Electric Vehicle Longitudinal Stability Control Based on a New Multimachine Nonlinear Model Predictive Direct Torque Control

Abstract

In order to improve the driving performance and the stability of electric vehicles (EVs), a new multimachine robust control, which realizes the acceleration slip regulation (ASR) and antilock braking system (ABS) functions, based on nonlinear model predictive (NMP) direct torque control (DTC), is proposed for four permanent magnet synchronous in-wheel motors. The in-wheel motor provides more possibilities of wheel control. One of its advantages is that it has low response time and almost instantaneous torque generation. Moreover, it can be independently controlled, enhancing the limits of vehicular control. For an EV equipped with four in-wheel electric motors, an advanced control may be envisaged. Taking advantage of the fast and accurate torque of in-wheel electric motors which is directly transmitted to the wheels, a new approach for longitudinal control realized by ASR and ABS is presented in this paper. In order to achieve a high-performance torque control for EVs, the NMP-DTC strategy is proposed. It uses the fuzzy logic control technique that determines online the accurate values of the weighting factors and generates the optimal switching states that optimize the EV drives' decision. The simulation results built in Matlab/Simulink indicate that the EV can achieve high-performance vehicle longitudinal stability control.

Anti-Lock Braking System Components Modelling

“…For superior ABS performance, the slip ratio should be kept close to the ideal value 15. Tracking performance of the braking force using mean square error is expressed in the following equation 10: (14) The differential equation of PID controlled is [10]: (15) Next, the transfer function to be added to MATLAB/Simulink is as follows [30]: (16) The tracking error is calculated as follows [30]: (17) Modern controllers require signals calculated in digital or discrete time 23. In the Proportional-Integral-Derivative controller (PID) P is related to the error that happens in the present, I show the error collected from the past, and D indicates the predicted upcoming error 1.…”

Review and Development of Electric Motor Systems and Electric Powertrains for New Energy Vehicles

“…The final voltage vector suppressing harmonic current of the stator was obtained; thus, the fast dynamic response and good steady performance were kept unchanged. A novel multi-machine robust DTC scheme based on the nonlinear model prediction (NMP) method was proposed [31]. It achieved the acceleration slip regulation (ASR) and anti-lock braking system (ABS) functions of four wheels PMSMs and better driving performance and vehicle stability.…”

Acceleration‐based wheel slip control realized with decentralised electric drivetrain systems

“…[23], model predictive control (MPC) shows better traction performance than PID control due to the implementation of the non-linear model. However, MPC needs much more computing resources, which makes its practical application harder [24]. In addition, fuzzy logic is also utilised in some studies to maintain slip ratios by controlling traction torque.…”