Fuzzy-PID控制算法在永磁电磁混合悬浮系统中的应用

Application of fuzzy-PID control algorithm to hybrid maglev system

永磁电磁混合磁悬浮平台控制系统是典型的非线性迟滞系统,单纯采用经典PID控制或Fuzzy控制难以满足系统的快速性、稳定性、鲁棒性等要求.虽然可以采用PID控制算法结合分段调节PID控制参数的所谓非线性PID来进行控制,但是这种整定方法由于采用了分段控制,在每个分段内PID参数不再变化,在受到较大扰动时控制作用可能会不及时,从而导致吸死现象的发生.针对以上问题,提出采用Fuzzy控制和PID控制相结合的Fuzzy-PID控制算法,在常规PID调节器的基础上运用模糊推理思想,根据不同的偏差、偏差变化率对PID参数进行自校正.仿真结果表明,系统具有较好的动静态性能,满足混合磁悬浮系统的要求.

The characteristic of hybrid maglev system is nonlinear and hysteretic, so the conventional PID or Fuzzy control is difficult to meet system requirements of rapidity, stability and robustness. Although nonlinear PID control algorithm can be applied to this system, but it may not be acting promptly when it is affected by larger disturbance as the control parameters will not change in every subsection. Aimed at the above problem, a composite control model combining PID with Fuzzy is introduced. The composite control model based on the conventional PID regulator employs fuzzy reasoning and accomplishes PID parameter self-tuning according to different error and change rate of error. The simulation results prove that this composite controller has better static and dynamic performances and meets the requirements of hybrid maglev system.