Calculation of Vehicle Real-time Position Overcoming the GPS Positioning Latency with MEMS INS

GPS (Global Positioning System) always has the problem of positioning latency which make it can't output the real-time position. Different GPS may have different latencies. The positioning latency of consumer-grade GPS often used in vehicles is especially relatively larger. In this paper, we present a method to calculate the vehicle real-time position overcoming the GPS positioning latency with low-cost MEMS (Micro-Electro-Mechanical System) INS (Inertial Navigation System). We compute the latency through comparing the degree of correlation between the velocity difference time series obtained from the GPS output and the acceleration time series outputted by the accelerometer. Then fuse the GPS/INS data according to the latency in order to improve accuracy for the position that has been outputted by the GPS, and estimate the vehicle real-time with the acceleration time series outputted in the latency. At last, a neural network is established to correct the estimated position to reduce the error. Meanwhile, a GPS/INS data synchronization method is presented for the GPS which can't output 1 pps (Pulse Per Second) signal. The experimental results show the methods can calculate the accurate vehicle real-time eliminating the positioning error caused by the GPS latency. The methods achieve a good effect.