Vehicle measuring apparatus and method for toll collection system

• US 20040008514A1
• Filed: 12/11/2002
• Published: 01/15/2004
• Est. Priority Date: 07/09/2002
• Status: Active Grant

• Current Assignee: Jin Tay Industries Co.
• Original Assignee: LG Industrial Systems Co., Ltd (LG Corporation)
• Inventors: Jun, Joon-Suk, Lee, Sang-Jean, Lim, Dae-Woon, Song, In-June
• Granted Patent: US 6,965,438 B2
• Time in Patent Office: Days
• US Class Current: 362/259
• CPC Class Codes: G07B 15/06 Arrangements for road pricing or congestion charging of vehicles or vehicle users, e.g. automatic toll systems
• CPC Class Codes: G08G 1/015 with provision for distinguishing between two or more types of vehicles, e.g. between motor-cars and cycles
• CPC Class Codes: G08G 1/04 using optical or ultrasonic detectors

Abstract

Vehicle measuring apparatus and method are disclosed to accurately measure height and width of a vehicle moving at a high speed. The vehicle measuring apparatus includes: a plurality of laser sensors separated from the road surface with a predetermined height and installed closely to each other corresponding to width of every roadway on the road, and receiving a reflection light of a laser light emitted onto the road from the plurality of the laser sensors and outputting a vehicle measurement signal; and a processor means electrically connected to the laser sensors and calculating height and width of the vehicle on the basis of the signal to measure the vehicle and previously stored installation information of the plurality of laser sensors.

Claims

1. A vehicle measuring apparatus comprising:

a plurality of laser sensors separated with a predetermined height from a road surface and installed closely to each other corresponding to width of every road way, and for providing a signal to measure the vehicle; and

a processor means electrically connected to the laser sensors and for computing height and width of the vehicle on the basis of the signal received from the laser sensors and previously stored installation information of the plurality of laser sensors.

2. The apparatus of claim 1, wherein each of the plurality of laser sensors comprising:

a laser emitter for emitting laser light onto the road surface; and

a laser receiver for receiving laser light reflected from the road surface or from the vehicle on the road, and for providing the processor means with a signal to measure the vehicle depending on receiving the reflected laser light.

3. The apparatus of claim 2, wherein each of the plurality of laser sensors further comprise a reflection plate for reflecting the laser light received from the laser emitter onto the road surface.

4. The apparatus of claim 2, wherein each of the plurality of laser sensors further comprise a lens for collecting the laser light reflected from the road surface or from the vehicle on the road and for providing the laser light to the laser receiver.

5. The apparatus of claim 1, wherein the processor means comprising:

a multiplexer for generating a drive signal to drive the laser sensors, for applying simultaneously the generated drive signal to the plurality of laser sensors, and for receiving signals to measure the vehicle from the plurality of laser sensors; and

a computation circuit for computing height and width of the vehicle with reference to the driving signal generated from the multiplexer, the vehicle measurement signal received by the multiplexer and the installation information of the plurality of laser sensors.

6. The apparatus of claim 1, wherein the processor means comprises:

a multiplexer for generating a drive signal to drive the laser sensors, for applying selectively the generated drive signal to the plurality of laser sensors, and for selectively receiving signals to measure the vehicle from the plurality of laser sensors; and

a computation circuit for computing height and width of the vehicle on the basis of the signal for vehicle measurement received from the multiplexer unit, and the installation information of the plurality of laser sensors.

7. The apparatus of claim 6, wherein the multiplexer comprising:

a pulse generator for generating a pulse signal to drive the laser sensors;

a pulse counter for counting the pulse signals generated from the pulse generator;

a first multiplexer for sequentially outputting the pulse signal generated from the pulse generator to the plurality of laser sensors according to a pulse count value from the pulse counter;

a plurality of switch units installed corresponding to the plurality of laser sensors and being switched to a position for providing the signal for vehicle measurement outputted from the plurality of laser sensors or a position for cutting off the signal for vehicle measurement; and

a second multiplexer for selectively operating a switch unit corresponding to a laser sensor to which the first multiplexer has outputted the pulse signal among the plurality of switching units according to the pulse count value from received from the pulse counter.

8. The apparatus of claim 6, wherein the computation circuit comprising:

an edge detector for detecting an edge of the pulse signal generated from the pulse generator and for providing an instruction signal to initiate measurement of a lapse time from a light emitting time point to a light receiving time point of laser sensors;

a lapse time measuring unit for measuring a lapse time from the light emitting time point to the light receiving time point of the laser sensors according to the instruction signal provided from the edge detector and the signal for the vehicle measurement received from the switch unit;

a first computing unit for computing height of an object on the road on the basis of the lapse time measured by the lapse time measuring unit; and

a second computing unit for computing height of the vehicle on the basis of the height information of the object on the road computed by the first computing unit and previously stored minimum height information with which something can be determined as a vehicle, and computing width and height of the vehicle on the basis of information of the number of laser sensors corresponding to the height information of the object which can be determined as a vehicle and the installation information of the laser sensors.

9. The apparatus of claim 1, wherein the processor means comprising:

a multiplexer for simultaneously driving a plurality of laser sensor groups corresponding to width of each road way by generating a pulse signal for driving the laser sensors, for transmitting simultaneously in parallel the pulse signal to each laser sensor group so that the plurality of laser sensors belonging to the same laser sensor group can be driven sequentially one by one, and for simultaneously receiving a signal outputted from each of laser sensor groups to measure the vehicle; and

a computation circuit for computing height and width of the vehicle on the basis of the pulse signal generated from the multiplexer, the signal for vehicle measurement received by the multiplexer and the installation information of the plurality of laser sensors.

10. The apparatus of claim 9, wherein the multiplexer comprising:

a pulse generator for generating a pulse signal for driving the laser sensors;

a pulse counter for counting the pulse signals generated from the pulse generator;

a first multiplexer for outputting simultaneously in parallel the pulse signal to the plurality of laser sensor groups each having the plurality of laser sensors which are adjacent within a distance that a mutual interference can occur, according to a pulse count value from the pulse counter, and for outputting sequentially one by one the pulse signal to the laser sensors in the same laser sensor group;

a plurality of switch units installed corresponding to the plurality of laser sensors belonging to each of the laser sensor groups, and for selecting a signal to measure the vehicle outputted from the laser sensors by the laser sensor groups and for outputting it to the computation circuit unit; and

a second multiplexer provided corresponding to each of the laser sensor groups, and selectively operating the switch unit corresponding to a corresponding laser sensor by laser sensor groups to which the first multiplexer has transmitted the pulse signal among the plurality of switch units according to the pulse count value received from the pulse counter.

11. The apparatus of claim 9, wherein the computation circuit comprising:

an edge detector for detecting an edge of the pulse signal generated from the pulse generator and for providing an instruction signal to initiate measuring a lapse time from a light emitting time point to a light receiving time point of the plurality of laser sensors;

a lapse time measuring unit for measuring a lapse time from the light emitting time point to the light receiving time point of the laser sensors in response to the instruction signal provided from the edge detector and the signal received by the multiplexer unit to measure the vehicle;

a first computing unit for computing height of an object on the road on the basis of the lapse time measured by the lapse time measuring unit; and

a second computing unit for computing height and width of the vehicle on the basis of the height information of the object on the road computed by the first computing unit and previously stored minimum height information of vehicle, and computing width and height of the vehicle on the basis of information of the number of laser sensors corresponding to the height information of the object which can be determined as a vehicle and the installation information of the laser sensors.

12. The apparatus of claim 8 or 11, wherein the lapse time measuring unit comprising:

a pulse generator; and

a pulse counter for initiating counting of pulses generated from the pulse generator in response to the instruction signal received from the edge detector, and for terminating the pulse counting in response to the signal received from the multiplexer unit to measure the vehicle and for outputting the lapse time to the first computing unit.

13. The apparatus of claim 8 or 11, wherein the lapse time measuring unit comprising:

a capacitor;

a charging current supplier for charging the capacitor in response to the instruction signal received from the edge detector and for stopping the charging of the capacitor in response to the signal received from the multiplexer to measure the vehicle;

a voltage detector for measuring a charged voltage of the capacitor;

a lapse time information storing unit for providing a previously stored lapse time data corresponding to the capacitor charge voltage; and

a means for reading the lapse time data corresponding to the capacitor charged voltage from the lapse time information storing unit, and for outputting the read lapse time data to the first computing unit.

14. The apparatus of claim 1, wherein the installation information of the laser sensors includes distance information between the plurality of laser sensors.

15. The apparatus of claim 14, wherein the distance information between the laser sensors includes length information towards a roadway width direction of the laser sensor or information of a value obtained by adding an installation interval between laser sensors to the length towards the roadway width direction of the laser sensor.

16. The apparatus of claim 1, wherein the signal to measure the vehicle includes an information signal of a lapse time from a time point that laser light is emitted from the plurality of laser sensors onto the road surface or onto the vehicle on the road to a time point that laser light reflected from the road surface or the vehicle on the road is received by the laser sensors.

17. A vehicle measuring method comprising the steps of:

sequentially driving a plurality of laser sensors separated from the road surface with a predetermined height and installed closely to each other corresponding to width of every roadway on the road;

measuring a lapse time from a time point of emitting a laser light emitted from the plurality of laser sensors according to driving of the plurality of laser sensors to a time point of receiving light;

calculating a distance corresponding to the measured lapse time; and

computing height and width of a vehicle on the base of the calculated distance value.

18. A vehicle measuring method comprising the steps of:

grouping a plurality of laser sensors separated from the road surface with a predetermined height and installed closely to each other corresponding to width of every roadway on the road into a plurality of groups corresponding to each roadway;

sequentially driving the plurality of laser sensors in a group one by one and simultaneously driving the plurality of laser sensor groups;

measuring a lapse time from a time point of emitting a laser light emitted from the plurality of laser sensors according to driving of the plurality of laser sensors to a time point of receiving light;

calculating a distance corresponding to the measured lapse time; and

computing height and width of a vehicle on the base of the calculated distance value.