Automatic continuous nulling of angular rate sensor
First Claim
1. A device for generating a signal representing the angular rate of motion of a body, comprising:
- a first accelerometer having a first force sensing axis and being adapted to produce a first output signal indicative of acceleration along the first force sensing axis;
a second accelerometer having a second force sensing axis and being adapted to produce a second output signal indicative of acceleration along the second force sensing axis;
mounting means for mounting the first and second accelerometers such that their force sensing axes are both parallel to a common sensing axis and such that the accelerometers can be moved along a vibration axis normal to the sensing axis;
signal generator means for producing a periodic drive signal having a predetermined frequency;
drive means connected to the mounting means and responsive to the drive signal for vibrating the first and second accelerometers along the vibration axis at said predetermined frequency; and
signal processing means connected to receive the first and second output signals and adapted to generate a Coriolis signal representing the Coriolis acceleration along the sensing axis resulting from movement of the accelerometers along the vibration axis and rotation of the body about a rate axis normal to the vibration axis and to the sensing axis, the signal processing means including detection means connected to receive the Coriolis signal and to produce a feedback signal that is a function of those components of the Coriolis signal that are in phase with respect to the drive signal, the drive means including means for combining the feedback signal with the drive signal such that said components are driven towards a null value.
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Accused Products
Abstract
An angular rate sensor comprising a pair of accelerometers that includes means for continuously nulling error signals resulting from misalignment of the accelerometers. The first accelerometer (10) has a first force sensing axis and produces a first output signal (a1) indicating acceleration along the first force sensing axis. The second accelerometer (12) has a second force sensing axis and produces a second output signal (a2) indicating acceleration along the second force sensing axis. The accelerometers are mounted by mounting means such that their force sensing axes are both parallel to a common sensing axis and such that the accelerometers can be moved along a vibration axis normal to the sensing axis. A signal generator (76) produces a periodic deive signal having a predetermined frequency, and drive means (80, 82, 84) connected to the mounting means is responsive to the drive signal for vibrating the first and second accelerometers along the vibration axis at the predetermined frequency. Signal processing means (104) receives the first and second output signals and generates a Coriolis signal representing the Coriolis acceleration along the sensing axis resulting from movement of the accelerometers along the vibration axis and rotation of the body about a rate axis normal to the vibration axis and to the sensing axis. The signal processing means includes the detection means (92) that receives the Coriolis signal and produces a feedback signal that is a function of those components of the Coriolis signal that are in phase with respect to the drive signal. The drive means includes means (80) for combining the feedback signal with the drive signal, such that the in phase components are continuously driven towards a null value.
52 Citations
16 Claims
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1. A device for generating a signal representing the angular rate of motion of a body, comprising:
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a first accelerometer having a first force sensing axis and being adapted to produce a first output signal indicative of acceleration along the first force sensing axis; a second accelerometer having a second force sensing axis and being adapted to produce a second output signal indicative of acceleration along the second force sensing axis; mounting means for mounting the first and second accelerometers such that their force sensing axes are both parallel to a common sensing axis and such that the accelerometers can be moved along a vibration axis normal to the sensing axis; signal generator means for producing a periodic drive signal having a predetermined frequency; drive means connected to the mounting means and responsive to the drive signal for vibrating the first and second accelerometers along the vibration axis at said predetermined frequency; and signal processing means connected to receive the first and second output signals and adapted to generate a Coriolis signal representing the Coriolis acceleration along the sensing axis resulting from movement of the accelerometers along the vibration axis and rotation of the body about a rate axis normal to the vibration axis and to the sensing axis, the signal processing means including detection means connected to receive the Coriolis signal and to produce a feedback signal that is a function of those components of the Coriolis signal that are in phase with respect to the drive signal, the drive means including means for combining the feedback signal with the drive signal such that said components are driven towards a null value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification