导引头稳定转台伺服系统设计

Design of seeker servo system of stabilized turntable

针对导引头稳定转台系统受摩擦、力矩耦合、质量不平衡及载体扰动等因素影响而造成的非线性、强耦合的特点,提出一种基于扰动观测器的非线性PID控制策略.该策略非线性PID保留了传统PID控制器结构简单、易于实现的优点,同时对外部扰动和系统参数变化有较强的抗扰能力.在此基础上引入扰动观测器估计系统干扰并将其补偿信号前馈到控制输入端,以进一步减小干扰对系统的影响.在某型号电视跟踪稳定转台的实验结果表明,该复合控制算法一方面能满足导引转台系统实时性高的要求,同时能很好地隔离外部扰动,提高了系统跟踪精度和抗扰能力,达到了很好的控制效果.

As the seeker servo system of stabilized turntable is a kind of nonlinear system with strong coupling which is influenced by many uncertain factors such as friction,kinematic coupling,imbalance and carrier disturbance,a nonlinear PID( proportional-integral-derivative) controller based on a disturbance observer is proposed to control the system. The nonlinear PID controller has the same simple structure as the conventional linear PID controller which is easy to realize,besides,it exhibits some attractive features such as robustness to parameter variations and insensitivity to load disturbance. Then a disturbance observer which is independent of the accurate model of disturbance is introduced to estimate and compensate the lumped disturbances of the system. It is shown by experiment results that the proposed compound control scheme can meet the demand of real-time property and insulate the lumped disturbance,which can achieve higher precision and obtain a perfect control performance.