Roll angle estimation device and transport apparatus

A roll angle estimation device for estimating a roll angle of a moving body, comprising:

• first and second angular velocity detectors which detect a roll angular velocity and a yaw angular velocity respectively around first and second axes and along two mutually different directions;
• first, second, and third acceleration detectors which respectively detect first, second, and third accelerations along three mutually different directions;
• a velocity detector which detects information concerning a moving velocity of the moving body in a direction of travel of the moving body;
• and
• arithmetic circuitry configured to estimate
• a current value of the roll angle of the moving body,
• a current value of a pitch angle of the moving body,
• a current value of a pitch angular velocity of the moving body, and
• a current value of at least one offset error of the first and second angular velocity detectors and the first, second, and third acceleration detectors, based on:
• detection values of the roll angular velocity and the yaw angular velocity by the first and second angular velocity detectors;
• detection values of the first, second, and third accelerations by the first, second, and third acceleration detectors;
• a detection value of the information by the velocity detector;
• estimated previous values, from a previous estimation operation of the arithmetic circuitry, of the roll angle, the pitch angle, and the pitch angular velocity;
• and
• an estimated previous value of the at least one offset error from the previous estimation operation of the arithmetic circuitry, wherein
• the arithmetic circuitry estimates the current value of the pitch angle and the pitch angular velocity of the moving body by integrating
• d
• dt
• ⁡
• [
• θ
• ω
• p
• ]
• =
• [
• ω
• p
• (
• -
• 1
• /
• τ
• )
• *
• ω
• p
• ]
• wherein
• θ is the pitch angle,
• ωp is the pitch angular velocity,
• (l/τ) represents an exponential decay factor of the pitch angular velocity;
• wherein the arithmetic circuitry comprises a Kalman filter which estimates the estimated current values for the roll angle, the pitch angle, the pitch angular velocity and the at least one offset error, and the Kalman filter is extended by application of an observation equation that calculates a value of vertical acceleration Gz, a value of lateral acceleration Gy and a value of rear-wheel speed vr based on at least the estimated value of the pitch angle θ and the estimated value of the pitch angular velocity ωp.