FR2522906A1 - Identification system for animal feed control - uses station at feed stall to transmit power to identification generator carried by animal - Google Patents

Abstract

An animal carries an identifier (IS) around its neck. This contains a receiver (RE) and a transmission modulator (ME) driven from an identification signal generator (GE). When the animal enters a stall to eat, an identification station (PI) transmits power at medium frequency to the identifier to power its circuits. This allows the signal generator and modulator to operate to issue an hf signal. This contains a binary coded signal unique to each animal. The signal is applied to a local processor (PL) which provides local control and issues signals to a central processor (PC). The central processor issues control signals which are used to operate actuators (ACT) to provide the correct food automatically.

Description

 The present invention relates to an identification device, of the responder type, making it possible to identify individuals in a population.

 Such devices generally comprise at least one identification station having an emitter of electromagnetic energy and a receiver of electromagnetic signals and at least one identifier, worn by each individual to be identified, the identifier comprising a receiver of electromagnetic energy, an identification signal generator and a transmitter-modulator suitable for the transmission of these signals by radio waves.

 In order to better understand the objects of the present invention, the operation of these identification devices, already known and used in the prior art, will be briefly described.

In these devices, the identifier, worn by each individual to be identified, is an active responder which is remotely powered by the energy transmitter of the identification station. This energy is available in the form of a high frequency signal emitted at high level (some
Watts at the output amplifiers) by said energy transmitter. This signal, strongly attenuated, is picked up by the receiver and transformed into a DC voltage capable of supplying the generator and the transmitter modulator of the identifier.

 In general, the generator and the transmitting modulator are elements suitable for generating and transmitting at high frequency, a signal carrying a code specific to the identification of the individual concerned This signal is picked up by the receiver of the identification station, it is then decoded and processed in appropriate equipment located downstream of said receiver.

 Such devices are particularly useful when it proves inconvenient to use other known identification systems, such as those based on the use of a card carrying magnetic data.

 This is, for example, the case when it comes to implementing an automatic and personalized feeding of a herd of animals. For this purpose, it is necessary to be able to identify with certainty the animal which appears before a manger to be able to distribute to it, by appropriate automatic means, the food to which it is entitled. It will therefore be understood that the use of magnetic cards proves to be impossible for this application.

 Of course, there are other applications in other areas of the industry which will not be listed exhaustively here. In all cases, it is a question of identifying an individual carrying an identifier of the type described above, when he is in the vicinity of a fixed or mobile identification station.

 Although the devices of the prior art are satisfactory to a certain extent, they nevertheless have a certain number of drawbacks.

 As recalled above, these devices operate the transfer of electromagnetic energy from the identification station to the identifier (s), at high frequency. The high frequency signal is modulated by a significantly lower frequency signal.

 For such a device to have satisfactory reliability and, therefore, allow identification almost certainly, when the identifier is placed only a few centimeters from the energy transmitter, it is necessary to transmit a signal whose power is of the order of a few Watts to recover the few hundred milliwatts necessary to supply the generator and the modulator-transmitter of the identifier.

 We can therefore already emphasize that the energy door is extremely weak (of the order of two or three centimeters for the powers considered).

 On the other hand, the radio range of such a signal can be significantly too large (of the order of a few kilometers, or even a few tens of kilometers). This results in a certain nuisance for neighboring users of tele-communication or radio-broadcasting systems employing HF channels close to the frequency band used for the transfer of energy, or the harmonics of the latter.

 it is therefore to be expected that, in the near future, these devices will no longer be in compliance with the regulations in force concerning the use of radio frequency bands, both in France and abroad.

 Another drawback, linked to the use of high frequency for energy transfer, is that, if we want to achieve with current techniques, transfer of reliable information between the identifier, carried by the individual to identify, and the identification station, high frequency must also be used. As this signal is at a much lower level than the energy transfer signal, there is a potential risk of interference of the identification signal by the intermodulation products of the energy transfer signal. This risk is considerably aggravated if, for whatever reason, several HF channels are used for the transfer of identification signals.

 Another drawback of known identification devices is linked, on the one hand, to the lack of selectivity of the identification transmitters used and, on the other hand, to a poor definition of the operating thresholds of the transmitters of identification signals used. .

 Indeed, these two drawbacks, most often combined, cause, for example when the identifiers are carried by animals, a jamming of the identification signal emitted by an identifier, by an equivalent signal emitted by another identifier. it therefore appears useful to propose an identification device, the selectivity of which at the level of the signals transmitted, such that a sure identification of the bearer of the identifier, can take place and the triggering threshold of which the transmitter is such that only an identifier placed at a predetermined distance from the identification station can transmit an identification signal.

The present invention relates to an identification device which overcomes the above drawbacks and whose
reliability is notably improved compared to identification devices of the kind considered in the prior art.

 According to one of the characteristics of the invention, the electromagnetic energy transmitter comprises an oscillating circuit tuned in medium frequency, and this circuit comprises at least one winding supported by an induction guide comprising a ferrite.

 According to another characteristic of the invention, the modulator-transmitter comprises a first critical tuned oscillating circuit, frequency controlled by a second critical tuned oscillating circuit, quartz, the oscillation of said first and second oscillating circuits being controlled by at least one signal generated by a modulator that includes said modulator-transmitter.

 Thanks to these provisions, the present invention overcomes the drawbacks mentioned above.

 As the transfer of electromagnetic energy is carried out at medium frequency, by means of a winding supported by an induction guide comprising a ferrite, the range, as for energy, is notably improved compared to the devices of the prior art. Indeed, the use of a ferrite considerably increases the directivity of the signal ensuring this energy transfer. The efficiency of the installation is thereby increased. Thus, the range of the device, as for energy, is of the order of ten centimeters, or even more for an emitted power of the order of a few Watts.

 On the other hand, the radio range of the energy transfer signal is practically zero by the use of medium frequency. In addition, the directivity of the ferrite makes it possible to greatly limit, in space, the field of radio nuisance and the risks of interference.

 The medium frequency energy level emitted can be significant without causing radio interference, the emission remaining very directive.

 it should also be emphasized that the use of a ferrite considerably increases the selectivity of the oscillating transmission circuit (s) and that consequently, the bandwidth of the transmitted signal is very narrow.

 It will also be noted that the medium frequency band is relatively unencumbered, which makes it possible to select a working frequency channel not used by broadcasting. This fact, combined with the short range and the weak power of the radio signal emitted, makes it possible to eliminate practically any nuisance for possible listeners neighbors of broadcast programs.

 The use of medium frequency for energy transfer and high frequency for information transfer makes it possible to avoid any risk of interference of the identification signal by the energy transfer signal.

 As the first and second oscillating circuits are critically tuned, that is to say that they do not oscillate in the quiescent state, either that their supply voltage is insufficient, or that there is no no signal present at the output of the modulator, any untimely operation of the modulator-transmitter that each identifier contains is thus avoided.

 The present invention therefore provides a circuit which is particularly insensitive to disturbances and the reliability of the present device, compared with those of the prior art, is significantly improved.

Other characteristics and advantages of the present invention will emerge from the description which follows, by way of example, with reference to the appended drawings in which
- Figure 1 is a block diagram of an identification station and an identifier according to the present invention
- Figure 2 is a block diagram of an identification station and an identifier according to the present invention
- Figure 3 is a block diagram of an embodiment of the energy transmitter-receiver assembly of Figure 2
- Figure 4 is a block diagram of the modulator-transmitter of the identifier of Figure 2;
- the. FIG. 5 is an example of a block diagram corresponding to the diagram of FIG. 4.

 An application of a device according to the present invention is illustrated, by way of example, in FIG. 1. This application relates to automatic and programmed feeding of a herd of cattle, but it goes without saying that all other applications of the device described and shown can be envisaged.

 According to the embodiment shown, this installation comprises in particular a central processor PC which ensures the general control of the processes and which develops in particular the conditions and the commands necessary for operation.

 It is also connected to a number of feeding stations. Two of these positions (PA1, PA2) are shown diagrammatically in dashed lines in FIG. 1.

 Each feeding station, which in practice is in the form of a stall (not shown) into which the animal enters, comprises an identification station PI and actuators ACT and a local processor PL ensuring the local management of the device.

 Each animal carries an ID identifier which, in practice, is in the form of a collar which it wears around the neck.

 Such an installation is provided to allow automatic and personalized feeding of each animal. When it is hungry, the animal presents itself in front of one of the stalls and approaches a manger placed at the bottom of it.

 When, by instinct, the animal approaches its head from the feeder, the collar, and consequently the identifier it wears, comes to be placed in the immediate vicinity of the identification station and identification can take place.

 The structure and operation of the PI identification station and the ID identifier, objects of the invention are described below.

 At this stage, it should be remembered that as soon as the animal is identified, the central processor PC can determine, according to a series of appropriate criteria, the quantity of food to which the animal is entitled.

This food is poured into the manger by automatic means (not shown), the implementation of which is controlled by the ACT actuators.

 The identification device constituted by the PI identification stations and the ID identifiers will now be described.

 Each identification station includes an EE energy transmitter and an RC identification signal receiver.

 Each identifier comprises an energy receiver RE, a modulator-transmitter ME and a generator of identification signals GE (FIG. 2).

 According to the invention, the electromagnetic energy transmitter EE transmits a high level electromagnetic signal at medium frequency for the transfer of energy. This signal is shown diagrammatically by the arrows MF.

 We will now describe, using FIG. 3, an embodiment of an energy transmitter EE according to the invention and, by way of example, an energy receiver RE.

 The EE energy transmitter, which each PI identification station includes, is supplied from an alternating voltage of 220 Volts. The EE energy transmitter includes a transformer TR1 whose primary is mains and the secondary to a diode bridge rectifier (D31 to D34). This power supply part also includes filtering capacitors C27, C28, and a voltage stabilizing device constituted by a transistor T3, the capacitors C29 to C32, a resistor R17, a Zener diode Z2 and a diode D35.

 The energy transmitter comprises an output stage having an oscillating circuit constituted by a coil L1 and the capacities C35 and C39 and a power transistor T4.

 According to the invention, the coil L1 is wound on a ferrite induction guide F2.

 This output stage is controlled by a stage constituted by an IC circuit, ensuring the time base function, the resistors R18 to R20 and the capacitance C33, allowing the adjustment of the maintenance pulse of the oscillator.

The energy receiver RE that each identifier ID comprises, in this example, consists of a voltage doubling rectifier comprising the coil L2, the capacitors C13, C14, the diodes D21, D22 and a diode
Zener stabilization Z1.

 In operation, the voltage of 220 Volts at the primary winding of the transformer TR1 is rectified by the diode bridge D31 to D34. This DC voltage is stabilized by the device mentioned above. The parasites are filtered by capacitors C27 and C28.

 According to the invention, the oscillator constituted by the coil L1 and the capacitors C35, C39 is tuned at medium frequency. The output stage comprising the oscillator and the transistor T4 is controlled by the stage comprising the elements IC, R18 to R20 and C33. The power emitted by the output stage T4 is, in this example, about twenty Watts.

The energy transfer signal (shown diagrammatically in Figures 1 to 3 by the arrow MF) is picked up by the winding
L2 of the power receiver voltage doubler rectifier
RE. The voltage induced in the winding L2 is rectified so that a substantially continuous voltage VA appears on the output terminal AL of the energy receiver RE.

 The ferrite F1, chosen for its directivity qualities, makes it possible to concentrate the electromagnetic energy in a preferred direction. In this example, when the collar of the animal, which carries the identifier ID is placed approximately 10 cm above the ferrite F2, the power captured and rectified in the receiver RE, is of the order of a few hundred milliwatts.

 It should be recalled that in the devices of the prior art to induce sufficient power in the identifier, the latter had to be placed at a distance of only a few centimeters from the identification station. Thanks to the use of both the medium frequency and the F2 ferrite, this distance is therefore, for the device according to the invention, of the order of ten centimeters for a transmitted FM power of the order of a few Watts.

 We will now describe, using Figures 4 and 5, an embodiment of a modulator-transmitter according to the invention.

 The ME modulator-transmitter comprises three stages an OSE emission oscillator, an OSP pilot oscillator controlling the first at a well-determined frequency and a MO modulator (FIG. 4).

 According to the invention, the OSE and OSP oscillators are critical tuned, that is to say that they do not oscillate in the idle state or in the absence of sufficient stress. The oscillation of said oscillators is controlled by a signal generated by the modulator MO. For its part, it only generates a signal if it receives a signal from the GE generator.

 In this example, the generator GE is a binary code generator adapted to produce a binary signal representing the code number of the animal carrying the identifier.

 Of course, each generator GE can be provided adjustable, that is to say that one can change the code number or can be, on the contrary, provided non-adjustable. These arrangements, which are not part of the present invention, will not be described in more detail here.

 In the absence of a binary signal at the output of the GE element, the modulator does not generate any signal and the OSE and OSP oscillators are not energized. No broadcast can therefore take place.

The same applies if the supply voltage, generated by the RE energy generator, is insufficient to supply the modulator-transmitter correctly.
ME or the GE generator.

As soon as the animal approaches an identification post, and the collar carrying the identifier
ID is located at a distance of the order of ten centimeters from the ferrite F2, the energy receiver picks up a signal making it possible to generate a direct voltage VA suitable for supplying both the modulator-transmitter ME and the GE generator. The generator GE then generates a binary signal representing the code of the animal wearing the collar.

This signal is modulated in the MO modulator which, in this example, modulates in amplitude, the signal emitted by the OSE transmission oscillator. This signal is demodulated by the RC receiver of the PI identification station (Figure 2).

 We will now describe, in support of FIG. 5, a diagram representing an embodiment of the modulator-transmitter described in support of FIG. 4.

In this example, the OSE oscillator and the MO modulator are constituted by the same output stage comprising an oscillating circuit whose resonant frequency is located in the high frequency range (capacitance ClO, self-antenna AT, transistor T2, resistance polarization R16 and a coupling capacitor C12). The modulation signal from the generator GE, line LGE, attacks the base of the transistor T2 through a coupling capacitor C9 and a shock inductor SC1. The base of the transistor
T2 is polarized by two resistors R11 and R 13. The pilot oscillator OSP consists of a stage-comprising an oscillating circuit (capacity C6, Quartz Q1), a transistor T1, polarization resistors R10, R12, R14, R15.

This stage also includes a capacity for feedback
C7.

 The two stages are coupled by a C8 capacity.

 The two oscillation stages comprising the transistor T1 and the transistor T2 respectively are critical tuned, that is to say that they do not oscillate in the quiescent state. In the absence, either of a modulation signal on the line LGE, or of a sufficient voltage VA on the line VC, the transistor T2 is blocked.

The conduction can only be done on the appearance of a pulse on the LGE line, therefore in the presence of a modulation signal.

 In the presence of such a signal, the transistor T2 saturates and the oscillator, constituted by the capacitor C10 and the self AT, starts to oscillate, this oscillation being modulated in all or nothing by the pulses present on the line LGE.

As soon as the transistor T2 is saturated, the transistor
T1, which is also blocked in the idle state, becomes conductive.

This conduction is done by a return of the high frequency signal from the oscillator C10, AT, this return being possible since the frequency used is well beyond the cut-off frequency of the diode
Zener Z1 of the energy receiver R1 (Figure 3). This switching on of the transistor T1 allows the triggering of the oscillator C6, Q1 and therefore allows the whole stage to oscillate at the frequency chosen for the transmission of the animal code.

 The capacitor C8 couples the output of the pilot stage with the input of the power stage (base of the transistor T2).

 The whole oscillates at the frequency of the quartz Q1 and a high frequency signal modulated by the signal present on the LGE line is emitted. This signal corresponds to the animal code.

 As soon as the animal withdraws, the voltage delivered to the output of the energy receiver becomes insufficient.

No code can be generated by the generator GE and the transistors T1 and T2 are blocked. There can therefore be no spurious emission.

 Of course, the invention is not limited to the embodiments described and shown, but encompasses all variant embodiments.

Claims (4)

 1. Gender identification device comprising at least one identification station, having an electromagnetic energy transmitter and a receiver of electromagnetic identification signals, and at least one identifier carried by each individual to be identified, the identifier comprising an electromagnetic energy receiver, a generator of identification signals and a transmitter-modulator, characterized in that the electromagnetic energy transmitter (EE) comprises at least one oscillating circuit (C35, C33, L1) tuned in medium frequency, and in that this circuit comprises at least one coil (L1) supported by an induction guide comprising a ferrite (F2).  2. Gender identification device comprising at least one identification station, having an electromagnetic energy transmitter and a receiver of electromagnetic identification signals, and at least one identifier carried by each individual to be identified, the identifier comprising an electromagnetic energy receiver, an identification signal generator and a transmitting modulator, characterized in that the transmitting modulator (ME) comprises a first critical tuned oscillating circuit (OSE), controlled in frequency by a second oscillating circuit (OSP) , tuned critical, quartz, and in that the oscillation of said first and second oscillating circuits is controlled by at least one signal generated by a modulator (MO) that includes said modulator-transmitter.  3. Gender identification device comprising at least one identification station, having an electromagnetic energy transmitter and a receiver of electromagnetic identification signals, and at least one identifier carried by each individual to be identified, the identifier comprising an electromagnetic energy receiver, a generator of identification signals and a modulator-transmitter, characterized in that the electromagnetic energy (EE) transmitter comprises at least one oscillating circuit (C35, C33, L1) tuned on average frequency, in that this circuit comprises at least one winding (L1) supported by an induction guide comprising a ferrite (F2), in that the modulator-transmitter (ME) comprises a first oscillating circuit (OSE), tuned critical , frequency controlled by a second oscillating circuit (OSP), critical tuned, of quartz, and in that the oscillation of said first and second oscillating circuits is controlled by at least one signal generated by a modulator ( MO) that includes said modulator-transmitter.  4. Device according to any one of claims 2 or 3, characterized in that the modulator (MO) is coupled to a generator (GE) of code.