Navigation system with speed calculation mechanism and method of operation thereof

• US 9,797,742 B2
• Filed: 03/10/2015
• Issued: 10/24/2017
• Est. Priority Date: 03/12/2014
• Status: Active Grant

• Current Assignee: TeleNav Incorporated
• Original Assignee: TeleNav Incorporated
• Inventors: Lei, Liu
• Primary Examiner(s): Khatib, Rami
• Assistant Examiner(s): Foster, Gerrad A
• Application Number:
  US14/643,937
• Publication Number:
  US 20150260522A1
• Time in Patent Office: 959 Days
• Field of Search: None
• CPC Class Codes: G01C 21/3697 Output of additional, non-guidance related information, e.g. low fuel level G01C21/3679 takes precedence
• CPC Class Codes: G01P 1/122 Speed recorders
• CPC Class Codes: G08G 1/052 with provision for determining speed or overspeed speed measuring in general G01P

Abstract

A method of operation of a navigation system includes: calculating a speed difference value based on a sensor speed measurement and a location speed measurement; generating a speed probability distribution with the speed difference value and the sensor speed measurement calculating a density regression based on a speed density peak of the speed probability distribution; determining a speed adjustment factor from the density regression; and calculating an adjusted sensor speed from the sensor speed measurement with the speed adjustment factor.

Claims

1. A navigation system comprising:

a control unit, including a processor, configured to;

calculate a speed difference value based on a sensor speed measurement and a location speed measurement, wherein the location speed measurement is calculated based on global positioning system tracking;

generate a speed probability distribution with the speed difference value and the sensor speed measurement;

calculate a density regression based on a speed density peak of the speed probability distribution;

determine a speed adjustment factor from the density regression;

calculate an adjusted sensor speed from the sensor speed measurement with the speed adjustment factor; and

a storage unit, coupled to the control unit, configured to store the sensor speed measurement and the speed difference value.

2. The system as claimed in claim 1 wherein the control unit is configured to generate the speed probability distribution based on an accuracy threshold.

3. The system as claimed in claim 1 wherein the control unit is configured to calculate the density regression based on a peak weight of the speed density peak.

4. The system as claimed in claim 1 wherein the control unit is configured to:

generate a speed log having speed entries with pairs of the speed difference value and the sensor speed measurement; and

remove speed entries from the speed log based on a speed relevance factor.

5. The system as claimed in claim 1 wherein the control unit is configured to determine the speed density peak for one or more sensor speed increments of the speed probability distribution.

6. The system as claimed in claim 1 wherein the control unit is configured to generate the speed probability distribution as a two dimensional kernel density estimation.

7. The system as claimed in claim 1 wherein the control unit is configured to calculate the density regression based on the speed density peak as a linear regression with a method of least square.

8. The system as claimed in claim 1 wherein the control unit is configured to calculate the speed difference value as the difference between the location speed measurement and the sensor speed measurement.

9. The system as claimed in claim 1 wherein the control unit is configured to receive the sensor speed measurement calculated based on motion of mechanical components of a vehicle.

10. The system as claimed in claim 1 wherein the control unit is configured to receive the location speed measurement calculated based on the change in location of a vehicle over a period of time.

11. A method of operation of a navigation system comprising:

calculating a speed difference value based on a sensor speed measurement and a location speed measurement, wherein the location speed measurement is calculated based on global positioning system tracking;

generating a speed probability distribution with the speed difference value and the sensor speed measurement;

calculating a density regression based on a speed density peak of the speed probability distribution;

determining a speed adjustment factor from the density regression; and

calculating an adjusted sensor speed from the sensor speed measurement with the speed adjustment factor.

12. The method as claimed in claim 11 wherein generating the speed probability distribution includes generating the speed probability distribution based on an accuracy threshold.

13. The method as claimed in claim 11 wherein calculating the density regression includes calculating the density regression based on a peak weight of the speed density peak.

14. The method as claimed in claim 11 further comprising:

generating a speed log having speed entries with pairs of the speed difference value and the sensor speed measurement; and

removing speed entries from the speed log based on a speed relevance factor.

15. The method as claimed in claim 11 wherein determining the speed density peak includes deterring the speed density peak for one or more sensor speed increments of the speed probability distribution.

16. A non-transitory computer readable medium including instructions for operating a navigation system comprising:

calculating a speed difference value based on a sensor speed measurement and a location speed measurement, wherein the location speed measurement is calculated based on global positioning system tracking;

generating a speed probability distribution with the speed difference value and the sensor speed measurement;

calculating a density regression based on a speed density peak of the speed probability distribution;

determining a speed adjustment factor from the density regression; and

calculating an adjusted sensor speed from the sensor speed measurement with the speed adjustment factor.

17. The non-transitory computer readable medium as claimed in claim 16 wherein generating the speed probability distribution includes generating the speed probability distribution based on an accuracy threshold.

18. The non-transitory computer readable medium as claimed in claim 16 wherein calculating the density regression includes calculating the density regression based on a peak weight of the speed density peak.

19. The non-transitory computer readable medium as claimed in claim 16 further comprising:

generating a speed log having speed entries with pairs of the speed difference value and the sensor speed measurement; and

removing speed entries from the speed log based on a speed relevance factor.

20. The non-transitory computer readable medium as claimed in claim 16 wherein determining the speed density peak includes deterring the speed density peak for one or more sensor speed increments of the speed probability distribution.