Patent ID: 8401788

Claim:
An angular velocity sensor correcting apparatus, including a processor and a memory storing a program for execution by the processor, the program comprising: an obtaining module for obtaining measurement data of an object measured on the basis of a signal from a GPS satellite, and for obtaining angular velocity of the object output from an angular velocity sensor; an estimating module for estimating a running condition of the object on the basis of the measurement data and the angular velocity obtained by the obtaining module; an offset value deriving module to sequentially derive a temporary offset value of the angular velocity sensor while changing combination of the measurement data and the angular velocity obtained by the obtaining module in accordance with the running condition of the object estimated by the estimating module; and an offset value filter process module operative to derive an offset value of the angular velocity sensor for correcting the angular velocity output from the angular velocity sensor by executing a statistical process on the temporary offset value of the angular velocity sensor, the temporary offset value sequentially derived by the offset value deriving module, wherein the estimating module estimates that the running condition of the object is either a first state, in which the object stops or runs straight, or a second state, wherein the offset value deriving module sequentially derives a temporary offset value of the angular velocity sensor on the basis of the angular velocity obtained by the obtaining module when the estimating module estimates that the running condition of the object is the first state, and the offset value deriving module sequentially derives the temporary offset value of the angular velocity sensor on the basis of the measurement data and the angular velocity obtained by the obtaining module when the estimating module estimates that the running condition of the object is the second state, and wherein the offset value filter process module changes a forgetting factor in the statistical process in accordance with the running condition of the object estimated by the estimating module, and the offset value filter process module uses a forgetting factor by which influence of the temporary offset value obtained in the past, in derivation of the offset value of the angular velocity sensor in the first state becomes smaller than that in the second state in the statistical process.