Method and apparatus for handling vertical orientations of devices for constraint free portable navigation

• US 10,054,442 B2
• Filed: 01/17/2014
• Issued: 08/21/2018
• Est. Priority Date: 01/17/2013
• Status: Active Grant

• Current Assignee: Trusted Positioning Inc. (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: Georgy, Jacques, Syed, Zainab
• Primary Examiner(s): Bui, Tha-O H
• Application Number:
  US14/760,973
• Publication Number:
  US 20150354962A1
• Time in Patent Office: 1,677 Days
• Field of Search: 702151
• CPC Class Codes: G01B 21/22 for measuring angles or tapers; for testing the alignment of axes
• CPC Class Codes: G01C 21/20 Instruments for performing navigational calculations G01C21/24, G01C21/26 take precedence

Abstract

The present disclosure relates to a method and apparatus for enhancing a navigation solution of a device within a platform (such as for example person, vehicle or vessel), wherein the mobility of the device may be constrained or unconstrained within the platform, and wherein the device can be tilted to any orientation including vertical or near vertical orientations, while still providing a seamless navigation solution. This method can enhance navigation solutions utilizing measurements from sensors (such as, for example, accelerometers, gyroscopes, magnetometers, etc.), whether in the presence or in the absence of absolute navigational information (such as, for example, GNSS or WiFi positioning).

Claims

1. A method for enhancing a navigation solution about a device, wherein mobility of the device may be constrained or unconstrained within a platform and the device can be tilted to any orientation, including vertical or near vertical orientations, the device having sensors configured to provide sensor readings, the sensors have a corresponding axes frame comprising three orthogonal axes, wherein the axes frame has a first definition, and the readings having error parameters, characterized by:

i) detecting a transition in a forward axis of the device, wherein the transition involves a vertical or near vertical orientation,

ii) where the transition is detected, updating the axes frame, wherein updating the axes frame comprises changing the axes frame to a second definition, and wherein at least one axis of the three orthogonal axes of the second definition is changed to another axis as compared to the first definition, changing the sensor readings and error parameters according to the updated axes frame, adjusting an estimated orientation of the device according to the updated axes frame, and at least partially re-initializing the navigation solution, and

iii) outputting the enhanced navigation solution.

2. The method of claim 1, wherein the transition in the forward axis of the device is one of the following:

from horizontal or near horizontal to vertical or near vertical, from vertical or near vertical to horizontal or near horizontal, from vertical up or near vertical up to vertical down or near vertical down, or from vertical down or near vertical down to vertical up or near vertical up.

3. The method of claim 1, wherein the method further comprises a re-alignment routine for fully or partially re-initializing the navigation solution.

4. The method of claim 1, wherein the method is operable whether in the presence or in the absence of absolute navigational information.

5. The method of claim 1, wherein the method further comprises a routine configured to avoid the use of continuous unneeded transitions between axes frames.

6. The method of claim 1, wherein the method further comprises a routine configured to detect whether a transition is legitimate.

7. The method of claim 1, wherein the method further comprises a routine configured to adjust output pitch and roll angles of the device to a default axes definition.

8. The method of claim 1, wherein the method further comprises any one or any combination of the following routines:

a. a routine configured to avoid the use of continuous unneeded transitions,

b. a routine configured to detect whether a transition is legitimate,

c. a re-alignment routine, wherein the method is utilized for enhancing a navigation solution about the device, or

d. a routine configured to adjust output pitch and roll angles of the device to a default axes definition.

9. A device having constrained or unconstrained mobility within a platform and being tiltable to any orientation including vertical or near vertical orientations, the device comprising:

a. an assembly of sensors configured to provide sensor readings relating to navigational information about the device and producing an output indicative thereof, the sensors having a corresponding axes frame comprising three orthogonal axes, wherein the axes frame has a first definition, and the readings having corresponding error parameters; and

b. at least one processor for enhancing a navigation solution about the device, coupled to receive the readings from the sensor assembly, and operative to;

i) detect a transition in a forward axis of the device, wherein the transition involves a vertical or near vertical orientation,

ii) where the transition is detected, update the axes frame, wherein updating the axes frame comprises changing the axes frame to a second definition, and wherein at least one axis of the three orthogonal axes of the second definition is changed to another axis as compared to the first definition, change the sensor readings and error parameters according to the updated axes frame, adjust an estimated orientation of the device according to the updated axes frame, and at least partially re-initialize the navigation solution, and

iii) output the enhanced navigation solution.

10. The device of claim 9, wherein the transition in the forward axis of the device is one of the following:

from horizontal or near horizontal to vertical or near vertical, from vertical or near vertical to horizontal or near horizontal, from vertical up or near vertical up to vertical down or near vertical down, or from vertical down or near vertical down to vertical up or near vertical up.

11. The device of claim 9, wherein the processor operates in the presence or in the absence of absolute navigational information.