Researches On Magnetic Levitation Ball System Using Discrete Sliding Mode Control

The main principle of the magnetic levitation technology is to overcome the gravity of the object by the electromagnetic force generated by the electromagnet to keep the object in a suspended state. The biggest characteristic of the magnetic levitation technology is that there is no friction in the running of the system, which avoids the wear and the energy loss caused by the mechanical contact. Due to the above characteristics, the application of magnetic levitation technology has become more and more widely in industrial production, transportation and other fields.The magnetic levitation ball system is a typical structure of a magnetic levitation system, other forms of magnetic levitation system can learn from the research results of it. External disturbance, measurement noise and parameter perturbation can adversely affect the stability of magnetic levitation ball system. Therefore studying the stability of magnetic levitation ball system can form more profound understanding of the composition of the control system and the complex operating conditions of the magnetic levitation ball system can be an experimental platform to test the advantages and disadvantages of the control algorithm.On the basis of summarizing the previous studies, this paper designs a single degree of freedom magnetic levitation ball control system by using STM32. The magnetic levitation ball system is used an improved reaching law to eliminating the controller Chattering which is produced by using exponential reaching law of sliding mode control in discrete control system. On the other hand, The measurement noise of the sensor has a bad effect on the accuracy of the system. The common action of the measurement noise and the process noise will cause the magnetic levitation ball system producing a violent shock. Therefore, we need to design a reasonable filter to reduce the impact of system measurement noise. But the Kalman Filter system needs accurate model, and the error between the actual system and the model will lead to the variation of the filtering effect. By using the fading memory filtering method to increase the new proportion of the measured data to solve the above problems. The results of simulation and experiment also show that the above control strategy of magnetic levitation ball system stability has an obvious control effect.