| 摘要 |
The invention provides a direction sensor and a method of calibrating a direction sensor having a relative heading sensor (14) and an absolute heading sensor (16). The method allows calibration (22) of both the relative heading sensor (14) and the absolute heading sensor (16) at the same time, by taking advantage of the known angular relationship between maxima and minima on the measurement curve of the absolute heading sensor (16). Such maxima and minima are found by rotating the sensors (12-18) through an angle of at least 360 DEG , reading the absolute and relative heading sensor outputs at numerous points and comparing each successive output. The relative heading sensor output at the minimum is subtracted from that at the maximum, and the difference divided by the known angle to arrive at a conversion constant for the relative heading sensor (14). The center and radii of the measurement curve of the absolute heading sensor (16) may be found by determining the maxima and minima of the curve in two perpendicular directions. |
