Research On Coordination And Collision Avoidance Control Algorithm For Dual-arm Cooperative Robot

Due to some limitations of single arm have not been able to meet people's expectations of production and life automation,while dual-arm cooperative robots have many advantages,such as better flexibility and better coordinated operation,which can stand out in cumbersome work and diverse workspaces.Therefore,dual-arm cooperative robots have become a research hotspot.Moreover,there are complex coupling constraints between the dual-arm in coordinated operation,which makes coordinated control become the focus of the dual-arm research.In this paper,aiming at the problems of collision and low tracking accuracy caused by external disturbance in the process of dual-arm compact coordinated operation,the research on the coordination and collision avoidance algorithm for the dual-arm cooperative robots is carried out.The main research contents are as follows:The Baxter robot with two seven-degree-of-freedom manipulators is regarded as the exploration target.The D-H parameter method is used to create its kinematic model,and the forward and inverse kinematics analysis is performed to determine the position and posture relationship of the dual-arm.The Robotics Toolbox equipped with MATLAB 2016 is used to carry out the simulation experiment,and the motion of the 7-DOF manipulator is demonstrated to prove the rationality of the theoretical calculation and the correctness of the model.Aim at the defect of self-collision during the operation of dual-arm cooperative robots,this paper proposes a method of avoiding self-collision with dual-arm.The operation of the dual-arm is regarded as collision avoidance movement and terminal trajectory tracking.Based on the principle of minimum distance,two variables that can realize the transformation of the motion form are introduced into the inverse kinematics equation to avoid the error produced by the motion conflict caused by the change of arms state.This method not only achieves the requirements of avoiding self-collision between dual-arm,but also ensure that the system runs according to the desired trajectory.Finally,simulation experiments verify the effectiveness of the proposed method.Focus on the problem that external disturbance affects the accuracy of dual-arm,a compact coordination control algorithm based on impedance control is proposed.Firstly,the simple impedance control is introduced,and the joint dynamics model of dual-arm and clamping object is constructed based on the restriction relation of dual-arm during the coordinated operation.Secondly,the disturbance observer based on the generalized momentum is designed to observe the external interference force of the manipulator.And combining it with impedance control to design an impedance control strategy of the compact coordinated operation,which ensures dual-arm complete coordination task with high accuracy.The manipulator will occur chattering during motioning,in order to improve this situation,a fuzzy sliding mode control scheme is applied to approach the switching gain of the sliding mode control,so as to obtain a continuous smooth gain curve to control the sudden change of the speed.The chattering phenomenon is weakened,the reliability and robustness of the system are ensured,and the position tracking accuracy of the manipulator is increased.Finally,the reliability of the fuzzy sliding mode control method is verified by experiments.