SFC引出静电偏转板运动控制系统设计实现

Key words: 
• electrostatic deflector /
• motion control /
• PLC /
• compensation algorithm

Abstract: 

SFC（扇聚焦回旋加速器）是兰州重离子加速器HIRFL重要组成部分，其束流引出效率直接关系到整个加速器的运行效率。原SFC引出静电偏转板运动控制系统由于其设备陈旧，控制方式及控制精度都已不能满足调束的需求，加之位置检测功能的缺失，给调束带来极大不方便。基于此状态，本项目在有限的检修时间内，分两期实现了偏转板的位置检测和运动控制功能。在设计过程中，使用实际位置拟合测量数据的方法，提高了位置检测的精度，特别是用了特定的软件补偿算法消除机械传动回程差，大大提高了电机控制精度，目前整体控制精度在0.2mm左右。用户界面能够显示每个电机的相对位置、模拟动画、限位开关状态指示等信息。界面简洁直观，操作方便。系统自2014年夏季运行以来，稳定可靠，提高了供束效率，减少了故障时间，得到调束人员一致好评。

SFC (Sector Focusing Cyclotron) is an important part of the Heavy Ion Research Facility in Lanzhou.The beam extraction efficiency of SFC is directly related to the efficiency of the whole accelerator. Because of the old equipment and control mode, as well as the low control accuracy of the SFC electrostatic deflection plate motor control, the motion control system was not able to meet the demand of beam tuning staff. In addition, there were no position detection function for this deflection plate; the beam tuning staff cannot get the current position of the deflection plate when they move these motors. Based on this situation, we designed and realized SFC motor control and position detection system in the summer maintain period in 2014 and 2015. In the design, we used the actual position to fit the measured voltage signal to improve the accuracy of position detection. Meanwhile, a specific compensation algorithm was designed to eliminate the mechanical transmission return difference, which greatly improved the motor control accuracy. At present, the overall control accuracy is about 0.2 mm. The user interface has numbers to shows the relative position of each motor and related animation, indicator led to show the status of each limit switches, easy operate buttons to control the motor moving. The system has been running stably and reliably since 2014. It has improved the efficiency of the beam tuning and reduced the fault time, so it is well praised by the beam tuning staff.