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Method for correction of dynamic output signals of inertial sensors having mounting offsets

  • US 8,639,415 B2
  • Filed: 08/24/2009
  • Issued: 01/28/2014
  • Est. Priority Date: 08/25/2008
  • Status: Active Grant
First Claim
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1. A method for compensating an axial accelerometer output for use in a vehicle control system, comprising the steps of:

  • (a) providing an axial accelerometer at a first location that is different from a vehicular center of gravity location, the first location defining a moment arm from an axis of a vehicle center of gravity coordinate system to the axial accelerometer, the moment arm being defined from the first location and is perpendicular to a plane that includes one of the x, y, and z axes of the vehicle center of gravity coordinate system that corresponds to the axis of rotational movement as measured by the angular rate sensor, also providing at least one angular rate sensor, and further providing a control module that is in communication with the axial accelerometer and the angular rate sensor, the control module further being operative to compensate an output signal generated by the axial accelerometer, the control module including an algorithm, the algorithm having an operation to compute the rate of change of the angular rate sensor output signal in step (d) as dω

    /dt where ω

    is an angular velocity of at least one of the yaw, roll, and pitch rotational movement, the algorithm further having an operation to compensate the axial accelerometer output by a term of (ω

    2 R) and ((dω

    /dt)R) where R is the inertial sensor moment arm defined from the first location that is perpendicular to a plane that includes one of the x, y, and z axis of the vehicle center of gravity coordinate system that corresponds to the axis of rotational movement as measured by the angular rate sensor, the operation to compensate the axial accelerometer output is in the form of an equation;


    acorrected=ameasured

    ω

    2R

    (

    /dt
    )R;

    (b) sensing an acceleration at the first location with the axial accelerometer and generating an output signal that is proportional to the acceleration;

    (c) sensing a rate of change of a rotational movement about at least one axis of the vehicular center of gravity coordinate system with the angular rate sensor, the angular rate sensor generating an angular rate sensor output signal that is proportional to the rate of change of the rotational movement; and

    (d) the control module receiving the axial accelerometer output signal and the angular rate sensor output signal, the control module being responsive to the angular rate sensor output signal to calculate an angular acceleration, such that the control module determines a correction factor that is proportional to the moment arm and the angular acceleration and modifies the axial accelerometer output signal in response to the correction factor.

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