Effects Of Driver Take-over Characteristics Of Non-driving Tasks In Man-machine Shared Driving Mode

The man-machine shared driving mode,as a kind of intelligent driving mode,will exist for a long time.When encountering system failure or complex traffic environment,the driver needs to take over the control of the vehicle in time.When the driver is in a non-driving related task,it will reduce the perception and reaction ability to the traffic environment to a certain extent and even cause traffic accidents.Therefore,by studying the effects of non-driving related tasks on the takeover characteristics,safety recommendations can be provided for driver behavior in the man-machine shared driving mode.In this paper,based on the study of the basic theory of man-machine shared driving mode,five non-driving related tasks(We Chat text,We Chat speech,handheld call,hands-free call,no task)were identified with the help of questionnaires,two kinds of takeover request times(TTC-5s and TTC-7s)were set at 5s and 7s,and the human-vehicle-environment driving simulator and Smart eye pro 8.0 non-contact eye-tracking device were used to The vehicle motion data and driver’s eye movement data were recorded during the takeover and obstacle avoidance test.The effects of non-driving related tasks on the takeover behavioral characteristics and takeover visual characteristics were analyzed in the man-machine shared driving mode.The takeover behavioral characteristics were evaluated in terms of takeover time and takeover quality,and the effects of different states on the driver’s recovery of situational awareness and takeover actions were evaluated.The visual characteristics of takeover were evaluated by using three indicators: fixation behavior,saccade behavior,and blinking behavior,which included the distribution of driver’s fixation points,the difficulty of capturing information,the amount of information,the speed of processing information,and the good and bad takeover states.The results showed that the takeover time under the influence of non-driving-related tasks was ranked from longest to shortest by We Chat text,We Chat speech,handheld call,hands-free call,and no task,and the correlation between the indicators was significant;the four nondriving-related tasks had different visual,physical,and cognitive loads on the driver,so there were significant differences in the takeover quality,among which the text task had the most negative impact on the horizontal and vertical control ability of the vehicle,and the hands-free task had the least.The text task has the greatest negative impact on the vehicle’s transverse and longitudinal control ability,and the hands-free task has the least and is similar to the no task;by analyzing the visual characteristics of the takeover,it is easy to see that the text task is harder to capture key information,faster to process information,and slightly more stressful to takeover,and the hands-free is the opposite.Compared to the 5s takeover request time,the 7s approach has a longer takeover time,better takeover quality,and a more relaxed process of capturing environmental information and processing information.