| With the intensification of environmental pollution and the gradual depletion of traditional resources such as oil and coal,the exit of traditional fuel vehicles has gradually been put on the agenda.Electric vehicles,due to their environmentally friendly characteristics,have entered the eyes of researchers and consumers.Compared to traditional cars,electric wheel technology integrates drive motors,transmission systems,and braking systems into the wheel hub,resulting in low vehicle weight and large space,which is beneficial for chassis layout.This has been actively studied by scholars both domestically and internationally,and has become an important part of the development of new energy vehicles.In this context,the research on the electromechanical magnetic coupling characteristics of electric wheels in distributed drive electric vehicles has become a key research topic.This article takes the electric wheels of distributed drive electric vehicles as the research object,and based on bond graph theory,constructs an electromagnetic coupling model of distributed drive electric vehicle electric turbines that integrates mechanical,electrical,hydraulic,magnetic,etc.It explores the motor characteristics under the coupling effect of road excitation and unbalanced electromagnetic force caused by motor stator and rotor eccentricity,and designs a fuzzy PID controller to improve the negative effect caused by the coupling effect,providing reference for the design and improvement of electric wheels in distributed drive electric vehicles.The main research content of the paper is as follows:(1)Based on bond graph theory,the electromagnetic coupling model of the1/4 vehicle angle module system,namely the electric turbine,was constructed.The random road excitation model and the mathematical analytical model of the unbalanced electromagnetic force were established.Based on the analysis of the working process of the electric wheel and its energy transmission path,the physical models of each part were established.Then,according to the modeling rules of bond graph theory,the bond graph models of the drive motor,wheel,brake system,and suspension parts including the unbalanced electromagnetic force were established respectively.Finally,the various parts of the bond graph model were connected and coupled together,and the electromagnetic coupling model of the quarter vehicle angle module system,i.e.the electric turbine,was built based on bond graph theory.(2)Simulate and analyze the electromechanical magnetic coupling characteristics of electric wheels in distributed drive electric vehicles using MATLAB/Simulink.On the basis of the electromechanical magnetic coupling bond graph model of the wheel hub motor,corresponding mathematical models and MATLAB/Simulink simulation models were established.Finally,simulations were conducted for different working conditions,using the vertical acceleration of the vehicle body,dynamic deflection of the suspension,dynamic load of the tires,and eccentricity of the stator and rotor of the driving motor as evaluation indicators,and the characteristic curves were obtained.The simulation results show that on the B-class road surface,when driving at 40km/h and 80km/h,the coupling effect increases the vertical acceleration of the vehicle by 6.3% and10.68%,the suspension dynamic deflection by 37.4% and 12.7%,the tire dynamic load by 20.7% and 3.25%,and the motor stator and rotor by 35.3% and 12.89%,respectively.Verified the rationality of bond graph theory in the study of electromagnetic coupling characteristics of distributed drive electric vehicle electric turbines;At the same time,it indicates that the coupling effect of road excitation and unbalanced electromagnetic force has a negative effect on the smoothness and handling stability of the vehicle.(3)A PID controller based on fuzzy control was designed,and the suppression effect of coupling effect before and after fuzzy PID control was analyzed through comparative simulation.The results showed that on B-level road surfaces,when driving at 40km/h and 80km/h,the designed fuzzy PID controller reduced the vertical acceleration of the vehicle body by 4.8% and 9.48%,the suspension dynamic deflection by 10.77% and 9.53%,the tire dynamic load by11.63% and 27.47%,and the motor stator and rotor by 18.1% 12.66%.It can effectively suppress the negative effects caused by coupling problems and improve the smoothness and handling stability of the car. |
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