| Permanent Magnet Synchronous Motor(PMSM)has attracted great attention in the field of AC speed regulation due to its advantages of high efficiency,energy saving and high power density.At present,the automatic baler mostly uses PMSM as the conveyor belt motor to bundle the goods.Because the PMSM with high-resolution position sensor will not only increase the size of the motor,increase the production cost,but also reduce the performance of the sensor in environments such as vibration,high temperature,and humidity,which will affect the motor control effect.Therefore,in order to reduce the investment cost of the enterprise and ensure the normal operation of the baler under various working conditions,this paper uses a small,low-cost,vibration-resistant,low-resolution Hall sensor to detect the PMSM position signal.However,the Hall sensor can only obtain low-precision discrete position signals.In order to meet the control requirements of the baler system,the low-precision discrete position signals are used to estimate the high-resolution position signals.At the same time,this paper applies Active Disturbance Rejection Controller(ADRC)to the baler servo system to improve the disturbance resistance.The main work of this paper is as follows:(1)The significance of the research and the analysis of the domestic and foreign status of the technology related to the subject.The background and research significance of the subject are pointed out,the packaging process and the requirements of the control system of the baler are introduced,and the PMSM torque mode,the low-resolution sensor position control algorithm,the baler and the development status of ADRC at home and abroad are expounded.(2)Establishment of PMSM mathematical model and rotor position estimation.Briefly describe the mathematical model of PMSM in the ABC coordinate system,and establish the PMSM voltage equation in the coordinate system.The electromagnetic torque formula of PMSM is obtained by using the principle of energy conservation.The basic principle and realization process of Space Vector Pulse Width Modulation(SVPWM)technology are expounded.Estimate the rotor position of a low-resolution PMSM.(3)Design PMSM linear ADRC control and conduct simulation experiments.Aiming at the contradiction between rapidity and overshoot of PID control and poor resistance to load disturbance,ADRC control is used instead of PI control,and a linear ADRC controller is designed on PMSM double closed-loop.The system simulation model is built in Matlab/Simulink,and the vector control current single-loop simulation experiment is carried out to verify the feasibility of the PMSM torque mode.Through the comparison of PI control and linear ADRC control simulation experiments,the superiority of ADRC control is obtained.(4)Design the hardware and software circuit system.Design the hardware circuit using STM32F103VET6 as the main control chip,mainly including flyback switching power supply circuit,bus voltage detection and protection circuit,current sampling circuit and so on.Design the overall program of the software,and elaborate the realization process of the main program,the interrupt program and the operation panel program in detail.(5)Build an experimental platform for experimental verification and installation testing.The comparative experiment of position estimation and correction of discrete Hall position signals proves the feasibility of the average acceleration method to estimate the position and the average correction position method.Through the comparative experiments of linear ADRC control and PI control,the superiority of ADRC control performance is verified.Experiments are carried out on the speed mode and torque mode of PMSM on the experimental platform.The experimental results show that the research strategy in this paper meets the requirements of the baler control system.The PMSM installation site tests the packaging effect,which can meet the performance requirements of the belt take-up and belt feed control of the packer. |
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