基于PSO的多叶准直器PID控制器参数优化研究

针对放射治疗系统中多叶准直器叶片位置精度的控制要求,描述了适形放射治疗装置中多叶准直器的结构和工作原理.把驱动多叶准直器叶片运动的无刷直流电机作为被控对象,提出了基于PSO算法的PID控制器的设计方法.首先,对无刷直流电机进行了建模,而后,采用基本粒子群算法对无刷直流电机的PID控制器各项参数进行优化,以保证多叶准直器叶片的到位精度,满足适形放疗的要求.仿真结果表明所使用的方法能较好地满足多叶准直器叶片位置控制的精度要求,各项控制指标明显优于传统整定方法.

Parameters Optimization Based on PSO for PID Controller of MLC

According to requirements of the leaves position precision control of multi-leaf collimator, the structure and working principle of multi-leaf collimator of conformal radiation therapy apparatus are de- scribed. The motor that drives the leaf of the MLC is taken as the control object,and the design method of PSO-PID controller is proposed. Firstly, the module of the motor has been established,then PSO algorithm is used for the parameter optimization of PID controller in order to ensure the position accuracy of the MI.C leaves and meet the requirements of conformal therapy. The results indicate that this algorithm can meet the needs of the control precision of the leaves＂ position of the multi-leaf collimator. In conclusion, the con- trol index is obviously better than the traditional tuning method.