Gear Collision Reduction of Geared In-Wheel-Motor by Effective Use of Load-Side Encoder

Requirement of large motor torque with limited mounting space for In-wheel-motors (IWMs) expects a geared drivetrain, but the vibration and noise caused by gear collision deteriorates ride comfort. In our previous study, our research group proposed to apply joint torque control using motor-side encoders and additional load-side encoders to geared IWMs and the effectiveness is validated. However, in point of space and costs, the effect of mounting load-side encoders should be investigated carefully. In this paper, joint torque control using both motor-side and load-side encoders is compared with joint torque control using only motor-side encoders. Simulations and experiments demonstrate that load-side encoders make it possible to design controller without vehicle parameters and to reduce the impact of collision sufficiently.