Precision Od Measurement Precision Study

In recent years land vehicles such as ground-ground missile-launching vehicle, increased distance gun, command vehicle, reconnaissance vehicle etc call for enhancing precision of position and azimuth determining system. At the same time it emphasized in cutting time and reducing cost. The typical inertial navigation system of zero velocity update is difficult to satisfy all above requirements. Global position system (GPS) is not completely reliable in autonomy and anti-jamming ability. So traditional dead reckoning system makes reassess option. Dead reckoning system is not exist in positioning error with time increasing by gyro drift. It adapts to use in land vehicle navigation. Precision of this system is dependent on velocity precision of high-precision OD and precision of heading angle pitch angle by inertial measurement system. The aim of this thesis discusses velocity precision of high-resolution OD.Resolution of high-resolution OD can reach to 1.5mm/p. Noise can also be superior to ±6 pulse. But relative precision of OD scale factor is influenced by tire temperature, pressure and surface abrasion etc. It can only reach to around 0.5%. It is the main factor to confine OD positioning. The thesis tries to use OD scaling with DGPS. Precision of OD scaling can improve one order through measurement of tire temperature field and building up OD scale factor with temperature model especially. After compensation(2000S～3600S),several straight line segment is used to assess precision of OD. The research results that distance difference measurement of OD and DGPS is only 0.4m(1 σ).The thesis discusses influence of OD scale factor when the vehicle accelerates and decelerates. Furthermore, the fault detection such as slip etc and disposal methods for OD are analyzed briefly.