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In this research, we examine the three controls inside-outside wheel braking force and driving force, camber angle, and the derivative steering assistance to determine how angle differences affect cornering performance and controllability. This is accomplished by comparing body slip angle area differences in a closed loop examination of the grip to drift area using a driving simulator. The results show that inside-outside wheel braking force and driving force control in the area just before critical cornering occurs has a significant effect on vehicle stability. We also clarified that controlling the camber angle enhances grip-cornering force, and confirmed that the sideslip limit could be improved in the vicinity of the critical cornering area. Additionally, when the counter steer response was improved by the use of derivative steering assistance control in the drift area exceeding the critical cornering limit, corrective steering became easier.

I studied the driver steer characteristics in the severe lane change with a drift. And, I studied the technique by which the performance of running in the vehicle at the severe lane change with a drift was improved. It has been understood that the severe lane change with a drift is a steer proportional to the body slip angle unlike the grip running. Moreover, I have understood importance in the vehicle movement performance improvement the cornering force characteristic where the maximum cornering force of the tire was exceeded. Next, I have understood the differentiation steer assistance is more effective.

To improve both the sensing of grip critical cornering and drift control, it is desirable to increase the body slip angle at critical cornering. To discover why this facilitates driver control, the gaze of the driver was monitored, and the relationship between the gaze movement of the driver and the vehicle behavior was investigated. It was found that the driver steered by gazing at the target course in the direction of the inside forward of the vehicle in the grip driving area. On the other hand, the gaze movement of the driver corresponded to the change in the body slip angle in the grip critical cornering area-drift cornering area. That is, in the drift driving area, it was found that the drift was controlled by gazing at the direction of the drift angle of the outside forward of the vehicle, feeding back the body slip angle, and sensing the change from the grip critical cornering to the drift area.

Various studies have been done into the steering models that describe how the driver steers the vehicle. However, no steering models for critical cornering have been developed. In this paper, the steering characteristic was investigated by monitoring the gaze of the driver during critical cornering. The direction of the steering model during critical cornering was considered. Since the driver can readily perceive the vehicle body slip angle if body sensory information is combined with visual information, it is important for the driver to be able to look at the target course easily and to control the drift well. Drivers exhibit the tendency to position their gaze point on a difficult corner exit to drive when body sensory information is combined with visual information. Thus, it was found that the driver can perceive the roll motion and visual feedback the body slip angle, and drive while stabilizing the vehicle from the corner exit to back straight.

In a new technology called “in wheel motor,” in which the motor is installed in the wheel, the electric vehicle can become more compact, which leads to a new type of mobility. Moreover, the front wheel steering is controlled by an electrical unit instead of the traditional mechanical unit of a steering wheel inside the car. In such a “steer-by-wire” method, the motor uses an electric signal. Because the degrees-of-freedom of this steer control are increased and a variety of steer controls based on the electric signal are possible, further improvement of the control stability is needed. In other words, the steer control technique can pose a problem for drivers, and so further research in this area is needed. That is, proportional derivative steering assistance can improve emergency evasion performance and the steering delay upon counter steering. Moreover, rear-wheel active steering can improve vehicle response during emergency evasion maneuvers.

In this study, a steering model and vehicle velocity control model were applied for a driver in drift cornering in order to maintain an intentional drift angle at the time of cornering. The driver was assumed to steer based on feedback from the body slip angle and the body slip velocity during drift cornering. It is found that the driver not only controls the drift angle at the time of the drift cornering but also controls the turn radius by changing vehicle velocity. Moreover, at the return from drift cornering to the straightaway, feedback is based on not only the body slip angle but also the body slip angle velocity, which is differentiated steer based on the phase is advanced.

In this study, an effective technique for improving drift running performance was examined. Basically, a driver model with counter steering was examined with the assumption that the body slip angle, along with the body slip angle velocity, served as feedback. Next, the effectiveness of adding front wheel steer angle velocity feedback to steering angle compensation as a drift running performance improvement technique of a vehicle was analyzed.