| Along with the ever-increasing demand of the products with higher performance, better quality, and shorter manufacturing cycle, it is very important that the modern manufacturing equipment has a better servo performance for high-speed, high acceleration and high-precision. High speed and high acceleration movement is the base of the high productivity, while the high precision is the assurance of quality. In the BGA (Ball Grid Array) encapsulation device which takes linear motor as a drive, the nonlinear friction of the motor and guide brings dead zone and nonlinear of the control system, consequently reduces the position resolution and repeatability, as well as jumpiness and crawl while the system is under low speed. Friction disturbance is one of the main factors which depress the servo performance of the system. On the purpose of how to depress the influence of nonlinear friction on the system precision, the main content of this paper includes:1. By the comparison of the traditional linear feed organ and linear motor, the later is taken as the drive of this system and, its d-q model is established as well. Then by the method of vector control, an equivalent DC motor model is established.2. According to the basic principles of friction, several kinds of friction models and their mathematical expressions are presented and, kinds of basic friction compensation methods are analyzed.3. PID+DOB (Disturbance Observer) control system and Sliding Model control system are detailed analyzed and applied to the control system of the linear motor in BGA encapsulation device.4. By using MATLAB software, a simulation research on the established control system model is taken to validate the effectiveness of the aforementioned methods.
|
PDF Full Text Request