Energy-Efficient Direct Yaw Moment Control for In-Wheel Motor Electric Vehicles Utilising Motor Efficiency Maps

Abstract

An active energy-efficient direct yaw moment control (DYC) for in-wheel motor electric vehicles taking motor efficiency maps into consideration is proposed in this paper. The potential contribution of DYC to energy saving during quasi-steady-state cornering is analysed. The study in this paper has produced promising results which show that DYC can be used to reduce the power consumption while satisfying the same cornering demand. A controller structure that includes a driver model and an offline torque distribution law during continuous driving and cornering is developed. For comparison, the power consumption of stability DYC is also analysed. Simulations for double lane change manoeuvres are performed and driving conditions either with a constant velocity or with longitudinal acceleration are designed to verify the effectiveness of the proposed controller in different driving situations. Under constant velocity cornering, since the total torque demand is not high, two rear wheels are engaged and during cornering it is beneficial to distribute more torque to one wheel to improve energy efficiency. In the simulated driving manoeuvres, up to 10% energy can be saved compared to other control methods. During acceleration in cornering, since the total torque demand is high, it is energy-efficient to use all the four in-wheel motors during cornering.

Energy efficiency and stability of electric vehicles utilising direct yaw moment control

“…The investigated vehicle is a 4IWMs EV and the vehicle planar motion models can be seen in reference [13]. The vehicle parameters are shown in Table 1.…”

“…That gives a potential to be more energy-efficient by having a yaw moment range to choose from. A DYC for energy-efficiency was proposed in previous work [13], which provided a range of direct yaw moment for low-level torque distribution controller. With the pre-known information of the motor efficiency, optimisation was carried out in the yaw moment range to find the most energy-efficient yaw moment.…”

“…The energy saving function of the DYC for energy-efficiency in [13] has been demonstrated under non-safety-critical cornering manoeuvres. The behaviour of the DYC for energy-efficiency is also analysed under safety-critical cornering manoeuvres in this work.…”

Evaluation of Combined Energy-Efficient and Stability Strategies Utilising Direct Yaw Moment Control

“…4. The controller structure for energy-efficient DYC [4] the same direction of a yr to avoid counter-steering. The offline torque distribution rule is optimised based on the motor efficiency map in Fig.…”

“…Although stability control is prioritized, during non safety-critical driving manoeuvres, energy-efficient driving should play the dominant role. An active energy-efficient DYC method taking into account the motor efficiency map was proposed in previous work [4]. In this paper, stability judgements consisting of yaw rate and body slip angle are designed and the switching principles betweenenergy-efficient DYC andstability DYC are devised.…”