## 1 Introduction
It has a fixed structure and inherits the core of active disturbance rejection technology--a state observer, and the number of the parameters that need adjustment is greatly reduced. Therefore, linear active disturbance rejection control is regarded as an ideal technology to replace PID control. At present, scholars have done research on applying linear active disturbance rejection control to the magnetic suspension control. [PERSON] et al. [18] applied the active disturbance rejection control technology to the magnetic suspension platform with three degrees of freedom. Compared with PID control, it has been proved that the proposed controller has good transient response performance and the system is robust to parameter uncertainties and external disturbances. [PERSON] et al. [19] designed a linear active disturbance rejection control method for the five-degrees-of-freedom magnetic bearing control system and compared it with the traditional PD and PID control strategies. The results show that linear active disturbance rejection can effectively improve the dynamic and static performance of the system, improve the control accuracy and meet the requirements of rapid response of the system. [PERSON] et al. [20] applied the active disturbance rejection technology to the composite vibration isolation control of the mechanical-electromagnetic suspension system and verified the effectiveness of the controller through experiments, which can meet the needs of the broadband vibration control and avoid problems such as the insufficient broadband vibration isolation effect of the system caused by PID control and the reduction of the dynamic response characteristics of the system caused by the integration link. The linear active disturbance rejection control method has a strong ability to suppress the uncertain disturbance in the system, and can solve the problem that the traditional control method relies too much on the precise model of the controlled object. However, setting the control law parameters in LADRC is difficult to adapt to the state of the dynamic system at different times, while the fuzzy control has the ability of adaptive reasoning and parameter estimation and can dynamically adjust the control law parameters according to the actual state of the system, and then improve the control performance of the system. Based on the above research and the permanent magnet Halbach array suspension system of the red rail system shown in Figure 1, in order to improve the stability of the PMS system the electromagnetic damping structure is introduced, the permanent magnet hybrid suspension experiment (PEMS) platform is built and a fuzzy linear active disturbance rejection control (Fuzzy-LADRC) method is proposed with an air gap deviation integrator to improve the dynamic and static performance of the PEMS system. The structure and dynamic model of the suspension control unit are introduced. The decentralized control strategy is adopted to stabilize the suspension of the platform. Compared with the LADRC and PID control methods in stability, anti-interference, robustness and adaptability, the results show that the proposed control methods have better control effect and can effectively improve the control performance of the suspension platform.