漂浮基柔性臂空间机器人输出力矩受限的自适应 PID 输出反馈

摘要

The control problem of the free-floating flexible manipulators space robot with bounded torque outputs was discussed .With the momentum conservation relations , system dynamics model was set up by the Lagrange method .Based on the singular perturbation method ,an adaptive PID out-put-feedback control algorithm was designedin the slow subsystemwith only position measurements , modeling uncertainties and disturbances under space robot manipulators ' coordinated motion with limited output torque , and a linear-quadratic optimal control was designed in the fast subsystem . High precision filter was used in the algorithm to estimate the joint velocity of the manipulators , which made the whole closed-loop control with only position feedback measurements .A saturation function was introduced in the control law , which guaranteed the output torque within any specified range.While an adaptive PID controller was used to compensate the modeling uncertainties and in-terferences .Based on Lyapunov stability theory , this algorithm is proved to be able to ensure that the control system is asymptotically stable .The simulation results based on a planar two-joint free-floating flexible manipulators space robotshow that the proposed control scheme is designed with good trajectory tracking and fast convergence .%针对输出力矩受限的漂浮基柔性臂空间机器人的控制问题,结合系统动量守恒关系和拉格朗日方法建立了系统动力学模型;利用奇异摄动法,慢变子系统设计了输出力矩受限情况下仅有位置传感、建模不确定性及干扰的空间机械臂系统协调运动的自适应PID输出反馈控制算法,快变子系统设计了线性二次最优控制方法主动抑制. 该算法采用高精度滤波器估计机器人关节速度,使得整个系统的闭环控制仅需位置输出反馈;在控制率中引入饱和函数,保证输出力矩在给定限制范围内,同时采用自适应PID控制器补偿建模不确定性和干扰. 基于Lyapunov稳定性理论证明了该算法可确保控制系统是渐近稳定的,针对平面两关节漂浮基柔性臂空间机器人的仿真结果表明了所提出的控制方案良好的跟踪性和快速收敛性.