FR2834813A1 - Proximity opening mechanism site access control/programming having identification code transmitter/receiver communicating with electrical connection variable capacitive couplers effected - Google Patents

Abstract

The proximity opening mechanism has a protection mechanism . A transmitter communicates an identification code with a receiver providing a protection mechanism drive. Electrical connection between the transmitter and receiver is via two variable capacitive couplers.

Description

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SECURE DEVICE FOR PROGRAMMING AND CONTROLLING THE OPENING OF A PROTECTION MEANS OF A PROTECTED AREA OR BUILDING
The invention relates to a device for programming and controlling access to a site. It relates more particularly to the field of secure programming and control control of the opening of a means of protection of a protected area or building, by proximity and without galvanic contact between a mobile device carried by the user and a receiver.

 The invention relates to particular operations, requiring certainty that the wearer of the mobile device is in the immediate vicinity of a defined point of the fixed installation.

 Such an operation relates, for example, to putting a control device into learning mode before transmitting an identification code which will be recorded. Most often, a switch or a push button is electrically connected to a control device and placed at a defined point. This simple solution is for example used in the transition to learning mode of actuators for garage overhead doors.

 But as soon as it is a device placed outside, such as for example a gate, the sealing constraints make an expensive solution of this type which, moreover then loses all security aspect since it becomes easy for a criminal to provoke the learning of his own code.

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 Such operation also relates to the operation of certain closing means for which the regulations require that all of the movements take place under visual contact of the user. These are for example grids placed on each entry way to a store. The order must then be of the deadman type, that is to say that it must be interrupted if the order is not maintained or if the user departs from the defined perimeter. The simplest solutions use intermittent contact switches, this time controlled by a security key.

 Access control solutions use the reading of badges, cards or electronic or magnetic keys, or even fingerprints.

 In this case, as in the previous one, vandalism very easily attacks locks, card or fingerprint readers, which today leads to prefer solutions without any contact, even optical, and without mechanical intervention.

 Transponders commonly respond to this type of problem. They have the particular advantage of being able to supply the portable device (transmitter) at a short distance, and to lend themselves to a dialogue allowing authentication, the transmitter and the receiver then being bi-directional. However, nothing prevents a criminal with a sensitive receiver and an overpowered transmitter from practicing remote communication, replacing the authorized transponder, provided that he also has sufficient means of recording and calculation to break the code.

 There is therefore a need for a proximity communication method which is reliable and inexpensive, and which guarantees proximity

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 effective user without requiring mechanical, electrical or optical contact.

 It is already known to use capacitive coupling antennas in different fields.

 For example, in the case of radio frequency transmission, as described in US patent US 5,760,745, there is provided a capacitive coupling between a telescopic whip antenna and the high frequency terminal of the portable transceiver , the purpose of the capacitive coupling being to make the transmission between one and the other of the elements more reliable, which is not the case, due to the telescopic nature of the antenna, for a galvanic connection subject to wear.

 In this same field of transmission, US Patent US 6,020,855 describes a capacitive connection means between an antenna integrated in the windshield of an automobile and the high frequency terminal of the receiver. For frequency modulation bands, the coupling is said to be visually and electrically transparent.

 In another field, American patent US Pat. No. 5,847,447 proposes a communication system between a portable unit, such as a credit card, and a fixed base, in which a double capacitive coupling is used, produced by two pairs of conductive plates ensuring the paths back and forth of an alternating current transmitted by capacitive link. In this device, the distances between planar conductors are small, and to avoid the transmission being dependent on the inevitable variations in capacity between the card and the base, due to misalignments, the inventors propose to include a capacitor in series with the capacitor formed by the approximation of the plates. In this embodiment, the capacitive link with the earth is not used.

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 There is also, in US patent 6,236,316, a communication system between mobile unit, such as an electronic tag, and a fixed base, with capacitive double link, a connection of which is provided by the metal frame of the installation. This patent relates to communication with moving objects, supporting said electronic tags. Due to this movement, the description provides two fixed transmission antennas (capacitive plates), one to ensure interrogation transmission and the other to receive some time after the response, but a fixed antenna would suffice if the transmissions are fast enough. The electronic label contains a transponder and two capacitive antennas. The transmission path at a given time is, for example, by capacitive coupling between the fixed antenna and one of the mobile antennas while the return is carried out by capacitive coupling between the second mobile antenna and the chassis or one of the rollers. conveying.

 Of course, this embodiment does not exploit capacitive coupling by the body of a user, nor the passage through the earth.

 Furthermore, in the prior art, devices exist which involve the human body in detection and control devices by use of a variable capacity, such as, for example, that described in American patent US Pat. No. 3,789,419.

 In this patent, a system is described intended for the automatic opening of doors when a user passes over a flat horizontal antenna integrated in the ground in front of the automatic door. This antenna is electrically connected to the output of an oscillator. The receiving antenna is placed above the door. The set of these two antennas forms a capacitor. When a user shows up, the ability

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 increases and the current becomes sufficient to be detected by the synchronous detection device used.

 A similar embodiment is found in American patent US 3,973, 208.

 In the US patent US 4,176, 348 is also exploited the variation in capacity between the earth and an antenna playing on the oscillation frequency of an oscillator whose potential reference is connected to earth.

 More formerly, US patents 3,508, 120 and US 3,723, 885 describe capacitive control switches.

 None of these achievements is intended to transfer data.

 American patent US Pat. No. 6,144,303 discloses a data transmission system (of the electronic tag type) and capacitive coupling. However, the data transmission is carried out by conventional means, while the capacitive coupling is intended to generate an alarm if the patient ceases to carry the electronic label on him. This patent therefore relates to the use of capacitive coupling for the sole presence detection, and not for the transmission of information by this same means.

 The prior art therefore presents, on the one hand, embodiments with capacitive coupling intended for the electronic transfer of data and using a mode of coupling of the outward and return currents not using the earth and even less the human user in the propagation mode. .

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 The prior art, on the other hand, presents a use of the properties of capacitive conduction through the ground and the human body for the purpose of detecting the presence of said human body.

 At no time has it been thought to involve the properties of electrical capacity (and conduction) of the human body to allow data communication between a mobile unit and a fixed base while ensuring the location of the carrier of said mobile unit.

 Even less has it been imagined to use such a means in the secure control of building closings.

 The invention therefore proposes a device secured by proximity and without contact, for programming and controlling the opening of a means of protection of a protected area or building which involves the properties of electrical capacity (and of conduction) of the human body to allow data communication between a mobile unit and a fixed base while ensuring the location of the carrier of said mobile unit.

 Thus, according to the invention the device secured by proximity and without contact, for programming and controlling the opening of a means of protection of a protected area or building of the type comprising a transmitter intended to communicate with a identification code with a receiver intended to allow the actuation of the protection means, is characterized in that the electrical connection between the transmitter and the receiver is ensured by two variable capacitive couplings.

 According to an additional characteristic, there is provided a first variable capacitive coupling between the transmitter and the receiver, and a second variable capacitive coupling between the transmitter and the ground.

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 According to another characteristic, the first capacitive coupling is achieved by the cooperation of two conductive elements, one of the elements, the first element of the first coupling being on the transmitter while the other element, the second element of said first coupling is on or connected by a galvanic link to the receiver.

 According to another characteristic, the second capacitive coupling is constituted by the link between the user who holds the transmitter, and the ground, link which is both resistive and capacitive.

 According to a preferred embodiment, the conductive element of the transmitter, and the conductive element connected to the receiver are flat metallic conductive surfaces, for example constituted by an area of a few square centimeters of bare copper.

 Let us add that the transmitter is, for example, constituted by a box which includes a voltage generator which may or may not be connected to a conductive plate, depending on the state of an emission frame produced by a processing unit sensitive to the state of a control push button, the second pole of the generator being connected to a potential reference.

 Other characteristics and advantages of the invention will emerge from the description which follows with reference to the appended drawings which are given only by way of nonlimiting examples.

 Figure 1 shows schematically the general principle of the invention.

 Figure 2 illustrates an embodiment of a transmitter, held by the hand of the user

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FIG. 3 represents an embodiment of a receiver,
Figure 4 is a diagram illustrating an alternative embodiment of the transmitter, held by the user
FIG. 1 represents the general principle of the device of the invention in an installation (1) constituted by a closing device (2) comprising a closing element (3) such as a metal grid intended to be wound around a winding drum (4) in the open or unwound position to close. It is of course provided an electric motor (5) ensuring the rotation of the drum (4) and a receiver (6) also called actuator, intended to receive orders from a mobile control unit (7) said transmitter carried by a user (8) and thus ensure the desired actuation of the closure element.

 The invention is illustrated with the aid of an example in the context of a closure with a vertically movable grid, but can be applied to any type of closure or concealment and to any type of access control which whether.

 The mobile control unit (7), called transmitter, carried by a user (8), contains an identification code and control codes, intended to be transmitted to the receiver (6). Said receiver is capable of controlling the opening of the closing element (3).

 According to the invention, the electrical connection between the transmitter (7) and the receiver (6) is ensured by two variable capacitive couplings, namely - on the one hand, by a first variable capacitive coupling (9) between the transmitter (7 ) and the receiver (6).

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 - on the other hand, by a second variable capacitive coupling (10) between the transmitter (7) and the earth (13).

 The first capacitive coupling (9) is produced by the cooperation of two conductive elements (9a, 9b), one of the elements, the first element (9a) of the first coupling (9) being on the transmitter (7) while the Another element, the second element (9b) of said first coupling is on or connected by a galvanic link (11) to the receiver (6).

 According to the preferred embodiment of the invention, the conductive element of the transmitter (9) is a flat metallic conductive surface (9a). This surface consists of an area of a few square centimeters of bare copper. The conductive element (9b) connected to the receiver (6) is also a conductive plate identical to that of the transmitter. The latter is arranged on a support (12) to be placed at a defined point (A) with which the user must be in order to actuate the closure element.

 Advantageously, a protective plate of insulating material can be provided in front of the conductive element (9b), made for example from glass or from plastic material such as polycarbonate, or the like.

 The assembly formed by the two conductive surfaces (9a, 9b) constitutes the first capacitor (9) forming the first capacitive coupling of variable capacity. This capacity depends in particular on the distance between the conducting elements (9a, 9b), and on their respective orientation in space. The order of magnitude of this capacity is for example picofarad (pF, 10-12 F).

 By way of example, the surface of the metallic conductive flat surface (9a) of the conductive element of the transmitter (9) is an area of 3 cm by 3 cm, which corresponds to 0.15 pF for

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 a distance of 5 centimeters in the air and 0.80 pF for the same distance in the glass.

 The second capacitive coupling (10) is constituted by the connection between the user (8) which holds the transmitter (7), and the earth (13), connection which is both resistive and capacitive. The resistive part of this bond depends enormously on the human body, the nature of the ground and the soles of shoes and can vary on several orders of magnitude. On the other hand, the capacitive part of this link, although variable, will remain within a range of the order of 100 to 300 pF.

 We therefore see that it is quite possible, if the receiver (6) is also connected to the ground (13), to have a current transmission between the transmitter (7) and the receiver (6) in a mesh which simultaneously uses the first capacitive coupling (9) and the second capacitive coupling (10).

 It is therefore sufficient that the transmitter (7), without even having recourse to radio frequency modulation, directly transmits the binary elements of identification and control codes, for example with a transmission rate of 10 to 40 kbits / s, in presenting as a generator connected or cut so that the current flowing in this mesh is the image of the message transmitted.

 The connection of the receiver (6) with the earth (13) can be of the galvanic and direct type, like the connection referenced by (14) in FIG. 1, or even be done via the closing element (3 ) and its mechanical transmission system (4) such as the link referenced by (15). Without being galvanic, the connection of the receiver (6) with the earth (13), can be made by means of a capacitor of high capacity.

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 From the numerical values which have just been provided, it can be seen that the system thus proposed will function almost indifferently for a very wide variety of users.

 Figure 2 illustrates an embodiment of the transmitter (7), held by the hand of its user (8).

 The transmitter (7) consists of a housing (20), which comprises a voltage generator (21) which may or may not be connected, for example depending on the state of a control push button (22), by a processing unit (23) at the conductive plate (9a). The second pole of the generator is connected to a potential reference (24).

 The conductive surface (9a) is advantageously a surface formed on the printed circuit comprising all the components of the processing unit (23).

 The processing unit (23) for example produces a binary frame as a function of the actuated push button (22) corresponding to the desired command, and as a function of the identifier of the transmitter. According to the instantaneous state of this frame, the potential of the conductive metallic surface (9a) of the conductive element of the transmitter (9), takes either a zero value, or the value of the potential of the voltage generator (21).

 The housing (20) is for example made of insulating plastic, but to allow good contact between the potential reference (24) and the hand of the user, the housing can advantageously include a surface metallization (25). Note however that it suffices that the push button (22) is sufficiently conductive for this contact to be made by the finger. In either case, a charged polymer would suffice. Finally, we note that the link between the potential reference and the hand of

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 the user can also be done in a capacitive manner without altering the correct operation, provided that this capacity is itself very large compared to that of the two capacitive couplings (9,10).

 The conductive connection between the user's hand and the ground (13) is illustrated by a resistor (26). As has been said, this value is extremely variable, and the proper functioning essentially depends on the capacity of the second capacitive coupling (10).

 Figure 3 shows an embodiment of the receiver (6) connected by the galvanic link (11) to the conductive plate (9b) of the first capacitive coupling. The receiver (6) includes its own power supply (30) for the electronic components for signal amplification (31) and logic processing (32) ensuring, for example, the control of a motor (33) for driving a device. (34) such as the winding drum (4) of the installation given as an example. The connection (35) between the processing unit (32) and the motor (33) is here represented symbolically by a single line.

 The second pole of the power supply (30) is connected to a potential reference (36) which is itself connected to earth (13).

 Figure 4 is a diagram illustrating an alternative embodiment of the transmitter (7), held by the user, constituting the preferred embodiment of the invention. Said transmitter (7) comprises a logic processing unit (40) intended to generate a binary frame available as desired on two outputs (41,42). The first output (41) is connected to a high frequency antenna (43) via a radio frequency modulator (44). The second output (42) is used as previously to directly control the potential of the conductive plate (9a),

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Thus, the same mobile transmitter housing (7) of the variant can be used, optionally according to two operating modes, depending on the circumstances, in a remote control or proximity control mode.

 Of course, the signals from the two separate outputs (41,42) could come from a single output if it is not desired to differentiate the two operating modes, or even come from a single output associated with a manual switch or electronic.

 Finally, the processing unit will advantageously include means making it possible to make variable over time (and therefore easily transmissible by capacitive link) a signal corresponding to a frame of which a large number of consecutive bits would be in the same state. The methods giving such a result are widely known to those skilled in the art.

 Of course, the invention is not limited to the embodiments described and shown by way of examples, but it also includes all the technical equivalents and their combinations.

Claims (8)

1. Device secured by proximity and without contact, for programming and controlling the opening of a protection means (3.34) of a protected area or building of the type comprising a transmitter (7) intended for communicate with an identification code with a receiver (6) intended to allow the actuation of the protection means, characterized in that the electrical connection between the transmitter (7) and the receiver (6) is ensured by two variable capacitive couplings (9,10).  2. Device secured by proximity and without contact, for programming and controlling the opening of a protection means (3.34) of a protected area or building, according to claim 1, characterized in that 'There is provided a first variable capacitive coupling (9) between the transmitter (7) and the receiver (6), and a second variable capacitive coupling (10) between the transmitter (7) and the earth (13).  3. Device secured by proximity and without contact, for programming and controlling the opening of a protection means (3.34) of a protected area or building, according to claim 2, characterized in that the first capacitive coupling (9) is achieved by the cooperation of two conductive elements (9a, 9b), one of the elements, the first element (9a) of the first coupling (9) being on the transmitter (7) while the 'other element, the second element (9b) of said first coupling is on or connected by a galvanic link (11) to the receiver (6).  4. Device secured by proximity and without contact, for programming and controlling the opening of a protection means (3.34) of a protected area or building, according to claim 3, characterized in that the second capacitive coupling (10) consists of <Desc / CRUD Page number 15>  the link between the user (8) who holds the transmitter (7), and the earth (13), a link which is both resistive and capacitive.  5. Device secured by proximity and without contact, for programming and controlling the opening of a protection means (3.34) of a protected area or building, according to claim 4, characterized in that the conductive element (9a) of the transmitter (9) and the conductive element (9b) connected to the receiver (6) are flat metallic conductive surfaces.  6. Device secured by proximity and without contact, for programming and controlling the opening of a protection means (3.34) of a protected area or building, according to claim 5, characterized in that the transmitter (7) consists of a housing (20) which comprises a voltage generator (21) which may or may not be connected to a conductive plate (9a), depending on the state of a transmission frame produced by a processing unit (23) sensitive to the state of a control push button (22), the second pole of the generator being connected to a potential reference (24).  7. Device secured by proximity and without contact, for programming and controlling the opening of a protection means (3.34) of a protected area or building, according to claim 6, characterized in that the housing (20) is made of insulating plastic material, comprising a surface metallization (25).  8. Device secured by proximity and without contact, for programming and controlling the opening of a protection means (3.34) of a protected area or building, according to any one of the preceding claims, characterized in that there is associated with it a radio frequency modulator (44) so as to be able to operate according to <Desc / Clms Page number 16>  two operating modes, namely, a proximity control mode, and a remote control mode.