WO2005086111A1

WO2005086111A1 - Road traffic monitor

Info

Publication number: WO2005086111A1
Application number: PCT/GB2005/000848
Authority: WO
Inventors: Martin Edward Dicks
Original assignee: Astucia UK Ltd
Current assignee: Astucia UK Ltd
Priority date: 2004-03-06
Filing date: 2005-03-04
Publication date: 2005-09-15
Anticipated expiration: 2006-09-06
Also published as: GB0405150D0; GB0619260D0; GB2427297A

Abstract

The invention relates to a road traffic monitor. There are a number of circumstances where effective traffic monitoring is highly desirable. Thus, and for example, there is the general management of traffic where knowledge of the volume and types of vehicles can provide data to allow adjustment or redirection of traffic flow. There has been the growing use of roadside cameras to provide information relating to vehicles and number plates, predominantly part of vehicle speed control, but which can be adapted to provide other traffic related information. However, road side cameras are obtrusive, and not environmentally friendly, and are relatively expensive to install and maintain and vandalism is a particular proem with high attendant costs. An object of the invention is to avoid the above disadvantage whilst functioning as required, an objective met by a road traffic monitor comprising a socket, a lens mounted on the socket, and a camera located in the socket below the lens, refraction of light through the domed lens to the camera lens providing to the camera a field of vision along a predetermined direction to allow a vehicle or a part thereof to be photographed. Preferably, and with a still camera, there may be sensor means to trigger the camera when a vehicle is in a position to be photographed.

Description

ROAD TRAFFIC MONITOR This invention relates to a road traffic monitor. There are a number of circumstances where effective traffic monitoring is highly desirable. Thus, and for example, there is the general management of traffic where a knowledge of the volume and types of vehicles can provide data to allow adjustment or redirection of traffic flow. More particularly there is speed enforcement on predetermined road sections and vehicle tracking, together with such as approved entry into locations, bus lane monitoring, bus schedule checking and vehicle usage of toll roads. In all such areas there is an essential need to identify a vehicle and record its number plate for entry in an appropriate data base for subsequent analysis, and to provide an immediate signal when a stolen vehicle has been monitored. There has been the growing use of roadside cameras to provide information relating to vehicles and number plates, predominantly part of vehicle speed control, but which can be adapted to provide other traffic related information. However, road side cameras are obtrusive, and not environmentally friendly, and are relatively expensive to install and maintain. Vandalism is a particular problem with high attendant costs. The accuracy of existing number plate reading equipment that has been used hitherto is a function of the complex algorithms that are necessary to read a number plate of an approaching vehicle with the camera mounted on the side of the road or on a gantry spanning a roadway, these algorithms add to the inaccuracies of the reading and therefore have a wide tolerance of accuracy. In addition to this, a major problem that affects all existing cameras is that the headlights from approaching vehicles can cause the image to over expose and in this situation the number plate becomes unreadable. The object of the present invention is to provide a means of monitoring of road traffic that reduces to a significant degree those disadvantages mentioned above, and which can be adapted for other purposes. According to the present invention, a road traffic monitor comprises a socket, a lens mounted on the socket, and a camera located in the socket below the lens, refraction of light through the domed lens to the camera lens providing to the camera a field of vision along a predetermined direction to allow a vehicle or a part thereof to be photographed. Preferably, and with a still camera, there may be sensor means to trigger the camera when a vehicle is in a position to be photographed. Equally, the camera maybe a video camera that runs continuously. The lens may be flat or domed and the camera may be so located below the lens such that the camera lens faces upwards, and the lens be such that it is mono-directional in the sense of allowing light to reach the camera lens. Here, the camera would record vehicles travelling in one direction only. Alternatively, the lens may be such as to be bi-directional in the sense of allowing light to reach the camera lens from two opposite directions, when the camera can record traffic travelling in both directions. It is further possible with a circular lens that recordal can be multi-directional in the sense of allowing light to reach the camera lens over360°, and allow the recording of traffic irrespective as to its particular location in relation to the socket. Ideally, the lens on the socket has a large radius of curvature such that it only protrudes marginally above the edge of the socket, and when the socket is positioned in a hole formed in the road the lens lies substantially flat to the road surface thereby minimising the possibility of damage by traffic at large, and specifically by such as snow ploughs when they are clearing the road surface. Additionally it is desirable to form the lens from a so-called "self-healing" plastics material, with a memory that results in scratches being self healing. It is further possible to mount the domed lens on the socket with an interposed resilient support, to allow the domed lens to yield and sink into the socket if it is hit by vehicle wheels or a snow plough blade. The camera can be mounted in the socket on a cradle, to ensure that the camera is held still and hence avoid any camera judder that would affect the clarity of a photograph taken by it. Preferably, the camera, still or moving, is a digital camera able to take and store a considerable number of photographs. The camera may be hard wired to a suitable power source, but also may be operated by batteries, preferably rechargeable batteries, and solar cell/capacitor means provided to charge the batteries during daylight hours, to maintain the camera operational during the hours of darkness. The sensor means, when used, to trigger the camera may be an optical sensor, but preferably is an infra red or sonic detector better suited to night time operation. The socket with its camera, may also be provided with reflectors for the assistance of drivers during hours of darkness, and ideally a number of camera sockets are strategically located along a length of road. When it is intended that the camera stud is for traffic speed monitoring, vehicle speed detection means may be provided in remote spaced location along a road, and connected to the camera in the socket, such that if a vehicle is detected travelling at a higher speed than the limit for the road at issue, the camera is triggered to photograph its number plate. Equally, two spaced camera studs could have integral speed detection means, and when again the number plate of a vehicle travelling at an illegal speed can be photographed. A memory card associated with the camera may be periodically removed and "read", but desirably a means of providing an RF signal may be provided in the socket to relay information to a roadside receiver from where it can be relayed to a central control unit for analysis and processing. However, and advantageously, a microprocessor may be provided, roadside located or positioned within the monitor, and hardwired to mains supply and to the camera. The microprocessor may serve as a speed detector for vehicles travelling along the road in which the monitor is mounted, and serve to signal the camera to record a vehicle that is detected as travelling in excess of the speed limit for the road in question. Instead of selective photographing of speeding vehicles, the system associated with the camera in the socket may be such that all passing vehicles are photographed, and that information relayed continuously to a central control unit for comparison with listings of number plates of known stolen vehicles. Equally, and in a security context, the underside of vehicles can be photographed, to match a car type to a database and to scan for explosives. In a different application of vehicle recognition, a memory can be provided and associated with the camera, the memory containing information regarding the number plates of approved vehicles. Thus, and for example at the entrance to a restricted area or car park, an approaching vehicle can be photographed, and if its number plate recognised, a barrier can be operated to allow the vehicle to enter. Similar considerations apply to such as bus lane monitoring, where the number plates of buses/taxis that are expected to use a particular stretch of road can be stored, and compared with the number plates of vehicles photographed when using the bus lane. Vehicles with no authority to use the bus lane can then be dealt with appropriately. Equally the number plate of a bus photographed in a bus lane can give information of its location and time, to determine if it is meeting an approved timetable. As an extension to vehicle recognition, a means may be provided in the socket to sense when the front of a vehicle reaches the socket and sense when the rear of the vehicle leaves the socket to provide information of vehicle length. By providing a central register of number plates and vehicle lengths, a photograph of a number plate and details of the length of that vehicle can be passed simultaneously to the central register, and if the photographed number plate is stored with a different vehicle length that has been sensed, it would signal that a vehicle is using false number plates. It will be understood that the above proposed uses of a camera stud is not exhaustive. By locating a camera in a road stud it can be used in a wide number of applications. Thus, it can be positioned along a road length, or at access and exit ramps of motorways at no greater installation cost than that of a conventional reflective stud, and provides a camera that is considerably less obtrusive than existing road side cameras, is much less susceptible to accidental damage and vandalism, and avoids distortion of an image as can be caused by vehicle headlights. Two embodiments of the invention will now be described with reference to the accompanying drawings in which:- Figure 1 is a schematic sectional side elevation of one embodiment of road traffic monitor according to the invention; Figure 2 is a perspective view of a second embodiment of road traffic monitor according to the invention; Figure 3 is a side elevation of Figure 2 with the socket removed; Figure 4 is a section on the line 4-4 of Figure 3; Figure 5 is an exploded perspective view of the inner components of the second embodiment of the invention, to reduced scale; and Figure 6 is a schematic view of a road mounted monitor and an associated control and storage unit. In Figure 1 a road traffic monitor 1 has a socket with an upper part 2 and a lower part 3.

Located in the upper part 2 is a lens 4 with a shaped lower face 5 and recesses to receive solar cells 6. The solar cells 6 are connected to a rechargeable battery or capacitor 7. In the lower socket part 3 a camera 8 is located on a mounting plate 9 and within a camera holder 10. The outer surface of the lens 4 has a large radius of curvature, and such that with the socket located in a hole in a road surface, the lens protrudes only marginally above the level of the road, thus minimising damage to the lens by passing traffic or by such as the blades of a snowploughs. The lens 4 and its shaped under surface 5 is such that light 11 approaching the lens from both sides in the direction of the road in which the monitor is located is refracted and directed at the lens of the camera 8, allowing the camera to photograph vehicles to both sides of the monitor 1. Within the socket lower part 3 is a detector 12 to sense the presence of an approaching vehicle along with a sight path 13, or receive a signal 13 from a remote source to activate the camera lens and capture the image of the vehicle number plate. In Figures 2 to 6 a second embodiment of road traffic monitor 14 has a socket 15 secured to a base 16. To the opposite, upper, end of the socket, a lens cover or lens head 17 is provided with an aperture 18 aligned with a shaped lens 19 fitted in a lens holder 20 located within the socket. The lens holder 20 is fitted to a camera holder 21 having an aperture 22 in its upper face, and a camera 23 is secured to a mounting plate 24. The lens head 17 has a large radius of curvature such that when the socket is located in a hole in the road, the lens head protrudes marginally above the level of the road, to minimise damage to the lens head by passing traffic and by such as the blades of snowploughs. The height of the lens head is further reduced by providing a flattened area 25 to one side of its crown, and by having a flattened area26 co-planar with the outer surface of the lens 19. With the socket mounted in the road, and with the lens 19 aligned with the direction of traffic moving along the road, an effective means of photographing traffic, continuously or selectively is provided. As with the embodiment of Figure 1 , solar cells or rechargeable batteries can be provided, but preferably the monitor is hard wired by a cable 27 to a mains supply strategically located to the side of a road. As is indicated in Figure 6, the monitor is road mounted and positioned on a carriageway to give its camera a clear view of an approaching vehicle, or ensure that the vehicle passes over the monitor. To the side of the road is a microprocessor 28 connected by a cable 29 to the camera in the socket 15. The camera 18 is a digital camera with a single photograph and video facility. It will be understood that the microprocessor can be positioned within the socket. Thus, with power supplied to the camera, its video facility runs continuously, filming each approaching vehicle, and discarding that image unless instructed otherwise. When signalled by microprocessor 28, the camera captures the image of the number plate of a selected vehicle, and feeds the image back to the microprocessor for storage, or converts the image into character recognised form, and signals the vehicle number to the microprocessor for storage. Thus, the road side microprocessor can be a speed detector to signal the camera to capture the number of a vehicle sensed travelling at a speed greater than the limit for that road.

Alternately, and with a socket mounted microprocessor, two adjacent monitors in the road can be connected, to sense the speed of a vehicle travelling between them and to signal the camera in the second socket to capture the vehicle number. The microprocessor can also sense the presence of a vehicle in such as a bus-only lane, and signal the camera to capture its number plate. Equally, the microprocessor can have a memory including the numbers of stolen vehicles, the camera signalling the microprocessor with the numbers of every passing vehicle, to enable a signal to be released by the camera that a stolen vehicle has passed it at an identified date and time. Also, the camera can have software to scan the underside of a passing vehicle, having captured its number, to signal the microprocessor that explosives have been sensed on a vehicle of an identified number. With secure car parking, the microprocessor located at an entrance with a monitor mounted in the road approaching the entrance can have a memory on which approved numbers are stored, the camera signalling the microprocessor with the number of each approaching vehicle, and if the number matches with a number in the microprocessor memory, the microprocessor signals door or barrier means to open to allow the approved vehicle in.

Claims

CLAIMS 1. A road traffic monitor characterised by a socket, a lens mounted on the socket, and a camera located in the socket below the lens, refraction of light through the domed lens to the camera lens providing to the camera a field of vision along a predetermined direction to allow a vehicle or a part thereof to be photographed. 2. A road traffic monitor as in Claim 1 characterised in that there is a sensor means to trigger the camera when a vehicle is in a position to be photographed. 3. A road traffic monitor as in Claim 1 characterised in that the camera is a video camera that runs continuously. 4. A road traffic monitor as in any of Claims 1 to 3 characterised in that the lens is domed and mono-directional to record vehicles travelling in one direction only. 5. A road traffic monitor as in any of Claims 1 to 3 characterised inthat the lens is bidirectional to record vehicles in two opposite directions. 6. A road traffic monitor as in any of Claims 1 to 3 characterised in that the lens is multi- directional to record vehicles approaching the monitor in any direction. 7. A road traffic monitor as in any of Claims 1 to 6 characterised in that the lens on the socket has a large radius of curvature such that it only protrudes marginally above the edge of the socket, and when the socket is positioned in a hole formed in the road the lens lies substantially flat to the road surface thereby minimising the possibility of damage by traffic at large. 8. A road traffic monitor as in any of Claims 1 to 7 characterised in that the lens is formed from a so-called "self-healing" plastics material, with a memory that results in scratches being self healing. 9. A road traffic monitor as in any of Claims 1 to 8 characterised in that the domed lens is mounted on the socket with an interposed resilient support, to allow the domed lens to yield and sink into the socket if it is hit by a vehicle wheel. 10. A road traffic monitor as in any of Claims 1 to 9 characterised in that the camera is operated by mains supply by being hard wired to an available source. 11. A road traffic monitor as in any of Claims 1 to 9 characterised in that the camera is battery powered, and solar cells and capacitor means provided to charge the batteries. 12. A road traffic monitor as in any of Claims 1 to 11 characterised in that optical sensor means are provided to activate the camera. 13. A road traffic monitor as in any of Claims 1 to 11 characterised in that infrared means are provided to activate the camera. 14. A road traffic monitor as in any of Claims 1 to 11 characterised in that sonic means are provided to activate the camera. 15. A road traffic monitor as in any of Claims 1 to 9 characterised in that a microprocessor is provided, hard wired to mains and to the camera. 16. A road traffic monitor as in Claim 15 characterised in that the microprocessor is remotely located from the monitor. 17. A road traffic monitor as in Claim 15 characterised in that the microprocessor is located within the monitor. 18. A road traffic monitor as in any of Claims 15 to 17 characterised in that the microprocessor serves as a speed detector to sense the speed of vehicles and signal the camera to record the vehicle number. 19. A road traffic monitor as in any of Claims 15 to 18 characterised in that the camera is a digital video camera that continuously records the numbers of vehicles approaching the monitor and discards them unless signalled by the microprocessor to retain the number of a selected vehicle. 20. A road traffic monitor as in Claim 19 characterised in that the microprocessor memory is provided with vehicle numbers that need to be recognised. 21. A road traffic monitor as in Claim20 characterised in that the stored numbers are those of stolen vehicles. 22. A road traffic monitor as in Claim 20 characterised in that the stored numbers are those of approved vehicles to be allowed access to an otherwise closed area. 23. A road traffic monitor as in any of Claims 15 to 22 wherein software associated with the camera causes the conversion of a photographed number plate to be converted into characters to be relayed to the microprocessor. 24. A road traffic monitor as in any of Claims 15 to 23 wherein vehicle numbers and the length of the vehicle are stored in the microprocessor, and the monitor provided with sensors to sense the front and the rear of a vehicle passing the monitor, whereby details of the number and the length of a passing vehicle are fed to the microprocessor, for comparison with the stored number and length, to sense a difference that would indicate that a vehicle is utilising false number plates.