中文摘要：

针对在第2关节和第3关节仅有两个驱动器的PAA（passive-active-active）型欠驱动三连杆机器人，提出一种基于力矩变换的鲁棒镇定控制方法．首先对第3关节的控制输入引入一种与第2关节控制输入和机器人状态相关的力矩变换，以消除第3关节控制输入对系统的影响，将机器人动力学方程化为更简单的形式，然后基于能量进行摇起控制设计．在平衡区，将机器人第1连杆和第2连杆的角速度看成一种不确定性，得到机器人在不稳定平衡点附近的不确定模型；然后基于线性矩阵不等式推导鲁棒镇定状态反馈控制律，达到较大范围的平衡控制．仿真结果表明，该控制方法具有稳定时间短和控制力矩小等优点．

英文摘要：

Robust stabilization control based on torque transform is proposed for an underactuated three-link manipulator, named a passive-active-active （PAA） robot. It is equipped with only two actuators on the second and third joints. A torque transform, as a function of control input of the second joint and state of the robot, is used for the control input of the third joint. The robot dynamics is transformed to a simpler form, where the influence of control input of the third joint is explicitly eliminated. An energy-based swingup control law is then designed. In the balancing area, an uncertain model is obtained by treating velocities of the first and second links around the unstable equilibrium as uncertainties. A robust stabilizing state feedback control law is derived to reach a large balancing region based on a technique of linear matrix inequality （LMI）. Simulation results show that the proposed approach has advantages of short settling time and small control torques.