阻尼比约束的时滞系统最优PI调节器设计

Design of Optimal PI Regulators for Low-order Plus Dead-Time Processes with Damping Ratio Constraints

对含有时滞的低阶过程,提出了基于阻尼比约束的比例积分(PI)调节器最优化设计方法。由系统闭环特征方程可导出PI调节器的比例增益和积分增益与系统阻尼比和振荡频率的显示关系,在特定阻尼比下能够得到使系统积分增益最优的参数值。同时,对于不同PI调节器,也能够图解分析控制系统的阻尼比。针对低阶时滞过程,给出了能用于参数自整定的最优PI运算方法。仿真表明,该方法所得PI控制系统针对不同时滞过程都有满意的鲁棒性和积分性能,对其他过程控制器参数优化有极大借鉴作用。

For the dead-time process, the optimizing method of proportional-integral （PI） regulator is introduced. By the characteristic equation of the closed-loop control system, the proportional and integral gain of the PI regulator could be related explicitly to the closed-loop damping ratio and oscillation frequency. Then the PI parameters can be obtained to get the optimal integral gain due to oscillation frequency with assigned damping ratio constraint. Meanwhile, the damping ratio of various PI control systems can be graphically compared in parameter space of PI. With this, auto-tuning formulas or parameter calculation method of the PI controller are given for low-order process plus dead-time. Simulation results show that the proposed PI control method can achieve satisfying robustness and performance for different dead-time processes, so it has great reference to other controller design and other processes.