Research On Multi Linear Switched Reluctance Motor Lifting Platform

In the modern industrial manufacturing,human transport has been replaced by modern machinery and equipment,which plays a significant role in our daily life.The traditional lifting machinery,such as cable elevators and hydraulic elevators,are faced with the problems of slow speed,high energy consumption,poor control precision and safety hidden trouble.The lifting equipments based on linear motors have the advantages of high speed,high precision and clean energy,which can make up for the shortage of traditional lifting equipments and become the research hotspot.The performance of single motor is often limited by cost and mechanical structure,and the ability to resist load disturbance is not strong enough.While the multi motor coordinated control lifting platform can improve the performance of the whole system.Linear switched reluctance motor(LSRM)has many advantages,such as fast response,high control precision,strong structure and low cost.It is suitable for multi linear motor coordinated control lifting platform.In the field of cooperative control,the communication topology between multiple nodes and the asynchronous reference input interference of each node are the key issues that affect the accuracy of the whole system.To solve the above problems,this paper presents a cooperative control lifting platform based on multiple LSRMs Various communication topologies are analyzed and compared in this paper.A hierarchical,two-level synchronization control strategy is proposed.The problem of asynchronous reference input disturbance is solved.In this paper,a bilateral linear switched reluctance motor with asymmetric structure is adopted.Firstly,the structure,principle and excitation strategy of the motor are introduced.Secondly,the real-time control system based on RT-LAB and the hardware structure of the system are introduced.The control precision of the single motor is optimized by using the double loop position controller.Through the comparative analysis of various communication topologies,we discover that the communication link redundancy can increase the system error and influence the stability of the system.The topological structure of multiple LSRMs coordinated control lifting platform is selected.Then,aiming at the problem of asynchronous reference input disturbance between each node,a hierarchical synchronization control strategy is proposed.The high-level synchronization module is used to coordinate the asynchronous reference input of each node,while the low level tracking module is used to ensure the tracking performance of each motor.The proposed hierarchical synchronization control strategy can effectively eliminate the asynchronous input between distributed systems,and has a certain degree of fault tolerance.The experimental results show that the error between the reference input of the motor is reduced with the coordination of the control strategy.In the case of strong asynchronous reference input,the dynamic error of each motor can be controlled within the range of 1.5mm.In this paper,the anti load capacity of the lifting platform is also tested.In the reference input sine signal,amplitude 30 mm,frequency 0.2Hz,6kg load state,the dynamic error can be controlled within the range of 1.2mm which shows the ability of rejection load disturbance.