A magnetic levitation motor is a transmission device that converts electrical energy directly into linear mechanical energy without any intermediate conversion mechanism. It can be thought of as a rotating motor cut radially and flattened into a plane.
The side derived from the stator is called the primary, and the side derived 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 within the required range of travel. Linear motors can have a short primary and a long secondary, or a long primary and a short secondary. Considering manufacturing and operating costs, let's take a linear induction motor as an example: when AC power is applied to the primary winding, a traveling magnetic field is generated in the air gap. The traveling magnetic field cuts through the secondary winding, inducing an electromotive force and generating a current. This current interacts with the magnetic field in the air gap to produce electromagnetic thrust. If the primary is fixed, the secondary moves linearly under the thrust; otherwise, the primary moves linearly. Linear motor drive control technology: A linear motor application system requires not only a high-performance linear motor but also a control system that can meet technical and economic requirements under safe and reliable conditions. With the development of automatic control and microcomputer technology, a growing number of control methods for linear motors have emerged.
Research on linear motor control technology can be broadly divided into three areas: traditional control technology, modern control technology, and intelligent control technology. Traditional control technologies, such as PID feedback control and decoupling control, have been widely used in AC servo systems. PID control incorporates information from the dynamic control process and offers strong robustness, making it the fundamental control method in AC servo motor drive systems. To improve control effectiveness, decoupling control and vector control techniques are often employed. Traditional control technologies are simple and effective when the plant model is fixed, unchanging, and linear, and the operating conditions and operating environment are fixed and unchanging. However, in high-performance applications requiring high-precision microfeed, changes in plant structure and parameters must be considered. Time-varying and uncertain factors, such as various nonlinear effects, changes in the operating environment, and environmental interference, must be considered to achieve satisfactory control results. Therefore, modern control technology has attracted significant attention in the study of linear servo motor control. Common control methods include 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's strengths and overcome their weaknesses in order to obtain better control performance.
