Torque vectoring control design based on objective driving dynamic parameters

Due to the good controllability of electric motors the possibilities of driving behaviour control are increased. The amount of applicable yaw moment on the car compared to previous systems is increased; therefore it is essential to investigate the possibilities of influencing the driving experiences. Thus the subjective impression of the vehicle dynamics can be improved although the narrow roll-resistant optimized tyres on electric cars have less lateral potential than conventional ones. The objective of this study is to find the key driving dynamic parameters to evaluate the behaviour already in the simulation and to adjust the torque vectoring control unit to improve the drivability. The vehicle dynamics evaluation of the small electric car is based on characteristic values from literature research and handling tests. Further dynamic simulations and test drives with different torque vectoring target specifications generate a range for each parameter, where the driving behaviour for the driver is still on a high level. A correlation between the objective parameters gives a detailed overview of their specific importance in different driving manoeuvres. Depending on the uncontrolled vehicle behaviour a recommendation for the design criteria of the torque vectoring control unit is given. Thus in the time intensive driving tests only the control target (the yaw rate) has to be validated and adjusted.