Research On Coal Mine Vehicle Scheduling System Based On GPS

GPS (Global positioning system) has been applied to various fields with the rapiddevelopment of modern science and technology. A vehicle scheduling system is proposed forthe opencast coalmine in this paper. Because of the complicated mine environment inopencast coalmine, the multipath effect will be produced in the receiver when the GPS signalsare through something or with a reflex. The GPS receiver cannot keep a better performanceand an accurate positioning with the traditional method. Improving the imprecision of thereceiver can ensure the vehicle traveling safety when traveled in mountain environment.First of all, GPS positioning system in opencast coalmine environment for precisepositioning of the application is introduced in this paper; the structure and the function of thecoal mine dispatching system are stated simply. The system of the whole receiver is designed,and every part of the hardware in the receiver is designed and described in detail.After the introduction of the GPS signal format, the signal’s baseband processingalgorithm which includes the signal catching, tracking, bit synchronizing and framesynchronizing is mainly studied. The GPS satellite signals which created by Matlab softwarehave the same characteristic with the signals collected from the logic analyzer. Theimplementation processes of hardware are introduced in this paper, and then contrasted withthe results of Matlab simulation to verify the validity and practicability of the algorithm.Finally, in view of the multipath effect of the GPS vehicle scheduling receiver in theopencast coalmine environment, an immune algorithm which estimates the multipath signalsfrom the composite signals is presented this paper. According to the correlation properties ofthe C/A (Coarse Acquisition) code, a mathematics model which includes the direct pathsignals and the multipath signals is established. The correlation between the composite signalsand the local signals shows the characteristic of the direct path and the multipath signals.According to the principle of immune algorithm, the parameters of the model can be figuredout when the multipath signal is approached to the optimal model. Restraining the multipath signals by using immune algorithm can estimate the direct path signals and multipath signals,and eliminate the disturbance of the multipath effect. In the situation of the short time delaymultipath, eliminating the multipath signal can improve the measurement precision of thepseudo range, and enhance the precision of the GPS positioning. Therefore, it is veryimportant to research the precise positioning of GPS vehicle scheduling in the opencastcoalmine environment.