机载光电跟踪系统的自抗扰与快速非奇异终端滑模组合控制方法

Compound Control Method of ADRC and FNTSM for Airborne Object Tracking System

机载目标跟踪系统由于受到外部干扰、内部参数摄动和未建模动态等扰动的影响,使跟踪控制分系统设计面临巨大的挑战。以两轴四框架的光电稳定平台为对象研究抗扰动控制方法,针对自抗扰控制的扰动补偿一般留有扰动残差和滑模控制会引入较大抖振的问题,设计一种自抗扰与快速非奇异终端滑模组合控制的方法。利用线性扩张状态观测器来估计总扰动量并在控制端进行补偿,从而允许设计滑模控制的控制率时采用较小的滑模切换增益,并通过设计快速非奇异终端滑模面得到控制率,加快系统收敛的同时避免非奇异现象。数值仿真结果表明,该组合控制方法在外部扰动和模型不确定性的影响下,可以实现快速收敛与高跟踪精度的同时引入较小的抖振,并且实现了机载目标跟踪系统需求的快速响应性能,验证了这个组合控制方法的有效性。

Due to the influence of external disturbances,internal parameter perturbations and unmodeled dynamics,the design of the tracking control subsystem of the airborne object tracking system is faced with great challenges.A disturbance rejection control method is studied based on the optoelectronic stabilized two-axis four-gimbal platform.To solve the problems that the disturbance compensation of active disturbance rejection control(ADRC)is generally accompanied by disturbance residuals and that sliding mode control will introduce large chattering,a compound control method of ADRC and fast non-singular terminal sliding mode(FNTSM)control is designed.The linear extended state observer is employed to estimate the total disturbance and compensate it,thus allowing a smaller switching gain for the sliding mode when designing the control rate of sliding mode control,and fast non-singular terminal sliding surface is designed to obtain the control rate,which accelerates system convergence and avoids non-singular phenomena.The simulation results show that the proposed method can achieve high stability accuracy and introduce small chattering despite the influence of external disturbances and model uncertainties,which verifies the effectiveness of the compound control method.