×

Inertial measurement unit using rotatable MEMS sensors

  • US 7,212,944 B1
  • Filed: 05/01/2006
  • Issued: 05/01/2007
  • Est. Priority Date: 09/02/2004
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method for making an inertial measurement including the steps of:

  • a) providing a plurality of MEM inertial sensors, each of the plurality of MEM inertial sensors further comprising;

    an independently rotatable MEM stage;

    a MEM inertial sense element having a sense axis, disposed on the independently rotatable MEM stage, whereby the MEM inertial sense element is rotatable about an axis substantially perpendicular to the sense axis of the MEM inertial sense element;

    means for independently rotating the rotatable MEM stage;

    means for electrically accessing the MEM inertial sense element at least two angular positions of the independently rotatable MEM stage;

    b) setting an initial rotational position for the MEM inertial sense element of each of the plurality of MEM inertial sensors, whereby the sense axes of at least two of the MEM inertial sense elements, of the plurality of MEM inertial sensors, are not collinear;

    c) fixing each MEM inertial sense element of the plurality of MEM inertial sensors in a non-rotating state;

    d) selecting a compensating sensor from the plurality of MEM inertial sensors;

    e) initiating a rotation of the MEM inertial sense element of the selected compensating sensor, whereby the MEM inertial sense elements of the non-selected MEM inertial sensors, remain in the non-rotating state;

    f) measuring the outputs of each of the MEM inertial sense elements of the non-selected MEM inertial sensors, remaining in the non-rotating state;

    g) calculating an inertial measurement from a geometric summation of the measured outputs of each of the MEM inertial sense elements of the non-selected MEM inertial sensors, remaining in the non-rotating state;

    h) terminating the rotation of the MEM inertial sense element of the selected compensating sensor, at a rotated position, rotatably displaced up to 360 degrees, from an initial position of the MEM inertial sense element of the selected compensating sensor;

    i) resetting the initial position of the MEM inertial sense element of the selected compensating sensor, to correspond to the rotated position of the MEM inertial sense element of the selected compensating sensor;

    j) fixing each MEM inertial sense element of the plurality of MEM inertial sensors in a non-rotating state; and

    ,k) repeating steps d through j, whereby the calculated inertial measurement is compensated over time for a bias of each MEM inertial sense element of the plurality of MEM inertial sensors.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×