| 摘要 |
<p>To accurately detect a zero gravity offset in an acceleration sensor. As an embodiment of the present invention, in the case where position information can be obtained from a GPS processing section, a velocity detecting unit performs an operation according to Expression (15), using real detected acceleration Gr that was actually obtained from the acceleration sensor, vehicle acceleration ± P based on the position information, distance Dm, an amount of height change Dh based on pressure PR, and gravity acceleration g. Therefore, offset acceleration ± o can be accurately calculated, and an acceleration detection signal can be converted into detected acceleration ± G with high accuracy, based on a zero gravity offset value Vzgo by that the above offset acceleration ± o was converted.</p> |
