Fault Tolerant Control Model And System Design Of Redundant Magnetic Suspension Bearing Under Dual Core Architecture

The magnetic suspension bearing has the advantages of no mechanical contact,no wear,no lubrication,low loss,high speed and long life.It can achieve better rotor dynamic characteristics,and it can be an ideal supporting mode for high-speed and high-precision rotor system.Therefore,the magnetic suspension bearing system has a wide range of applications in aerospace,vacuum technology,turbomachine and machine tools.However,when local fault happens in magnetic bearing system,its original control loop will not be realized,resulting in the drop of the rotor system and the serious influence.Especially in extreme conditions,its reliability problem is particularly prominent.Redundant design is a practical and effective method to improve the reliability of magnetic suspension bearing.It requires that the bearing system has fault tolerance,which can detect and express fault characteristics quickly and effectively,providing fault tolerant control for faults.So the system could continue to provide effective electromagnetic bearing characteristics.The research of magnetic levitation fault tolerant control model and system based on dual core processor architecture was carried out in this paper.The main research contents are as follows:(1)In order to meet the needs of fault diagnosis and real-time control of a multi degree of freedom magnetic suspension system,a heterogeneous dual core processor ARM + DSP architecture was designed.The corresponding hardware platform and software system were put forward,which realized the assignment and operation of fault diagnosis and real-time control tasks;and efficient information interaction to cope with the real-time requirements of the parallel tasks.(2)The linearization model of electromagnetic force under the exact redundant structure was proposed.Considering the errors of the existing linear electromagnetic force method with rotor in non-equilibrium position,this paper introduced the Taylor series expansion of electromagnetic force and displacement compensation matrix.So the electromagnetic force could be compensated when the rotor deviated from the center.A unified linearized description of electromagnetic force and current and displacement was realized under the redundant magnetic suspension structure,and an accurate electromagnetic force model with larger linear space was obtained.(3)A method of solving the current distribution matrix based on the exact linearization model of electromagnetic force was put forward.The fault-tolerant control model was established,and the simulation analysis based on Matlab/Simulink was carried out.In allusion to control of hardware platform based on dual-core processor,the software algorithm was designed to conduct the experimental research.The simulation and experimental results showed that the proposed method had obvious advantages of precision,which would help to improve the dynamic performance of rotor in the implementation of fault tolerant control.The innovation of this paper is to correct the model based on displacement compensation for the electromagnetic force model in the non-equilibrium position of the conventional method,establish a unified electromagnetic force linearization model of current and displacement under redundant bearing and propose a new fault tolerant control strategy based on the model.The research results were of great significance to the reliability of the magnetic bearing in extreme cases.