Study On Embedded Dynamic Detection System Of Overweight Vehicle

With the vigorous development of automobile industry and the science technology, at the same time, the phenomenon of overrun and overload all over the country increases seriously. Which caused many highway traffic accidents and severely damaged roads and public facilities, also caused the PM2.5 pollution to the atmospheric environment. Dynamic vehicle weighing system is beneficial to the development of intelligent traffic control and management. In recent years, there are dozens of enterprise focusing on the dynamic weighing, the enterprises that focus on whole-vehicle-measuring method are rare, this kind of products are high precision, but the engineering cost is high and construction is difficult. Axis measurement of dynamic measurement technology is the current popular, but the precision of the domestic manufacturer is not good, use effect is poor, and the function of product is too single. Therefore, how to develop a WIM system with high precision, feature-rich, reasonable cost, has a great significance to weighing apparatus industry in China, and the improvement of traffic management.Firstly, this thesis introduces the research background of the subject and the present development situation at home and abroad, puts forward the research goal and significance. Then thesis has carried on a thorough analysis on the working principle and key difficulties of dynamic vehicle weighing. In order to make the weighing instrument has good performance, convenient function expansion, this thesis designs a embedded dynamic overweight vehicle detection system based on ARM9 and Linux. The ARM9 minimum system is the core of the whole hardware system, while the Linux kernel is the heart of the entire software system. The overall scheme of the system framework uses hierarchical design thought, is divided into hardware driver, operating system software and application software.In theoretical analysis, by means of mathematical modeling of the dynamic weighing device, thesis finds out noise components in the weighing signal, and discusses the effect of adaptive FIR filter based on LMS algorithm in the application of this system, eventually through MATLAB simulation proves that it can effectively inhibit mixed noises, helps to improve the sampling accuracy.In the design of hardware circuit, involves the construction of the overall frame, module division and interconnection. The system hardware circuit mainly includes the microprocessor minimum system, power supply circuit, AD sampling and anti-interference circuit and other auxiliary modules design. Among them, the power supply circuit module and AD sampling and anti-interference circuit module is the key of the design, the design quality of this two modules has a decisive influence on system measurement accuracy.In the design of system software, the use of the Linux operating system, can provide good multi-threaded scheduling policy and process management mechanism, easy to implement multitasking, and the kernel can be customized and stable running. This part mainly introduces the transplantation of U-boot and the Linux kernel, to complete the construction of the system software platform. Then according to the Linux driver model, to write device drivers required in the system. Finally, this thesis designs a weighing system interface combining with the embedded QT graphical library.