一类大时滞对象控制器参数寻优目标函数仿真研究

Simulation Study on Objective Function to Optimize Controller Parameters for a Class of Long Time-Delay Plants

在对一类大时滞对象的PID控制器参数进行寻优过程中,如果采用常规的目标函数,系统存在超调量大、调节时间长、适应性差的缺陷.为解决上述问题,在常规目标函数ITAE的基础上,提出一种改进型目标函数,将误差的变化率和对象的动态特征参数引入到目标函数中,以克服因大时滞和对象特性改变所带来的不利影响.用一阶惯性加大滞后系统作为被控对象,分别基于ITAE和改进的目标函数进行PID控制器参数寻优和仿真对比.仿真结果表明,基于改进目标函数寻优的控制器可使系统获得更好的动态性能和适应性能,从而充分证明了改进方案的正确性和有效性.

In the process of optimizing the PID controller parameters for a class of large time-delay plants,if the conventional objective function is used,the system has the following defects:large overshoot,long settling time and poor adaptability.In order to solve the above problems,an improved objective function is proposed on the basis of the conventional objective function ITAE.The error change rate and the dynamic characteristic parameters are introduced into the objective function to overcome the bad effects for the large time-delay and the changes of plant characteristics.The first-order inertia plus large time-delay system is used as the controlled object,and the PID controller parameters optimization and simulation comparison are performed based on the ITAE and the improved objective function respectively.The simulation results show that the improved objective function optimization based controller can obtain better dynamic performance and adaptive performance,which fully proves the correctness and effectiveness of the improved approach.