectronic tweezers(OET)has brought significant research interests recently.However,the parallel manipulation of multiple objects in complex obstacle-dense microenvironment using OET technology based on negative dielectrophoresis(nDEP)remain a big technical challenge.In this work,we proposed an adaptive light pattern design strategy to achieve automated parallel OET manipulation of multiple micro-objects and navigate them through obstacles to target positions with high precision and no collision.We first developed a multi-micro-object parallel manipulation OET system,capable of simultaneous image processing and microparticles path planning.To overcome microparticle collisions caused by overlapping light patterns,we employed a novel adaptive light pattern design that can dynamically adjust the layout of overlapping light patterns according to surrounding environment,ensuring enough space for each microparticle and preventing unintended escapes from the OET trap.The efficacy of this approach has been verified through systematic simulations and experiments.Utilizing this strategy,multiple polystyrene microparticles were autonomously navigated through obstacles and microchannels to their intended destinations,demonstrating the strategy’s effectiveness and potential for automated parallel micromanipulation of multiple microparticles in complex and confined microenvironments.
