Abstract
Research and/or Engineering Questions/Objective
As the proportion of older people in the population is growing, the demand for older driver safety is increasing sharply because their driving abilities are changing. Their cognitive ability is lowered and the ability to cope with unexpected situations in various inevitably falls. Thus, requirements for safety-related vehicle technologies are increasingly growing. In this paper, we prepared for older people by developing this system.
Methodology
This system consists of perception, decision, control and HMI parts. The perception part which recognizes around the test vehicle is consisted of a camera, radars, and ultrasonic sensors. The decision part which determines such as critical level, decision of safety region, and control command. The control part which performs steering and acceleration/deceleration of the vehicle is constituted by a vehicle chassis system. The HMI part which controls an emergency stop input signal is composed of a driver state monitoring system.
The system is performed as follows: When an emergency accident occurs, the system recognizes the situation around the vehicle using sensors. The vehicle changes lanes to the last lane, and then the vehicle recognizes the guardrail and stops on the safety zone.
Results
The system test is performed by simulation and vehicle test. Prior to the vehicle test, autonomous stop simulation system based CarSim software and a simulation viewer were first implemented. The simulation is for the decision and control algorithms, and the vehicle test is performed by dividing longitudinal/lateral control, yaw rate control, and lateral path generation/tracking. The lane keeping driving test is the integration of smart cruise control and lane keeping system. Lane-changing is an entering test to the target lane in the lane changing mode. Lane changing function is performed by yaw rate control. When the critical level is safe, the time of lane changing is calculated. Based on recognized lane, the vehicle velocity, and time of lane changing, reference yaw rate is determined and the vehicle is controlled.
Limitations of this study
We assume the scenario that the test is performed. To perform the scenario, we assume there are lane marks and guardrails. It was not problem for us, because we performed the test for highway and most of highways have well-defined lanes, guardrails, and kerbs. If the system must perform in different situation, it needs more functions because the system is started with lane marks and guardrails.
What does the paper offer that is new in the field including in comparison to other work by the authors?
A point of this system is that we just use easy to get and automotive grade sensors in vehicle for recognition. The system is a temporary autonomous system to stop the vehicle on the side of the road by taking over control of the vehicle when an emergency situation occurs.
Conclusions
In this paper, we have presented development result of the temporary autonomous system to stop automatically the vehicle on side of the road by decision of critical level/region and lane changing. We propose an autonomous emergency stop system using only easy to get and automotive grade sensors in vehicle.
Key Words: Lane Changing; Safety Region Decision; Yaw Rate Control; Lateral Path Generation Research