Barriers' Automatic Alarm System On Vehicle Based On ARM9 And Embedded Linux

With the development of the urbanization and prevalence of vehicle, transportation problems are getting worse and worse. In order to solve the problem of heavy traffic and increasing vehicle accidents, intelligent transportation system is introduced. As an important part of ITS, the barriers'automatic alarm system on vehicle provides drivers with a useful and practical assistant safe driving system. According to statistics, unsafe distance and fatigue driving are the immediate cause of our country's highway accidents. As shown in an European research, 50% accidents can be avoided by a five minutes early alarm to divers before the collision, while 90% accidents avoided by one minute early alarm. Obviously, it is very necessary to introduce barriers'alarm system into driving process.Barriers'alarm system is generally composed of vehicular sensors (microwave radar, laser radar, video camera and other kinds of sensor), vehicular computer and execution mechanism and so on. Firstly, the alarm system measures objects around by vehicular sensors and finds out barriers which block the car or endanger the driver. Then, vehicular computer processes the data according to the barrier situation. At last, the execution mechanism sends corresponding orders to realize the alarm function.With a reduction in the cost of optical devices and embedded computers, intelligent vehicle will take the responsibility of monitoring drivers and road condition in the next couple of years. Meanwhile, with the economic development in China, more families can afford for vehicle, which results in a huge vehicle consumer market. Therefore, barriers'automatic alarm system will have a very broad market prospects. Currently, the United States, Japan, Germany, Italy and other developed countries'research institutes have some achievement in this field. Relatively, our country has a certain gap compared with those developed countries. Now some our country's institutes are working on this field, such as Jilin University, the National Defense University and Tsinghua University.This paper is generated on the project of State Development and Reform Commission, named as Research and Industrialization Project on Vehicular Information System Based on IPV6. The main functions of this system cover acquiring real-time road image by the vehicular video camera and detecting the right, left lane divider and the barrier in the lane by image processing algorithm. Additionally, when some barriers are detected within the specified distance, the sound and light alarm signals are sent to drivers, so the driver can slow down or bypass the barrier to avoid accidents, such as the rear-end collision and so on. If the barrier is so near as to nearly have collision with vehicle, electronic braking device is used to force vehicle deceleration or stop-off so as to prevent accidents and realize assistant safe driving.Based on function analysis above, the main work of this paper is described as follows:At the aspect of overall system design, requirement analysis and feasibility analysis go first according to project requirement. With a consideration of cost and the current development of barriers'alarm system, the program is decided to build on the basis of ARM9 and embedded Linux.At the aspect of hardware, each hardware electronic circuit of modules is designed and implemented, including ARM and CAN network communication module and CAN Network module. The main steps are as follows: Firstly, according to selected chips'function, price and availability, each chip's manual is comprehended and the parameters and the interfaces are obtained to confirm whether they are suitable for the system. Secondly, the cooperative capability of each chip is analyzed, in accordance with CAN Bus norms, ARM and CAN network communication module's features and selected chips'features, then design all network nodes and develop chip communication parameters. Thirdly, the minimum circuit for each chip and the circuit for each node are designed. At last, the testing codes are programmed according to its basic function, and the basic hardware adjustment is completed.At the aspect of software, each software function modules are designed and implemented as follows.(1)Video input module: the main function is acquiring video information from road.(2)ARM master control module: the core module of the system. Including the following sub modules:Video image acquisition module, acquiring image from the video input module and saving image information in the designated buffer; video image Abstractprocessing module, processing the video images acquired, identifying the right and left lane divider and barriers in the lane, and classifying barrier; execution module, using ARM and CAN network communication module to guide the corresponding part to take action according to barrier's rank; ARM and CAN network communication module, carrying out the communication work with the CAN network through CAN controllers connected by SPI interface.(3)CAN network execution module include three sub modules, including sound alarm module and optical alarm module, which produce sound alarm and light flickering to let the driver notice the barrier in front and take the action of a corresponding slowdown or bypassing the barrier to keep traffic safety, and electronic brake module, which is used to brake and decelerate vehicle to prevent accidents happened.The innovations of the barriers'automatic alarm system are as follows:1. The system uses the electronic network to integrate the inner structure of the vehicle and has a good prospect of application.2. As the image acquisition, processing and vehicular CAN network are combined together, system can guide the execution module by different barrier situation, and realize safe assistant driving.3. A new lane divider search algorithm is proposed. The new algorithm has characteristics of simple and faster processing speed, which are validated by final system experiment.Due to time limitation, the system still needs some improvements. For example, this system is not suitable for barrier detection in a night driving condition. The following work is to realize the system's real-time function in a real vehicle environment and connect system modules with corresponding nodes on vehicle to implement the wireless function.