Position And Force Control For Coordinated Multiple Manipulators

With the development of science and technology,the research on the robot has become a hot issue.In terms of the position/force control problem of robot,studies on single manipulator are very popular in the domestic and overseas,but those on multiple manipulators are paid little attention to,especially in our country.The multiple manipulators system has some great advantages,such as,grasping heavier object easily and being adapt to the complex and changeable industrial environment,but there are many difficulties in the control of multiple manipulators system.When multiple manipulators grasp the object,a closed-loop chain structure is formed in the system,which makes the state variable strongly coupled,and this will make the controller become more complicated.For the coordinated multiple manipulators system,we extend the dynamic model of the single manipulator(using the Lagrange method)to the modeling of the multiple manipulators system,and also establish dynamic models of the fixed and time-varying constrained coordinated multiple manipulators system.During the process of dynamic modeling,we design the model based on the task space instead of conventional joint space model.We also calculate the detail parameter of the Simulink model and Simulink programming in MATLAB.For the position/force control problem of coordinated multiple manipulators grasping a rigid object,some control strategies including the robust controller and adaptive controller are proposed based on the linear sliding mode and the terminal sliding mode.In the process of controller design,we improve the linear sliding mode and terminal sliding mode,which can make the position error and force error converge to zero asymptotically(linear sliding mode)or in finite time(terminal sliding mode),but the conventional controller can only guarantee the position error converge asymptotically but the force error bounded.For the position/force(constraint force and internal force)control problem of fixed constrained coordinated multiple manipulators system,we firstly design the position/force(constraint force)controller based on the model of reducing dimension,and then add the internal force control term into the controller.The designed controller can guarantee the position error converge to zero asymptically and the force(constraint force and internal force)error bounded.And for the position/force(constraint force and internal force)control problem of time-varying constrained coordinated multiple manipulators system considering uncertainties,we introduce the fuzzy control method and improve the terminal sliding mode.In the process of controller design,we abandon the conventional method of reducing dimension,and the finally designed controller can guarantee the position error and constraint force error converge in finite time and the force error bounded.The Lyapunov stability analysis and simulation results of the two planar two-link manipulators are presented to validate the proposed method finally.