Research On Synchronous Control Of The Linear Elevator Maglev Guiding System

The subject was achieved with the support of the Nature and Science Foundation subject of Liaoning province, which is” Study on robust degree freedom control about the maglev guiding system of the Linear Elevator”(No.2014020114). When the linear elevator was in operating, the environment of its maglev guiding system was extremely complex, its load changed very fast with the time, and will be affected by unknown external disturbance. The research object of this paper is linear elevator guide magnetic levitation system, the research main point of this paper is the synchronous control for the four single magnetic levitation device in the x axis of the linear elevator.First, "Eight-Maglev" topology is introduced in this paper for the characteristics of the Maglev guiding system of the linear elevator as the above mentioned, mathematic model of it is established, the model is linearized for its strong non-liner, by using feedback linearization method, comparing the two kinds of linearization model: the current control model and the voltage control model, the voltage control model was chose to make the model closer to the actual system.Secondly, in order to solve the system problem of stability and robustness, the fractional calculus theory is introduced into this article, makes the integer order PID controller expansion in the field of fractional order, compared with the integer order PID controller, fractional order μλDPI controller increases the two more degrees of freedom, which will allow the controller obtain more flexible design and better control performance, in addition, the integral part of the fractional order μλDPI has a memory function, this can make the present and future control results are affected by historical information, so the system control precision is improved. In order to make the system have better robustness, steady-state accuracy and better rapidity, the fractional order μλDPI was combined with the fuzzy control theory, the fuzzy fractional μλDPI can not only improve the steady accuracy of the system, but also improve the resistance to the external disturbance.Then, the control strategy was put forward to eliminate the multi- factors, which can affect the synchronization error of the synchronous control system in multi-single magnetic levitation device; Master-slave control, command control, cross coupling control, adjacent cross-coupling control and deviation coupling control are analyzed to distinguish the advantages and disadvantages of the synchronous control structure, this paper proposed a new improved deviation coupling control structure; after the simulation about the synchronous control structures as above-mentioned, the results show that the new structure can make the system stability and synchronization performance, compared with other control structures, have different degrees of increase. What is more, in order to obtain a better synchronization performance of the multi-single magnetic suspension device, it can change the proportion coefficient of the control structure.Finally, in view of the controller and synchronous control structure designed for the subsystem in the x axis of the maglev guiding system, Using Matlab to simulate the system, the simulation results show that the designed controller and synchronous control structure can not only make the system achieve better rapidity, stronger robustness and better steady accuracy, but the synchronization performance is also more outstanding.