Model-based drive shaft torque estimation and control of a hybrid electric vehicle in energy regeneration mode

In automotive applications, effective and affordable acquirement of drive shaft torque value could greatly benefit the vehicle driveline feedback control. This paper presents a model-based torque observer to estimate the drive shaft torque using transmission output shaft angular speed and driven wheel angular speed. A detailed drive line model used for characterizing the behavior of the HEV driveline and a simplified model used for observer design will be constructed. The estimated torque will be used for carrying out brake system feedback control in a HEV. Several simulations will be presented to demonstrate the effectiveness of the proposed observer.