Implementation of Two-Wheel Independence Drive System Based on Indirect Field-Oriented and Direct Torque Control Strategies

Proposed wheel independence drive structures presented improvement of maneuverability and stability of vehicles. In this paper, torque of two brushless direct current motors were regulated in cases that a vehicle is moving in straight lines and during curves based on indirect field-oriented control and direct torque control. Simulation results presented different torque and power requirements of two control strategies. Programmed to the proposed drive system, the torque-speed response of two control strategies were verified by experimental results both in static and dynamic conditions.

I. Introduction

Traction drives of electric vehicles can be divided into two categories: single and multi-drive systems. In single drive system, the traction shaft is driven by one or more motors. Drive power is transmitted to two half axles of left and right wheels through a differential. On the contrary, in multi-drive systems, the wheels are independently driven by their own motor, i.e. wheel-side motor or hub motor. The power is directly transmitted to the wheel axle without the differential [1] [2]. However, the drivetrain can provide different wheel speeds and has a benefit in space flexibility by eliminating the large central drive motor, the differential and wheel axles.