Study On Impact Of IVIS To Driver Vision Feature

Vision is the main channel driver obtaining traffic information. Analysis of drivervisual characteristics is the basis of establishing the driver information processing model. Inrecent years, with the rapid development of in-vehicle communication technology, as theintelligent transportation system terminal, in-vehicle information system has been widelyused in cars’ running process. With abundant information services content and variety ofways to disseminate information, in-vehicle information system adds the number andcomplexity of in-vehicle secondary task the driver performing and changes the driver’svisual characteristics to some extent. The competition for information processing resourcesbetween primary task and secondary task will lead to an increasing of mental workload anddistraction, decreasing the ability of cognition and judgment, etc. All these may objectivelyaffect driving behavior and lead to accidents. The visual characteristic of drivers under theinfluence of in-vehicle information system was studied in this paper. Research results havetheoretical significance for research of driver information processing model and providebasis and reference for the design of in-vehicle information system.Indicators of driver visual characteristic include fixation point, fixation duration andpupil area were collected by eye-tracking system. By driving simulator experiments and theon-road test, visual characteristics of drivers with or without in-vehicle information system,with different mounting positions, different ways of information issue and differentoperating mode were compared. During data preprocessing stage, the cluster analysis wasused on the driver visual attention area division and the invalid data were weed out. Duringdata analysis stage, the conception such as the vision area variation coefficient wasintroduced to quantitatively describe the degree of the fixation point concentration.Meanwhile, the characteristics of divided vision zones were analyzed by statistical methodand the following phenomena were found.Using in-vehicle information system leads to a siginificant decrease of drivers’ visualsearch area and fixation times at the front road zone, results in a significant increasing offixation duration, the ratio of cumulative fixation time and the pupil area. When IVIS was installed at the front windshield, it makes the least fixtion times on the front zone as well asthe fixation duration. Audio-visual information release is better than visual-only informationrelease at all indexes and has less effect on drivers. With the complexity of manually tasksincrease, the indexes of fixation point concentration, fixation duration and pupil areasignificantly change. Pupil area increases with the difficulty of secondary task.It can be seen from above results, the use of in-vehicle information system hassignificant effect on drivers obtaining road informatio, which increases the driver’s mentalworkload. IVIS installed at different positions have remarkable difference among theinfluences on the driver obtaining road information. When IVIS is installed on the frontwindshield, drivers’ attention on the road information is the shortest as well as theprocessing time. Compared with the audio-visual information， the issue way of visual-onlyinformation has greater effect on drivers peripheral detection performance as well as themental workload. With the difficulty of manual tasks increasing, drivers’ mental workloadincreases and peripheral information detection performance decreases. Drivers’ mentalworkload increases with the difficulty of secondary task. It should pay attention to designand application of in-vehicle information. The less impact form of IVIS should be selectedto avoid adverse situations.