DEDUCED RECKONING NAVIGATION WITHOUT A CONSTRAINT RELATIONSHIP BETWEEN ORIENTATION OF A SENSOR PLATFORM AND A DIRECTION OF TRAVEL OF AN OBJECT

• US 20120072166A1
• Filed: 09/22/2010
• Published: 03/22/2012
• Est. Priority Date: 09/22/2010
• Status: Active Grant

• Current Assignee: Invensense Incorporated (TDK Corporation)
• Original Assignee: Invensense Incorporated (TDK Corporation)
• Inventors: Keal, William Kerry, Sachs, David, Lin, Shang-Hung, Anderson, Erik
• Granted Patent: US 8,594,971 B2
• Time in Patent Office: Days
• US Class Current: 702/150
• CPC Class Codes: G01C 21/1654 with electromagnetic compass
• CPC Class Codes: G01C 22/006 Pedometers

Abstract

Systems, methods, and apparatus for performing deduced reckoning navigation without a constraint relationship between orientation of a sensor platform and a direction of travel of an object are described herein. A sensor fusion component can be configured to receive data from sensors of a sensor platform coupled to a pedestrian; and generate world coordinate information based on the data. Further, a gait recognition component can be configured to record one or more walking patterns of the pedestrian in a training database; and determine whether the world coordinate information is associated with a walking pattern of the one or more walking patterns. Furthermore, a position estimation component can be configured to estimate a position of the pedestrian based on the world coordinate information if the world coordinate information is associated with the walking pattern, regardless of an orientation of the sensor platform with respect to the position of the pedestrian.

Claims

1. A method, comprising:

receiving signals from a sensor platform physically coupled to an object;

generating world coordinate information based on the signals; and

estimating, based on the world-frame coordinate information, a direction of travel of the object irrespective of the orientation of the sensor platform relative to the object.

2. The method of claim 1, wherein the estimating further comprises:

converting the world-frame coordinate information into p-frame coordinate information; and

correlating the p-frame coordinate information with step profiles of a pedestrian stepping with the sensor platform in a particular location, wherein the estimating further includes estimating the direction of travel of the pedestrian based on the correlated p-frame coordinate information.

3. The method of claim 2, further comprising:

detecting false steps of the pedestrian based on the correlating the p-frame coordinate information with the step profiles, wherein the estimating further includes estimating the direction of travel of the pedestrian by rejecting the false steps.

4. The method of claim 2, further comprising:

recording, over a period of time, one or more gait patterns of the pedestrian in a training database; and

generating the step profiles based on the one or more gait patterns.

5. The method of claim 2, further comprising:

utilizing a learning algorithm to generate the step profiles.

6. The method of claim 2, further comprising:

filtering the p-frame information, wherein correlating the p-frame coordinate information with the step profiles further includes correlating the filtered p-frame information with the step profiles.

7. The method of claim 1, wherein the estimating further comprises:

utilizing map information to estimate the direction of travel of the object.

8. The method of claim 1, further comprising:

reducing power consumption of the sensor platform based on the estimating the direction of travel of the object.

9. The method of claim 1, further comprising:

determining a wheel revolution rate of a vehicle based on the signals.

10. A system, comprising:

a sensor fusion component configured to;

receive data from sensors of a sensor platform coupled to a pedestrian; and

generate world coordinate information based on the data;

a gait recognition component configured to;

record one or more walking patterns of the pedestrian in a training database; and

determine whether the world coordinate information is associated with a walking pattern of the one or more walking patterns; and

a position estimation component configured to;

estimate a position of the pedestrian based on the world coordinate information if the world coordinate information is associated with the walking pattern, regardless of an orientation of the sensor platform with respect to the position of the pedestrian.

11. The system of claim 10, wherein the sensors include at least one of an inertial sensing device, a magnetic sensor, an altimeter, or a global positioning system (GPS) sensor.

12. The system of claim 10, wherein the sensor fusion component is further configured to generate, based on the data, an orientation, a linear acceleration, and an angular velocity of the sensor platform in a world coordinate system.

13. The system of claim 10, wherein the sensor fusion component combines information received from a 3-axis gyroscope and a 3-axis accelerometer to generate the world coordinate information in quaternion form.

14. The system of claim 10, wherein the position estimation component estimates, via Bayesian inference, the position of the pedestrian utilizing map information.

15. The system of claim 11, further comprising a GPS power management component configured to regulate a duty cycle of the GPS sensor based on a tracking state, a stationary state, and a learning state.

17. The system of claim 10, wherein the sensor platform, the sensor fusion component, the gait recognition component, and the position estimation component are included in an integrated circuit.

18. The system of claim 15, wherein the integrated circuit is included in at least one of an earphone, an earring, a pen, or eye glasses.

16. The system of clam 10, wherein the sensor fusion component, the gait recognition component, and the position estimation component are included in an integrated circuit.

19. The system of clam 16, wherein the position of the pedestrian is transmitted to a display device via a wireless protocol.

20. An apparatus, comprising:

means for combining information received from different sensors of a sensor platform physically coupled to an entity;

means for converting world-frame data of the combined information into p-frame data;

means for correlating the p-frame data with profiles of the entity moving with the sensor platform; and

means for estimating a direction of travel of the entity based on the means for correlating the p-frame data with the profiles, irrespective of an orientation of the sensor platform with respect to the entity.