Patent ID: 8758275

Claim:
A moving body attitude angle processing apparatus for estimating an attitude angle of a moving body in accordance with outputs from an acceleration sensor, a magnetic sensor, and a gyro sensor that are mounted to the moving body, and for outputting the attitude angle thus estimated, the moving body attitude angle processing apparatus comprising: a gyro sensor that outputs an angular velocity vector; an acceleration sensor that outputs an acceleration vector; a magnetic sensor that outputs a magnetic field vector of an ambient magnetic field that is different from a geomagnetic field; a movement state determining device that determines a movement state of a moving body in accordance with an output from the acceleration sensor; a gyro-sensor zero-point output estimating device that, when the movement state determining device determines the movement state to have been detected as a stationary state of the moving body, carries out a process of estimating a zero-point output of the gyro sensor in accordance with the output from the acceleration sensor, an output from the magnetic sensor, and an output from the gyro sensor, the gyro-sensor zero-point output estimating device is embodied by an extended Kalman filter having, as its components, only a gravitational acceleration vector, a magnetic field vector of the ambient magnetic field, an angular velocity vector, and an offset value of zero-point output of angular velocity by the gyro sensor, a zero point of the gyro sensor being corrected by utilizing an output from the gyro-sensor zero-point output estimating device; and an attitude angle estimating device that estimates the attitude angle in accordance with the outputs from the acceleration sensor, the magnetic sensor, and the gyro sensor.