Load meter and load measurement method

Patent metadata

Field	Value
Publication number	US-11536602-B2
Application number	US-201916372499-A
Country	US
Kind code	B2
Filing date	Apr 2, 2019
Priority date	Feb 28, 2017
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

A load meter includes a detector, a storage unit, and a load calculator. The detector detects, by using a captured image obtained by capturing a road and a vehicle present on the road, a displacement amount in the captured image, the displacement amount corresponding to displacement caused on the road by application of a load of the vehicle. The storage unit stores information indicating a relation between the load and the displacement amount. The load calculator calculates the load based on the displacement amount and the information.

First claim

The invention claimed is:

1. A load meter comprising:
a projector configured to project patterned light onto a road;
a detector configured to detect, by using a captured image obtained by capturing an area having the patterned light projected onto the road and a vehicle present in the area, a displacement amount of the patterned light in the captured image, the displacement amount corresponding to displacement caused on the road by application of a load of the vehicle;
a storage unit configured to store information indicating a relation between the load and the displacement amount; and
a load calculator configured to calculate the load based on the displacement amount and the information.

2. The load meter according to claim 1 , wherein the patterned light includes a design having a line segment that is not substantially parallel to an imaging direction of the captured image.

3. The load meter according to claim 1 , wherein the projector is disposed so that a projecting direction by the projector is not substantially parallel to an imaging direction of the captured image.

4. The load meter according to claim 1 , wherein
the projector generates a timing signal indicating a timing of projecting the patterned light, and
the captured image is an image captured at the timing indicated by the timing signal.

5. The load meter according to claim 1 , wherein based on a signal from a sensor for detecting the vehicle traveling on the road, the projector projects the patterned light, and the captured image is captured.

6. The load meter according to claim 1 , further comprising a calibrator configured to:
generate a histogram of a plurality of the displacement amounts by aggregating the displacement amounts detected by the detector, and
update a displacement coefficient for calculating the load of the vehicle based on a shape of the histogram.

7. The load meter according to claim 6 , wherein the load of the vehicle is an axle load of the vehicle.

8. The load meter according to claim 6 , further comprising an axle identifying unit configured to identify an axle number of an axle of the vehicle,
wherein the calibrator generates the histogram for each axle number identified by the axle identifying unit, and updates the displacement coefficient based on the shape of the histogram.

9. The load meter according to claim 8 , wherein
the axle identifying unit identifies a first axle serving as a forefront axle of the vehicle, and
the calibrator updates the displacement coefficient based only on the shape of the histogram corresponding to the first axle.

10. The load meter according to claim 6 , further comprising a speed calculator configured to calculate a speed of the vehicle,
wherein the calibrator generates the histogram for each speed calculated by the speed calculator, and updates the displacement coefficient based on the shape of the histogram.

11. The load meter according to claim 6 , further comprising a vehicle type recognizer configured to recognize a type of the vehicle,
wherein the calibrator generates the histogram for each type recognized by the vehicle type recognizer, and updates the displacement coefficient based on the shape of the histogram.

12. The load meter according to claim 6 , wherein the detector calculates reliability of the displacement amount, and
the calibrator aggregates the displacement amounts only when the reliability is higher than a predetermined value.

13. The load meter according to claim 6 , wherein the calibrator updates the displacement coefficient based only on the shape of the histogram corresponding to a section that does not include a mode of the histogram.

14. The load meter according to claim 6 , wherein the calibrator updates the displacement coefficient only when a predetermined condition is satisfied.

15. The load meter according to claim 6 , further comprising a notification unit,
wherein the notification unit performs notification when a difference between a displacement coefficient before being updated by the calibrator and the displacement coefficient updated by the calibrator is a predetermined reference value or more.

16. The load meter according to claim 6 , wherein
the storage unit records a histogram of a plurality of the loads, and
the calibrator updates the displacement coefficient based on the shape of the histogram of the displacement amounts and a shape of the histogram of the loads.

17. A load measurement method comprising:
projecting patterned light onto a road;
detecting with a detector configured to detect an image, by using a captured image obtained by capturing an area having the patterned light projected light onto the road and a vehicle present in the area, a displacement amount of the patterned light in the captured image, the displacement amount corresponding to displacement caused on the road by application of a load of the vehicle; and
calculating with a load calculator the load based on the displacement amount and information, stored in a storage unit, indicating a relation between the load and the displacement amount.

18. The load measurement method according to claim 17 , further comprising:
generating a histogram of a plurality of the displacement amounts by aggregating the displacement amounts detected in the detecting; and
updating a displacement coefficient for calculating the load of the vehicle based on a shape of the histogram.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Imagawa Taro
• Noda Akihiro
• Kusaka Hiroya

Classifications

• G01G19/03 Primary

  for weighing during motion ({G01G19/022, G01G19/045,} G01G19/04, G01G19/07 take precedence {; weighing a continuous stream material during flow G01G11/00; check weighing of materials dispensed into removable containers G01G15/00}) · CPC title

• G01G23/01

  Testing or calibrating of weighing apparatus · CPC title

• G01G9/00

  Methods of, or apparatus for, the determination of weight, not provided for in groups G01G1/00 - G01G7/00 · CPC title

• G01G19/024 Primary

  using electrical weight-sensitive devices · CPC title