| 摘要 |
In order to improve the accuracy of borehole survey systems utilizing probes with inertial components including inclinometers, two ring laser gyro units are included to provide rotation information 56, 58 to the system. When the probe is moving in a borehole, inclinometer information 50, 52, 54 is used 78 to produce a synthetic rotation signal 80 to take the place of a third gyro and the earth's rotation OMEGA , 68 is used 66 for a similar purpose in combination with signals from the two ring laser gyros when the probe is stopped (Vp = 0 at 74). Wire line velocity Vp, 60 is used in combination with the inclinometer and gyro information to provide signals representing the probe velocity and position (152). Coordinate transformations 64, 104, 126-130 are provided in the probe to transform the inertial signals and wire line velocity signals into earth reference coordinate system. Kalman filtering 142 incorporates non-inertial velocity data to reduce the effect of errors inherent in the generation of various input signals to the system. <IMAGE> |
