Research And Implementation Of Fuzzy PID Control System Based On DSP For Linaer Motor

Because of its unique properties, Linear motor is now widely used in various precision positioning of occasions. With the demands of positioning accuracy and speed of response is increasingly higher, on the one hand the linear motor processing requirements are strict;on the other hand, linear motor processing is completed, the basic properties have been determined. In order to make linear motor show good performance, the requirements of control system are increasingly higher.As the first control strategy, conventional PID control is still widely used in practical industrial control. Fuzzy algorithm is one of the intelligent control strategies which is gradually developed in recent decades. With the generation of hardware chips which support fuzzy algorithm, fuzzy algorithm is used in more and more various fields. However, two algorithms still have faults. Conventional PID algorithm is generally adapted to control the objects whose mathematical models have been established and are linear. This can get a better control rules to meet the control requirements. Indeed, many objects are not linear, the mathematical models can not be established, and there is more interference in the working environment. Fuzzy algorithm is a nonlinear algorithm which has good dynamic performance and certain anti-interference ability, and can be used in nonlinear systems. But the fuzzy algorithm does not have own analysis and modeling methods, only through the expertise and the actual control process to get the fuzzy rules which has led the accuracy of control not very high, and has a static error. It can not be applied in high-speed and high-precision linear motor control.To address the above issues and combine with the requirements of high-speed response of permanent magnet synchronous linear motor, this paper studies the PID algorithm and fuzzy algorithm to build a fuzzy PID controller based on the combination of the two methods for the permanent magnet synchronous linear motor speed loop. Meanwhile, this paper proposes a new fuzzy algorithm which uses the relations generated rules of Mamdnai algorithms and a new fuzzy inference rules. This paper has completed the linear motor control system, including hardware platforms and software algorithms. Hardware includs the control board which uses DSP chip as the core, and driver board which uses the power module IRAMS10UP60B as the core. Software algorithms include three closed-loops: displacement loop, speed loop and current loop. Conventional PID algorithm is used in displacement loop and current loop, and the fuzzy PID algorithm is used in speed loop. The control system simulation model of linear motor is established in Matlab software platform. According to simulation, response curves of speed loop which uses two algorithms are analyized by comparison. Simulation results show that the fuzzy PID algorithm is more applicable to the system. Finally, we experiment in the hardware platform which has been completed for the linear motor control system, then we can find that speed loop which uses fuzzy PID algorithm has small overshoot, anti-interference ability, good dynamic performance, it can meet the positioning accuracy and speed response requirements.