模型参考自适应滑模控制方法在前向像移补偿中的应用

为了提高航空相机的飞行分辨率,提出了一种基于模型参考自适应的滑模控制方法。用模型参考自适应算法对时变系统参数进行在线辨识,并改变滑模控制器的控制参数。采用基于衰减控制的变速趋近律作切换函数,加快系统收敛速度,减小切换过程中的抖动。实验结果表明,同PID控制方法相比较,模型参考自适应滑模控制方法将速度补偿误差降低了60%,相应地将航空相机的飞行分辨率提高了2倍。因此,基于此方法的前向像移补偿系统可提高速度跟踪精度和鲁棒性,对时变干扰力矩具有较强的抑制能力。

Application of model reference adaptive sliding mode control to forward compensation system in camera

In order to improve the flight resolution of a aerial camera,a new Model Reference Adaptive Sliding Mode Control(MRAC-SMC) solution is presented.The model reference adaptive algorithm is used to identify time-variant system parameters and modify switching function of sliding mode controller,and the variable rate reaching law based on attenuation control is taken as the switching function of SMC to quicken the convergence in system and reduce the chattering caused by switching.The experiment results indicate that the velocity compensation error can be reduced by 60% and accordingly flight resolution can be increased by 200% by MRAC-SMC compared with PID control.Therefore,forward image motion compensation system based on MRAC-SMC can improve velocity tracking accuracy and robust performance and can overcome the effect of uncertain time-varying forces also.