Foreword
As the Chinese road communication was developed swiftly and violently, the car recoverable amount has already exceeded 150 million, and keep continuing the trend of growth. The flourishing development of the road communications and transportation has offered powerful support for transportation undertaking of China, but brought the huge traffic potential safety hazard at the same time. The road traffic accident has already become the first of various accidents, the significance that it is traffic system of setting up safe sustainable development of communications and transportation is hindered. So, setting up the insurance system of road traffic through the technological means is the task of top priority in order to reduce the traffic accident. This text is on the foundation of pilot’s visual function in the course of dissecting and driving, make an introduction and analyze to the research current situations of different car safety engineering based on vehicle carried machine vision, and look forward to the development trend of this field.
1 drives procedure description
According to people behavioral amazing & mdash; The classical mode of a response of the organism, driving the behavior of the car can be divided into three stages, ,namely perception stage, judging decision stage and operating stage. During the course of perceiving, the pilot obtains and understands the real time traffic status information tentatively, pass the operation environmental condition of the perception car of sense organ; During the course of judging decision, the pilot accords with and drives experience and skill, analyse and judge through the central nervous system, confirm that helps the measure that the car goes safely; During the course of operating, the pilot, according to judging decision, make actual responses and actions through the locomotor organ. When the car goes, it is a constituent information processing procedure that is carrying on to drive the behavior reciprocally, that is to say the perception acts on and judges decision to influence and operate. Perception stage is a foundation of guaranteeing safety drive. If have perception get accurate prompt environmental message, result in, judge decision and fault of movement most probably, lead to the traffic accident. Obtain information and mainly depend on the vision, touch, olfaction and sense of hearing during the course of perceiving, among them more than 80% obtained information through pilot’s vision. Drive the broadness, depth and reliability of the information volume of the perception of visual direct influence, so, the pilot’s visual characteristic has direct contacts with traffic safety. The safe auxiliary driving technology of car based on vehicle carried machine vision aims at improving pilot’s visual efficiency, through improving the vision and driving the behavioral relation, and assist and drive in order to reduce and bring due to visual reasons improperly and operate, thus make the people – car – way system more stable and more reliable and improve the initiative safety of the vehicle.
The machine vision of 2 vehicles of external information assists driving technology
People’s ophthalmic function ability is definite, pass a series of the intersection of vehicle and machine vision of external information, assist driving technology may raise visual adaptability, increase visual range, strengthen vision, understand the depth. It is divided that from vehicle operational process, the machine vision of the external information of vehicle assists and drives technical research to include: Drive the vision of the environment and strengthen and expand and drive the machine visual identity of the environment.
2.1 Drive the vision of the environment to strengthen and expand and reveal
2.1.1 The vision is strengthened
The visual enhancement system is one of the control technique of advanced vehicle in intellectual transportation system, can offer in different it (thick weather, rainy day, dust and sand) , pilot’s vision of enhancement of different time in one day. Generally have two kinds of accentuation methods: Control the traffic environment of the road by sensory system of the sensor, process information gets the traffic of real-time road, and offer the associated visual information to the pilot, thus achieve the goal that the intellectual vision strengthens; Through improving the pilot’s visual environment, improve pilot’s visual effect. Remove rainwater and frost at the windscreeno, it raises the intersection of car and head-light to be intelligent, etc mainly, visual purpose of the pilot that achieves and strengthens under unfavorable conditions such as low visibility, low illumination level.
Utilize ophthalmic visual characteristics of people, adopt sensors such as CCD, infrared sensor, speed sensor, GPS and millimeter wave radar,etc. to obtain road information, go on information processing and merge, draw the useful information that low visibility, low illumination level make the traffic environment and reject the noise, and offer to the pilot in the form of picture. The visual enhancement system of low visibility was applied to aircraft landing first, from latter stage of the eighties of the 20th century to initial stage of the 1990s, people have proposed the virtual views system (VisionSystem) Concept. Adopt the virtual views system formed of different means and different integrated approaches and is divided into:
( 1) Virtual views system of the sensor (SensorVS)
Look at and see the scene outside the real-time detected cockpit of the forward sight sensor, can be produced by the single sensor or the multisensor is comprehensive, its virtual views is close to the true world natural scene.
( 2) Formate the virtual views system (SVS)
Called and formates the virtual views (SV) by the fictitious virtual views that the relief model that the topographical database stores constructs .
( 3) Strengthen the virtual views system (EVS)
Sensor virtual views and formating the folding of the virtual views and is called strengthening the virtual views (Enhancedvision) . There is a natural virtual views detected in real time, there is fictitious virtual views that a database produces too, the two match and fold, namely utilize the deep contour line of the fictitious virtual views to strengthen the fuzzy virtual views, including SensorVS and SVS two systems, they can strengthen the visibility [1 ] of the virtual views outside the window under the abominable meteorological condition.