Evaluation of in-vehicle GPS-based lane position sensing for preventing road departure

The dynamic performance of the Novatel RT-20 differential global positioning systems (DGPS) unit is quantified based on a series of dynamic tests carried out on the RT-20 to verify its actual accuracy while on a moving vehicle. The approach adopted incorporates synchronized data acquisition using two separate computer systems, and experimental verification of the computational latency of the RT-20. The image processing scheme achieved high accuracy by taking advantage of sub-pixel resolution in the image processing algorithm. The RT-20 system exhibited a mean error of 2.03 cm in the longitudinal direction while moving at speeds ranging from 15 mph through 40 mph. The corresponding error standard deviations were 1.98 cm and 34.87 cm respectively.