| 摘要 |
<p>A borehole sensor is presented including a three axis gimbal device for determining (1) a vertical plane, using the force of gravity as a reference, (2) a horizontal plane, using the force of gravity as a reference, and (3) the north direction, using the earth's magnetic field as a reference. A motor drive system drives parts of the mechanism to desired positions about the three axes, and error transducers determine the deviation from desired positions about the axes and provide feedback to the motor drive system to eliminate the error.</p> |
