| 摘要 |
<p>A self guided vehicle employs a highly accurate velocity sensor (12) to determine vehicle speed and position. The velocity sensor (12) includes a resolver (14) connected to and rotatable with a ground engaging wheel (16). A resolver to digital converter (R/D) (18) provides a highly accurate 8-bit digital signal representative of the angle of wheel rotation. A second less expensive and less accurate velocity sensor (66) also receives the modulated sine and cosine signals from the resolver (14) and produces a series of pulses representative of vehicle speed. The pulses are produced by detecting the zero crossings of the sine, cosine, and combinations of the sine and cosine signals. The velocity information present in the second velocity sensor signal is not used to actually guide the vehicule, but merely to generally validate the information present in the R/D signal.</p> |
