In this paper, we conducted research on compliance steering with respect to lateral force and tire drag force (longitudinal force) in order to achieve good steering feel and smooth yaw motion, focusing on strut-type front suspensions widely used in front-wheel drive vehicles equipped with transverse engines. Experimental methods included measuring tire characteristics at low speeds (10 km/h, 30 km/h) and high speeds (100 km/h), and using a K&C device to measure compliance characteristics of three vehicle models, including Japanese and European vehicles, to calculate dynamic compliance steering. The results showed that vehicle A, a Japanese vehicle, exhibited toe-out compliance steer with respect to tire drag force compliance steer, while vehicles B and C, European vehicles, exhibited toe-in compliance steer with respect to tire drag force compliance steer. When focusing on the total compliance steer values for lateral force and tire drag force in relation to toe angle changes, the European vehicle (vehicle B) with a larger compliance steer value for lateral force and the Japanese vehicle (vehicle A) with a smaller compliance steer value for lateral force showed nearly equivalent toe angle changes. Additionally, it was found that the European vehicle maintained a constant compliance steering-induced steering angle change ratio even as speed varied. Furthermore, compliance steering was compared and evaluated in relation to lateral force, tire drag force, and self-aligning torque. The results showed that compliance steering dominated in relation to lateral force and self-aligning torque during turns with slip angles of 0 to 1.3 degrees, while compliance steering in relation to tire drag force was negligible.
Ogawa et al. (Thu,) studied this question.