Compound Intelligent Control Of The Linear Motor Systems

Compared with the conventional rotary motor, the linear motor doesn’t have the intermediate transmission equipments, which lets it retain lots of advantages such as direct transmission, small, low wear abrasion, high precision, no speed limited and so on. It has been widely used in the military field, manufacturing and also the daily life. The linear motor has been successfully used in electromagnetic emission device, maglev train, high-speed machining, chips and IC processing and precision Instruments, etc. With the modern manufacturing technology developing towards high-speed and precision, the application of linear motors will be more and more widely. Therefore, studies about the control of the linear motor motion and its structure principles are very necessary and meaningful.The PID control method is one of the first developed control methods, while it has been widely used in industrial process control. It is necessary to adjust the parameters during the PID control process. Currently, the PID parameters tuning methods are generally manual tuning or algorithms based on the experience rules. The effects of PID controls tuned by these methods are usually unsatisfactory, because the real industrial control processes are mostly diverse, non-linear and time-varying. It will become worse, while it comes to the linear motor whose requirements are higher accuracy. This article designs a intelligent PID parameters tuning method based on the linear motor model, after studying various tuning methods of the PID controller parameters. In view of the model and the characteristics of the linear motor, it proposes a BP neural network modified by fruit fly optimization algorithm to tune the linear motor PID parameters automatically. This article sets up the Matlab/Simulink model according the experiment linear motor to finish the simulation. Its result is better than the traditional BP neural network PID control.Generally, traditional linear motor servo systems are mostly using PID control method based on the location tracking feedback. The control accuracy requirements are becoming more and more increase, but the accuracy of the PID feedback controller is limited and there are a lot of disturbance factors during the control process. As the results, the control results don’t achieve the desired effect usually. This article proposes a way of adaptive velocity plus acceleration feedforward control for the linear motor control based on the PID feedforward control, after analyzing of the feedback and feedforward control. The new control design can greatly reduce the overshoot and settling time, as well as has a faster respond speed and better static and dynamic characteristics compared with the only Acceleration feedforward or feedback control. This method can take advantage of the velocity feedforward and acceleration feedforward control, while retaining the advantages of the PID feedback controller. Therefore, it allows linear motor to be applied during the high-speed and high-precision system.Finally, the article gives its MATLAB simulation model based on the adaptive velocity plus acceleration feedforward PID control for the linear motor control and complicated the simulation based on the speed up and down curve. In addition, we do a lot of experiments on the computer controlled linear motor test system, whose results confirm the feasibility of the method. In other words, it finishes the compound intelligent control of the linear motor systems.