基于PID算法的磁场闭环控制技术研究

已有的束流磁场控制方法大多采用开环的方式，即根据磁场需求直接设置磁铁电源输出的电流或电压值。但开环状态的磁场在现场噪声以及磁铁自身涡流效应的影响下，极容易发生偏移。针对此问题，设计了基于PID算法的磁场闭环控制系统。该系统以偏转磁铁为控制对象，使用霍尔传感器获取磁场值作为反馈，磁铁电源励磁电流的输出作为控制系统的输入量。控制器使用PID算法对磁铁电源输出进行自动调整，从而实现对磁场的闭环控制。最终结果表明，在PID参数调试得当的情况下，使用磁场在线测量值作为反馈信号，去实时调节磁铁电源的励磁电流大小的闭环控制方法，可以有效地降低磁场偏移。

Research on Closed Loop Control Technology of Magnetic Field Based on PID Algorithm

Most of the existing methods for beam control using magnet field use the open-loop mode, which is to directly set the value of current and voltage of the magnet power supply output based on the demand of magnetic field intensity. However, magnetic fields in the open-loop state are easy to be deflected due to the field noise and the eddy current effect of the magnet. To solve this problem, the closed-loop control system of the magnetic field based on the PID algorithm is developed in this article. This system takes the deflection magnet as the control object, uses the Hall sensor to obtain the magnetic field intensity as the feedback, and utilizes the output of the excitation current of the magnet power supply as the input of the control system. The controller uses the PID algorithm to automatically tune the output of the magnet power supply to achieve the closed-loop control of the magnetic field. The result shows that when the PID parameters are properly set, the magnetic field offset can be significantly reduced by the closed-loop control method which takes the online measured value of the magnetic field as the feedback signal to simultaneously tune the excitation current value of the magnet power supply.