WO2002089090A1

WO2002089090A1 - Device and method based on permanent magnets for supplying information to vehicles

Info

Publication number: WO2002089090A1
Application number: PCT/HU2002/000034
Authority: WO
Inventors: Sándor HÉDL
Original assignee: Hedl Sandor
Priority date: 2001-04-27
Filing date: 2002-04-26
Publication date: 2002-11-07
Also published as: HUP0101720A2; DE60205895D1; EP1395967B1; DE60205895T2; ATE303644T1; HU224667B1; EP1395967A1; ES2248543T3; HU0101720D0

Abstract

Method applicable to supplying binary coded time invariant information to vehicles travelling along roadways, in which permanent magnet pieces disposed at predetermined positions and embedded in the road surface are provided, and induction detectors are located on a structural member of the vehicles which passes over the magnets within a certain range of action, and the output signals of the induction detectors varying with time are processed by a processing unit decoding binary code sequences, and the decoded information is displayed and/or used for activation of an operational unit. The permanent magnet pieces are arched flat bar-shaped magnetic elements(1). Perpendicular to direction of travelling of vehicles pockets(6) are formed in the road surface, the cross-section of the pockets corresponds to a circle segment, and they are arranged in a predefined way, and the magnetic elements are located and fixed in these pockets with their concave side facing upwards.

Description

DEVICE AND METHOD BASED ON PERMANENT MAGNETS FOR SUPPLYING INFORMATION TO VERHICLES

The invention relates to a method of supplying binary coded time invariant information to vehicles travelling along roadways, wherein permanent magnet pieces disposed at predetermined positions and embedded in the solid road surface are provided and the vehicles are equipped with induction detectors located on a structural member which passes over the magnets within a certain range of action, and the output signals of the induction detectors varying with time are processed by a processing unit decoding binary code sequences, and the decoded information is displayed and/or used for automatic activation of a certain operational unit.

The invention further relates to permanent magnet pieces for using the method.

There are several known proposals where effort is made to enable signals or pieces of information to be transmitted partly to the driver of a vehicle partly to different units that somehow have relations with traffic and automatically get active during transport. This unit can be for example an instrument or dispatcher system indicating the position of a vehicle, but also, an adjusting system that automatically sets the technical parameters of vehicles (e. g.: shock absorption) according to certain road conditions as well as marking under-road public utilities may be realised this way.

One approach is where active signalling elements are used. A channel of information flow is produced in such a way that signals are transmitted from transmitters located along the roadway and received by receivers located on a vehicle. The disadvantage of this approach is that the transmitter needs energy source and it can easily get damaged.

Another approach is where passive signalling elements are used. Hungarian patent application HU 219 078 describes an embodiment in which passive signalling elements are used for giving notice about location of impending danger. Preferably in the vicinity of the location to be marked permanent magnets are positioned in holes drilled in the roadway and when travelling over them a detector located on the vehicle senses the magnetic field from the magnets as it intersects the magnetic lines of force. In case of plurality of magnets the positioning thereof relative to each other may carry additional information which may be interpreted by the detector or this information may contribute to more reliable recognition of warning. A critical point is the range of action of the detector, i. e. the maximal distance between the magnet and the detector when the latter is still able to recognize the magnet. When the shape of the magnet pieces located in the roadway in the drilled holes is straight or cylindrical then the range of action is typically between 0.3-0.4 m because of the unfavourable orientation of the magnetic lines of force, in which case the detectors must be located at the vehicle's lowest point possible. In addition, the exact pass line must be determined or more rows of magnets must be located perpendicular to the direction of travelling in order to cover the necessary width of the road effectively. In case of longer bar-magnets positioned horizontally the range of action can be improved, however, the road surface necessary to be broken up is increased significantly.

The object of the present invention is to provide a permanent magnet piece having increased range of action which can be located easily and can be manufactured economically; and to provide a method of locating the permanent magnet piece for the aforementioned magnetic signalling system.

It has been realised that when using arched bar-shaped magnetic elements as permanent magnet pieces, the formation of lines of force is more advantageous and the range of action may be between 0.6-0.8 m, i.e. it can be doubled without significant increase in costs. When the permanent magnet piece is relatively long then the middle part of it can be made of soft iron material having high conductivity for magnetic lines' of' force. A further significant advantage of forming:' the magnet piece arched resides in the technology for location since it is satisfactory to cut only "slits" shaped as a segment of a circle in the solid road surface by a road cutter disk which can be done easily and rapidly by means of an apparatus generally used, and the permanent magnet pieces can be inserted in these slits. Fixing can be done by covering the slits with asphalt or similar material that is easy to shape in its hot state.

In the method mentioned in the introductory part according to the present invention arched bar-shaped magnetic elements are used as permanent magnet piece whose thickness perpendicular to a plane defined by the radius of curvature of arching is less than the width of the arched bar-shaped magnetic elements in said plane; and perpendicular to usual direction of travelling of vehicles pockets are formed in the solid road surface whose cross-section is similar to a segment of a circle using a cutter disk rotated around a horizontal shaft, the pockets are arranged in a predefined way relative to each other, and the magnetic elements are located and fixed in these pockets with their concave side facing upwards.

The bar-shaped permanent magnet piece according to the invention with the two end parts having N-S magnetic polarity is an arched bar-shaped magnetic element whose thickness perpendicular to a plane defined by the radius of curvature of arching is less than the width of the arched bar-shaped magnetic element in said plane.

The present invention will be described with reference to the accompanying drawings in which:

Fig. 1 shows a permanent magnet piece in accordance with the preferred embodiment of the present invention;

Fig. 2 shows the arrangement of the permanent magnet piece of Fig. 1 in a roadway having solid surface; and

Fig. 3 shows the arrangement of Fig. 2 in a roadway having solid surface, with number of magnet pieces.

Figure 1 shows an example of a permanent magnet piece according to the preferred embodiment of the present invention. According to the basic idea of the invention arched magnetic element 1 is to be embedded in the roadway. In Figure 1 the magnetic lines of force between S-N poles are shown drawn in outline. Magnetic element 1 is flat, having a cross-section of a square and having a shape of a segment of an annulus when viewing front-wise, and its thickness perpendicular to the plane defined by the segment of the annulus is less than the width of the segment of the annulus. The thin, flat formation of the magnetic piece is advantageous in terms of locating as previously described. At the poles of the magnetic element 1 there are two end pieces 2 made of magnetized ferromagnetic material, for example slices of cobalt-magnet, which are coupled by a middle piece 3 made of soft iron. Alternatively the whole segment of annulus can be the permanent magnet itself, however, this kind of embodiment is more expensive. The middle piece 3 can be made of soft iron material having a flat square profile which is cut up in order to get pieces of predefined length which are then bent by means of a bending machine. For mounting the end pieces 2 any kind of adhesive suitable for metal can be used, but care must be taken of the order of magnetic polarity. By performing perpendicular cut when cutting the middle piece 3, after its bending, the two ends of the segment of annulus will have a closing surface 4 of radial direction respectively. This solution is very simple in terms of technology. An improved formation of magnetic lines of force as well as improved outgoing and incoming front surfaces can be achieved with thinner surfacing material applied over the ends, if cutting is performed in a slanting direction when cutting off the pieces, at an angle that results in a closing surface 5 of secant direction after bending. Figure 2 shows an example for this.

The length of the middle piece 3 after cutting off may be typically e.g. 0.25 m and the radius of bending may be 0.4 m. Bending is performed edgeways of the flat soft iron material.

Locating of the permanent magnet pieces according to the present invention can be performed simply and rapidly since only small parts of the road surface must be broken up and must be covered back with asphalt. In the solid road surface pockets 6 having cross-section of a segment of a circle are formed by a cutter disk. During cutting the powered cutter disk must be held in such a way that its axis of rotation should be horizontal and perpendicular to the usual travelling direction of the vehicles. Several pockets 6 are cut in a given arrangement relative to each other, so that the pockets 6 whose longitudinal cross-section is of a cross-section of a segment of a circle should be positioned lengthwise in a line parallel to a line of the vehicles' usual direction of travelling. Also, pockets 6 can be formed in several parallel lines each of which corresponds to a line of the vehicles' usual direction of travelling as it can be seen in Figure 2.

The positioning is performed such a way that the detector mounted on the vehicles passing over is able to compare the periods of time elapsed between intersections of the peaks of individual magnetic lines of force.

It is most likely that the speed of the vehicle during passing can be considered substantially stable so the periods of time between detected peaks which change as a function of speed in traffic direction, are proportional to each other according to the geometry of location, in the same manner as spacings 8, 9 of Figure 3.

Permanent magnet pieces, i. e. magnetic elements 1 are inserted and fixed in these pockets 6 with their concave side facing upwards. Fixing may be done by using any kind of known material for road repairs which is easy to shape in its hot state, in such a way that the pockets are filled with this material up to the level of the superficial plane of solid road surface 7. Preferably, magnetic elements 1 are located in the pockets 6 in such a way that the direction of their magnetic polarization would be the same which is advantageous in terms of effective detection. Also, it is preferable to choose the direction closest to the direction of the natural geomagnetic polarization (W-S direction), since mass of iron in the vehicles passing in the same direction would automatically polarize the located permanent magnet pieces into W-S direction.

In Figure 2 pocket 6 and one of the located permanent magnet pieces can be seen embedded in the layered structure of a typical public road. The layered structure comprises wearing surface 11 having a thickness of 1-4 cm, binder course 12 and gravel-ballast 13. When permanent magnet pieces are located in a new roadway, there is no need for breaking up the wearing surface 11 at all, since the wearing surface can be laid over the closing surface 5 of the located magnetic elements 1 which are brought to the same level as the final step of the building technology. In other cases the cuts the direction of which corresponds to the direction of travelling are not disturbing and are not subjected to increased wearing at all.

Induction coils of the magnetic sensing detectors may be located on the chassis or in the bumper of the vehicles travelling along a road, or in an optional additional apparatus connected to the vehicle, or in case of passenger cars they might be in the passenger compartment as well, and the output signals of the induction detectors varying with- time- may be transmitted to an appropriate decoding processing unit. Shaping up of this unit does not fall within the scope of the present invention. Generally, it can be said that the processing unit should produce a binary code sequence from the signals of the detector and should display the decoded information and/or make it usable for automatic activation of a certain operational unit.

Claims

1. Method for supplying binary coded time invariant information to vehicles travelling along roadways in which permanent magnet pieces disposed at predetermined positions and embedded in the solid road surface are provided; and induction detectors are located in the vehicles on an affixed or structural member which travels over said magnets within a certain range of action; and output signals of said induction detectors varying with time are processed by a processing unit decoding binary code sequences; and the decoded information is displayed and/or used for automatic activation of a given operational unit, wherein said permanent magnet pieces are arched bar-shaped magnetic elements (1 ) whose thickness perpendicular to a plane defined by the radius of curvature of arching is less than the width of said arched bar-shaped magnetic elements (1 ) in said plane; and perpendicular to usual direction of travelling of vehicles pockets (6) having a cross-section of a circle segment and arranged in a predefined way relative to each other are formed in the solid road surface by a cutter disk rotated around a horizontal shaft; and said magnetic elements (1 ) are located and fixed in said pockets (6) with their concave side facing upwards.

2. Method according to Claim 1 wherein said operational unit is a transmitter transmitting signals to a dispatcher centre.

3. Method according to Claim 1 wherein said operational unit is a counter which is shifted by a given code.

4. Method according to Claim 1 wherein said operational unit is an acoustic and/or visual means for calling attention to danger and on activation of said means signals are given to the driver of the vehicle.

5. Method according to any of Claims 1 to 4 wherein said pockets (6) whose longitudinal cross-section is of a cross-section of a segment of a circle are cut in the solid road surface and are arranged along a line parallel to the usual direction of travelling of vehicles.

6. Method according to Claim 5 wherein said pockets being arranged lengthwise in a line are separated from each other by different spacings (8, 9) corresponding with given binary codes.

7. Method according to any of Claims 1 to 4 wherein said pockets (6) whose longitudinal cross-section is of a cross-section of a segment of a circle are cut in the solid road surface and are arranged lengthwise in several parallel lines parallel to the vehicles' usual direction of travelling.

8. Method according to Claim 7 wherein said pockets (6) being arranged lengthwise in several parallel lines are separated from each other in a different way for each of the parallel lines by different spacings (8, 9) corresponding with given binary codes.

9. Method according to any of Claims 1 to 8 wherein said magnetic elements (1 ) serving as magnet pieces are located in said pockets (6) in such a way that the direction of their magnetic polarization would be the same.

10. Method according to Claim 9 wherein said magnetic elements serving as magnet pieces are located in said pockets (6) with a polarization direction which is closer to the geomagnetic polarization direction.

11. Method according to any of the Claims 1 to 10 wherein said magnetic elements (1 ) inserted in said pockets (6) with their concave side facing upwards are located beneath a superficial plane (7) of the solid road surface and said pockets are filled up to the level of the superficial plane of solid road surface (7) with some material which is easy to shape in its hot state.

12. Permanent magnet piece with two end parts having N-S magnetic polarity for performing the method of Claim 1 wherein the magnet piece is an arched bar- shaped magnetic element (1 ) whose thickness perpendicular to a plane defined by the radius of curvature of arching is less than the width of the arched bar-shaped magnetic element (1 ) in said plane.

13. Permanent magnet piece according to Claim 12 wherein said permanent magnet piece is flat, having a shape of a segment of an annulus, and its thickness perpendicular to the plane defined by the segment of the annulus is less than the width of the segment of the annulus.

14. Permanent magnet piece according to Claim 13 wherein said permanent magnet piece is made of magnetized ferromagnetic material.

15. Permanent magnet piece according to Claim 13 wherein two end pieces (2) of said segment of annulus are made of magnetized ferromagnetic material which are coupled by a middle piece (3) made of soft iron material.

16. Permanent magnet piece according to Claim 15 wherein said ferromagnetic two end pieces (2) of said segment of annulus and said middle piece (3) made of soft iron are bound together with some adhesive suitable for metal.

17. Permanent magnet piece according to Claim 15 or 16 wherein said middle piece (3) made of soft iron is formed by bending a straight bar.

18. Permanent magnet piece according to Claim 13 wherein said flat segment of annulus has two ends with a closing surface (4) of radial direction, respectively.

19. Permanent magnet piece according to Claim 13 wherein said flat segment of annulus has two ends with a closing surface (5) of secant direction, respectively.

20. Permanent magnet piece according to Claim 18 or 19 wherein said ferromagnetic end pieces (2) of said segment of annulus are slices which form said closing surfaces (4, 5), which are bound to said middle piece (3) made of soft iron having parallel end surfaces.