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Regenerative braking has been widely accepted as a feasible option to extend the mileage of electric vehicles (EVs) by recapturing the vehicle’s kinetic energy instead of dissipating it as heat during braking. The regenerative braking force provided by a generator is applied to the wheels in an entirely different manner compared to the traditional hydraulic-friction brake system. Drag torque and efficiency loss may be generated by transmitting the braking force from the motor, axles, differential and, specifically in this paper, a two-speed dual clutch transmission (DCT) to wheels. Additionally, motors in most battery EVs (BEVs) and hybrid electric vehicle (HEVs) are only connected to front or rear axle. Consequently, conventional hydraulic brake system is still necessary, but dynamic and supplement to motor brake, to meet particular brake requirement and keep vehicle stable and steerable during braking.

This paper introduces a vehicle model in CarSim, and replaces a portion of its standard suspension system with an HIS model built in an external software to implement co-simulations. The maneuver we employ to characterize the HIS vehicle is a constant radius method, i.e. observing the vehicle’s steering wheel angle by fixing its cornering radius and gradually increasing its longitudinal speed. The principles of the influence of HIS systems on cornering mainly focus on two factors: lateral load transfer and roll steer effect. The concept of the front lateral load transfer occupancy ratio (FLTOR) is proposed to evaluate the proportions of lateral load transfer at front and rear axles. The relationship between toe and suspension compression is dismissed firstly to demonstrate the effects of lateral load transfer and then introduced to illustrate the effects of roll motion on cornering.

This paper proposes an approach to optimize the economy performance of a two-speed electric vehicle (EV) by combining gear shifting schedule design and gear ratios selection. Mathematic models for the two-speed EV subsystems are developed, including those of the battery module, electric machine, the driver, transmission and vehicle. Then a procedure for obtaining the optimal gear ratio pairs and corresponding shift schedule for the two-speed EV is presented in detail. The optimized EV powertrain parameters can not only ensure that basic requirements in dynamic performance are achieved, but realize the optimal economic performance of the EV as well. In order to investigate the effectiveness of the proposed method for EV design, simulations based on the developed powertrain model is conducted using different test driving cycles, including NEDC and constant speed. Results of these simulations validate the effectiveness of the proposed optimization method.

The purpose of this paper is to present a concept of Hydro-Pneumatic Interconnected Suspension (HPIS) and investigate the unique property of the zero warp suspension stiffness. Due to the decoupling of warp mode from other modes, the road holding ability of the vehicle is maximized meanwhile the roll stability and ride comfort can be tuned independently and optimally without compromise. Ride comfort can be improved with reduced bounce stiffness and the progressive air spring rate can reduce the requirement of suspension deflection space. The roll stability can also be improved by increased roll stiffness. Vehicle suspension system modelling and modal analysis are carried out and compared with conventional suspension. The frequency response of tyres' dynamic load reveals that the proposed zero-warp-stiffness suspension enables the free articulation of front and rear axles at low frequency.

This paper presents a smart electric scooter system consisting of a microprocessor based vehicle controller (integrating an embedded regenerative braking controller), a 300W Permanent Magnet (PM) DC motor, two low-power DC-DC converters to form a higher power DC-DC converter pack, a motor controller, a supercapacitor bank and a capacitor cell balancing sub-system.

Electric vehicles (EV) are considered a practical alternative to conventional and hybrid electric passenger vehicles, with higher overall powertrain efficiencies by omitting the internal combustion engine. As a consequence of lower energy density in the battery energy storage as compared to fossil fuels powered vehicles, EVs have limited driving range, leading to a range phobia and limited consumer acceptance. Particularly for larger luxury EVs, electric motors with a single reduction gear typically do not achieve the diverse range of function needs that are present in multi-speed conventional vehicles, most notably acceleration performance and top speed requirements. Subsequently, multi-speed EV powertrains have been suggested for these applications. Through the utilization of multiple gear ratios a more diverse range of functional needs can be realized without increasing the practical size of the electric motor.