Torque vectoring algorithm based on mechanical elastic electric wheels with consideration of the stability and economy

Abstract

How to coordinate the relationship between stability and economy according to the current motion state of the vehicle is an urgent problem to be considered in torque distribution. To solve this problem, a novel torque vectoring algorithm is proposed based on a novel type of mechanical elastic electric wheel. The tire model of mechanical elastic wheel is identified based on Fibonacci tree. Considering the nonlinearity of tire force, a linear parameter-varying linear quadratic regulator upper controller based on a 2-degree of freedom (DOF) model is designed. In addition, considering the inaccuracy of the vehicle model, a nonlinear model predictive control is designed based on the 7-DOF model. For the lower controller, a torque allocation algorithm considering stability and economy is proposed, which ensures the stability of the vehicle and reduces the energy consumption of the powertrain. Moreover, the weight distribution of stability and economy is dynamically coordinated based on the phase portrait. Finally, the algorithm is verified under the conditions of low adhesion road, joint road, driving cycle and hardware-in-the-loop test. The results show that the proposed torque vectoring algorithm can ensure the vehicle handling stability and improve the energy efficiency of the powertrain at the same time.