GB2368959A

GB2368959A - Energy management system for vehicle monitoring equipment

Info

Publication number: GB2368959A
Application number: GB0027331A
Authority: GB
Inventors: Peter Michael Hutchinson
Original assignee: D SYSTEMS Ltd AG
Current assignee: D SYSTEMS Ltd AG
Priority date: 2000-11-09
Filing date: 2000-11-09
Publication date: 2002-05-15
Also published as: GB0027331D0

Abstract

An apparatus is provided such that when a low powered sensor detects the presence of a vehicle a control means activates a high powered traffic monitoring device thus optimising the energy usage of the equipment. Preferably, once the frequency of detected vehicles reaches a predefined limit the control means will restrict the activation of the monitoring device. The control means may be a power switch to control the activation of the device. The high powered device may be a passive IR sensor, radar activated camera, digital beacon or an automatic licence plate reader. The power source may be a battery and rechargeable using solar power.

Description

ENERGY MANAGEMENT SYSTEM

This invention relates to an energy management system for traffic monitoring applications.

The use of traffic monitoring devices situated on road-sides, centre divides and gantries have become common and wide-spread. These devices typically take the form of radar-actuated cameras which capture information relating to vehicles that exceed the speed limit ; licence plate readers which use an infra-red actuated camera to obtain details of a vehicle's registration plate, thereby allowing a comparison to be taken between two cameras and thus a state of the road's congestion to be ascertained; and Dedicated or Digital Short Range Communication (hereinafter DSRC) beacons which have traffic management applications, such as automatic road tolling.

The fundamental problem with these devices is that they have a high power consumption and typically reside in an activated state twenty-four hours per day, year round, even when there are no vehicles on the road. This makes it necessary for each device to have an uninterrupted power supply sourced from a power grid.

A further problem that consequently arises due to the requirement of a power grid supply occurs in an area where it is desirable to place a monitoring device, but which has no conveniently available link to the grid. Since the devices are usually in a permanently activated state, batteries will quickly drain and require replacing or recharging, and alternative energy collectors are typically unable to cost-effectively

provide sufficient levels of power on an uninterrupted basis to permanently energise the devices.

The present invention seeks to overcome these problems.

According to a first aspect of the present invention, there is provided an energy management system comprising a sensing device for detecting the presence of a vehicle and having a relatively low power consumption, a traffic monitoring device for obtaining information about the vehicle and having a relatively high power consumption, and control means, responsive to a vehicle detection signal from the sensing device, for activating the traffic monitoring device so that energy usage by the traffic monitoring device is optimised or substantially optimised.

Preferred and/or optional features of the first aspect of the present invention are set out in claims 2 to 7.

According to a second aspect of the present invention, there is provided an energy management system in accordance with the first aspect of the present invention in combination with a power source, the power source supplying the sensing device and the traffic monitoring device.

Preferred and/or optional features of the second aspect of the present invention are set out in claims 10 and 11.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawing, in which is shown a schematic representation of one embodiment of an energy management system and a power source.

Referring to the drawing, the energy management system comprises a sensing device 10, a traffic monitoring device 12, and control circuit 14.

The sensing device 10 has a low power consumption and is, typically, a movement sensor, such as a passive infra-red (PIR) sensor.

The traffic monitoring device 12 has a high power consumption and may typically be a radar-activated speed camera, an infra-red activated licence plate reader, and/or a DSRC beacon.

The control circuit 14 is connected to the traffic monitoring device 12 in such a manner as to be able to activate and deactivate it. Deactivation may include being placed in a'stand-by'or'sleep'mode.

The operation of the control circuit 14 is governed by the sensing device 10, based on whether the sensing device 10 detects the presence of a moving vehicle.

In this embodiment, although the control circuit 14 includes switch 16 by which a power supply to the traffic monitoring device 12 can be controlled, other means can

be utilised by which a reduction in energy usage by the traffic monitoring device 12 can be achieved.

In use, the sensing device 10 is set to be able to detect the presence of a moving vehicle. When a vehicle is detected, the sensing device 10 outputs a signal to the control circuit 14, which in turn causes the switch 16 to close so that the power supply to the traffic monitoring device 12 is reconnected. The traffic monitoring device 12 is thus activated, or'brought on-line', in preparation for it to record relevant information about the passing vehicle.

When a vehicle is not detected by the sensing device 10, the control circuit 14 causes the switch 16 to open and thereby place the traffic monitoring device 12 in a deactivated, or'off-line', state.

By the use of this energy management system, energy usage by a high power consumption traffic monitoring device can be significantly reduced and thus optimised or substantially optimised.

This reduction in the amount of energy required to power a traffic monitoring device makes the requirement of a power supply sourced from a power grid unnecessary. As shown in the drawing, the energy management system can have a dedicated power source 18 which utilises one or more batteries (only one being shown at reference 20) to supply power to the sensing device 10 and the traffic monitoring device 12.

The one or more batteries 20 may be rechargeable, in which case the power source 18 may include an alternative energy collector 22, such as a solar panel, for use as a recharger.

The alternative energy collector 22 will typically be of suitable size to at least enable the one or more batteries 20 to have sufficient charge to provide a permanent and uninterrupted power supply to the sensing device 10 and an occasional, or'ondemand', supply to the traffic monitoring device 12.

Typically, owing to the high power consumption of the traffic monitoring device 12, a battery power supply will only be able to support a predetermined rate of operation of the traffic monitoring device 12, i. e. a certain number of activations or operations per minute.

To prevent the traffic monitoring device 12 being in a permanently or unsupportable activated state for extended or prolonged periods, for example when the frequency of vehicles is high such as at rush-hour, the control circuit 14 can be set to recognise when the sensing device has detected a frequency of vehicles which exceeds a predetermined limit that can be handled by the power source 18. In this case, the control circuit 14 controls the switch 16 in such a manner that the activation of the traffic monitoring device 12 is restricted to a level that can be supported by the power source 18.

For example, if the dedicated power source 18 can support the traffic monitoring device 12 at a rate of activation or operation in the order of fifteen times per minute (once every four seconds), the control circuit could be set to only permit activation or operation of the device 12 once in every four seconds.

It should be noted that the control circuit 14 may form part of the sensing device 10.

The embodiment described above is given by way of example only, and various modifications will be apparent to persons skilled in the art without departing from the scope of the invention. For example, the sensing device may be one that can detect a vehicle whether or not it is moving.

Claims

1. An energy management system comprising a sensing device for detecting the presence of a vehicle and having a relatively low power consumption, a traffic monitoring device for obtaining information about the vehicle and having a relatively high power consumption, and control means, responsive to a vehicle detection signal from the sensing device, for activating the traffic monitoring device so that energy usage by the traffic monitoring device is optimised or substantially optimised.

2. An energy management system as claimed in claim 1, wherein, when a frequency of vehicles detected by the sensing device exceeds a predetermined limit, the control means restricts the activation of the traffic monitoring device.

3. An energy management system as claimed in claim 1 or claim 2, wherein the control means includes switching means by which the power supply to the traffic monitoring device is controlled to thereby control its activation.

4. An energy management system according to any one of the preceding claims, wherein the sensing device is a passive infra-red (PIR) movement sensor.

5. An energy management system according to any one of the preceding claims, wherein the traffic monitoring device is a Dedicated or Digital Short Range Communication (DSRC) beacon.

6. An energy management system as claimed in any one of claims 1 to 4, wherein the traffic monitoring device is a licence plate reader.

7. An energy management system as claimed in any one of claims 1 to 4, wherein the traffic monitoring device is a radar-activated camera.

8. An energy management system substantially as hereinbefore described with reference to the accompanying drawing.

9. An energy management system as claimed in any one of claims 1 to 7 in combination with a power source, the power source supplying the sensing device and the traffic monitoring device.

10. The combination as claimed in claim 9, wherein the power source comprises at least one battery.

11. The combination as claimed in claim 10, wherein the said at least one battery is a rechargeable battery and the power source further comprises a solar energy collector which is connected to the said at least one rechargeable battery to recharge it.

12. The combination substantially as hereinbefore described with reference to the accompanying drawing.