欠驱动冗余度空间机器人优化控制

欠驱动控制是空间技术中容错技术的重要方面.本文研究了被动关节中有制动器的欠驱动冗余度空间机器人系统的运动优化控制问题.从系统动力学方程出发,分析了欠驱动冗余度空间机器人的优化能力和控制方法;给出了主、被动关节间的耦合度指标;提出了欠驱动冗余度空间机器人系统的“虚拟模型引导控制”方法,在这种方法中采用与欠驱动机器人机构等价的全驱动机器人作为模型来规划机器人的运动,使欠驱动系统在关节空间中逼近给出的规划轨迹,实现了机器人末端运动的连续轨迹运动优化控制;通过末关节为被动关节的平面三连杆机器人进行了仿真,仿真的结果证明了提出算法的有效性.

Optimal control of under-actuated redundant space-robot system

The underactuated control is an important aspect of the fault tolerance technology in space field. In this paper the optimal motion planning and control method are studied for the underactuated redundant space robot system with passive joints equipped with lockers. The optimizing ability and control method for such a system are analyzed on the basis of dynamic equations. A coupling index between the actuated and passive joints is introduced and an optimizing control algorithm is proposed, which is called the virtual model lead control method (VMLCM). By this method, a fully actuated manipulator that structurally is equivalent to the underactuated one is used as the virtual model to plan the motion, and the underactuated manipulator approximates the planned trajectory in the space of joint. Therefore, the algorithm can drive the manipulator to track a desired trace and improve the tracking accuracy. A three DOFs planar robot with passive end joint is used for simulation, and the simulation results justify the proposed algorithm.