Driver Torque Demand Analysis Method for Hybrid Electric Vehicles

Abstract

The invention relates to a hybrid vehicle driver torque demand analyze method; the hybrid vehicle comprises an engine, a drive motor, a speed changer, and a high voltage battery assembly; the hybrid vehicle driver torque demand analyze method comprises a power system torque capability calculating method: calculating the maximum driving torque of a power source applied to a driving wheel end according to the engine present torque capability, the motor present torque capability, the power train transmission ratio, the transmission loss corresponding to the present transmission ratio, and the power train torque capacity. The driver torque demand analyze method can calculate and parse the present power system output torque according to the power system maximum output torque, the accelerator pedal opening degree and the speed information; when the accelerator pedal opening degree is at the maximum value, the torque demand is same with the power system maximum output torque.

Description

technical field [0001] The invention relates to a driver's torque demand analysis method for the control of a power system of a hybrid electric vehicle, and belongs to the field of complete vehicle control of electric vehicles. Background technique [0002] Currently, driver torque demand resolution for conventional automobiles does not resolve driver torque demand in a manner that is compatible with both conventional internal combustion engine vehicles and hybrid vehicles. The traditional analysis methods of driver demand torque are mostly based on analyzing the driver's torque demand at the flywheel end of the engine, while the driver's real expectation should be reflected in the driving force at the wheel end. The traditional analysis method does not identify the driver in a way that meets the driver's expected standard. Inputs, and variations in powertrain torque capability in different environments are not adequately considered. [0003] The torque capacity of the powe...

AI Technical Summary

Problems solved by technology

The traditional analysis methods of driver demand torque are mostly based on analyzing the driver's torque demand at the flywheel end of the engine, while the driver's real expectation should be reflected in the driving force at the wheel end. The traditional analysis method does not identify the driver in a way that meets the driver's expected standard. input, while variations in powertrain torque capability in different environments are not adequately accounted for

[0003] The torque capacity of the power system is constantly changing with the environment. When the ambient temperature of the vehicle is low or the vehicle is in a plateau environment, the torque capacity of the engine will decrease, which will eventually lead to a decrease in the torque capacity of the power system.

Especially for hybrid electric vehicles, when the battery temperature exceeds the working range or the battery power is seriously insufficient, the output power of the electric motor of the hybrid electric vehicle will be greatly reduced, which will eventually lead to a reduction in the torque capacity of the power system

When the transmission temperature is too high, the torque capacity of the driveline will also be reduced, which will eventually lead to a reduction in the torque capacity of the power system

[0004] If the driver’s torque demand analysis does not consider the torque capacity of the power system, when the driver’s demand torque exceeds the torque capacity of the power system, the accelerator pedal continues to increase but the vehicle’s power does not increase accordingly, and the vehicle’s performance does not match the driver’s intention.

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