System and method for calibrating sensors for different operating environments

• US 9,316,513 B2
• Filed: 01/08/2013
• Issued: 04/19/2016
• Est. Priority Date: 01/08/2012
• Status: Expired due to Fees

• Current Assignee: Sensor Platforms, Incorporated (Knowles Corporation)
• Original Assignee: Sensor Platforms, Incorporated (Knowles Corporation)
• Inventors: Joseph, Benjamin E., Chen, Ian, Steele, James V., Shaw, Kevin A
• Primary Examiner(s): Lau, Tung S
• Application Number:
  US13/736,570
• Publication Number:
  US 20130179108A1
• Time in Patent Office: 1,197 Days
• Field of Search: 702/104
• US Class Current: 1/1
• CPC Class Codes: G01D 18/00 Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
• CPC Class Codes: G06F 17/00 Digital computing or data processing equipment or methods, specially adapted for specific functions information retrieval, database structures or file system structures therefor G06F16/00
• CPC Class Codes: G06F 3/0304 Detection arrangements using opto-electronic means constructional details of pointing devices not related to the detection arrangement using opto-electronic means G06F3/033; optical digitisers G06F3/042
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/046 by electromagnetic means

Abstract

A computer system stores calibration information corresponding to respective sets of sensor measurements associated with respective operating environments. After storing, in a first data structure, calibration information for a first operating environment, the system determines a current operating environment of the device. When the current operating environment of the device is consistent with the first operating environment and the calibration information for the first operating environment meets predefined measurement diversity criteria, the system calibrates at least one sensor for the first operating environment using the stored calibration information for the first operating environment. When the current operating environment of the device is inconsistent with the first operating environment, the system excludes the stored calibration information for the first operating environment when calibrating one or more sensors for the current operating environment.

Claims

1. A method comprising:

at a computer system including one or more processors and memory;

at each respective time of a plurality of respective times;

collecting a respective set of sensor measurements from a first set of sensors of a device at the respective time; and

associating a respective operating environment of the device with the respective set of sensor measurements, wherein the respective operating environment corresponds to values of one or more environmental parameters of a physical environment in which the device is operating at the respective time;

storing calibration information corresponding to the respective set of sensor measurements in a respective data structure associated with the respective operating environment of the device; and

after storing, in a first data structure, calibration information corresponding to a first operating environment;

determining a current operating environment of the device;

in accordance with a determination that the current operating environment of the device is consistent with the first operating environment and that the calibration information corresponding to the first operating environment meets predefined measurement diversity criteria, calibrating at least one sensor of the first set of one or more sensors for the first operating environment using the sensor measurements from the first data structure;

in accordance with a determination that the current operating environment of the device is inconsistent with the first operating environment, excluding the calibration information stored in the first data structure from consideration when calibrating one or more sensors of the first set of sensors for the current operating environment; and

in accordance with a determination that the current operating environment of the device is consistent with the first operating environment, the calibration information corresponding to the first operating environment does not meet the predefined measurement diversity criteria, and a calibration time threshold has been exceeded, prompting a user of the device to reorient the device so that one or more additional sets of sensor measurements can be retrieved in the first operating environment, wherein the one or more additional sets of sensor measurements are sensor measurements that enable the calibration information corresponding to the first operating environment to meet the predefined measurement diversity criteria.

2. The method of claim 1, wherein the measurement diversity criteria include one or more of:

spatial orientation diversity criteria;

spatial position diversity criteria;

non-inertial frame of reference diversity criteria; and

inertial frame of reference diversity criteria.

3. The method of claim 1, wherein:

the device comprises a second set of one or more sensors for determining environmental parameters for the environment within which the device is located, in accordance with sensor measurements from the second set of sensors; and

the current operating environment of the device is determined in accordance with the environmental parameters determined by the second set of sensors.

4. The method of claim 1, wherein

the device comprises a processor programmed to obtain information related to environmental parameters for the environment within which the device is located;

and

the current operating environment of the device is determined in accordance with the environmental parameters.

5. The method of claim 1, wherein:

the device is configured to be operated in any of a plurality of different physical configurations; and

the operating environment of the device at the respective time is determined based at least in part on a current physical configuration of the device at the respective time.

6. The method of claim 1, wherein the first set of sensors includes one or more of:

a magnetometer, an accelerometer, a gyroscope, a camera, a barometer, a thermometer, and a range estimator.

7. The method of claim 1, wherein each of the operating environments corresponds to measurements of one or more of:

atmospheric pressure, temperature, magnetic field, focal distance, stereoscopic distance, location, and magnetic inclination.

8. The method of claim 1, wherein excluding the calibration information stored in the first data structure from consideration when calibrating one or more sensors of the first set of sensors for the current operating environment includes deleting the calibration information stored in the first data structure.

9. The method of claim 1, wherein excluding the calibration information stored in the first data structure from consideration when calibrating a respective sensor of the first set of sensors for the current operating environment includes using only data stored outside of the first data structure for calibrating the respective sensor, while retaining the data stored in the first data structure for future calibration operations.

10. The method of claim 1, further comprising, after collecting, from the first set of sensors, a particular set of sensor measurements associated with the first operating environment:

evaluating the contribution of the particular set of sensor measurements from the first set of sensors to a diversity of previously collected sets of sensor measurements associated with the first operating environment; and

in accordance with a determination that the contribution of the particular set of sensor measurements to the diversity of previously collected sets of sensor measurements associated with the first operating environment is below a predefined threshold, discarding the particular set of sensor measurements or storing the particular set of sensor measurements in the first data structure and discarding an older set of sensor measurements from the first data structure.

11. The method of claim 1, further comprising, for each of a plurality of respective operating environments:

generating a respective operating environment identifier that corresponds to the values for environmental parameters that characterize the respective operating environment; and

storing the operating environment identifier in association with a plurality of sets of sensor measurements collected in the respective operating environment.

12. The method of claim 1, further comprising, after determining the current operating environment of the device, and

in accordance with the determination that:

the current operating environment of the device is consistent with the first operating environment,

the calibration information corresponding to the first operating environment does not meet the predefined measurement diversity criteria, and

a calibration time threshold has been exceeded,

calibrating at least one sensor of the first set of one or more sensors for the first operating environment using the sensor measurements from the first data structure.

13. The method of claim 1, wherein:

prior to calibrating the first set of sensors for the first operating environment, the first set of sensors were calibrated for a prior operating environment having a prior set of environmental parameters; and

the method further comprises;

while the first set of sensors are calibrated for the prior operating environment, using the first set of sensors to determine an attitude of the device in the prior operating environment; and

after calibrating the first set of sensors for the first operating environment, using the first set of sensors to determine an attitude of the device in the first operating environment.

14. The method of claim 3, wherein the second set of sensors includes at least one sensor that detects a quantity with no direct effect on the environmental parameters and the detected quantity is combined with a known relation between the detected quantity and the environmental parameters to determine the current operating environment of the device.

15. The method of claim 3, wherein the first set of sensors and the second set of sensors include at least one common sensor.

16. The method of claim 3, wherein the first set of sensors includes at least one sensor that is not included in the second set of sensors.

17. The method of claim 3, wherein the second set of sensors includes at least one sensor that is not included in the first set of sensors.

18. The method of claim 3, wherein the second set of sensors includes one or more of:

a magnetometer, an accelerometer, a gyroscope, a camera, a barometer, a thermometer, and a range estimator.

19. The method of claim 4, wherein the information related to the environmental parameters includes an angle between predefined vectors corresponding to a magnetic field and gravity.

20. The method of claim 4, wherein the information related to the environmental parameters includes battery status information indicating that a battery of the device has been changed.

21. The method of claim 5, wherein the current physical configuration of the device at the respective time is determined in accordance with system information stored on the device.

22. The method of claim 10, wherein, the older set of sensor measurements comprise sensor measurements not needed to meet the predefined measurement diversity criteria after the particular set of sensor measurements have been stored in the first data structure.

23. A computer system, comprising:

one or more processors;

a first set of one or more sensors;

memory; and

one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for;

at each respective time of a plurality of respective times;

collecting a respective set of sensor measurements from the first set of sensors of a device at the respective time; and

associating a respective operating environment of the device with the respective set of sensor measurements, wherein the respective operating environment corresponds to values of one or more environmental parameters of a physical environment in which the device is operating at the respective time;

storing calibration information corresponding to the respective set of sensor measurements in a respective data structure associated with the respective operating environment of the device; and

after storing, in a first data structure, calibration information corresponding to a first operating environment;

determining a current operating environment of the device;

in accordance with a determination that the current operating environment of the device is consistent with the first operating environment and that the calibration information corresponding to the first operating environment meets predefined measurement diversity criteria, calibrating at least one sensor of the first set of one or more sensors for the first operating environment using the sensor measurements from the first data structure;

in accordance with a determination that the current operating environment of the device is inconsistent with the first operating environment, excluding the calibration information stored in the first data structure from consideration when calibrating one or more sensors of the first set of sensors for the current operating environment; and

in accordance with a determination that the calibration information corresponding to the first operating environment does not meet the predefined measurement diversity criteria, prompting a user of the device to reorient the device so that one or more additional sets of sensor measurements can be retrieved in the first operating environment, wherein the one or more additional sets of sensor measurements are sensor measurements that enable the calibration information corresponding to the first operating environment to meet the predefined measurement diversity criteria.

24. A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which when executed by a computer system with one or more processors, cause the computer system to:

at each respective time of a plurality of respective times;

collect a respective set of sensor measurements from a first set of sensors of a device at the respective time; and

associate a respective operating environment of the device with the respective set of sensor measurements, wherein the respective operating environment corresponds to values of one or more environmental parameters of a physical environment in which the device is operating at the respective time;

store calibration information corresponding to the respective set of sensor measurements in a respective data structure associated with the respective operating environment of the device; and

after storing, in a first data structure, calibration information corresponding to a first operating environment;

determine a current operating environment of the device;

in accordance with a determination that the current operating environment of the device is consistent with the first operating environment and that the calibration information corresponding to the first operating environment meets predefined measurement diversity criteria, calibrate at least one sensor of the first set of one or more sensors for the first operating environment using the sensor measurements from the first data structure;

in accordance with a determination that the current operating environment of the device is inconsistent with the first operating environment, exclude the calibration information stored in the first data structure from consideration when calibrating one or more sensors of the first set of sensors for the current operating environment; and

in accordance with a determination that the calibration information corresponding to the first operating environment does not meet the predefined measurement diversity criteria, prompt a user of the device to reorient the device so that one or more additional sets of sensor measurements can be retrieved in the first operating environment, wherein the one or more additional sets of sensor measurements are sensor measurements that enable the calibration information corresponding to the first operating environment to meet the predefined measurement diversity criteria.