Line motors are also called linear motors, linear motors, linear motors, and push rod motors. The most common types of linear motors are flat and U-slots. The typical composition of the coil is three-phase, and the Hall element realizes brushless commutation.
The side from which the linear motor evolved from the stator is called the primary, and the side that evolved from the rotor is called the secondary. In practical applications, the primary and secondary are manufactured to different lengths to ensure that the coupling between the primary and secondary remains constant over the desired range of travel. Linear motors require a feedback device that feeds back linear position - a linear encoder that directly measures the position of the load to improve the positional accuracy of the load. It can be a short primary long secondary or a long primary short secondary.
The drive control technology of linear motors not only requires a linear motor application system to have not only a linear motor with good performance, but also a control system that can achieve technical and economic requirements under safe and reliable conditions. With the development of automatic control technology and microcomputer technology, there are more and more control methods for linear motors.
The research on linear motor control technology can be basically divided into three aspects: one is traditional control technology, the other is modern control technology, and the third is intelligent control technology.
Traditional control technologies such as PID feedback control and decoupling control have been widely used in AC servo systems. Among them, PID control implies information in the dynamic control process and has strong robustness. It is the most basic control method in AC servo motor drive system. In order to improve the control effect, decoupling control and vector control techniques are often used. The traditional control technique is simple and effective under the condition that the object model is determined, does not change, and is linear, and the operating conditions and operating environment are determined to be constant. However, in high-performance micro-feeding high-performance applications, changes in object structure and parameters must be considered.
A variety of non-linear effects, changes in operating environment and environmental disturbances, such as time-varying and uncertain factors, can achieve satisfactory control results. Therefore, modern control technology has attracted a lot of attention in the research of linear servo motor control.
Common control methods: adaptive control, sliding mode variable structure control, robust control and intelligent control. It mainly combines fuzzy logic, neural network with existing mature control methods such as PID and H∞ control to learn from each other to obtain better control performance.