# US 10,480,943 B2 · Systems and methods for noise and drift calibration using dithered calibration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,943 B2 - Document ID: US10480943B2 - Status: Granted - Kind: B2 - Application number: 15/366,971 - Filed: 2016-12-01 - Published: 2018-04-05 - Granted: 2019-11-19 - Earliest claimed: 2016-02-04 - Assignees: Honeywell International Inc. - Applicants: Honeywell International Inc. - Inventors: Daniel Endean; Grant Lodden; John Reinke - Web page: https://patentgrep.com/patent/US10480943B2 ## CPC - G01C 19/5776: Signal processing not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719 - G01C 19/5691: of essentially three-dimensional [3D] vibrators, e.g. wine glass-type vibrators - G01C 19/5783: Mountings or housings not specific to any of the devices covered by groups G01C19/5607 - G01C19/5719 - G01C 25/005: {initial alignment, calibration or starting-up of inertial devices} - G01R 33/0017: {Means for compensating offset magnetic fields or the magnetic flux to be measured; Means for generating calibration magnetic fields} - G01R 35/005: {Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references (G01R33/0035, G01R35/002 take precedence)} - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract Systems and methods for noise and drift calibration using dithered calibration, a system comprising a processing unit; and two or more dithered calibrated sensors that provide directional measurements to the processing unit, wherein a dithered calibrated sensor in the dithered calibrated sensors has an input axis that rotates about an axis such that bias error can be removed by the processing unit; wherein the dithered calibrated sensor provides a zero-bias measurement along a first axis and a low-noise measurement along a second axis, the second axis being orthogonal to the first axis; wherein the dithered calibrated sensors are arranged such that the dithered calibrated sensor provide low-noise and zero-bias measurements along the measured axes; and wherein the processing unit executes an algorithm to combine measurements that are along the same axis to produce a measurement for each measured axis that has both low-noise and zero-bias. ## Claims ### Claim 1 A system for providing low-noise and low-bias measurements, the system comprising: a processing unit; and two or more dithered calibrated sensors that provide directional measurements to the processing unit, wherein a dithered calibrated sensor in the two or more dithered calibrated sensors has an input axis that rotates about an axis such that bias error can be removed by the processing unit; wherein the dithered calibrated sensor provides a zero bias measurement along a first axis and a low noise measurement along a second axis, the second axis being orthogonal to the first axis; wherein the two or more dithered calibrated sensors are arranged with respect to each other such that the first axis of a first dithered calibrated sensor in the two or more dithered calibrated sensors is aligned with the zero-bias measurement of a second dithered calibrated sensor in the two or more dithered calibrated sensors; and wherein the processing unit executes an algorithm to combine measurements produced by the two or more dithered calibrated sensors that are along the same axis to produce a measurement for each measured axis that has both low-noise and zero-bias, wherein the measurement is produced by combining the low-noise measurement from the first dithered calibrated sensor with the zero-bias measurement from the second dithered calibrated sensor. ### Claim 2 (depends on 1) The system of claim 1, wherein the two or more dithered calibrated sensors are at least one of: inertial sensors; magnetometers; electric field sensors; and velocity sensors. ### Claim 3 (depends on 1) The system of claim 1, wherein the low-noise and zero-bias measurements are passed through a low pass filter to produce a simple moving average for the low-noise and zero-bias measurements. ### Claim 4 (depends on 1) The system of claim 1, further comprising an in-plane rotator configured to dither the two or more dithered calibrated sensors about a respective axis. ### Claim 5 (depends on 1) The system of claim 1, wherein the two or more dithered calibrated sensors comprise at least one set of three sensors that are arranged to provide the low-noise measurements and the zero-bias measurements in three directions/measurement axes. ### Claim 6 (depends on 1) The system of claim 1, wherein a dithered calibrated sensor in the two or more dithered calibrated sensors measures two different quantities simultaneously. ### Claim 7 (depends on 6) The method of claim 6, wherein the two different quantities include acceleration and rotation. ### Claim 8 A method for providing low-noise and low-bias measurements, the method comprising: mounting two or more dithered calibrated sensors within a package; coupling the two or more dithered calibrated sensors to a processing unit, wherein the dithered calibrated sensors provide directional measurements to the processing unit; dithering each dithered calibrated sensors in the two or more dithered calibrated sensors rotationally about a rotation axis such that each dithered calibrated sensor provides a low-noise measurement along a first axis and a zero-bias measurement along a second axis, wherein the second axis is orthogonal to the first axis, wherein the first axis of a first dithered calibrated sensor in the two or more dithered calibrated sensors is aligned with the second axis of a second dithered calibrated sensor in the two or more dithered calibrated sensors; and processing the measurements from the two or more dithered calibrated sensors such that low-noise and zero-bias measurements are produced for the axes measured by the two or more dithered calibrated sensors, wherein a low-noise and zero-bias measurement is produced by combining the low-noise measurement from the first dithered calibrated sensor with the zero-bias measurement from the second dithered calibrated sensor. ### Claim 9 (depends on 8) The method of claim 8, wherein the two or more dithered calibrated sensors are at least one of: inertial sensors; magnetometers; electric field sensors; and velocity sensors. ### Claim 10 (depends on 8) The method of claim 8, further comprising passing the low-noise and zero-bias measurements through a low pass filter to produce a simple moving average for the low-noise and zero-bias measurements. ### Claim 11 (depends on 8) The method of claim 8, wherein the two or more dithered calibrated sensors comprise at least one set of three sensors that are arranged to provide the low-noise measurements and the zero-bias measurements in three dimensions. ### Claim 12 (depends on 8) The method of claim 8, wherein a dithered calibrated sensor in the two or more dithered calibrated sensors measures two different quantities simultaneously. ### Claim 13 (depends on 12) The method of claim 12, wherein the two different quantities include acceleration and rotation. ### Claim 14 A sensor assembly, the sensor assembly comprising: two or more dithered calibrated sensors that provide directional measurements to a processing unit, wherein a dithered calibrated sensor in the two or more dithered calibrated sensors has an input axis that rotates about an axis such that bias error can be removed by the processing unit; wherein the two or more dithered calibrated sensors are arranged with respect to each other such that a low-noise measurement axis of a first dithered calibrated sensor in the two or more dithered calibrated sensors is aligned with a zero-bias measurement axis of a second dithered calibrated sensor in the two or more dithered calibrated sensors; and wherein the processing unit executes an algorithm to combine measurements produced by the two or more dithered calibrated sensors that are along the same axis to produce a measurement for each measured axis that has both low-noise and zero-bias, wherein the measurement is produced by combining a low-noise measurement by the first dithered calibrated sensor along the low-noise measurement axis and the zero-bias measurement by the second dithered calibrated sensor along the zero-bias measurement axis. ### Claim 15 (depends on 14) The sensor assembly of claim 14, wherein the low-noise and zero-bias measurements are passed through a low pass filter to produce a simple moving average for the low-noise and zero-bias measurements. ### Claim 16 (depends on 14) The sensor assembly of claim 14, further comprising an in-plane rotator configured to dither the two or more dithered calibrated sensors about a respective axis. ### Claim 17 (depends on 14) The sensor assembly of claim 14, wherein the two or more dithered calibrated sensors comprise at least one set of three sensors that are arranged to provide the low-noise measurements and the zero-bias measurements in three dimensions. ### Claim 18 (depends on 14) The sensor assembly of claim 14, wherein a dithered calibrated sensor in the two or more dithered calibrated sensors measures two different quantities simultaneously. ### Claim 19 (depends on 18) The sensor assembly of claim 18, wherein the two different quantities include acceleration and rotation. ### Claim 20 (depends on 14) The sensor assembly of claim 14, wherein the two or more dithered calibrated sensors are at least one of: inertial sensors; magnetometers; electric field sensors; and velocity sensors.