Angular rate sensor utilizing two vibrating accelerometers secured to a parallelogram linkage
AssigneeSundstrand Data Control, Inc.
InventorRex B. Peters
Life of this patent
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Abstract
In an inertial system for sensing the angular rotation and translational motion of a structure utilizing a pair of accelerometers in a back-to-back arrangement vibrating substantially linearly along an axis normal to their force sensing axes, a mechanism utilizing a parallelogram structure is used to impart the vibratory motion to the accelerometers.
Claims28
An apparatus for generating a signal representing the angular rate motion of a structure comprising:
- a first accelerometer having a first force sensing axis;
- a second accelerometer having a second force sensing axis;
- a parallelogram mechanism including a first accelerometer support member secured to said first accelerometer, a second accelerometer support member secured to said second accelerometer and a linkage mechanism attached to said first and said second accelerometer support members and secured to the structure such that said first and said second force sensing axes are aligned in parallel;
- drive means operatively connected to said parallelogram mechanism for vibrating said first and second accelerometer support members in a direction substantially normal to said first and second force sensing axes at a frequency .omega.;
- and
- signal processing means operatively connected to said first and second accelerometers for generating a rate signal representing the angular rate motion of the structure.
The apparatus of claim 11 wherein said first and second accelerometers are vibrating through an angle .theta. offset by an angle .PSI. from a nominal position and wherein said drive means includes adjustment means for adjusting the offset angle .PSI. to a desired value.
An angular rate sensing accelerometer structure comprising:
- a central support member;
- a first linkage member pivotably connected to one end of said central support member;
- a second linkage member pivotably connected to the other end of said central support member;
- a first accelerometer support member pivotably connected to one end of each of said first and second linkage members;
- a first accelerometer secured to said first accelerometer support member such that its force sensing axis is generally normal to said first accelerometer support member;
- a second accelerometer support member pivotably connected to said other end of each of said linkage members;
- and
- a second accelerometer secured to said second accelerometer support member such that its force sensing axis is generally normal to said first accelerometer support member and generally parallel to the force sensing axis of said first accelerometer.
A drive signal generator circuit for vibrating at least one accelerometer in an inertial measurement system at a frequency .omega. comprising:
- a periodic signal generator circuit for generating an output signal having the frequency .omega.;
- an amplifier circuit operatively connected to said periodic signal generator circuit for amplifying the output of said periodic signal generator;
- a drive element operatively connected to said accelerometer and responsive to said amplified periodic signal for vibrating the accelerometer at frequency .omega.;
- and
- feedback means responsive to the position of the accelerometer for applying a feedback signal to said amplifier circuit to control the amplitude of the vibration.
A drive signal generator circuit for vibrating at least one accelerometer at a frequency .omega. in an inertial measurement system comprising:
- a pulse generator for generating pulses at a frequency that is a function of .omega.;
- a sine wave generator circuit connected to said pulse generator and responsive to said pulses for generating a sinusoidal drive signal for a frequency .omega.;
- a high gain amplifier circuit connected to said sine wave generator for amplifying said sinusoidal drive signal;
- a drive element operatively connected to the accelerometer and said high gain amplifier and responsive to said amplified drive signal to vibrate the accelerometer at a frequency .omega.;
- feedback means including a position element for generating a feedback signal indicating the amplitude of accelerometer vibration and for applying said feedback signal to said high gain amplifier;
- and
- a vibration phase control circuit operatively connected to said sine wave generator.
A drive signal generator circuit for vibrating at least one accelerometer at a frequency .omega. in an inertial measurement system comprising:
- a pulse generator for generating pulses at a frequency that is a function of .omega.;
- a sine wave generator circuit connected to said pulse generator and responsive to said pulses for generating a sinusoidal drive signal for a frequency .omega.;
- a high gain amplifier circuit connected to said sine wave generator for amplifying said sinusoidal drive signal;
- a drive element operatively connected to the accelerometer and said high gain amplifier and responsive to said amplified drive signal to vibrate the accelerometer at a frequency .omega.;
- feedback means including a position sensing element for generating a feedback signal indicating the amplitude of accelerometer vibration and for applying said feedback signal to said high gain amplifier;
- and
- an adjustment circuit operatively connected to said high gain amplifier circuit for applying a voltage to said high gain amplifier circuit for adjusting the position of the center point about which the accelerometer vibrates.
Dependencies are inferred from the claim text.