空压机的智能PID控制与SPC在线故障检测

Intelligent PID Control and On-Line Fault Inspection Based on SPC Algorithm on the Air Compressor

根据用户需求,结合空压机的运行特点,采用了蚁群算法进行PID控制器的参数在线整定,从而利用MM440变频器模拟量控制的方式,通过闭环控制较好地实现了空压机的智能控制,使其压力能够控制在2.5%范围内,达到系统工艺要求;并利用传感器实现空压机的各项运行状态参数(温度、压力、电流、电压、振动等)的在线监测,通过VB与SQL Server强大的数据处理能力实现了数据的在线查看以及统计分析,从而利用x-R控制图的变化趋势分析,根据异常判断准则来实现各类故障的提前报警,实现了空压机的在线故障检测,较好地避免了由于空压机故障带来的损失。

According to the user＇s demands and the running characteristics of the air compressor, a kind of intelligent PID algorithm based on the ant colony algorithm was introduced. This algorithm was used to pressure control of the air compressor. In this system, it contains some components such as some sensors, PLC, and frequency converter driver （MM440）. By comparing the present pressure value and the preset value, the PID controller would give an optimum by computing. The optimum digital signal would he changed to the analog signal by A/D module. Then the analog signal would be sent into MM440 which would change the output pressure indirectly. By the application of this intelligent control algorithm in the air compressor, it could keep the pressure value in a small tolerance of 2. 5 per- cent. Because of the complex operation environment, it is unavoidable that the fault appeared for the air compressor. So a set of monito- ring system had been designed which could not only real time monitor the running parameter status, but also predict the running state of the device according to the parameters~ changing trends based on a statistical process control. VB and SQL Server were synthetically ap- plied in this monitoring system.