Internal force-based impedance control for cooperating manipulators

1996 ◽  
Vol 12 (1) ◽  
pp. 78-89 ◽  
Author(s):  
R.C. Bonitz ◽  
T.C. Hsia
Author(s):  
S. Ali A. Moosavian ◽  
Hadi R. Ashtiani

PurposeThe aim of this paper is to present the non‐model‐based multiple impedance control (NMIC) law for object manipulation tasks, which can be implemented with reasonable limited on‐line computations.Design/methodology/approachThe multiple impedance control (MIC) is a model‐based algorithm that enforces a designated impedance on all cooperating manipulators, and the manipulated object itself. In this paper, the MIC law is modified to be implemented without using system dynamics. Therefore, this modified MIC law is a quick and more realistic algorithm for implementation in cooperating robotic systems, and so is called NMIC. Developing the NMIC law, error analysis shows that under the NMIC law all participating manipulators, and the manipulated object exhibit the same designated impedance behavior. Next, the proposed NMIC law is applied on an object manipulation task with three cooperating PUMA 560 manipulators while two of them are equipped with a remote compliant centre.FindingsDeveloping the NMIC law, error analysis shows that under the NMIC law all participating manipulators, and the manipulated object exhibit the same designated impedance behavior. The obtained results show good tracking performance even in the presence of impacts due to contact with an obstacle, and also system flexibility.Practical implicationsThe obtained results show good tracking performance even in the presence of impacts due to contact with an obstacle, and also system flexibility. These results reveal the merits of NMIC law as a non‐model‐based algorithm for object manipulation tasks, which can be implemented with reasonable limited on‐line computations.Originality/valueThe proposed NMIC law is applied on an object manipulation task with three cooperating PUMA 560 manipulators while two of them are equipped with a remote compliant centre.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4653
Author(s):  
Xuefei Liu ◽  
Xiangrong Xu ◽  
Zuojun Zhu ◽  
Yanglin Jiang

To meet the high-accuracy position/force control requirements of dual-arm robots for handling a target object, a control algorithm for dual-arm robots based on the modified sliding mode impedance controller MSMIC(tanh) is proposed. First, the combinative kinematics equation of the dual-arm robots and the unified dynamics model combining the manipulated object is established. Second, according to the impedance control motion model for the object, the desired joint angular accelerations of the manipulators are obtained, and the sliding mode controller based on the hyperbolic tangent function as the switch function is introduced to design the coordinated control strategy for dual-arm robots. The stability and convergence of the designed controller are proved according to the Lyapunov function theory. Finally, the operation tasks of the coordinated transport the target object for dual-arm robots are carried out in the simulated experiment environment. Simulation results show that the proposed control scheme can stably output the required internal force and achieve a high-precision trajectory tracking effect while reducing the periodic torque and joint chattering amplitude generated in the conventional sliding mode control algorithm.


1992 ◽  
Vol 114 (2) ◽  
pp. 213-219 ◽  
Author(s):  
M. Nahon ◽  
J. Angeles

The control of multiple manipulators handling a common object entails the solution of an underdetermined system of linear equations which represents the system’s dynamics. In order to choose an optimal solution to this problem, various approaches have been proposed: minimum internal force and minimum power, among others. The present work investigates an approach for minimizing the power losses in these systems. It is shown that the power imparted to the manipulator/payload system cannot be optimized once the system’s motion is prescribed. However, assuming certain loss characteristics for the dc servomotors commonly used on robotic manipulators, it is shown that the minimization of power losses can be cast as a linear-quadratic optimization problem. Local and global performance indices are introduced to allow comparison of the minimum power loss and the minimum internal force approaches. An example of two Puma 560 robots handling a common payload is shown to demonstrate the proposed technique.


2010 ◽  
Vol 34-35 ◽  
pp. 265-270
Author(s):  
Wen Jun Li ◽  
Bai Ling An ◽  
Hong Kun Zhang

Adaptive multiple impedance control based on passivity is studied about two robot manipulators cooperating an object which interacts with external environment actively. The dynamic model is derived by Newton-Euler equation and the relations between the forces are analyzed. The relations between stiffness coefficient and convergence are explained by solving the differential equation when the stiffness coefficient is known. The adaptive impedance controller based on passivity is designed combining adaptive control and generalized impedance control when the stiffness coefficient is unknown. The impedance control based on internal force is adopted for the cooperative system. The simulation results prove the validity of the method.


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