EP3252731A1 - System for detecting a rf beacon area - Google Patents

Abstract

The present invention relates to a system for detecting (1) a radiofrequency tagging zone (3) intended to warn a user of a risk of collision, said system (1) having a volume of less than 8 cm 3 and, preferably at 6 cm 3, and comprising: warning means of said user, - Wireless energy charging means, means for storing said energy for powering the warning means.

Description

OBJECT OF THE INVENTION

The present invention relates to the field of anti-collision detection systems. More specifically, it relates to a system comprising a universal RF beacon zone detector.

BACKGROUND

It is known to use anti-collision detection devices comprising a radiofrequency (RF) module communicating with a beacon carried by a pedestrian located in the risk zone. We can quote the document US7,167,082 where the pedestrians wear a helmet or a bracelet equipped with an RF receiver module communicating with a vehicle equipped with an RF transmitter. Pedestrians are warned of danger via tactile or visual stimulus. We can mention in the same register the documents US 2008/0018472 , US 2011/0249118 , US 2011/0227747 and FR 2 761501 .

Pedestrians subjected to noisy environments and vibrations in the case of a jackhammer operator may not perceive stimuli. It is therefore necessary to provide means to amplify these stimuli. However, these means have increased energy needs that must be filled while ensuring the tightness of the support in these muddy and wet environments.

GOALS OF THE INVENTION

The object of the invention is to integrate in a small support RF tag equipped with means that increase the feeling of the user and ensure the electrical charging of the various components while maintaining the seal of the support.

MAIN CHARACTERISTIC ELEMENTS OF THE INVENTION

• des moyens d'avertissement dudit utilisateur,
• des moyens de chargement en énergie sans fil,
• des moyens de stockage de ladite énergie pour l'alimentation électrique des moyens d'avertissement.

The present invention relates to a system for detecting a radiofrequency tagging zone intended to warn a user of a risk of collision, said system having a volume of less than 8 cm ³ and, preferably, 6 cm ³ , and comprising :

• warning means of said user,
• wireless energy charging means,
• means for storing said energy for the power supply of the warning means.

• les moyens d'avertissement comportent un ou plusieurs moteurs vibrateurs fournissant une force supérieure à 4G, de préférence à 8G, et plus préférentiellement à 10G et/ou comportent un buzzer sonore de puissance supérieure à 90 dB ;
• les moyens de stockage comportent minimum deux condensateurs en série ;
• les moyens de chargement sans fil comportent une bobine d'induction présentant un espace D1 entre les spires de la bobine de minimum 120 µm et, de préférence, de minimum 200 µm, afin de laisser passer des ondes radiofréquences ;
• il comporte au moins deux bobines d'induction, par exemple 3 ou 4 bobines, lesdites bobines formant chacune une trace sur un circuit imprimé, les traces étant superposées et/ou disposées l'une à côté de l'autre ;
• le diamètre D2 de la spire intérieure est compris entre 2 et 10 mm ;
• le diamètre extérieur D3 de la bobine est compris entre 10 et 40 mm lorsque le système comporte une seule bobine et entre 10 et 15 mm lorsque le système comporte plusieurs bobines ;
• la largeur L de chaque spire est égale à l'espace D1 entre les spires.

According to particular embodiments of the invention, the system comprises at least one or an appropriate combination of the following characteristics:

• the warning means comprise one or more vibrator motors providing a force greater than 4G, preferably 8G, and more preferably 10G and / or comprise a sound buzzer greater than 90 dB;
• the storage means comprise at least two capacitors in series;
• the wireless charging means comprise an induction coil having a space D1 between the turns of the coil of minimum 120 μm and, preferably, of minimum 200 μm, in order to let radiofrequency waves pass;
• it comprises at least two induction coils, for example 3 or 4 coils, said coils each forming a trace on a printed circuit, the traces being superimposed and / or arranged next to each other;
• the diameter D2 of the inner turn is between 2 and 10 mm;
• the outside diameter D3 of the coil is between 10 and 40 mm when the system comprises a single coil and between 10 and 15 mm when the system comprises several coils;
• the width L of each turn is equal to the space D1 between the turns.

The present invention also relates to the support comprising the detection system described above, said support being a watch, a bracelet, a belt element or a helmet. The support can also be sold as a kit also including the RF transmitter module creating the markup zone.

The present invention also relates to a method for increasing the feeling by a user of vibrations from one or more vibrator motors, said method comprising a step of pulsation of the motor or motors.

• elle comprend une étape d'alimentation du ou des moteurs à l'aide de minimum deux condensateurs en série pour assurer un apport suffisant en énergie ;
• en présence de deux moteurs, ils sont pulsés l'un après l'autre.

According to particular embodiments of the invention, the method comprises at least one or an appropriate combination of the following characteristics:

• it comprises a step of supplying the motor (s) using at least two capacitors in series to ensure a sufficient supply of energy;
• in the presence of two motors, they are pulsed one after the other.

BRIEF DESCRIPTION OF THE FIGURES

The figure 1 schematically represents a vehicle, the marking area covered by the transmitter RF module positioned on the vehicle, and the bracelet comprising, according to the invention, the detection system of the aforementioned RF marking zone.

The figure 2 schematically represents the detection system according to the invention. It includes the two printed circuits with the RF module, the RF antenna, the microprocessor, the induction coil, the capacitors, the battery, the vibrator motors and the external charger detector.

The figure 3 compares a conventional induction coil shown on the left with, on the right, an induction coil according to the invention adapted to let the radio waves.

The figure 4 schematically represents a variant of the invention with two superimposed induction coils.

Legend

1. (1) Unit or system for detecting an RF beacon zone, also known as a beacon
2. (2) Support
3. (3) Buoyage area
4. (4) Vehicle
5. (5) Main printed circuit board
6. (6) RF module
7. (7) RF Antenna
8. (8) Microprocessor
9. (9) Vibrator motor
10. (10) Induction coil
11. (11) Circuit board of the induction coil
12. (12) Capacitor
13. (13) Battery
14. (14) Power supply and induction charger
15. (15) External charger detector
16. (16) Energy from the external charger
17. (17) Electric field generated

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a unit for detecting an RF beacon zone, which will also be described as a system or beacon. The unit must be miniature to be incorporated into a small carrier having a volume of less than 8 cm ³ and preferably less than 6 or even 5 cm ^3. In terms of dimensions, they are of the order of maximum 35 mm x 35 mm x 5 mm thick and, preferably, of the order of 35 mm long by 20 mm wide and 5 mm thick (3.5 cm ³ ). The support can be a bracelet, a watch, a belt element, a helmet, etc. The figure 1 schematically represents the detection unit 1 integrated in a support 2, the RF markup zone 3 created by an RF transmitter module positioned, for example, on a vehicle 4.

According to the invention, the detection system 1 represented schematically at the figure 2 comprises on a printed circuit 5, an RF module 6, an RF antenna 7 and a microprocessor 8 to interpret the data from the RF detection and provide an output usable alert in case of risk of collision. The system further comprises one or more high power vibrating motors 9 which vibrate the support and allow the user to become aware of the risk of collision, all being small enough to be in contact with the skin. According to the invention, the motor or motors 9 make it possible to obtain an acceleration, commonly called a force, greater than 4G, of preferably greater than 8G, and more preferably greater than 10G with values up to 13G. To power the processor and engines that are large energy consumers, the system must also include means for loading and storing energy. In order for the medium to remain watertight on site, it is preferable that the loading is done wirelessly in order to avoid any opening in the support. According to the invention, the wireless charger has at least one induction coil 10. It must be small in order to be installed in the support. To do this, a trace on a printed circuit board (PCB) 11 acts as an induction coil. The coil is thus flat, made of a trace of round shape. According to the invention, each reel has been adapted to pass freely, ie without disturbing them, the radio waves of the RF module and part of the induction field, which allows other coils to coexist without resonance phenomenon. Compared to a classical coil visible to the left on the figure 3 , the coil 10 according to the invention comprises a space D1 between the turns so that the field of the RF module can pass without disturbance, ie. by maintaining the integrity of the radio signal, and without losing the efficiency of the coil to generate the current required for charging. Preferably, the distance D1 between each turn is at least 120 μm and preferably greater than 200 μm.

• La perméabilité aux ondes RF, c.à.d. que les ondes RF doivent passer au travers de la bobine sans problème ni distorsions comme déjà mentionné ci-dessus ;
• La transmission RF et le chargeur à induction ne sont jamais en fonction en même temps. On notera à cet égard que le système est à même de détecter la présence du chargeur externe grâce au détecteur 15 schématisé sur la figure 2 ;
• Les limites de la technologie de fabrication d'une telle bobine sur PCB, une bobine fil étant trop grosse en volume ;
• L'efficacité de l'induction en fonction de l'ampérage et le voltage requis pour le chargeur en fonction de la batterie choisie ;
• Le format le plus petit possible pour être intégré dans le support.

The other dimensions of the coil are calculated on the basis of the following constraints:

• Permeability to RF waves, i.e. that the RF waves must pass through the coil without problems or distortions as already mentioned above;
• The RF transmission and the induction charger are never in operation at the same time. It should be noted in this regard that the system is able to detect the presence of the external charger by means of the detector 15 schematized on the figure 2 ;
• The limits of the manufacturing technology of such a coil on PCB, a wire coil being too big in volume;
• The efficiency of the induction according to the amperage and the voltage required for the charger according to the chosen battery;
• The smallest possible format to be integrated in the support.

• Largeur L de chaque spire de minimum 120 µm, toujours de préférence la largeur L de la spire est identique à la distance D1 entre spires afin d'avoir une performance d'induction accrue ;
• Epaisseur E de chaque spire comprise entre 0.05 et 200 µm ;
• Diamètre D2 de la spire intérieure formant un passage libre pour le champ électrique du chargeur et pour les ondes RF compris entre 2 et 10 mm ;
• Diamètre extérieure D3 de la bobine compris entre 10 et 40 mm ;
• Distance de jeux d'air D4 à l'extérieur de la bobine de minimum 1 mm sur tout le pourtour de la bobine ;
• Nombre N de spires entre 10 et 30.

Thus, besides a distance D1 of minimum 120 μm between turns, the other dimensions are preferentially:

• Width L of each turn of at least 120 μm, still preferably the width L of the turn is identical to the distance D1 between turns in order to have an increased induction performance;
• Thickness E of each turn between 0.05 and 200 μm;
• Diameter D2 of the inner coil forming a free passage for the electric field of the charger and for RF waves between 2 and 10 mm;
• Outer diameter D3 of the coil between 10 and 40 mm;
• Clearance clearance D4 outside the coil of at least 1 mm all around the coil;
• Number N of turns between 10 and 30.

• D1 : 0,254 mm ;
• L : 0,254 mm ;
• E : 0,105 mm ;
• D2:9mm;
• D3 : 30,5 mm;
• D4 : 1,35 mm, donc diamètre total (D3+2xD4) de 33.2 mm ;
• N : 21.

By way of example, the results for the 2.5Ghz frequency band are:

• D1: 0.254 mm;
• L: 0.254 mm;
• E: 0.105 mm;
• D2: 9mm;
• D3: 30.5 mm;
• D4: 1.35 mm, so total diameter (D3 + 2xD4) of 33.2 mm;
• N: 21.

According to a variant of the invention shown in figure 4 the system comprises at least two induction coils 10 forming an induction matrix. The coils can be superimposed and formed by a trace on different layers of the printed circuit or arranged next to each other. It is also possible to combine a vertical arrangement of the coils with a horizontal arrangement of the coils. In this configuration with several coils, a part of the induction energy not captured by the first coil passes through the latter and induces a current in the second coil and so on. Thus, the energy loss is reduced, which allows either to gain electrical capacity or to reduce the size of the support while maintaining the same efficiency. Since the size aspect is particularly critical for the present invention, a reduction in size is preferred. In the presence of several coils, the number of turns can be reduced, which means that the diameter D3 can be reduced to a value less than 15 mm. As a consequence of this reduced diameter, the width of the support can be reduced. The thickness E of the coil can also be reduced to a value of less than 105 μm in order to be able to position a coil in the inner layers of the circuit board. The other dimensions of the coil are on the other hand similar. Regarding the space between coils, it is of the order of 0.5 mm. It will be specified that a layer of ferrite between the coils and the rest of the system may be required to avoid an induction phenomenon on the metal parts of the system.

The system further includes electronic components for storing charged energy and powering the motors. According to the invention, the storage and supply means comprise at least two capacitors 12 in series and a battery 13 (see FIG. figure 2 ). This configuration with at least two capacitors is preferred for the following reasons. A single battery, which must be small in order to enter the space of the support, is not powerful enough to draw maximum performance from the motors even if technically there is enough energy after recharging. Adding a single capacitor to accumulate the energy required to start the engine, which requires a large amount of instantaneous energy, is also not possible. Indeed, to start a powerful engine, it would require a large capacitor that is longer to recharge and that takes up space, which is not compatible with a small support.

A particular power supply with at least two capacitors in series has been designed to push motors normally too powerful for the size of the circuit and the battery. The first capacitor quickly charged loads the second. The alternation between the two capacitors makes it possible to maintain the current on the motors, to isolate the countercurrent caused by the mechanical resistance of the rotating mass of the vibrator motors and thus to save the total energy necessary.

To increase the feeling of the vibration by the user, it is advantageous to pulse the motor, ie. to apply vibration pulsation On / Off / On / Off fast motors. To do this, the use of double or triple capacitors takes all its importance because the engines are constantly restarting, which, as a reminder, requires a lot of instantaneous energy. The pulsation of the engine makes it possible to increase the striking force of the motors because, at start-up, the motors are not stable and therefore strike with a higher amplitude, whereas once in operation, the inertia of the motor and the relative balance achieved by the stability of the rotation reduces the amplitude of the vibration and therefore the feeling.

When two motors are used, it is important that the two motors do not rotate at the same time because the masses can be canceled if, for example, the mass is at the 0 degree position while the other is at the 0 degree position. opposite to 180 degrees. So both engines are engaged one after the other to better vibrate the entire support. To support these pulsations, the circuit with double, triple or even four capacitors for two motors is essential.

It will be specified that instead of vibratory motors, it is conceivable to use the means described above for supplying a high-power sound buzzer having a power greater than 90 dB, of the order of 95-100 dB, even of the order of 110 dB when the buzzer is pulsed, type beep beep. It is also possible to combine a sound buzzer and a vibrator motor. In general, the present invention is designed to power warning means of a user requiring a higher energy input than a device of such small size could deliver normally.

Finally, it will be specified that the vibratory motors or the buzzer can be placed next to the capacitors and the battery or be further removed in the support while having the energy supplied by loading and power supply circuit as described above. above.

Claims (14)

Detection system (1) of a radiofrequency tagging zone (3) for preventing a user from a collision risk, said system (1) having a volume of less than 8 cm ³ and, preferably 6 cm ³ , and including: warning means of said user, - Wireless energy charging means, means for storing said energy for powering the warning means. Detection system (1) according to claim 1, wherein the warning means comprise one or more vibrator motors (9) with a force greater than 4G, preferably 8G, and more preferably 10G and / or comprise an audible buzzer greater than 90 dB. Detection system (1) according to any one of the preceding claims, wherein the storage means comprise at least two capacitors (12) in series. Detection system (1) according to any one of the preceding claims, wherein the wireless charging means comprise an induction coil (10) having a space D1 between the turns of the coil of minimum 120 μm and preferably , minimum 200 μm, to let radiofrequency waves pass. Detection system (1) according to claim 4, comprising at least two induction coils (10), said coils (10) each forming a trace on a printed circuit (11), the traces being superposed and / or arranged one next to the other. Detection system (1) according to claim 4 or 5, wherein the diameter D2 of the inner coil is between 2 and 10 mm. Detection system (1) according to any one of claims 4 to 6, wherein the outer diameter D3 of the coil (10) is between 10 and 40 mm when the system (1) comprises a single coil (10) and between 10 and 15 mm when the system (1) comprises several coils (10). Detection system (1) according to any one of claims 4 to 7, wherein the width L of each turn is equal to the space D1 between the turns. Support (2) comprising the detection system according to any one of the preceding claims. Support (2) according to claim 9, being a watch, a bracelet, a belt element or a helmet. Kit comprising the support (2) according to claim 9 or 10 and an RF transmitter module creating the radiofrequency tagging zone. Method for increasing the user's perception of vibrations from one or more vibrator motors (9), said method comprising a step of pulsation of the motor (s) (9). A method according to claim 12, comprising a step of supplying the at least one motor (9) with at least two capacitors (12) in series to provide a sufficient supply of energy. Method according to claim 12 or 13, wherein in the presence of two motors (9), they are pulsed one after the other.

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