Micromachined rate and acceleration sensor
First Claim
1. A substrate for use in an acceleration and angular rate sensor comprising:
- first and second accelerometers formed in said substrate, said first and second accelerometers having generally parallel force sensing axes;
a dither frame formed in said substrate;
mounting means formed in said substrate for mounting said first and second accelerometers to said dither frame, said mounting means adapted to allow said first and second accelerometers to dither along a dither axis, said dither axis being perpendicular to said force sensing axes of said first and second accelerometers;
a linking means interconnecting said first and second accelerometers for allowing said first and second accelerometers to dither at the same frequency; and
said linking means further providing means for imparting a reaction force on said first accelerometer along said dither axis when an action force is imparted on said second accelerometer along said dither axis, said action and reaction forces being of substantially equal magnitude and being oppositely directed.
4 Assignments
0 Petitions
Accused Products
Abstract
A sensor (10) is disclosed for measuring the acceleration and angular rotation rate of a moving body and is micromachined from a silicon substrate (16). First and second accelerometers (32a and b) are micromachined from the silicon substrate (16), each having a force sensing axis (38) and producing an output signal of the acceleration of the moving body along its force sensing axis (38). The first and second accelerometers (32a and b) are mounted within the substrate (16) to be moved along a vibration axis (41). The first and second accelerometers (32a and b) are vibrated or dithered to increase the Coriolis component of the output signals from the first and second accelerometers (32a and b). A sinusoidal drive signal of a predetermined frequency is applied to a conductive path (92) disposed on each of the accelerometers. Further, magnetic flux is directed to cross each of the conductive paths (92), whereby the interaction of the magnetic flux and of the drive signal passing therethrough causes the desired dithering motion. A link (72) is formed within the silicon substrate (16) and connected to each of the accelerometers (32a and b), whereby motion imparted to one results in a like, but opposite motion applied to the other accelerometer (32). Further, a unitary magnet (20) and its associated flux path assembly direct and focus the magnetic flux through the first and second accelerometers (32a and b) formed within the silicon substrate (16).
-
Citations
21 Claims
-
1. A substrate for use in an acceleration and angular rate sensor comprising:
-
first and second accelerometers formed in said substrate, said first and second accelerometers having generally parallel force sensing axes; a dither frame formed in said substrate; mounting means formed in said substrate for mounting said first and second accelerometers to said dither frame, said mounting means adapted to allow said first and second accelerometers to dither along a dither axis, said dither axis being perpendicular to said force sensing axes of said first and second accelerometers; a linking means interconnecting said first and second accelerometers for allowing said first and second accelerometers to dither at the same frequency; and said linking means further providing means for imparting a reaction force on said first accelerometer along said dither axis when an action force is imparted on said second accelerometer along said dither axis, said action and reaction forces being of substantially equal magnitude and being oppositely directed. - View Dependent Claims (2, 3, 4, 5)
-
-
6. A generally planar monolithic substrate for use in an acceleration and angular rate sensor comprising:
-
first and second accelerometers formed in said substrate, said first and second accelerometers having generally parallel linear force sensing axes for measuring linear acceleration therealong, each of said first and second accelerometers having a proof mass, a support frame, and at least one flexure connecting said proof mass to said support frame; a dither frame formed in said substrate; a first pair of substantially parallel mounting flexures formed in said substrate and connecting said support frame of said first accelerometer to a first side of said dither frame, said first pair of substantially parallel mounting flexures adapted to allow said first accelerometer to dither along a first dither axis, said first dither axis being perpendicular to said force sensing axes of said first and second accelerometers; and a second pair of substantially parallel mounting flexures formed in said substrate and connecting said support frame of said second accelerometer to a second side of said dither frame, said second pair of substantially parallel mounting flexures adapted to allow said second accelerometer to dither along a second dither axis. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
Specification