LiDAR-car Navigation System Based On The Odometer

Vehicle-borne LiDAR system is Modern mapping equipment with laser ranging technology, computer technology, GNSS positioning technology, inertial navigation technology (INS), CCD technology and other high-tech. It has the characteristics of fewer ground control point, higher degree of automation, shorter operating cycle and so on. As high mobility, low cost, Vehicle-borne LiDAR has been widely used in3D data acquisition rapid emergency response, road assets census and three-dimensional modeling of digital city.The accuracy of the vehicle-borne LiDAR is influenced by many factors. In addition to the laser ranging angle error, IMU attitude error, sensor offset vector error and other system errors, the greatest impact is the combination navigation accuracy decline with signal failure of GPS caused by the complexity of the urban environment. Based on a combination of navigation accuracy decreased with the case of GPS signal failure, this articles study on performance of integrated navigation impact by DMI (Distance measuring instrument), the contents as follows:1. DMI Construction Technology based on the Hall element.As one of the most important navigation senor, DMI primarily records the mileage of the vehicle. The Hall proximity switch is mounted on the vehicle body as a stator, the magnetic mounted on the hub as a rotor. The Hall DMI pulse equivalent and vector offset relative to the IMU is calibrated on experiment.2. The application of DMI in Integrated Navigation.The impact on Plane accuracy and images posture and other aspects of DMI are analyzed through experiments, concluded as follows:A high resolution DMI is superior to the low resolution one in a certain extent; loss of lock for two minutes, the system accuracy of LiDAR vehicle with DMI plane deviation can be controlled within0.6m; while the DMI have some effect on the image posture correction.3. Methods to improve navigation accuracy In actual operation process, some special methods are needed to improve the accuracy of Vehicle-borne LiDAR integrated navigation. The experiment proved that zero speed by DMI correction, control track drift by track points and so on, can effectively control navigation accuracy when the GPS loss of lock. To some extent, data acquisition route planning can also ensure data accuracy and improve operating efficiency.