Motor vehicle-detecting system

• US 20060250279A1
• Filed: 02/13/2004
• Published: 11/09/2006
• Est. Priority Date: 02/19/2003
• Status: Active Grant

• Current Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Taniguchi, Yuichi, Shiranaga, Hideaki
• Granted Patent: US 7,835,853 B2
• Time in Patent Office: Days
• US Class Current: 340/933
• CPC Class Codes: G01V 8/10 Detecting, e.g. by using light barriers by reflection from the object G01S17/00
• CPC Class Codes: G08G 1/042 using inductive or magnetic detectors

Abstract

A vehicle detection system is provided for detecting vehicles with high precision recognition with less misdetection and less electricity consumption, the installation of the vehicle detection system causing less damage to a town'"'"'s aesthetic beauty. Vehicle detection is determined by processing an input level value provided from a sensor that detects infrared radiation irradiated from an object to be detected, and the vehicle presence judgment is carried out by calculating a background level value based on an input level value detected from infrared radiation during “absence of a vehicle”, and by comparing the value based on a difference between the input level value (comparative value) by a data processing unit. By using the sensor that passively detects infrared radiation, the system consumes less electricity, and maintains its accuracy of detection even if detection is performed sideways of vehicles.

Claims

1. A vehicle detection system for detecting a vehicle running through a monitoring range on a road, comprising:

a sensor detecting infrared radiation irradiated from an object to be detected, and

a vehicle presence judgment means to determine the presence of the vehicle by using an input level value detected by the sensor.

2. A vehicle detection system according to claim 1, wherein said sensor is a thermopile.

3. A vehicle detection system according to claim 1, wherein said sensor consists of only one kind of a thermopile.

4. A vehicle detection system according to any one of claims 1 to 3, wherein said infrared radiation is detected from the side of the road.

5. A vehicle detection system according to any one of claims 1 to 4, wherein said vehicle presence judgment means determines the presence of the vehicle when a comparative value exceeds a threshold value, the comparative value being defined as a value based on differences between a background level value and an input level value, wherein the background level value is defined as a value based on the intensity of the infrared radiation irradiated from objects other than vehicles.

6. A vehicle detection system according to claim 5 further comprising a calculation means to calculate said background level value.

7. A vehicle detection system according to claims 5 or 6, wherein said comparative value is an integrated value of the differences between the input level value and the background level values integrated during a predetermined time.

8. A vehicle detection system according to any one of claims 5 to 7, wherein a variation of the input level value per unit time is taken into consideration in said comparison value.

9. A vehicle detection system according to any one of claims 2 to 8, wherein said sensor has plural thermopiles.

10. A vehicle detection system according to any one of claims 2 to 9, wherein an infrared transparent lens is placed in front of the thermopile relative to a direction towards the object.

11. A vehicle detection system according to claim 10, wherein said infrared transparent lens is made of zinc sulfide.

12. A vehicle detection system according to claim 10 or 11, wherein a supporting unit is formed for supporting the thermopile and the infrared transparent lens together in one body.

13. A vehicle detection system according to any one of claims 10 to 12, wherein a housing box for housing the thermopile is provided, said housing box having an aiming unit for adjusting a directional angle of the infrared transparent lens to a direction towards the object.

14. A vehicle detection system according to any one of claims 1 to 13, wherein a radio communication means is provided for transmitting by radio the results supplied from the vehicle presence judgment means.

15. A vehicle detection system according to claim 14, wherein a power source control unit is provided for intermittently supplying electricity to said radio communication means.

16. A method of maintenance for the vehicle detection system according to claim 14 or 15, wherein the maintenance is carried out by transmitting maintenance data to said radio communication means by radio.

17. A method of maintenance for the vehicle detection system according to claim 16, wherein said radio communication means is provided with a maintenance judgment unit to determine the reception of said maintenance data such that said maintenance judgment unit determines the reception of said maintenance data when the power source for said radio communication means is in the ON-state, and the maintenance of said vehicle detection system is performed only when said maintenance data has been received.