VEHICLE DETECTION SYSTEM

Abstract

A vehicle detection system for monitoring stationary and moving vehicles is disclosed. The vehicle detection system includes a housing and a first sensor and a second sensor each configured to detect the moving vehicles. A control unit, and a first energy store as well as a second energy store configured to supply the vehicle detection system with electrical energy independently of one another are also provided. The control unit is designed in such a way that the first sensor is permanently switched on during operation of the vehicle detection system and the second sensor is only switched on for a predetermined time when the first sensor has detected a vehicle. The control unit is designed in such a way that, when the voltage of the first energy store falls below a first predetermined voltage, the vehicle detection system is supplied with electrical energy by the second energy store.

Claims

1. A vehicle detection system for monitoring stationary and moving vehicles, the vehicle detection system comprising: a housing, a first sensor and a second sensor configured and arranged to detect the vehicles, a control unit, a first energy store and a second energy store configured and arranged to supply the vehicle detection system with electrical energy independently of one another, and wherein the control unit is configured to permanently switch on the first sensor during operation of the vehicle detection system and to switch on the second sensor for a predetermined time only when the first sensor detected a vehicle, and wherein the control unit is configured such that when a voltage of the first energy store falls below a first predetermined voltage, the vehicle detection system is supplied with electrical energy by the second energy store.

2. The vehicle detection system according to claim 1, wherein the first sensor is a magnetic field sensor and the second sensor is a radar sensor.

3. The vehicle detection system according to claim 1, wherein the first energy store is a rechargeable energy store, a supercapacitor or an accumulator.

4. The vehicle detection system according to claim 3, wherein the vehicle detection system comprises at least one charging element configured to charge the first energy store.

5. The vehicle detection system according to claim 4, wherein the at least one charging element comprises at least one of a solar cell, an induction loop and a Peltier element.

6. The vehicle detection system according to claim 1, wherein the control unit is configured such that when a second predetermined voltage of the first energy store exceeded, the vehicle detection system is supplied by the first energy store.

7. The vehicle detection system according to claim 1, wherein the second energy store is an accumulator or a battery.

8. The vehicle detection system according to claim 4, wherein the second energy store is configured to be charged by the at least one charging element.

9. The vehicle detection system according to claim 1, wherein the vehicle detection system further comprises a wireless communication interface.

10. The vehicle detection system according to claim 9, wherein the wireless communication interface is a bidirectional communication interface.

11. The vehicle detection system according to claim 1, wherein the housing further comprises: a cylindrical wall; a top surface; and a bottom surface.

12. The vehicle detection system according to claim 11, wherein the top surface comprises at least a partially light-transmitting material.

13. The vehicle detection system according to claim 11, wherein the bottom surface comprises a larger circumference than the cylindrical wall.

14. The vehicle detection system according to claim 13, wherein the bottom surface comprises at least one recess and/or at least one passages.

15. The vehicle detection system according to claim 14, wherein the at least one recess and/or the at least one passage is arranged in regions of the bottom surface projecting beyond a lateral wall.

16. The vehicle detection system according to claim 11, wherein the top surface comprises, at least partially, of glass.

17. The vehicle detection system according to claim 7, wherein the second energy store is configured to be charged by at least one charging element.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0079] Further advantageous features and details of the various embodiments of this disclosure will become apparen from the ensuing description of preferred exemplary embodiment or embodiments and further with the aid of the drawings. The features and combinations of features recited below in the description, as well as the features and feature combinations shown after that in the drawing description or in the drawings alone, may be used not only in the particular combination recited by also in other combinations on their own without departing from the scope of the disclosure.

[0080] The following is an advantageous embodiment of the invention with reference to the accompanying drawings wherein:

[0081] FIG. 1 A block diagram of a vehicle detection system according to the invention in the form of a ground sensor with a magnetic field sensor and a radar sensor;

[0082] FIG. 2 A block diagram of a further ground sensor according to the invention which has two redundant magnetic field sensors;

[0083] FIG. 3 A perspective view of the housing of the ground sensor of FIG. 1;

[0084] FIG. 4 A schematic representation of the installation situation after the ground sensor in FIG. 3 has been cast into a recess in a roadway.

[0085] In principle, the same parts are provided with the same reference signs in the figures.

DETAILED DESCRIPTION OF THE INVENTION

[0086] As used throughout the present disclosure, unless specifically stated otherwise, the term or encompasses all possible combinations, except where infeasible. For example, the expression A or B shall mean A alone, B alone, or A and B together. If it is stated that a component includes A, B, or C, then, unless specifically stated otherwise or infeasible, the component may include A, or B, or C, or A and B, or A and C, or B and C, or A and B and C. Expressions such as at least one of do not necessarily modify an entirety of the following list and do not necessarily modify each member of the list, such that at least one of A, B, and C should be understood as including not only one of A, only one of B, only one of C, or any combination of A, B, and C.

[0087] FIG. 1 shows a vehicle detection system according to the invention schematically by means of a block diagram. The vehicle detection system is in the form of a ground sensor 1, which is housed in a housing 10 (see FIG. 3 for details of the housing).

[0088] The ground sensor 1 has a first sensor 6.1 in the form of a magnetic field sensor (Hall sensor) and a second sensor 6.2, which is a radar sensor. The first energy store 4.1 is a supercapacitor, while the second energy store 4.2 is an accumulator. The two energy stores 4.1, 4.2 can be supplied with current and charged via a charging element 3, in this case a solar cell, when it is illuminated by light L. The energy store 4.2 can be charged when the light L shines on it.

[0089] The ground sensor 1 also comprises a central control unit 2, which has a computing unit, a data memory and several interfaces for data exchange with the other components of the ground sensor and for power supply. The two sensors 6.1, 6.2 are connected to the control unit 2 via communication lines, while the two energy stores 4.1, 4.2 are connected to the control unit via supply lines.

[0090] The control unit 2 is designed in such a way that [0091] if the voltage of the first energy store 4.1 falls below the voltage of the second energy store 4.2, the ground sensor or its components are supplied with electrical energy by the second energy store 4.2, and [0092] when the voltage of the first energy store 4.1 rises again above the voltage of the second energy store 4.2, the ground sensor or its components are supplied by the first energy store 4.2.

[0093] Furthermore, the control unit 2 is designed in such a way that: [0094] the first sensor 6.1 carries out a measurement at regular intervals, in particular at a frequency of 100 Hz; [0095] The measured data is compared with a predefined sensor threshold value; [0096] A measurement algorithm starts when a measured value is above the predefined sensor threshold, [0097] Whereby, if the measured data obtained with the first sensor 6.1 meets a predefined condition, the measurement algorithm activates the second sensor 6.2 and performs at least one measurement; [0098] The measured data obtained with the two sensors 6.1, 6.2 are evaluated by the controller 2 so that one or more measured quantities are obtained; [0099] Whereby the second sensor 6.2 is switched off after each measurement and is only activated again for a new measurement if required.

[0100] The start of the measurement algorithm in step c), the activation of the second sensor and the execution of the at least one measurement in step d) take place, for example, within less than 1 millisecond, after the comparison of the threshold value in step b).

[0101] The control unit 2 is also connected to a communication module 7, which enables a bidirectional data exchange via a wireless connection, for example a radio network, with a gateway or a control station (not shown) via corresponding radio signals F.

[0102] FIG. 2 shows a second ground sensor 1, in which a further magnetic field sensor 6.1a of identical design is present in addition to the first sensor 6.1. The controller 2 is additionally designed in such a way that in the event of a failure of the first magnetic field sensor 6.1, the system automatically switches to the second magnetic field sensor 6.1a.

[0103] Furthermore, in addition to the charging element 3 or the solar cell, the ground sensor 1 also has a further charging element 3a in the form of a Peltier element which utilizes thermal energy W to charge the supercapacitor. The Peltier element is in contact with the solar cell or the first charging element 3.1 via a good conductive thermal bridge 8. The first energy store 4.1 or the supercapacitor can thus additionally be charged via the Peltier element. Instead of a second energy store in the form of an accumulator, a non-rechargeable battery is present in the ground sensor 1 as the second energy store 4.2. Accordingly, the battery is not connected to the charging elements 3.1, 3.1a.

[0104] The other components of the ground sensor 1 are identical in construction to the respective components of the first ground sensor 1.

[0105] FIG. 3 shows a perspective view of the housing 10 of the ground sensor 1 from FIG. 1. The housing 10 consists of a bottom surface 11, a cylindrical side wall 12 and a top surface 13. The top surface 13 contains a central glass plate 13a made of toughened safety glass, which rests on the side wall 12 and is fixed by a fastening ring 13b. The fastening ring is releasably connected to the side panel 12 by a total of six screws 14. The fastening ring also contains a pressure equalization device 15 in the form of a hole closed by an air-permeable and water-impermeable membrane.

[0106] Directly below the glass plate 13a, the first charging element 3 in the form of the solar cell is mounted inside the housing 10 (not visible in FIG. 3), and below it are the remaining components.

[0107] As can be seen in FIG. 3, the bottom surface 11 projects beyond the side wall 12 in a lateral direction, or the bottom surface 12 has a larger circumference than the side wall 12. This means that the ground sensor 1 can be cast in a form-fitting manner into a road surface 20 using a casting compound 21, for example, as shown in FIG. 4.

[0108] The embodiments described above are to be understood merely as illustrative examples, which may be modified as desired within the scope of the invention.

[0109] For example, the second energy store 4.2 in FIG. 1 may be a non-rechargeable battery instead of an accumulator. Similarly, the second energy store 4.2 in FIG. 2 may be in the form of an accumulator instead of a non-rechargeable battery.

[0110] Instead of a mounting ring 13b, the light-transmitting glass plate 13a in the embodiment of FIG. 3 may, for example, also be bonded directly to an inner and lowered section of the side wall 12, so that a non-releasable connection is present.

[0111] It is also possible to provide a larger bottom surface 11 (indicated by broken lines in FIG. 3) for the housing shown in FIG. 3, which projects even further beyond the cylindrical side wall. This further improved the retention of the housing in the base. Passages 11a can also be provided in the edge region of the bottom surface 11, which simplifies casting of the housing in roadway recesses.

[0112] In addition, rib-like projections 11b (indicated by broken lines in FIG. 3) running in the vertical direction can be provided, which project from the side wall 12 of the housing and secure it against twisting.

[0113] The bottom surfaces 11, 11 do not necessarily have to be flat as shown in FIG. 3. It is also possible that they comprise a curved or corrugated surface. It is also possible that the bottom surfaces 11, 11 are angled upwards or downwards at the edge areas, while the central area is flat, for example.

[0114] Likewise, the housing of FIG. 3 can also be cuboidal instead of cylindrical.

[0115] The scope of protection of the present invention is given by the claims and is not limited by the features illustrated in the description or shown in the figures.