欠驱动机器人最优运动轨迹生成与跟踪控制

以被动关节自由的欠驱动机器人为研究对象,对其最优运动规划与轨迹跟踪控制问题进行研究,控制目标为实现欠驱动机器人关节的任意位置控制.对欠驱动机器人系统的可控性条件进行分析,提出部分稳定规划器的思想,利用遗传算法对建立的适应度函数进行全局优化,得到部分稳定规划器的最优切换顺序.利用变结构控制方法进行反馈控制,实现了期望轨迹的精确跟踪.提出的方法一方面利用遗传算法的全局搜索能力,不必考虑机器人的严格线性化,能够快速、准确地实现路径寻优,且具有很好的稳定性:另一方面采用的变结构控制方法能够对系统干扰及参数变化具有良好的自适应性,因此本方法可以很容易推广到多自由度欠驱动机器人系统控制当中.通过末关节为被动关节的平面3自由度机器人进行仿真,仿真结果证明了方法的有效性.

Optimal Path Planning and Trajectory Tracking of Underactuated Robots

Optimal path planning and trajectory tracking of underactuated robots are investigated. The control target is to realize the arbitrary position control of joint angles. The controllability of underactuated robots is analyzed. The thought of partly stable controllers is introduced and the best switching sequence of partly stable controllers is obtained by using genetic algorithm. Sliding mode control method is utilized to realized accurate model tracking. The proposed method has following advantages: It does not make any hypothesis about the rigorous linearizations to the original nonlinear system. Also because of the global search ability of genetic algorithm, the optimal trajectory can be generated quickly and accurately. The accurate trajectory tracking can be guaranteed by the good adaptability to the disturbance and parameter changing of sliding mode control method. Therefore the proposed method can be used without modification for arms with a large number of degree of freedoms. At last numerical simulations are carried out on the planar 3R underactuated robot to verify the validity of the proposed method.