Research On Backstepping Sliding Mode Control Of Brushless DC Motor Based On DSP

Brushless DC motor(BLDCM)has been widely used in different industries such as manufacturing,electric vehicles,and military equipment for the characteristics of small size,easy control,reliable operation and low price.Proportion integration differentiation(PID)control is used in the BLDCM speed control system traditionally.However,BLDCM is a multivariable,coupling and non-linear system and the PID control is easily affected by parameter perturbation and external interference,and cannot be used in some situations with high control requirements.Therefore,the research on the advanced control method of brushless DC motor has practical engineering application value.This thesis introduces the control strategy,focuses on the current research status of the backstepping control method and the composition and working principle of BLDCM control system and establishes the mathematical model of BLDCM.This thesis designs a BLDCM double closed-loop control system,researches the general design method of the backstepping controller and designs the speed loop backstepping controller.The sliding mode control is presented with the strong robustness to design a backstepping sliding mode control considering the impact of sudden load and parameter disturbance and simulates the controller.The results show that the backstepping sliding mode control improves the anti-interference ability of the system but has the chattering.In order to weaken the chattering phenomenon,the second-order sliding mode control method is used to design the switching function.This thesis designs the adaptive backstepping second-order sliding mode control as the speed loop controller,simulates the controller and compares with PID control,the backstepping control and the backstepping sliding mode control.The results show that the adaptive backstepping second-order sliding mode control system has strong anti-interference ability and improves the system chattering effectively.The BLDCM control platform is built and the circuit diagram is designed with TMS320F28335 as the master chip.The motor control algorithm is implemented,the backstepping sliding mode control and the adaptive backstepping second-order sliding mode control are realized in the speed loop,and the experimental research work is carried out.The experimental results are in good agreement with the simulation results.The experimental results verify the effectiveness of the backstepping sliding mode control and the adaptive backstepping second-order sliding mode control studied in this thesis.