The Hybrid Control Research For Force/Position Of A Overactuated Compliance Parallel Mechanism

Compared with serial mechanism, parallel mechanism has high resolution position, high rigidity, strong bearing capacity, tight configuration, small error and other advantages, to make up for the lack of serial mechanism in industrial applications. However, the closed loop structure of parallel mechanism has some obvious disadvantages, for example, working space, hard to be calibrated, singularity and so on. For all this, overactuated is introduced into parallel mechanism to optimize input force, reduce the joint clearance of Mechanism, eliminate mechanism singularities, improve mechanism fault-tolerant performance. Overactuated parallel mechanism has been widely used in the industrial field, such as parallel machine tool, bionic machine and high-performance aircraft.This dissertation dominating research the plane2-dof four-leg overactuated parallel mechanism. In the first place, it analyses and researches parallel mechanism reverse kinematic solution, the forward kinematics, Jacobi velocity matrix, torque transmission performance and the working space. The kinematics model of redundantly actuated parallel mechanism is established, and a trace simulation experiment is carried out.Secondly, the kinematics models of plane2-dof overactuated parallel mechanism is established, which analysises and win the transform relationship between the speed of the drive space, the speed of torque limit the end actuator space and the acceleration limits.Thirdly, this paper deeply studies the control strategies of the redundantly actuated parallel mechanism, then lists several control strategies used in the control of Parallel Mechanism, meanwhile, which are theoretically analyzed and compared at the control point at the control point. Plane2-dof redundantly actuated parallel mechanism model is established, as well as PD controller and impedance controller are designed. Based on the trajectory simulation experiments of plane2-dof redundantly actuated parallel mechanism, this paper makes a comparison between PD control and position force control.Finally, the Parallel mechanism motion control system is established, which is controlled by Visual c++develop motion control program and PCI bus drive Motion control card (GT-400-SV-PCI). Software is running on the PC, completing the Circular trajectory tracking control experiments of position force controller.