并串联复合机器人的鲁棒控制

针对并联机构具有较高的刚度和精度,但工作空间小的特点,提出一种由3自由度平动并联机构和放大机构相结合的机构,从而组成新型并串联复合机器人。根据拉格朗日方法,建立并串联复合机器人的动力学方程, 并讨论动力学方程的性质。研究并串联复合机器人的鲁棒控制问题,根据动力学的性质在笛卡儿坐标系中设计一种鲁棒控制策略。控制器由两部分组成:一部分为基于标称模型设计的计算力矩控制器,其作用是镇定标称的机器人系统;另一部分为一种基于Lyapunov方法设计的鲁棒控制器,其作用是消除不确定性对跟踪性能的影响。理论分析与仿真结果表明,该控制器对改善并串联复合机器人的轨迹跟踪精度十分有效。

ROBUST CONTROL OF HYBRID PARALLEL-SERIAL ROBOT

A 3-DOF hybrid parallel-serial robotic manipulator which is constructed by combining a parallel mechanism and a pantograph is introduced to increase high stiffness as well as workspace, based on the fact that parallel mechanism has higher stiffness but smaller workspace, Dynamics equation is established by applying Lagrange's method and its feature is discussed. Then a robust control scheme for the robot is developed. The proposed controller which is designed in Cartesian coordinates consists of two parts. The first part is the model-based computed torque controller which is used to stabilize the nominal robot system. The second part is a robust compensating controller which is designed to handle the uncertainty in the system. The theory analysis and simulation results show that using this controller, the robot tracking performance can be improved effectively.