Working principle of linear motor

Linear motor is a kind of mechanical energy, which can be directly converted into linear motion mechanical energy without any intermediate conversion mechanism. It can be regarded as a rotary motor according to the radial cut open, and develop into a plane.

One side of the stator is called primary, and one side of the rotor is called secondary. In practical applications, the primary and secondary are manufactured into different lengths to ensure that the coupling between the primary and the secondary remains constant within the desired range of travel. Linear motor can be short primary and secondary, but also can be long primary short secondary. Considering the manufacturing cost, operation cost, to linear induction motor as an example: when the primary winding of the AC power, in the air gap produced traveling wave magnetic field, secondary in traveling wave magnetic field cutting, the induced electromotive force and current, the current and the air gap magnetic field phase is generated electromagnetic force. If the primary fixed, then the secondary in the role of the thrust to do a straight line motion; otherwise, the primary do linear motion. Linear motor drive control technology a linear motor application system not only to have a good performance of linear motor, but also must have a safe and reliable conditions to achieve technical and economic requirements of the control system. With the development of automatic control technology and micro computer technology, the control method of linear motor is more and more.

Linear motor control technology research can be divided into three aspects: first, the traditional control technology, two is the modern control technology, the three is the intelligent control technology. Traditional control technology, such as PID feedback control, decoupling control, has been widely used in AC servo system. PID control contains information in the process of dynamic control, which has strong robustness, and is the most basic control mode of AC servo motor drive system. In order to improve the control effect, the decoupling control and vector control technology are adopted. It is simple and effective to use the traditional control technology in the object model to determine, do not change and is linear, as well as the operating conditions, the operating environment is determined under the same conditions. However, it is necessary to consider the change of the structure and parameters of the object in high precision micro feed. In order to obtain satisfactory control effect, the influence of various nonlinear factors, such as the change of operating environment and the time varying and uncertain factors, can be obtained. Therefore, the modern control technology has attracted much attention in the research of linear servo motor control. Common control methods include: adaptive control, sliding mode variable structure control, robust control and intelligent control. Is mainly the combination of fuzzy logic, neural network and PID, H-infinity control existing mature control methods, learn from each other, in order to obtain better control performance.