基于滑模控制与工程设计法的随动系统

红外焦平面成像导引头的双框架陀螺稳定平台在不考虑内外框相互耦合的情况下,每个轴系可以独立视为直流电机控制的随动系统.借鉴实际系统,介绍随动系统的工程设计方法.针对系统设计过程中遇到的非线性和环境实验中抗振动冲击等问题,利用滑模控制在参数变化和干扰作用下具有较高控制精度的特性,在速度闭环中采用积分型滑模控制.滑模控制最大的缺点是由于实际系统存在惯性等因素造成抖振,因此通过工程设计方法缩短电流环的时延并利用该法选取积分型滑模状态参数,提高滑模控制的精度.结合电流环在一定条件下可以等效为惯性环节,导出滑模控制状态方程,并对扰动进行补偿以提高系统控制的准确性.通过仿真证明滑模控制结合工程设计方法的有效性.

A servo system based on SMC and engineering design method

In the design of a dual-frame gyro stabilized platform with an infrared focal plane arrays （IRFPA） imaging seeker, under the circumstances of not considering the coupling of inner and outer frames, every shafting can be independently regarded as a servo system controlled by a DC motor. In view of a real system, first, the engineering design method for a servo system is introduced. Then, aiming at such problems as non-linearity in the process of system design, anti-vibration impact occurred in the environmental experiments, etc., an integral sliding mode control （SMC） method is proposed for a closed-loop speed control based on the characteristics that with varying parameters, the sliding mode control has a higher control precision under disturbances. Due to system inertia in actual engineering practice, the biggest drawback of SMC is buffeting. So the engineering design method is adopted to cut down the time delay of the electric current loop and to choose the state parameters of the integral sliding mode, so as to improve the accuracy of SMC. And then, the equation of state of SMC is derived given that the electric current loop is identical to inertial element under a certain condition, and the disturbance is compensated to increase accuracy of the system control. Numerical simulations have demonstrated the effectiveness of the designed servo system which combines SMC and engineering design method.