Sensor installation monitoring
First Claim
1. A method for correcting a misalignment between an inertial measurement unit (IMU) and a moving platform utilizing one or more processors and memory, the method comprising:
- identifying a first attitude of the moving platform based on an attitude truth source;
calculating a second attitude of the moving platform using IMU measurements from the IMU and global positioning system (GPS) measurements from a GPS receiver on the moving platform, the IMU being installed on the moving platform, and the GPS receiver comprising an antenna operable to receive GPS signals from one or more GPS satellites;
calculating a delta attitude from a difference between the first attitude and the second attitude;
removing natural error from the delta attitude using a first low pass filter to produce an angular misalignment value between axes of the IMU and axes of the moving platform; and
determining a total misalignment value by adding the angular misalignment value to a baseline misalignment value,updating the baseline misalignment value, the IMU incorporating the total misalignment value for subsequent attitude measurements of the moving platform in order to produce attitude measurements of the moving platform when the axes of the IMU are physically misaligned with the axes of the moving platform, therefore negating the physical misalignment between the IMU and the moving platform.
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Abstract
Technology for correcting a misalignment between an inertial measurement unit (IMU) and a moving platform is described. A first attitude of the moving platform can be identified based on a truth source. A second attitude of the moving platform can be calculated using IMU measurements. A delta attitude can be calculated from a difference between the first attitude and the second attitude. Natural error can be removed from the delta attitude to produce an angular misalignment value between axes of the IMU and axes of the moving platform. A total misalignment value can be determined by adding the angular misalignment value to a baseline misalignment value. The IMU can incorporate the total misalignment value for subsequent attitude measurements of the moving platform in order to produce substantially accurate attitude measurements of the moving platform when the axes of the IMU are misaligned with the axes of the moving platform.
71 Citations
20 Claims
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1. A method for correcting a misalignment between an inertial measurement unit (IMU) and a moving platform utilizing one or more processors and memory, the method comprising:
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identifying a first attitude of the moving platform based on an attitude truth source; calculating a second attitude of the moving platform using IMU measurements from the IMU and global positioning system (GPS) measurements from a GPS receiver on the moving platform, the IMU being installed on the moving platform, and the GPS receiver comprising an antenna operable to receive GPS signals from one or more GPS satellites; calculating a delta attitude from a difference between the first attitude and the second attitude; removing natural error from the delta attitude using a first low pass filter to produce an angular misalignment value between axes of the IMU and axes of the moving platform; and determining a total misalignment value by adding the angular misalignment value to a baseline misalignment value, updating the baseline misalignment value, the IMU incorporating the total misalignment value for subsequent attitude measurements of the moving platform in order to produce attitude measurements of the moving platform when the axes of the IMU are physically misaligned with the axes of the moving platform, therefore negating the physical misalignment between the IMU and the moving platform. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for correcting a misalignment between an inertial measurement unit (IMU) and a moving platform utilizing one or more processors and memory, the method comprising:
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calculating a current attitude of the platform using IMU measurements from the IMU and global positioning system (GPS) measurements from a GPS receiver on the moving platform, wherein the IMU and the GPS receiver are installed on the moving platform; comparing the current attitude to a known attitude of the moving platform from an attitude truth source of the moving platform in order to determine a delta attitude; removing natural error from the delta attitude to produce an angular misalignment value between axes of the IMU and axes of the moving platform; determining a total misalignment value by adding the angular misalignment value to a baseline misalignment value; and updating the baseline misalignment value, and performing attitude measurements of the moving platform using the total misalignment value, wherein the physical misalignment between the IMU and the moving platform is effectively corrected when using the total misalignment value, therefore negating the physical misalignment between the IMU and the moving platform. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A system for correcting a misalignment between an inertial measurement unit (IMU) and a moving platform, the system comprising:
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the inertial measurement unit (IMU) installed on the moving platform, wherein the IMU is operable to perform IMU measurements; a global positioning system (GPS) receiver installed on the moving platform, the GPS receiver comprising an antenna operable to receive GPS signals from one or more GPS satellites, and operable to determine GPS measurements using the GPS signals; an attitude truth source comprising a known attitude of the moving platform, and operable to provide the known attitude of the moving platform; and one or more processors and memory to; identify the known attitude of the moving platform using the attitude truth source; calculate a current attitude of the moving platform using the IMU measurements from the IMU and the GPS measurements from the GPS receiver; calculate a delta attitude from a difference between the known attitude and the current attitude; determine an angular misalignment value between axes of the IMU and axes of the moving platform using the delta attitude; identify natural error from the angular misalignment value; determine that a mean of the natural error is less than a defined threshold; determine a total misalignment value by adding the angular misalignment value to a baseline misalignment value; and updating the baseline misalignment value, the IMU incorporating the total misalignment value for subsequent attitude measurements of the moving platform in order to produce attitude measurements of the moving platform when the axes of the IMU are physically misaligned with the axes of the moving platform, therefore negating the physical misalignment between the IMU and the moving platform. - View Dependent Claims (18, 19, 20)
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Specification