Research on energy recovery strategy in breaking of electric tractor-semitrailer

Tractor-semitrailers play an important role in the transportation industry. However, global warming and the rapid advancement of energy technologies have driven the transformation of high-emission vehicles, such as tractor-semitrailers, to be powered by new energy sources in order to achieve goals related to energy conservation, emission reduction, and cost savings. By using the motor as the primary driving force, the energy recovered during braking or coasting can be converted into electricity and stored in the battery for later use. While much research has been conducted on braking control and energy recovery for passenger cars, there is limited research on tractor-semitrailers. Additionally, the jackknife is a critical factor to consider under high-speed conditions. To investigate the braking energy recovery of electric tractor-semitrailers, tire and motor models were developed based on the turning and braking conditions of such vehicles. Taking into account the load transfer effect during braking, an 8-DOF nonlinear vehicle dynamics model was proposed. The paper then researches the principle of vehicle regenerative braking and, in conjunction with the vehicle dynamics model, explores a braking force distribution strategy optimized for energy recovery. Furthermore, the optimization of the braking energy recovery strategy is studied with respect to lateral stability, particularly addressing the jackknife during high-speed turning and braking. A comparison of results before and after optimization demonstrates that the optimization strategy effectively balances energy recovery with lateral stability.