DGPS를 이용한 주행차량의 정밀위치인식시스템에 관한 연구

As the first step to a DGPS-based autonomous driving system, the test ground was constructed and a DGPS RTK navigation system was developed fur the autonomous vehicle. Two sets of NovAtel DL-4 GPS receivers and Cisco-350 wireless LAN equipments were used for the DGPS test ground, and an accurate digital map for the test ground was made to provide the reference position of the vehicle. For the digital map, the test lane was measured five times using the DGPS RTK and the smooth lane data was obtained by the polynomial curve fitting. The positioning error of the traveling vehicle based on the digital map is composed of the map error and the navigation error of the vehicle.. The map error is composed of the DGPS rover setting error, measuring operation error and the inherent DGPS RTK measurement error with the curve fitting. The navigation error of the vehicle is composed of the DGPS RTK error and the GPS antenna installation error. Of course the positioning error due to latency should be examined and compensated in the autonomous system controller design later. The vehicle position was measured using the external equipments and compared with the estimated position to show the lateral positioning error of 3.2cm RMS.