Study On Speed Curve Design And Robust Control Of Pmsm Door Machine

As high buildings contiuously increase in this modern city, elevators have been more widely used in our daily life. Door machine which performs as a frequently used part by elevator riders, its operation condition such as speed, efficiency, stability and reliability has become important indexes in evaluation of elevator performance.This dissertation chooses control system of PMSM door machine which grows rapidly these years as research objective. It analyses the function of each part during the process of opening/closing doors, concludes the reasons of load fluctuations and factors changes, discusses the composition and characteristics of PMSM, and presents the vect control theory which has widely applied in the PMSM control. On the basis of physical and dynamic equation, the dissertation makes study on mathematics module of this system and establishes a simulation model by means of MATLAB/SIMULINK. By simulation experiments, the results show that the model can express most dynamic performances of the door machine system.For the purpose of reducing the run time, this dissertation designs a type of speeds curve which fits a high-order polynomial. The curve makes it possible that the door system can boast not only high speed and good quality of acceleration/deceleration but also light noise when under operation. By calculating, the results show that the speeds curve is in accordance with the basic indexes: the door motor can output the highest speed, close-energy is under the allowed values, and the doors don't tilt during the highest deceleration process.In order to restrain the interference of uncertain factors such as perturbation of the door machine's parameters and load fluctuations, this dissertation applies the theory of robust H_∞control and converts the issue into the solution of mixed sensitivity. After choosing the appropriate weighting functions, the dissertation designs a H_∞controller by means of MATLAB robust toolbox and replaces the former PI controller in speed circle. By simulation experiment, the outputs of system such as the diagrams of speed, current and torque show that robust stability of the system gets better. It can effectively restrain the interference of uncertain factors to the system of door machine.