基于状态观测器的空间机器人滑模容错控制

Sliding Mode Fault Tolerant Control of Space Robot Based on State Observer

研究了具有执行器故障的漂浮基空间机器人系统无速度反馈的关节轨迹跟踪控制问题,设计了基于状态观测器的神经网络积分滑模容错控制方案。首先,根据执行器故障类型建立执行器故障的数学模型,并结合拉格朗日法建立了执行器故障的空间机器人系统动力学方程;其次,为实现控制器的无速度反馈,设计了状态观测器对系统速度进行估计,并结合神经网络提高估计精度;再次,根据滑模控制理论设计了积分滑模控制器,通过神经网络补偿执行器故障的影响,并设计自适应律补偿神经网络的估计误差,保证了控制器的连续性与非奇异性,使系统获得良好的轨迹跟踪精度和容错能力;最后,通过李雅普诺夫方法证明了控制方案的稳定性,并通过MATLAB数值仿真运算,验证了控制方案有效性。

Considering joint trajectory tracking control of floating space robot system with non-speed feedback and actuator failure,a neural network integral sliding mode fault-tolerant control approach based on state observer is designed.Firstly,the mathematical model of the actuator fault is established according to the actuator fault type,and the dynamic equation of the space robot system is established based on Lagrange method.Secondly,a state observer is designed to estimate the system speed,and the neural network is used to improve the estimation accuracy.Thirdly,an integral sliding mode controller is designed according to the sliding mode control theory,and actuator failure terms were estimated through neural network with adaptive compensation of estimation error.These ensure the continuity and non-singularity of the controller,and improve the tracking accuracy and fault tolerance of the system.Finally,the stability of the control scheme is proved by Lyapunov method,and the effectiveness of the control scheme is verified by MATLAB numerical simulation.