Advances being made today in electronic technology are evolving the processes that make vehicles more intelligent, in addition to realizing safer and more comfortable driving. Lane departure prevention systems are also becoming practical due to millimeter-wave radar and onboard forward observation cameras. The U.S. Department of transportation has implemented a National Automotive Sampling System Crashworthiness Data System (NASS/CDS) for North America that found 10,743 accidents in 2019 involved departure from the road. There were 12,043 fatalities in these accidents. Lane departure prevention systems are expected to make a major contribution to reducing accidents of this kind. Advances are also being made in the development of systems that will enable autonomous driving, and the system to ensure safe and comfortable vehicle operation is being developed. These systems embody great potential for reducing the number of accidents caused by road departure. However, the validity of the systems is largely dependent on the level of acceptance by drivers. System validity will be determined by when they provide driving assistance, how much relaxation will be permissible on the driver’s side, given that the driver needs to maintain contact with the steering wheel, and the extent of assistance provided by the system. This paper will describe the improvement of the steering grip detection rate and its reliability regarding the minimum contact and contact strength of the driver to the steering wheel during lane keeping and autonomous driving systems. Using an actual vehicle, experiments were conducted on 20 subjects to investigate the relationship between the driver's steering angular velocity, steering angular velocity, steering torque, and steering contact state. The authors have improved the detection rate and reliability by clarifying the minimum steering grip during ADAS operation and the optimum detection range of the grip detection system at that time. The existing literature on driver modeling indicates that numerous factors contribute to driving, but only a limited number of simulations have utilized complete models. Thus, the present study aims to address this research gap by examining the correlation between the driver's steering contact range and steering operability, and exploring the relationship with the subject's grip strength. Additionally, the paper proposes an optimal detection system to improve the detection rate and reliability of the steering grip during ADAS operation, which could potentially contribute to the development of more realistic driver models and improved driver training and vehicle design. Based on the results of this verification, we determined the range of steering grasping, and accurately grasped the grasping with an electrostatic sensor built into the steering switch so that it can be installed in actual vehicles in the future. A sensor that can detect minute capacitance changes at a distance from the sensor is required. For this prob issue, we used a method called the absolute self-capacitance method. In this method, the parasitic capacitance of the detection electrode is reduced by the drive shield electrode on the back of the detection electrode, and the detection sensitivity of minute capacitance at a distance from the sensor is ensured. The study only involved a small sample size of 20 subjects, which may not be representative of the wider population. It aims to investigate the relationship between the driver's steering grip range and steering operability, as well as the relationship with the subject's grip strength, and provide insights into the complex interplay between these factors. As a conclusion of this study showed that there is a significant correlation between steering grip range and steering operability, indicating that the driver's ability to adjust their grip on the steering wheel plays an important role in controlling the vehicle's movement.
Mr. Shotaro Odate, Chief Engneer, Honda Motor Co., Ltd.