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2020年11月10日 (火)

Take-over evaluation by driving simulator (7)

​In our laboratory, we are also continuing research on the problem of driver wakefulness lowering, not from the standpoint of warning after wakefulness decreases, but from the standpoint of how to prevent wakefulness from decreasing. ​Automated driving frees the driver from the heavy task of driving, so when a new task is imposed so as not to lower the arousal level, the driver is selected with the least load.

​There are a number of tasks that don't reduce alertness if the load on the driver is ignored. ​Active conversation and singing do not reduce alertness, but it does burden drivers.  The tasks we tested in our lab that did not reduce alertness included gripping the steering wheel, providing information based on where the driver is driving, flashing LEDs based on breathing rate during high alertness, and flashing LEDs that trigger saccade stimulation. ​Of these, steering wheel gripping and saccade induction were particularly effective. ​If the driver holds the steering wheel, he/she will not be able to lower his/her alertness from his/her driving habits. ​Saccade induction seems to be effective due to the biological characteristics of humans, but there is a problem whether it can be performed voluntarily.

​The fact that the steering wheel grip is effective for preventing the lowering of the arousal is a method in which the automated driving level 1 is extended and cost is not required. ​Even when the level of automated driving has evolved from 1 to 2 or 3, the most effective means for take-over is to have the driver maintain the driving posture and hold the steering wheel.

​On the other hand, the problem on the side of the vehicle which cannot support the take-over is to suddenly shift the control to manual driving operation after the take-over request. ​In other words, this means that even if the driving control is suddenly moved to the driver while the vehicle is running, a problem arises because the driver is not ready for the driving operation. In the planned take-over, it is assumed that the take-over request is issued only on the straight line. ​This is because the driver will not be able to cope with the problem unless the line is straight.

​As described above, most of the drivers operated the steering wheel smoothly when changing the lane immediately after completing the take-over on the straight track and when changing the lane after driving on the same lane for a while after completing the take-over. ​This indicates that the manual driving operation of the driver requires a familiarization drive. ​There is also another study in which the steering wheel operation is disturbed when the vehicle is taken-over while driving on the curve. ​In view of this, it may be preferable to continue level 1 vehicle control such as lane keeping instead of stopping vehicle control at the time of take-over. ​However, it is necessary to verify whether lane keeping is working and there is no problem when quick steering is necessary to avoid obstacles.

We have found a number of challenges in take-overs. ​Switching from automated to manual driving operation cannot be done easily by determining specifications. ​Conversely, what about switching from manual driving operation to automated driving? The author has experienced this in the driving support system, and so there is no problem. With ACC, the driver simply turns on the set switch and the he/sher can safely leave the pedal. ​The same goes for switching to automated driving, where the driver can turn it on at any time. ​If you are worried that autonomated driving might require a special HMI, try it out on a driving simulator, as we did in the take-over experiments. ​In driving support systems and automated driving, the driver entrusts the driving operation to the automobile, which greatly increases the utilization of the driving simulator. ​When the driver drives the vehicle manually, the behavior of the vehicle in response to steering wheel operation and the feeling that the behavior of the vehicle imparts to the driver through the steering wheel are strictly required. ​However, in the case of the advamced driver assistance systems, the driver does not have a severe sense of feeling required to the vehicle through the steering wheel, and therefore, if the driving simulator pays attention to the graphics representing the driving environment, the generation of G may not be as accurate as during manual driving. ​Therefore, even low-cost driving simulators can be fully utilized.



« Take-over evaluation by driving simulator (6) | トップページ | Evaluation of automated driving ethics by driving simulator (1) »




« Take-over evaluation by driving simulator (6) | トップページ | Evaluation of automated driving ethics by driving simulator (1) »