基于关节约束的双臂机器人协调控制器研究

Research on Coordination Controller of Dual⁃arm Robot Based on Joint Constraints

为提高双臂机器人运动的协调性,设计了协调控制系统,并对机械臂运动轨迹跟踪误差和角速度变化进行仿真验证。创建了双臂机器人三维模型,利用相对雅克比矩阵推导机械臂末端执行器运动轨迹误差公式,设计机械臂运动协调控制器。根据层次优先的任务结构推导机械臂关节角速度方程式,设计双臂联合避免关节限制策略,通过优先级协调双臂运动。为验证关节约束条件下机械臂运动的协调性和稳定性,采用MATLAB软件对机械臂运动轨迹跟踪误差和角速度变化进行仿真,并与无关节约束条件下输出效果进行比较。结果表明:在无关节约束条件下,单臂机器人运动轨迹误差较小,但是双臂机器人运动轨迹跟踪误差较大,双臂产生的角速度峰值较大;在有关节约束条件下,单臂机器人运动轨迹误差较大,而双臂运动轨迹跟踪误差较小,双臂产生的角速度峰值较小。采用联合关节限制策略,可以提高机械臂运动的协调性,降低机械臂角速度产生的峰值,机器人运动相对稳定,效果较好。

In order to improve the coordination of the motion of the dual⁃arm robot,a coordinated control system was designed,and the trajectory tracking error and angular velocity change of the manipulator were simulated and verified.The three⁃dimensional mod⁃el of the dual⁃arm robot was created,and the motion trajectory error formula of the end⁃effector of the manipulator was deduced by using relative Jacobian matrix,and the motion coordination controller of the manipulator was designed.According to the hierarchical priority task structure,the angular velocity equation of the manipulator joint was deduced.The joint avoidance strategy of the dual⁃arm was de⁃signed,and the dual⁃arm movement was coordinated through the priority.In order to verify the coordination and stability of the manipu⁃lator motion under joint constraints,the trajectory tracking error and angular velocity change of the manipulator were simulated by using MATLAB software,and the output effect was compared with that without joint constraints.The results show that without joint con⁃straints,the motion trajectory error of the single⁃arm robot is small,but the motion trajectory tracking error of the dual⁃arm robot is large,and the angular velocity peak generated by the dual⁃arm is large;with joint constraints,the motion trajectory error of the single⁃arm robot is large,while that of double⁃arm robot is small,and the angular velocity peak generated by the dual⁃arm is small.Using joint restriction strategy can improve the coordination of the manipulator motion,reduce the peak value of the angular velocity of the manipulator,and the motion is relatively stable with good results.