The Research On GPS Location Arithmetic And Its Application In Intelligent Public Transport

GPS has great significance to IPTS and it speeds up the process of the Intelligent Management Bus. Using stand-alone GPS, the accuracy of positioning can not meet the higher requirements because of the big error caused by the system and measurement. No matter from the financial or the practical application point of view, using more expensive GPS receivers or obtaining the information form GPS reference station is difficult for large-scale promotion and application in IPTS.Kalman filtering is an effective method to eliminate the random error of the dynamic positioning data of GPS, moreover it need not set up a GPS reference station which can be avoid the sphere restrictions of the differential signal. So that it has important significance for improving the location accuracy in theory and practice. Therefore it's necessary for studying up on Kalman filter theory. This paper bases on analyzing the positioning principle and the error source of GPS, Then paper discusses the mathematical equation established by the current statistical model and positioning equation, finding out this filter function is difficult to carry out, in the other hand the real-time ability is weak and the filtering accuracy is low. In this respect, this paper takes a view from the output of the GPS receiver, at the same time adds the speed observation regarding it as a quantity of state and a bound term respectively, then the paper introduces it into kalman filter equation accordingly established routine kalman equation and kalman equation with bound term. This method can improve filtering accuracy and real-time ability, moreover it can be easy for real application.This paper, which use a hardware platform based on the FPGA module, discuss an application of the arithmetic in ITS device, containning a data acquistion and a design on kalman filter, and it espcially describes a design on DSP builder kalman filter.In the end, according to the application background about GPS used in IPTS, the paper fist introduces the application of GPS in monitoring system and explains the design and realization on monitoring platform. The software design of the system starts from the MapX form of electronic map, then a reasonable and explicit frame construction of the design is provided, and specifying the way on how to realize the function blocks of the software.