Design Of Highway Overrun Detection System

In recent years, with the rapid development of highway system, over-loading is becoming more and more common. As a major part of road control, the over-loading detection system plays an important role in the highway overrun governance. According to the survey, many domestic gauge stations still use static platform scales to measure overloading vehicles, which have to cease on the scale to waiting for the overrun test. It leads to a very low efficiency of weighing and seriously interface with traffic order. Based on the discussion of overrun vehicles, this paper will transform over-loading detection system used in the highway gauge station.Firstly, after investigation of existing hardware in gauge station, this paper proposed an improvement program which will prove to be feasible in the following.Then, after determine the improvement program, this paper designed hardware and software parts of weighing instrumentation. The hardware part is divided into several modules, include the microprocessor circuit of minimum system, the sensor signal acquisition circuit, digital processing circuits, communications interface circuits, keyboard circuits, display circuits, alarm circuits and power circuits. In addition, because of the lots of disturbing factors in gauge station, this paper designed special protect circuits for power circuit and the sensor signal acquisition circuit. Software parts are also divided into several modules. It brings great convenience for programming staff to understand and design. All action of hardware is packaged into separate function. Therefore, software programmer can design the software program with little knowledge of hardware. The ideal of module makes system more clearly. It is very easy for other people to understand the whole software system.Finally, the paper introduced wavelet transform to process sampled data. As the improvement of traditional Fourier transform algorithm, the wavelet algorithm can remove the high-frequency interference effectively while retaining useful information in the aspect of handling non-stationary signal. Then, this paper used the slope of weighing data to distinguish the axles of a vehicle.After a lot of reliability testing for instrumentation, the detection system has been proved to be very accurate. This instrumentation has been successfully used in many gauge stations.