The study presented in this paper discusses developments in the area of anti-lock braking control for full electric vehicles. The main contributions of the paper are the development and experimental validation of the combined electric and hydraulic brake system with application of a continuous anti-lock braking system, which is expected to be more effective than the existing industrial solutions. It covers the topic of high-performance braking and driving comfort under a direct slip control function. The research is related to the full electric sport utility vehicle equipped with four individual on-board motors and a decoupled electrohydraulic brake system. The brake controller architecture includes functions of the continuous anti-lock braking system strategy, a brake blending algorithm aimed at minimization of the friction brake torque and operational limitations of the electric brakes. The developed brake controller was subjected to different validation procedures but, within the framework of this paper, emergency braking tests on a wet surface with a low coefficient of friction are considered. The results obtained demonstrate significant improvements in the braking performance, the driving comfort and the control performance for continuous anti-lock braking control of the electric vehicle compared with those of diverse vehicle configurations and, in particular, with those of a sport utility vehicle of the same type equipped with an internal-combustion engine and a conventional hydraulic brake system.@en

Recent studies on torque vectoring control for electric vehicles proposed various efficient solutions demonstrating improvement of vehicle stability for evasive manoeuvres. However, the torque vectoring on very low friction surfaces such as black ice or wet snow is rarely investigated, especially for the electric vehicles with off-road capability. The presented study contributes to this topic by laying the groundwork for further advanced torque vectoring designs. Within the framework of this paper, the target vehicle is a sport utility vehicle equipped with four on-board electric motors controlling each wheel separately. The functionality of the developed controllers is tested under hardware-in-the-loop simulations for icy road conditions. For this purpose, the tyre model has been parameterized and validated based on the experimental data conducted on a unique terramechanics test rig at Virginia Polytechnic Institute and State University. The test results confirm very good functionality of the developed controllers and demonstrate an improvement of the electric vehicle driving performance.@en

The paper presents an overview of continuous wheel slip control (WSC) methods as the part of anti-lock braking system (ABS) for the several vehicles configurations with friction brakes and electric motors. Performance of proposed WSC design variants using several control techniques has been experimentally evaluated for three different test vehicles: Sport Utility Vehicle (SUV) with decoupled electro-hydraulic brake (DEHB) system, SUV with four individual on-board electric motors (OBM), and compact vehicle with four individual in-wheel motors (IWM). Obtained results demonstrated that proposed continuous WSC variants provide a simultaneous effect on braking efficiency and ride quality as well as robust operation in various road conditions. Presented summary provides outlook on future perspectives of the continuous WSC and compares its status with conventional rule-based ABS systems.@en

Anti-lock braking functions of electric vehicles with individual wheel drive can be effectively realized through the operation of in-wheel or on-board motors in the pure regenerative mode or in the blending mode with conventional electro-hydraulic anti-lock braking system (ABS). The regenerative ABS has an advantage in simultaneous improvement of active safety, energy efficiency, and driving comfort. In scope of this topic, the presented work introduces results of experimental investigations on a pure electric ABS installed on an electric powered sport utility vehicle (SUV) test platform with individual switch reluctance on-board electric motors transferring torque to the each wheel through the single-speed gearbox and half-shaft. The study presents test results of the vehicle braking on inhomogeneous low-friction surface for the case of ABS operation with front electric motors. The performed tests confirm considerable reduction of braking distance and accurate tracking of the reference slip as compared with the vehicle braking without ABS. Hence the pure electric ABS can be considered as an efficient alternative to anti-lock braking systems with friction brakes only.@en