The Research Of Vehicle Speed Measurement Methods

Transportation is an important basic industry of economic and social development, with the national economic development of China, demand of transport is continues growing for social, the number of motor vehicles is rapidly increasing, transportation is developing rapidly. At the same time, traffic problems are becoming increasingly prominent, road safety is becoming an important factor in sustainable development of the transport industry. High speed driving is one more prominent reason in traffic accidents, so the traffic control department took a lot of methods to limit the driving speed. Detecting the speed of target vehicle with the advanced equipment, took appropriate punitive if its speed will touch or break the limit speeding is one of the more effective management methods. Therefore, it is important for sustainable development of urban transport to research the methods of measuring vehicle speed.Therefore, in this thesis we made the following research:1. We made in-depth research of vehicle speed measurement method, it including: infrared detection, laser detection, video speed, GPS satellite velocity techniques. Compared speed Measurements of the mainstream device to analyze their respective advantages and disadvantages.2. We analyzed the radar gun device working principle and features, designed DSP-based radar speed measurement equipment, used the DSP TMS320VC5402 of TI Company as the main signal processing chip, and made the MATLAB simulate with the minimum variance method, and modified covariance method, MUSIC method and other methods.3. We present a more accurate laser switching -based speed system. A-type uncertainty and the B-type uncertainty were analysis from the affect in mechanical amount of laser switches, the frequency of laser switch. Error analysis of the speed of laser-based switching system was made as the fixed length was 10m for example, calculated its standard uncertainty and combined uncertainty and other parameters to ensure the speed the system can fully meet the requirement we reduced the hardware cost of the system design stage. We designed the hardware components of the speed system based on laser switching. The laser switch emission frequency was designed as 10MHZ, we used the microcontroller Atmega8 as the core with the counter 74LS393 to count, implemented by the industrial computer WMA-825 to control the various hardware. The system was actually tested, the test results were compared with the radar gun test results, and to meet the design requirements of the system obtained the conclusions. At last by analyzing the experimental results prove that the accuracy is up to the traditional gun the accuracy is 3-5 times...