Improvement in Steering Performance by Push-Pull Operation in Car Driving

Abstract

Collision avoidance is one of the most difficult driving operations in the domain of
intelligent vehicles. Steering operation error is one of the causes of traffic accidents.
Steering operability also contributes greatly to the comfort of drivers and their mental
workload during driving. Thus, with comfortable steering operation it is possible to
reduce shoulder stiffness and arm fatigue caused by long-time driving. The development
of automatic driving vehicles is becoming advanced worldwide. Consequently, the goal
is to implement a level 3 automatic driving vehicle for practical use, in which "the system
performs the acceleration, the steering, and the braking, and the driver responds when the
system requests it". For this system to be practical, when autonomous driving becomes
impossible for some reason, it is important to develop a system that allows the driver to
be in control regardless of driving experience or age. In conventional round steering
wheel, since there is no output muscle directly involved in the direction of movement of
the upper limbs, it is difficult to instantaneously exert a large force and control performance is not good. Therefore, a twin lever steering (TLS), which is a push / pull
alternate steering system, is proposed in this study. In the proposed TLS, there are output
muscles that are directly involved in the direction of movement of the upper limb,
including the biceps brachii muscle, and it is conceivable that the motor controllability is
higher than in the conventional system. In this research, the superiority of the proposed
TLS was verified using an experimental racing kart and driving simulator (DS).
Furthermore, using DS, the superiority of a TLS in the steering operation immediately
after the cancellation of automatic operation is clear.