APPARATUS AND METHODS FOR ULTRASONIC SENSOR NAVIGATION

• US 20170176188A1
• Filed: 01/25/2016
• Published: 06/22/2017
• Est. Priority Date: 12/18/2015
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: Al-Hamad, Amr, Georgy, Jacques, Goodall, Christopher
• Granted Patent: US 10,184,797 B2
• Time in Patent Office: Days
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G01C 21/1652 with ranging devices, e.g. LIDAR or RADAR
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence
• CPC Class Codes: G01S 15/60 wherein the transmitter and receiver are mounted on the moving object, e.g. for determining ground speed, drift angle, ground track
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

An apparatus and methods are disclosed for determining a navigational constraint for a portable device using an ultrasonic sensor. The navigational constraint may be used to supplement other navigational solutions or may be used independently. The ultrasonic sensor may provide a plurality of samples to be processed to determine the constraint. Processing the ultrasonic samples may include performing a flow analysis regarding detected external objects. Determining the constraint may include any or all of determining a context for usage, distinguishing usage modes, estimating relative heading changes, and estimating misalignment angle between device and platform needed to determine direction of motion of the platform and determining a speed of the portable device from the samples.

Claims

1. A method for navigating with a device comprising:

processing a sequence of samples from an ultrasonic sensor of the device;

determining a navigational constraint for the device based at least in part on the processed samples; and

providing a navigation solution for the device based at least in part on the determined navigational constraint.

2. The method of claim 1, wherein processing the sequence of samples from the ultrasonic sensor comprises performing an ultrasonic flow analysis

3. The method of claim 2, wherein performing the ultrasonic flow analysis comprises determining change in relative location to an external object.

4. The method of claim 2, wherein determining a navigational constraint comprises estimating a device angle.

5. The method of claim 2, wherein determining a navigational constraint comprises estimating a misalignment angle of the device with respect to a direction of motion.

6. The method of claim 5, wherein the device further comprises inertial sensors, wherein the method further comprises a navigation routine using inertial sensors and wherein the navigational constraint is applied to a navigational solution provided by the inertial navigation routine

7. The method of claim 6, further comprising processing the sequence of samples from the ultrasonic sensor using a Doppler analysis to determine a speed of the device, wherein the determined speed is applied to the navigational solution.

8. The method of claim 2, wherein determining the navigational constraint comprises estimating relative heading changes obtained with respect to an external object

9. The method of claim 8, wherein the device further comprises inertial sensors, wherein the method further comprises a navigation routine using inertial sensors and wherein the navigational constraint is applied to a navigational solution provided by the inertial navigation routine.

10. The method of claim 9, further comprising processing the sequence of samples from the ultrasonic sensor using a Doppler analysis to determine a speed of the device, wherein the determined speed is applied to the navigational solution.

11. The method of claim 1, further comprising processing the sequence of samples from the ultrasonic sensor using a Doppler analysis, wherein determining the navigational constraint comprises estimating relative heading changes obtained with respect to an external object based at least in part on the Doppler analysis

12. The method of claim 11, wherein the device further comprises inertial sensors, wherein the method further comprises a navigation routine using inertial sensors and wherein the navigational constraint is applied to a navigational solution provided by the inertial navigation routine

13. The method of claim 12, further comprising processing the sequence of samples from the ultrasonic sensor using a Doppler analysis to determine a speed of the device, wherein the determined speed is applied to the navigational solution.

14. The method of claim 1, wherein processing the sequence of samples from the ultrasonic sensor further comprises determining a distance to an external object by ranging

15. The method of claim 14, wherein processing the sequence of samples from the ultrasonic sensor comprises performing an ultrasonic flow analysis, wherein determining a navigational constraint includes estimating a speed of the device based at least in part on the ultrasonic flow analysis and the determined distance to the external object.

16. The method of claim 15, wherein the device further comprises inertial sensors, wherein the method further comprises a navigation routine using inertial sensors and wherein the navigational constraint is applied to a navigational solution provided by the inertial navigation routine.

17. The method of claim 15, wherein estimating the speed includes deriving a scale factor from the determined distance to the external object

18. The method of claim 14, wherein the device further comprises a supplemental sensor, further comprising processing a sequence of samples from the supplemental sensor to per form a flow analysis

19. The method of claim 18, wherein determining a navigational constraint includes estimating a speed of the device based at least in part on the flow analysis and the determined distance to the external object.

20. The method of claim 19, wherein the device further comprises inertial sensors, wherein the method further comprises a navigation routine using inertial sensors and wherein the navigational constraint is applied to a navigational solution provided by the inertial navigation routine.

21. The method of claim 18, wherein the supplemental sensor comprises an optical sensor

22. The method of claim 18, wherein the supplemental sensor comprises at least one of the group consisting of:

(i) an optical camera;

(ii) a thermal camera;

(iii) an infra-red imaging sensor.

23. The method of claim 21, wherein performing the optical flow analysis comprises aggregating estimations of pixel translations between the samples from the supplemental sensor.

24. The method of claim 5, wherein processing the sequence of samples from the ultrasonic sensor further comprises determining a distance to an external object by ranging and wherein the device further comprises a gyroscope, further comprising estimating a speed of the device based at least in part on the ultrasonic flow analysis and the determined distance to the external object, and providing a navigational solution based at least in part on the estimated speed, the estimated misalignment angle and information from the gyroscope.

25. The method of claim 5, wherein processing the sequence of samples from the ultrasonic sensor further comprises determining a distance to an external object by ranging and wherein the device further comprises a magnetometer, further comprising estimating a speed of the device based at least in part on the ultrasonic flow analysis and the determined distance to the external object, and providing a navigational solution based at least in part on the estimated speed, the estimated misalignment angle and information from the magnetometer.

26. The method of claim 1, wherein determining a navigational constraint comprises determining a context for the device.

27. The method of claim 26, wherein processing the sequence of samples from the ultrasonic sensor comprises performing an ultrasonic flow analysis and wherein deter mining a navigational constraint comprises estimating a device angle.

28. The method of claim 27, wherein determining the context of the device comprises assessing variance in a plurality of estimated device angles.

29. The method of claim 26, wherein determining the context of the device comprises comparing similarity between samples.

30. The method of claim 27, further comprising determining a usage of the device based at least in part on the estimated device angle.

31. The method of claim 30, wherein determining the usage of the device is also based at least in part on an orientation determination using an inertial sensor

32. The method of claim 27, wherein determining the context of the device comprises calculating an ultrasonic flow ratio.

33. The method of claim 27, further comprising determining the context corresponds to being static.

34. The method of claim 27, further comprising determining the context corresponds to fidgeting motion.

35. The method of claim 27, further comprising determining the context corresponds to dangling motion.

36. The method of claim 35, further comprising estimating a misalignment angle of the device with respect to a direction of motion based at least in part on the dangling motion context

37. A device comprising:

an ultrasonic sensor; and

an ultrasonic navigation module, wherein the ultrasonic navigation module is configured to;

process a sequence of samples from the ultrasonic sensor of the device;

determine a navigational constraint for the device based at least in part on the processed samples; and

provide a navigation solution for the device based at least in part on the determined navigational constraint.

38. The device of claim 37, wherein the ultrasonic navigation module is configured to process the sequence of samples by performing an ultrasonic flow analysis.

39. The device of claim 38, wherein the ultrasonic navigation module performs the ultrasonic flow analysis to determine a change in relative location to an external object

40. The device of claim 38, wherein the ultrasonic navigation module performs the ultrasonic flow analysis to estimate a device angle.

41. The device of claim 38, wherein the ultrasonic navigation module performs the ultrasonic flow analysis to estimate a misalignment angle of the device with respect to a direction of motion.

42. The device of claim 38, wherein the ultrasonic navigation module performs the ultrasonic flow analysis to estimate relative heading changes obtained with respect to an external object

43. The device of claim 37, wherein the ultrasonic navigation module is further configured to process the sequence of samples from the ultrasonic sensor using a Doppler analysis, wherein the ultrasonic navigation module is further configured to estimate relative heading changes obtained with respect to an external object based at least in part on the Doppler analysis

44. The device of claim 37, wherein the ultrasonic navigation module is further configured to process the sequence of samples from the ultrasonic sensor using a Doppler analysis to determine a speed of the device and apply the determined speed to the navigational solution.

45. The device of claim 37, further comprising inertial sensors, wherein the ultrasonic navigation module is configured to apply the determined navigational constraint to a navigational solution derived from the inertial sensors

46. The device of claim 37, further comprising a supplemental sensor, wherein the ultrasonic navigation module is further configured to process a sequence of samples from the supplemental sensor to perform a flow analysis and determine a navigational constraint.

47. The device of claim 46, wherein the supplemental sensor comprises an optical sensor.

48. The device of claim 46, wherein the supplemental sensor comprises at least one of the group consisting of:

(i) an optical camera;

(ii) a thermal camera;

(iii) an infra-red imaging sensor.

49. The device of claim 37, further comprising a gyroscope, wherein the ultrasonic navigation module is further configured to process the sequence of samples from the ultrasonic sensor to determine a distance to an external object by ranging, to perform an ultrasonic flow analysis on the sequence of samples, to estimate a speed of the device based at least in part on the ultrasonic flow analysis and the determined distance to the external object, to estimate a misalignment angle of the device based at least in part on the ultrasonic flow analysis and to provide a navigational solution based at least in part on the estimated speed, the estimated misalignment angle and information from the gyroscope.

50. The device of claim 37, further comprising a magnetometer, wherein the ultrasonic navigation module is further configured to process the sequence of samples from the ultrasonic sensor to determine a distance to an external object by ranging, to perform an ultrasonic flow analysis on the sequence of samples, to estimate a speed of the device based at least in part on the ultrasonic flow analysis and the determined distance to the external object, to estimate a misalignment angle of the device based at least in part on the ultrasonic flow analysis and to provide a navigational solution based at least in part on the estimated speed, the estimated misalignment angle and information from the magnetometer.

51. The device of claim 37, further comprising a gyroscope, wherein the ultrasonic navigation module is further configured to process the sequence of samples from the ultrasonic sensor using a Doppler analysis to estimate a speed of the device, to perform an ultrasonic flow analysis on the sequence of samples, to estimate a misalignment angle of the device based at least in part on the ultrasonic flow analysis and to provide a navigational solution based at least in part on the estimated speed, the estimated misalignment angle and information from the gyroscope

52. The device of claim 37, further comprising a magnetometer, wherein the ultrasonic navigation module is further configured to process the sequence of samples from the ultrasonic sensor using a Doppler analysis to estimate a speed of the device, to perform an ultrasonic flow analysis on the sequence of samples, to estimate a misalignment angle of the device based at least in part on the ultrasonic flow analysis and to provide a navigational solution based at least in part on the estimated speed, the estimated misalignment angle and information from the magnetometer.

53. The device of claim 38, wherein the ultrasonic navigation module performs the ultrasonic flow analysis to determine a context for the device.