| Magnetic suspension technology refers to a technology that uses magnetic force to overcome gravity to suspend objects without contact,which has the characteristics of being contactless,wide range of applications,can achieve active control,and is widely used in rail transportation,pipeline logistics,and magnetic floating bearings,etc.On the one hand,the permanent magnetic field provides part of the suspension force and the electromagnetic field plays a dynamic magnetic field regulation role,which largely reduces the suspension energy consumption;on the other hand,the introduction of permanent magnets effectively increases the suspension air gap and reduces the system’s accuracy requirements for the track.However,the introduction of permanent magnets also makes the suspension system nonlinear,and there are uncertainties such as permanent magnet and electromagnetic coupling,which affect the suspension performance of the system.For the control challenges of the permanent magnet electromagnetic hybrid suspension system,the following aspects of work are carried out in this paper:(1)Integrating the advantages and disadvantages of the permanent magnet electromagnetic hybrid suspension structure,the structural platforms of series and parallel singlepoint permanent magnet electromagnetic hybrid suspension systems are constructed respectively,and their working principles are analyzed,and the corresponding mathematical models are established by combining the mechanism modeling method,and the system model is analyzed by using the control theory,and it is concluded that the system is open-loop unstable,but has the energy-perceptible control characteristics,and the system can be stabilized by imposing feedback links and observation links.(2)To investigate the control effect of the active disturbance rejection control method in the permanent magnet electromagnetic hybrid suspension system due to its own mechanical and electrical characteristics and the degradation of the control performance caused by uncertainty interference such as shock and input signal noise.Based on the analysis of the components of the active disturbance rejection control,the complex form of the tracking differentiator and the problem of output chattering are replaced by an improved Levant differentiator,which is robust to signal noise,and the Levant differentiator is introduced in the system measurement feedback link for filtering to reduce the impact of signal noise on the performance of the observer.The advantages of the Levant differentiator and the feasibility of the proposed self-anti-disturbance control method based on the improved Levant differentiator are verified in conjunction with practical situations.Meanwhile,the simulated annealing particle swarm optimization algorithm with constraint factor is used to rectify the controller parameters,which solves the problems such as the strong correlation between the controller parameters and improves the experimental efficiency.(3)To verify the feasibility and superiority of the control method designed in this paper in the physical platform,a semi-physical joint simulation platform is built for the series and parallel single-point permanent magnet electromagnetic hybrid suspension structures,respectively,and the PID,self-anti-disturbance and improved Levant differentiator-based active disturbance rejection control methods are applied to the simulation platform for dynamic and static performance comparison experiments,The results show that the method effectively improves the control performance of the permanent magnet electromagnetic hybrid suspension system,which not only can suppress the influence of measurement signal noise on the system but also has stronger adaptability and robustness to the wide range of changes in the suspension air gap of the system and the unknown disturbances during operation.Based on the permanent magnet electromagnetic hybrid suspension structure,this paper constructs two types of permanent magnet electromagnetic hybrid suspension platforms,and analyzes their suspension control mechanisms to lay the theoretical foundation for the feedback control strategy;fuses the active disturbance rejection control method and the intelligent optimization-seeking control strategy to improve the control performance of the active disturbance rejection control method for the hybrid suspension structure and avoid the coupling influence between the control parameters;designs the semi-physical simulation platform for the hybrid suspension structure,and verifies the effectiveness of its simulation model and control strategy.The effectiveness of the simulation model and control strategy is verified.The research results provide a theoretical basis and methodological reference for solving the problem of difficult control of permanent magnetic suspension structures and permanent magnetic electromagnetic hybrid suspension structures and actively explore the application and development of a permanent magnetic suspension transportation system,which has good academic significance and practical application value. |
