Patent ID: 7747383

Claim:
An offset detecting system of an acceleration sensor, comprising: an acceleration sensor to obtain real detected acceleration corresponding to a sum of an offset variance and acceleration in a forward direction of a predetermined mobile body; calculating means for calculating a true acceleration that should be correctly detected by said acceleration sensor; offset calculating means for calculating said offset variance representing an amount that said real detected acceleration varied from the true acceleration due to a characteristic of said acceleration sensor, based on a difference between said real detected acceleration and the true acceleration; a pressure sensor to detect pressure; and moving distance calculating means for calculating a moving distance of said mobile body in a predetermined measurement time, wherein said calculating means calculates an amount of height change of said mobile body in said measurement time, based on the pressure detected by said pressure sensor, and calculates a component in said forward direction of gravity acceleration using a ratio of said moving distance to the amount of height change, and a gravity acceleration constant.