Research On Distributed Task Space Synchronization Control For Multiple Robotic Manipulators Systems

In modern industrial manufacturing,there are increasing numbers of scenarios in which a common task is accomplished by the cooperative operation of multiple mechanical arms,such as automobile welding,parts assembly,surface CNC machining and other manufacturing processes.Most of the industrial applications above require machining systems to have strong operability and multi-directional operating space,which is often difficult to achieve for a single robotic arm.In order to meet the increasingly complex industrial process requirements and implement the function of the tasks effectively,it is urgent and significant to carry on a research on multiple robotic manipulators systems(MRMS)synchronization control algorithm.Firstly,in view of the general directed graph of MRMS,this thesis establishes system dynamics model in task space using networked Euler-Lagrangian equation and task space transformation matrix,designs synchronization errors and cross coupling errors based on algebraic graph theory which reflect the mutual coupling among systems,and puts forward a distributed cooperative sliding mode controller based on feedback linearization,which guarantee each mechanical arm tracks its desired trajectory with high precision and system synchronization error converges.Secondly,considering the MRMS with fixed directed graph under uncertainty and interference,this thesis proposes a control strategy to tackle internal and external combined interference and uncertainty step by step using the nonlinear disturbance observer and adaptive control,respectively.According to the proposed task space cooperative control design framework of MRMS under general directed graph,a distributed adaptive sliding mode controller based on nonlinear disturbance observer is designed by using the defined cross coupling error and synchronization error,which improves the anti-interference and robustness of the system.Thirdly,considering the problem that communication topology changes often occur in the practical application of MRMS,a synchronization error consensus protocol for switching topology case MRMS distributed cooperative control is proposed by combining synchronization error method and multi-agent consensus design strategy.The system parameters with uncertainty are estimated by adaptive method,and a distributed sliding mode controller is designed based on exponential approach law.The bounded external interference is suppressed by using the anti-interference ability of sliding mode.The above control methods are all based on Lyapunov method for stability proof and convergence analysis,and the effectiveness of the algorithm is verified by simulation with MATLAB.