Research On In-wheel Driving Control System Of Distributed Driven Electric Vehicles

Distributed drive electric vehicles as a new electric drive mode. On the dynamicsand control have new definitions. In-wheel motor as the power unit of the electric car,Its dynamic characteristics is undoubtedly affects the dynamic characteristics of thevehicle. Coupling of motor and tire, so that the motor and the mechanical propertiesof the tire each other,influence each other. The control of the in-wheel motor is thecore control of distributed the driving electric vehicle. The article uses the in-wheelmotor is the permanent magnet brushless dc motor. This motor has high efficiency,simple control, low cost, etc.With low speed torque ripple at the same time. Thispaper launched a study from the motor control. This paper consists of mainlycomposed of the following chapters:The first chapter is the introduction.Respectively from the distributed dynamiccharacteristics of electric vehicles, motor torque ripples and minimize ripple arereviewed at the current research status, expounding the main methods and researchresults.The second chapter is the theoretical basis of the paper. First of all, introducingthe Lagrange dynamics of multidisciplinary unified modeling method. This papermainly introduces the different variables of the mechanical system and electricalsystem,then introducing the first Lagrange equation and the second Lagrangeequation，and expounds the unified expression of Lagrange differential algebraicequation format, finally the brushless dc motor was established based on the methodof dynamic equation and resolve the equation with the improved Euler method.The third chapter introduces the control method of permanent magnet brushlessdc motor, The motor controller is designed, including power circuit, drive circuit,signal acquisition circuit,etc. All parts in extremely detailed design method is given, then give detailed design on the reliability of hardware reference. The software designof the system is introduced at the same time.The fourth chapter in view of the permanent magnet in-wheel brushless dc motorof the characteristics of torque ripple. Analyzed the torque characteristics of squarewave drive and sine wave drive, though theoretical derivation can find the motortorque ripple is smaller by sine wave drive. Then using MATLAB simulationverification. The simulation results show that driven by sine wave can effectivelyweaken the torque ripple. And then discusses the two methods of sine wave drivingrespectively, SPWM control and SVPWM control, modeling and simulating theSVPWM method by the Simulink.In chapter5, according to the requirements of in-wheel motor control of torqueand speed,then design the estimates. In terms of torque observation,uses a slidingmode observer. The sliding mode observer has a good robustness, is not sensitive toparameter change, rapid reaction, simple implementation, etc. In the aspect of speedestimation, using the Extended Kalman Filter,Extended Kalman Filter is a local linearoptimal predict estimation of the nonlinear system, can eliminate the influence ofrandom disturbance process noise and measurement noise. So when the rotor speedestimation using the Extended Kalman Filter. Finally using second super-twistingsliding mode controller algorithm for brushless dc motor speed control and torquecontrol modeling and simulation,Simulation results show that the proposed algorithmis more effective than classical PID control, the effect is better.In chapter6, summary of full paper, this chapter summarizes the main researchcontent of this paper. And insufficient of this paper is also discussed and put forwardsome ideas for the subsequent work.