The Design Of Weigh-in-motion System Based ARM

The Weigh-In-Motion is weighing equipment for bulk cargo and usedwidely in transportation and other fields. With the development of rapideconomic, transportation become more and more advanced, the generalphenomenon of vehicle overloading seriously damage our country roads, It is ofgreat significance for social security and the maintenance of traffic order that themeasurement of vehicle weight fast and accurate to avoid overloading. In recentyears, the promotion and application of ARM technology has been developedrapidly, and the concept of embedded systems used in Weigh-In-Motion design isbecoming a trend.The principle of dynamic weighing was researched in this paper. Based onthe demand for truck scale weighing accuracy and automation, combined withARM technology and embedded μC/OS-Ⅱ operating system, a newWeigh-In-Motion instrument was designed for achieving weighing vehicles onthe highway fast and accurately in the case of non-stop traffic.After analyzing the car’s state of motion and vibration causes, FIR filterwas designed for simulation. The simulation results showed that, after filteringthe signal acquired from the sensor, peak to peak was significantly improved,3Hz frequency noise was effectively filtered, and measurement accuracy wasgreatly improved.S3C2440microcontroller was the core of the system and each unit of thehardware circuit of the controller were designed specifically. It was mainlyrelated to the detailed design of the unit circuit such as power supply module,data acquisition module, communication module, memory module,human-machine interaction module and so on. Appropriate measures were takenfor avoiding the interference of the system, which provided a platform for thedevelopment of software systems. In order to meet the requirements of the dynamic weighing system,μC/OS-Ⅱ operating system with strong real-time was chosen as the softwareplatform and transplantation of μC/OS-Ⅱ operating system on themicrocontroller was achieved. Corresponding to the working process of dynamicweighing, the software design was divided into seven tasks on the basis of thehardware, and the design method and process of each task was described indetail. Besides, the priority of each task was divided. Finally, through datacollection, vehicle identification and data processing, the information of loadaxis, the number of tires, speed, and vehicle arrival state was displayed on theLCD.