GB2431273A

GB2431273A - Inductive detection of vehicles using an inclined sensor.

Info

Publication number: GB2431273A
Application number: GB0616718A
Authority: GB
Inventors: David Stuart Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-08-24
Filing date: 2006-08-24
Publication date: 2007-04-18
Anticipated expiration: 2026-08-24
Also published as: GB2431272B; GB2431272A; GB0616718D0; GB0616649D0; GB2431273B

Abstract

An array of inductive sensors 1 comprises at least one sensor 2 generating a vertical sensing region 7 and at least one other sensor 3, 4 for generating a sensing region 5, 6 inclined at an angle to the road surface 8. A region of space between each sensing area enables vehicles in the sensing regions to be monitored or analysed by control means. The sensing means is preferably installed in a single saw cut in the road surface. The sensors may be arranged across a lane of the highway or in an alternative arrangement between the lanes. In the latter embodiment the sensing regions associated with the inclined sensors may lie wholly within a lane with the vertical sensing region lying along the lane boundaries. In this arrangement the sensor array can detect vehicles changing lane.

Description

Narrow Inclined Vehicle Sensing Region This invention relates to a

transportation vehicle sensing device for the purpose of detecting the presence of a vehicle, more particularly to a narrow prefabricated sensor arrangement specifically preformed for installation into a single slot in the infrastructure surface below, or otherwise adjacent to, the vehicle. It relates to two previously published UK patent applications, namely numbers GB 2417 593A and GB 2 418 5 ISA.

For an inductive loop coil to be able to detect a vehicle, it is typically required that the vehicle be positioned directly above the coil winding or above a section of the coil. Therefore, to be detected, a vehicle must be positioned substantially directly above any part of the inductive coil. This depicts a nominally perpendicular, or vertical, sensing region utilised in normal detection situations.

::::. The present invention enables the substantial detection of a vehicle without the vehicle *..S being positioned directly above any part of the inductive loop sensor. The narrow sensing region vertically oriented above the narrow loop sensor is tilted, or inclined, from the * : : perpendicular orientation towards, but not reaching, the horizontal plane of the roadway.

* * Examples of the embodiment of the invention will now be described by reference to the accompanying drawings. **..

*. : Figure 1 is a sectional view of the narrow sensor I in the roadway, also illustrating the * S.

detection fields 5,6,7;

Figure 2 is a plan view of the narrow sensor I in a roadway lane 12, also illustrating the

detection fields 5,6,16; and

Figure 3 is a plan view of narrow sensors I located along the demarcation line 13 between roadway lanes 12, also illustrating the detection fields 14,15,16.

The narrow inductive sensor I is a modified form of the two published UK patent applications GB 2417 593A and GB 2418 5 ISA. The narrow inductive sensor I consists of one or more vertically oriented inductive sensors 2 and one or more inclined inductive sensor 3,4. The vertical sensor 2 gives rise to a perpendicular sensing region 7 and the inclined sensors 3,4 give rise to an inclined, leaning or tilting, sensing region 5,6.

The distance A is the effective detection gap 10, along the direction of traffic, between the inclined sensing regions 5,6. The height B is the height 9 above the roadway of the effective detection gap 10. The distance C is the effective horizontal distance 11 away from the sensor I at which a vehicle is detected while approaching the sensor 1.

When a rectangular inductive coil is to be used to determine the presence, length and speed of a vehicle, it would normally require that two or more rectangular inductive coils be installed in each lane at the given location. For a moving vehicle, detection would first occur in the primary sensing region 6 and subsequently in the secondary sensing region 5. The effective distance 10 between the primary and secondary sensing regions 5,6 would be used by control equipment to determine the length and speed of the vehicle.

The centre sensing region 16 is a projection of the vertical sensing region 7. The centre sensing region 16 can be used to determine whether a simultaneous detection in the inclined sensing regions 5,6 are due to a single vehicle positioned above the sensor or due to more than one vehicle, in which the front part of one vehicle is positioned above the primary sensing * * region 6 and the rear part of another vehicle is positioned above the secondary sensing region 5.

If no vehicle is detected in the centre sensing region 16, then it would be deduced that two separate vehicles are being detected by the single narrow sensor 1.

*....: For a given sensor I, the centre sensing region 16 can be used to determine whether a simultaneous detection in the inclined regions 5,6 are due to a single vehicle straddling more than one lane 12 or due to more than one vehicle. If a vehicle was detected in the near sensing region IS, the far sensing region 14 and the centre sensing region 16, then it would be deduced *.S.

that a single vehicle is straddling both lanes 12. If a vehicle was detected in the near sensing region 15 and in the far sensing region 14 but not in the centre sensing region 16, then it would be deduced that two vehicles are being detected at the same point in time.

Claims

I. A sensing apparatus for the detection of transportation vehicles, in which: a sensing means is located in a roadway; the roadway is the structure on which vehicles traverse; a vehicle is detected without being positioned directly above any part of the sensing means; a sensing region is generated by the sensing means; the vertical sensing region is oriented perpendicularly to the plane of the roadway such that the angle of elevation of the vertical sensing region is nominally at a rigJn angle with respect to the plane of the roadway, and substantially in the direction of traffic; * * . . an inclined sensing region is oriented in such a way as to form an acute angle with respect to the **S* plane of the roadway, and substantially in the direction of traffic; the sensing means consists of one or more sensors which generate one or more vertical sensing regions; * S the sensing means consists of one or more sensors which generate one or more inclined sensing *.*s regions; * S * * 0I control and monitoring means controls the sensing regions and/or analyses the data from the sensing means; any part of the inclined sensing region is entered by a moving vehicle in a given direction of travel, before any part of the vehicle becomes perpendicularly aligned with any part of the sensing means, with respect to the plane of the roadway; any part of the inclined sensing region is entered by a moving vehicle in a given direction of travel, after any part of the vehicle first became perpendicularly aligned with any part of the sensing means, with respect to the plane of the roadway; a region of space exists in the direction of traffic between any two sensing regions, which enables vehicles in the sensing regions to be monitored and/or analysed by the control and monitoring means; two or more sensing regions generated by a sensing means to enable vehicle length and/or speed to be determined; a sensing means consisting of two or more sensing regions each with a different angle of elevation with respect to the plane of the roadway, in which one or more of the upstream sensing regions is/are designated as the primary sensing region, and one or more of the downstream sensing regions is/are designated as the secondary sensing region;
2. A sensing means as claimed in claim I, in which the sensing means does not require more than one position in each lane of the roadway.

: *
3. A sensing means as claimed in claims I and 2, in which the sensing means consists of: ***.

a vertical sensing region to provide indication that any part of a vehicle has become S...

perpendicularly aligned with the sensing means, with respect to the plane of the roadway;

S

*S*S.. * *

an inclined sensing region upstream of the sensing means to provide indication that any part of a S.....

* vehicle has entered the primary sensing region; * * I an inclined sensing region downstream of the sensing means to provide indication that any part *..: of a vehicle has entered the secondary sensing region;
4. A sensing apparatus as claimed in claims 1, 2 and 3, in which the vertical sensing region is used to determine whether simultaneous vehicle detection in both the primary and secondary sensing regions is due to: a single vehicle detected within both primary and secondary sensing regions; or one vehicle detected within the primary sensing region and another vehicle detected within the secondary sensing region.
5. A sensing means as claimed in claims 1, 2 and 3, in which the sensing means consists of: a vertical sensing region; one or more inclined sensing regions inclined towards the nearside edge or verge of the roadway; and one or more inclined sensing regions inclined towards the offside edge or verge of the roadway.
6. A sensing apparatus as claimed in claims 1, 2 and 5, in which the vertical sensing region is positioned at or near the division of two adjacent lanes, or at one side of a lane, and is used to determine whether simultaneous vehicle detection in both the nearside and offside sensing regions is due to: a single vehicle straddling both lanes; or :.:. one vehicle detected in one of the lanes or verges and another vehicle detected in the other lane orverge.

**.. *. * *
7. A sensing apparatus as claimed in claims 1, 2, 3, 4, 5 and 6, in which: *** the sensing means includes one or more narrow inductive loop arrangements installed in one or * . : more sawcut slots; and/or * ** the sensing means includes box-cut loop arrangements of any shape or circular-cut loop arrangements.
8. A sensing apparatus as claimed in claim I and substantially as herein described.