根据有限时间收敛控制理论,应用滑模控制方法设计了一种考虑导弹自动驾驶仪二阶动态特性的有限时间收敛导引律,其最终表达式中不含有视线角速率的高阶导数,更易于实际应用。该导引律有效地克服了导弹控制系统的动态延迟对制导精度的影响。将该导引律与未考虑导弹自动驾驶仪动态的自适应滑模导引律比较,对目标非机动和正弦机动进行仿真。仿真结果表明,在目标机动加速度快速变化,而且导弹自动驾驶仪存在较大滞后情况下,考虑导弹自动驾驶仪二阶动态特性的有限时间收敛导引律仍能够导引导弹精确地拦截机动目标。
Accounting for the missile autopilot as second-order dynamics, a guidance law with finite time convergence is designed using the sliding mode control method and finite time convergence control theory. The high-order derivatives of the line of sight angle are avoided in the expression of guidance law so that it can be implemented in practical applications. The proposed guidance law is effective in compensating the bad influence of the autopilot lag on guidance accuracy. In simulations of intercepting non maneuvering targets and targets with sinusoidal acceleration respectively, the guidance law is compared with the adaptive sliding mode guidance law in the presence of missile autopilot lag. Simulation results show that the proposed guidance law is able to guide a missile to accurately intercept a maneuvering target, even if it escapes in a great and fast maneuver and the autopilot has a relatively large lag.