Development of Steer-By-Wire System that Assumes Operation Without Changing Grip

Future steering systems must not only be compatible with automated driving systems, but also allow for improved driving space flexibility. To address these needs, we are currently developing a Steer-by-Wire system with no mechanical link. This paper proposes a fully redundant configuration, the state transition and, a control method of variable steering gear ratio and reaction force to achieve natural steering feel in a Steer-by-Wire vehicle assuming driver doesn't change hand position on the steering wheel. Moreover, taking advantage of the characteristics of Steer-by-Wire system, we also demonstrate the effectiveness of a control method to transmit only necessary road information to the driver.