×

Micromachined rate and acceleration sensor

  • US 5,557,046 A
  • Filed: 03/07/1994
  • Issued: 09/17/1996
  • Est. Priority Date: 02/08/1991
  • Status: Expired due to Fees
First Claim
Patent Images

1. A sensing device for measuring the linear acceleration and rate of rotation of a moving body, comprising:

  • a monolithic substrate having first and second substantially planar surfaces disposed substantially parallel to each other;

    first and second accelerometers formed of said substrate, each of said accelerometers having a force sensing axis for producing an output signal indicative of the acceleration of the moving body along said force sensing axis, each of said accelerometers further havingan accelerometer frame,a proof mass,hinge means interconnected between said frame and said proof mass for allowing said proof mass to rotate about a hinge axis when the moving body is subjected to a force along said force sensing axis, said proof mass having a first end interconnected by said hinge means to said frame and a free end permitted to rotate freely about said hinge axis with respect to said frame, said proof mass further having a center of gravity and a pendulous axis aligned to intersect said center of gravity and said hinge axis;

    flexible means interconnected between said frame and said free end of said proof mass for flexibly restraining the pivoting of said proof mass about said pendulous axis;

    a dither frame;

    flexure means for connecting the accelerometer frame of each of said first and second accelerometers to said dither frame, said flexure means being generally compliant to allow dithering of said first and second accelerometers along a dither axis, said dither axis being generally perpendicular to said force sensing axes of said first and second accelerometers;

    a conductive dither path disposed along at least said flexure means;

    means for directing a magnetic flux to cross the conductive dither path;

    signal generator means for producing and applying to said conductive dither path a periodic dither drive signal to dither said first and second accelerometers along said dither axis;

    a unitary magnet for emanating flux from first and second surfaces thereof, and magnetic circuit means for establishing a flux path between said second surface of said monolithic substrate and said second surface of said unitary magnet, said magnetic circuit means including a portion disposed adjacent said second planar surface of said monolithic substrate, said magnetic circuit portion concentrating said magnetic flux through said conductive dither path.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×