Miniaturized inertial measurement unit and associated methods
First Claim
1. An inertial measurement unit comprising:
- a base comprising a plurality of physically distinct sectors;
three sets of angle rate sensors orientable triaxially in a first direction, each set mounted on a different sector of the base orientable normal to the other two and comprising N gyroscopes oriented at 360/N-degree increments, where N≧
2;
three sets of angle rate sensors orientable triaxially in a second direction opposite the first direction, each set mounted on a different sector of the base orientable normal to the other two and comprising N gyroscopes oriented at 360/N-degree increments, where N≧
2;
at least one accelerometer positioned on the base adapted to provide six signals, three of the signals containing triaxial accelerometer data and three of the signals containing data for determining inclination; and
means for outputting signals from the six sets of angle rate sensors and the accelerometer to a processor for calculating at least one of a change in attitude, a change in position, a change in angular rate, a change in velocity, and a change in acceleration of the unit over a plurality of finite time increments.
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Accused Products
Abstract
A self-contained, integrated micro-cube-sized inertial measurement unit is provided wherein accuracy is achieved through the use of specifically oriented sensors, the orientation serving to substantially cancel noise and other first-order effects, and the use of a noise-reducing algorithm such as wavelet cascade denoising and an error correcting algorithm such as a Kalman filter embedded in a digital signal processor device. In a particular embodiment, a pair of three sets of angle rate sensors are orientable triaxially in opposite directions, wherein each set is mounted on a different sector of a base orientable normal to the other two and comprising N gyroscopes oriented at 360/N-degree increments, where N≧2. At least one accelerometer is included to provide triaxial data. Signals are output from the angle rate sensors and accelerometer for calculating a change in attitude, position, angular rate, acceleration, and/or velocity of the unit.
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Citations
24 Claims
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1. An inertial measurement unit comprising:
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a base comprising a plurality of physically distinct sectors; three sets of angle rate sensors orientable triaxially in a first direction, each set mounted on a different sector of the base orientable normal to the other two and comprising N gyroscopes oriented at 360/N-degree increments, where N≧
2;three sets of angle rate sensors orientable triaxially in a second direction opposite the first direction, each set mounted on a different sector of the base orientable normal to the other two and comprising N gyroscopes oriented at 360/N-degree increments, where N≧
2;at least one accelerometer positioned on the base adapted to provide six signals, three of the signals containing triaxial accelerometer data and three of the signals containing data for determining inclination; and means for outputting signals from the six sets of angle rate sensors and the accelerometer to a processor for calculating at least one of a change in attitude, a change in position, a change in angular rate, a change in velocity, and a change in acceleration of the unit over a plurality of finite time increments. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method of making an inertial measurement unit comprising the steps of:
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providing a base comprising a plurality of physically distinct sectors, the sectors foldable relative to each other; orienting a first angle rate sensor in a first direction on a first sector of the base and a second angle rate sensor in a second direction opposite the first direction on the first base sector; orienting a third angle rate sensor in the first direction on a second sector of the base and a fourth angle rate sensor in the second direction on the second base sector; orienting a fifth angle rate sensor in the first direction on a third sector of the base and a sixth angle rate sensor in the second direction on the third base sector; wherein each angle rate sensor comprises N gyroscopes oriented at 360/N-degree increments, where N≧
2;folding the first, the second, and the third base sectors relative to each other so as to be relatively normal to each other; positioning at least one accelerometer on the base, the accelerometer adapted to provide six signals, three of the signals containing triaxial accelerometer data and three of the signals containing data for determining inclination; and outputting signals from the angle rate sensors and the accelerometer; and calculating from the output signals at least one of a change in attitude, a change in position, a change in angular rate, a change in velocity, and a change in acceleration of the unit over a plurality of finite time increments. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
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Specification