| High-performance hybrid AWD vehicles have gained popularity because they combine the smoothness and economy of pure electric vehicles with the range and power of fuel-powered vehicles.Hybrid AWD vehicles’ improved performance depends on both structural and control optimization.Regarding the drive setup: a high-performance drive setup makes it easier to realize engine and motor power coupling and ensures that both power sources are situated in the high-efficiency range.It is possible to achieve the best economy and dynamics for system control by relying on intelligent control strategies and controllers.In this paper,we analyze the drive modes and optimize the economy,dynamics,and smoothness of a new multi-mode coupled hybrid AWD system.These are the primary research topics covered in this essay:(1)The entire vehicle model is established,and an analysis of the engine longitudinal multi-mode coupled AWD system configuration is performed.The feedback linearization technique is used to create the road-driven torque observer.By taking into account the conditions of the road attachment and the condition of the vehicle,the drive modes are separated into two-wheel drive,four-wheel drive,and torque transfer mode.The operational state of each mode’s power source is described.There is a formula provided for determining the front and rear axle torques on the road,and simulations are run.(2)To enhance the smoothness of mode switching,a new electric speed boost clutch was designed and machined.To complete the prototype test,clutch assembly and debugging are done in three dimensions.Structure and control are inseparable in the optimization of smoothness.To achieve good pressure curve following,a clutch model is constructed,the ideal pressure curve is optimized using a genetic algorithm,and a closed-loop controller is constructed using advanced control theory.To check the smoothness of the hybrid vehicle’s mode switching,the test condition is set to start the motor while the engine is being towed.(3)Three economy control strategies and one dynamics control strategy are built for power and economy optimization needs.The drive mode of the vehicle is selected to obtain the best performance.In addition to the economy strategy,based on the idea of equivalent fuel consumption,the energy consumption controller is built to select the best power source for driving.The controller and the control strategy jointly output and act on the whole vehicle.Build the control strategy to verify the effect of battery power consumption and retention.(4)Build flat roads and gradual ramps with different road surface adhesion coefficients,build vehicle models and controllers and control strategies,and perform joint simulations.Use the new multi-mode coupled hybrid 4WD system to compare with the BYD Song PLUS＿DMI system to verify the dynamics.Verify the 100-km equivalent fuel consumption when the vehicle loses power under multiple NEDC conditions to prove the economy of the system. |
