CA2377651A1

CA2377651A1 - Infrared presentation system

Info

Publication number: CA2377651A1
Application number: CA002377651A
Authority: CA
Inventors: Bojan Nokovic
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-03-13
Filing date: 2002-03-13
Publication date: 2003-09-13

Abstract

The invention allows pedestrian, vehicle or bicycle to signalize its presence on intersection by using IR(Infrared) transmitter. The signal is sent to IR
Receiver embedded into Pedestrian Push Button Box. From there signal is sent through existing wires to the traffic light control,system. Using this information the system can modify time for the green light on the same way it is modified when pedestrian pushs the button on the Push Button Box.
This will improve traffic flow efficiency on any kind of intersection specially on intersection of minor and major streets where the time duration of green light on the main street is much longer than time of green light on the minor street.

Description

DETAILED DESCRIPTION OF THE INVENTION
The typical situation is shown on FIG. 1. Cars 1 and 2 are waiting for the green light on the intersection between minor and major street.
Using IR Transmitter vehicle sends signal to the IR Receiver embedded into Pedestrian Push Button Box(PPBB) on the either poll 1 or poll 2 (FIG. 1 ).
The effect of receiving signal from IR Transmitter is same as pushing button on PPBB and it will turn ON
existing LED on the box as indicator that signal is received.
1R Receiver covers 90 Degrees area and can receive signal from the IR
Transmitter from the distance of up to 12 m. On the FIG. 2 PPBB with IR receiver on the front side is shown. If covering area of 90 Degrees is not enough additional receiver sensors can be placed on each side of the box so that up to 270 Degrees can be covered by one IR Receiver. This Receiver can be easily mounted into existing Pedestrian Push Button Box.
On the FIG. 3 the typical wiring is shown. Signal wire from IR Receiver and from Push Button can be joined and connected as one wire to the Intersection Control Cabinet which makes decision about timing on the intersection.
1R Transmitter The basic IR transmitter is a small handheld device, having a convenient shape (key-fob for example), made of an impact resistant plastic, for ruggedness. The transmitter circuit inside plastic enclosure comprises:
1 ) A (user replaceable) long life battery serving as the power source for the IR transmitter.

2) An electric circuit capable of generating a code modulated electric signal suited to drive an infrared LED.
The circuit may be hardware configurable, through jumpers installed in the manufacturing phase, to generate one of several available codes identifiable at system level as pedestrian, bicycle, vehicle, emergency etc.
code.

3) A momentary contact trigger switch actuated by user through a thumb or index button placed in a convenient position on the plastic enclosure of the transmitter.

4) An infrared LED (or several LEDs for longer range) functioning as the IR
emitter.
The modulated IR radiation emitted by the LED is in the near-visible wavelength range. Therefore it suffers little shielding from regular optical glass, making the fR transmitter useable from inside the cabin of a vehicle.
The specific encoding of the IR beam allows the receiver to identify a valid transmission from other IR
signals which may reach it. For example the coding of the traffic transmitter is different from the emission of a garage door opener transmitter or a VCR
remote.
1R Receiver The IR receiver is the essential element in the IR Presentation system. It has the capability to identify the presence and type of transmitter, whether pedestrian, vehicle or bicycle; and convey the information to the traffic light control system.
In its most basic embodiment, which can be readily implemented as a simple upgrade of the existing traffic lights present at many intersections, the receiver would comprise:

1 ) A weatherproofed enclosure with an IR transparent window.
2) Electronic circuitry inside the enclosure to detect and decode valid IR
signals and reject unwanted ones.
3) A power and signal connector to connect to the traffic light cantrol system.
The simplest yet very useful application of the receiver is in the intersections already equipped with a pedestrian push button.
The pedestrian actuated push-button has a simple two wire switch which momentarily closes the circuit when a person pushes the button. The closing of the switch circuit informs the traffic lights controller circuit that somebody is waiting. The controller takes the appropriate action of cycling the lights. The disadvantage of this system is that a motor vehicle or cyclist approaching the intersection on the secondary road' may have to wait for a long time for the light to change green if no pedestrian is present to push the button. This is frequently the case, because many small intersections traffic lights have no means to identify vehicle traffic and their control system relies solely on present timed cycling if the pedestrian button is not pushed.
The proposed IR Presentation system receiver, in its simplest form, would address exactly the type of situation described above. In this case the receiver would be installed in circuit in parallel with existing pedestrian button. The pedestrian button functionality is preserved unchanged, but the driver of motor vehicle, a cyclist or pedestrian equipped with IR transmitter would have the means to make their presence known to the traffic light control system, benefiting a sooner green. The physical installation of the receiver can be done on the luminaries, nearby the pedestrian button, or maybe in higher position for better visibility. Alternatively, the receiver may be included in the pedestrian button enclosure or even in lighting housing. The electrical power required by the receiver is 1 Watt or less and it can be provided from existing system as 12/241361115V ac or dc.

Claims

1) IR Presentation system can be used as low-cast replacement for existing systems of Loop Detectors(buried below the pavement) and Video Based Car Detection System, specially on the intersection between minor and major road.

2) It is possible to implement different code on IR Transmitter for pedestrian, vehicle, VIP or Official vehicles so that Control Cabinet can make appropriate action according to the level of importance

3) IR Presentation system can be also used together with existing systems of car, bicycles and pedestrian detections to improve over all performance

4) No problem of detecting small metallic objects such as bicycles - typical problem for the systems with Loop Detectors buried under pavement

5) IR Receiver can receive the signal from IR Transmitter from the distance of up to 12 m and covers 90 Degrees area. It is possible to built up to three receiving sensors on the same receiving board, so the covering area can be increased to 270 Degrees.