无人机两轴云台建模及其自适应容错控制

UAV two-axis pan-title modeling and its adaptive fault-tolerant control

根据两轴云台框架的运动学和动力学特性推导出它的动力学方程,通过对其进行简化并在平衡点线性化,得到适用于容错控制器设计的数学模型;采用自适应容错控制方法设计两轴框架云台容错控制器,该算法能够实时估计执行器故障,自适应率可进行自动更新用以补偿故障对系统造成的影响。该控制器的闭环扰动容许能力比传统的固定增益控制器的闭环扰动容许能力高,特别是在执行器饱和且有故障的状态下。该算法以线性矩阵不等式的形式得出,利用MATLAB的LMI工具箱计算仿真得出结果。结果表明该容错控制器算法的扰动容许能力强,能够满足无人机载系统稳定安全控制的需要。

Based on the kinematics and dynamics characteristics of UAV Two-axis Pan-title,the dynamic equations of two-axis platform were built. Moreover,the math model applicable to fault-tolerant controller design was built by predigesting and linearizing the model in the balance point. The adaptive fault-tolerant control method was used to design Two-axis Pan-title fault-tolerant controller,which could provide real time estimation of actuator faults. The adaptive fault-tolerant controller parameters could update automatically to compensate for the effects of fault on systems. The disturbance tolerance ability of the adaptive controller was higher than the fixed gain controller＇s,especially in the case of actuator saturation and actuator failures.The proposed algorithm was calculated and simulated in the form of linear matrix inequalities with the aid of MATLAB LMI Control Toolbox. Results showthat the controller has high disturbance tolerance ability,thus meeting the needs of stability and security control on UAV airborne system.