Design Theory for Speed Control by Using Increasing Edge Rate

Edge rate is an important source for driverpsilas perceptual speed. In this paper, the concept of edge rate and the theory about driverpsilas speed perception and control which based on edge rate were briefly described, and an introduction to the application effects of edge rate was also made. According to the concept of edge rate and Newton motion equation, a model fitting the comfortable uniformly decelerated motion was designed for speed control, which satisfied two restrictions, including the restriction of keeping edge rate increasing toward the directions of traffic and the restriction of time Weberpsilas law. Using the 3DMAX, the videos simulating car moving process on the freeway were made in which edge rate was a key manipulative parameter. Six males and two females took part in the experiments. 260 Subjectively Equal Speed experiments were implemented by using the Forced-Choice Method, and the reasonable bound of the edge rate value was educed by analyzing the experimental results. The Weber fraction was also determined through literature review. A case study was carried out in this paper, and the edge line spacing was calculated for controlling the speed from 120 km/h down to 90 km/h by the designed model. Comparison experiments were carried out between the condition when edge rate kept increasing and the condition when edge rate kept constant through the simulating video. The demonstration experiment indicated that the design mode of keeping edge rate increasing was more effective than the design mode of keeping edge rate constant.