Abstract:
A method for enabling an apparatus ( 15 ) to operate only after detecting with receiver elements ( 11 ) located proximate to the apparatus, a signal transmitted by portable transmitted elements ( 1 ), which consists in no longer taking into account detection by the receiver means ( 11 ) of the signal transmitted by the transmitting elements ( 1 ), after activating presence sensing elements ( 22 ) provided proximate to the apparatus, or integrated in the apparatus. Once activated, the presence sensing elements ( 22 ) neutralize the transmitter/receiver device ( 1, 11 ) and the apparatus can operate normally without being perturbed by possible statics or accidental losses of signal. The inventive method and device are applicable to an antitheft safety device for a motor vehicle.

Description:
BACKGROUND OF THE INVENTION 
   This invention concerns a secured method for managing the operation of an apparatus by a user, which method is of the type enabling the operation of the apparatus only after detection by receiving means situated close to the apparatus, of a signal transmitted by portable transmitting means; the invention also concerns the hardware for the implementation of the method. 
   One already knows safety systems adapted on an apparatus which, to authorize the operation of this apparatus, involve the existence of a link between a transmitter carried by the user and a receiver provided close to said apparatus or on said apparatus. 
   For example, the document EP-0 319 428 describes an anti-theft safety device for vehicle comprising a portable transmitter which transmits a high frequency signal (HF), and a fixed receiver adapted for cutting off automatically the ignition circuit of the engine of the vehicle assembly, when the distance between the portable transmitter and the on-board received exceeds a certain value. Such a system stops the motor of the vehicle, in particular in case of theft, as soon as the vehicle moves away from the carrier of the transmitter. 
   The transmitter transmits a low power, encoded cyclic HF signal. When this signal is acknowledged and validated by the reception means, a relay or equivalent closes the ignition circuit of the engine to ensure its operation. When the reception system does not receive the HF signal transmitted any longer, the relay or equivalent cuts off the ignition circuit in order to stop the motor. 
   A time-delay circuit is provided to maintain the control of the relay for a duration greater than that intermediate two encoded sequences, in order to avoid any false interruption in case of interferences, or more generally in case of accidental loss of the signal. 
   However, if the duration of accidental loss of this signal is greater than the time-delay duration, the ignition circuit is automatically cut off by means of the relay and the motor of the vehicle does not operate any longer. This may cause sizeable malfunctions, and may even prove dangerous. 
   The object of this invention is to remedy this shortcoming. 
   SUMMARY OF THE INVENTION 
   Within the framework of a method consisting in enabling the operation of an apparatus only after detection by receiving means situated close to said apparatus, of a signal transmitted by portable transmitting means, this invention allows not to take into account any longer the detection by the receiving means of the signal transmitted by the transmitting means, after activation of presence detection means arranged close to said apparatus, or integrated to said apparatus. 
   The method according to this invention consists in fact in activating a switching system interposed on the control circuit of the apparatus, in order to close such circuit after detection of the signal transmitted by the transmitting means, and to lock this closure by activating presence detection means arranged close to said apparatus, or integrated to said apparatus. 
   According to a preferred embodiment, the method according to this invention consists, once the apparatus in operation, in triggering by each activation of the presence detection means, a second safety detection of the signal transmitted by the transmitting means, for a preset time period and, once said time period has expired, in locking, either the closure of the control circuit of said apparatus in case of a validation of signal, or the opening of said circuit in case of non-validation of this signal, while not taking into account any longer, after locking said closure or opening of the circuit, the transmitter/receiver link. One then takes into account again the basic transmitter/receiver link, after a change of state (deactivation) of the presence detection means. 
   In case of absence of problem associated with a theft or with an aggression, the presence detection means neutralise the transmitter/receiver device and the apparatus may operate normally, without being disturbed by possible interferences or accidental loss of signal. 
   The hardware for the implementation of this method comprises:
         portable transmitting means,   a receiver module situated close to the apparatus whereof one wishes to manage the operation,   a switching system (such as relay, transistor, switch or equivalent) interposed on the control circuit of the apparatus,   presence detection means arranged close to said apparatus or integrated to said apparatus, and   control means (for example in the form of a microprocessor) which are laid out to close the control circuit of the apparatus by means of the switching system when the signal transmitted by the transmitting means is detected by the receiving means, and acknowledged, and which are laid out to lock the closure of this control circuit when the presence detection means are activated.       

   The transmitting means have preferably limited power, in order to authorize the reception of the signal by the receiver module, only within a radius of several meters. 
   Still according to the invention, the switching system is in the form of a power output interposed on the control circuit of the apparatus to cut off or restore such circuit in relation to the signal or of the absence of signal supplied by control means in the form of a microprocessor, which microprocessor manages the sending of this signal in relation to the information received by the receiving means. 
   According to another preferential characteristic, the control means of the safety hardware are laid out in order to, once the apparatus in operation, trigger by each activation of the presence detection means, a second safety detection of the signal transmitted by the portable transmitting means, for a pre-set time period (for example 15 seconds); once this time period has expired, said control means lock, either the closure of the control circuit of the apparatus in case of a validation of said signal, or the opening of said circuit in case of non-validation of said signal, this without taking into account any longer said locked closure or opening, of the transmitter/receiver link. The control means of the safety hardware take again into account the transmitter/receiver link, after a change of state (deactivation) of the presence detection means. 
   In an embodiment applied to an anti-theft safety device for an engine vehicle, the hardware according to this invention comprises portable transmitting means, a receiver module on board the vehicle, presence detection means integrated to said vehicle and control means of a switching system placed on at least a circuit necessary to the correct operation of said vehicle, for example the ignition circuit of the motorisation, the starter circuit, or the fuel incoming circuit. These control means are laid out to close said circuit by means of said switching system when the signal transmitted by the transmitting means is detected by the receiver module, and acknowledged; they are also laid out to manage the locking of the closure or of the opening of said circuit in relation to the second identification control triggered by the presence detection means. 
   In this particular application, the presence detection means may be in the form of a sensor implanted in or on the seat of the vehicle and adapted to be activated when the user of the vehicle sits down on said seat. According to embodiment variations, such presence detection means may be in the form of a system for detecting when a gear has been selected, or in the form of system for detecting a given threshold of an engine duty. 
   Within the framework of an application to an automotive vehicle or to a truck, such presence detection means may be in the form of a closure/opening sensor for the driver&#39;s door, in the form of a system for detecting when the seatbelt has been fastened, in the form of an infrared sensor positioned in the body of the vehicle, or other suitable means. 
   According to another characteristic, adapted means enable detection of the presence or the absence of a voltage at the ON/OFF contact of a starter for the vehicle motor, the corresponding information being transmitted by control means in order to activate the receiver module only in case of presence of said starter contact. 
   According to another particularity, within the framework of an application to an automotive vehicle or to a truck, a presence sensor may be laid out close to the driver&#39;s door, the activation information of said presence sensor being transmitted to the control means of the safety device, in order to activate the receiver module. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     But the invention will be better illustrated, without being limited thereto, by the following description of a particular embodiment, given only for exemplification purposes and represented on the appended drawings wherein: 
       FIG. 1  is a principle diagram of the portable transmitting means of an antitheft safety device for an engine vehicle, according to this invention; 
       FIG. 2  represents the principle diagram of reception and control means on board the vehicle. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The transmitting means  1  represented on  FIG. 1  comprise a transmission module  2 , for example high frequency (HF), whereof the operation is managed by a microprocessor  3  to send to an antenna  4  a cyclic and low power encoded signal. 
   The transmission module  2  may be a model LQ-TX 433A-S of LPRS-OXON-Great-Britain. The microprocessor  3  with integrated clock may be a model 2343 with EDPROM, of Société ATMEL (Paris, France). 
   The different components of the transmitting means  1  are implanted on a printed circuit and connected together logically. A battery  5  provides their electrical supply and the assembly is placed in a portable box which may be fitted with a system for hanging on a pocket or a belt. Putting into or off operation of the transmitting means  1  is control by an on/off switch  6  laid out on the portable box. This box comprises moreover a LED-type light-indicator  7  whereof the activation is managed by the microprocessor  3 . 
   The signal transmitted by the transmitting means  1  carries an encoding generated by the microprocessor  3  to secure the operation of the device. On the other hand, the signal is transmitted cyclically to spare the battery  5 ; for example the transmission is realised on the 868.35 MHz frequency, and this for one second every 2.5 or 3 second (the transmission duration and the period are managed by the microprocessor  3 ). 
   One also intends to limit the power of the signal transmitted (a few milliwatts) in order to enable the reception of this signal only within a radius of several meters. 
   The reception and control means  8  represented on  FIG. 2  are on board the vehicle assembly (for example a motorbike). They are composed of an antenna  10  connected to a reception module  11  associated with a microprocessor  12 . The purpose of such microprocessor  12  is to check by encoding identification that the signal received is indeed the one originated from the transmitting means  1  and, in relation to the information received, in order to manage the activation:
         of a power output  14  (relay or equivalent) placed on the ignition circuit  15  of the motorisation of the vehicle, and   of a power output  16  (relay or equivalent) which controls, simultaneously, a sound alarm  17  in the form of a buzzer and a redundant output with non-return diodes  18 ,  19  to supply the right  20  and left  21  indicator beams.       

   To manage the operation of the safety device, the microprocessor  12  also takes into account:
         the activation or the deactivation of a presence sensor  22  laid out on the driver&#39;s seat of the vehicle. This sensor  22  may be of FSR type distributed by ALCYON-Paris, France, and   the presence or the absence of a starter contact of the vehicle. The corresponding information is transmitted to the microprocessor by appropriate detection means  23  (for example from a voltage detected on the on/off contact of the starter).       

   The reception module  11  may be a model RX 5000 manufactured by RFM (USA) and distributed by EQUIPEMENT SCIENTIFIQUE-Garche, France. The microprocessor  12  is for example a model PIC 16C with integrated converter of MICROTCHIP (USA) and distributed by AROW-Rennes, France. The different electronic components of the reception and control means  8  are implanted on a printed circuit and connected together logically. The reception module  11  and the microprocessor  12  are supplied by the battery  24  of the vehicle. 
   Once the reception and control means  8  have been implanted correctly on the vehicle assembly, the anti-theft safety device operates as described below. 
   The transmitting means  1  and the receiver module  11  being deactivated, the microprocessor  12  controls the power output  14  in order to open the ignition circuit  15  of the vehicle, thereby preventing the operation of the motor. 
   Putting into service the transmitting means  1  is made by bringing the switch  6  into the ON position; the light-indicator  7  may signal such activation for example by a steady so-called long light, greater than 1 second. On the other hand, putting into service the receiver module  11  is made by the starter contact of the vehicle, by means of the key placed in 12 Volt position after contact. The receiver module is, in fact, actuated by the microprocessor  12  on the basis of a piece of information supplied by the detection means  23 . 
   As soon as the starter contact has been established, the receiver module  11  detects the HF signal transmitted by the transmitting means  1  and it sends the information to the microprocessor  12 . After identification of the signal, the microprocessor  12  closes the ignition circuit  15  by means of the power output  14 ; simultaneously it may initiate the transmission of an identification message while activating the blinkers  20 ,  21  and the buzzer  17  by means of the power output  16  (for example transmission of three short flashing signals according by three sound beeps. 
   The vehicle may then be started. 
   When the user sits down on the seat of the vehicle, the presence sensor  22  is activated and the microprocessor  12  then requests an additional safety validation of the signal transmitted by the transmitting means  1 , for a pre-set safety time period, which may be of the order of 15 seconds. 
   In the general case when the receiving means  11  detect and acknowledge the signal transmitted by the transmitting means  1  for the whole duration of the safety time-period aforementioned, with the expiration of this time period, the microprocessor  12  locks the closure of the ignition circuit  15  by means of the power output  14  without taking into account any longer the basic HF signal from the transmitting/receiving means. 
   The vehicle may be used conventionally, without this use being disturbed by possible accidental losses of the HF signal. 
   In the other case when the receiving, means  11  do not detect or do not recognise the HF signal transmitted by the portable transmitting means  1  for the whole duration of the safety time-period, the microprocessor  12  opens the ignition circuit  15  by means of the power output  14  and locks the opening of this circuit without taking into account any longer the HF signal of the transmitting/receiving means. 
   In either case mentioned aforementioned, the microprocessor  12  will again take into account the HF link of the transmitting/receiving means at the time of deactivation of the presence sensor  22 ; and the procedure detailed above will be repeated after new activation of said sensor  22 . Each activation of the presence sensor  22  involves a new identification request of the HF signal between the transmitting means and the receiving means. And each deactivation of said sensor causes the &lt;&lt;permanent&gt;&gt; HF link of the transmitting/receiving means to be taken into account again; taking into account the &lt;&lt;permanent&gt;&gt; HF link again may be performed after a time-delay which is greater than the cyclic transmission period of the HF signal. 
   Further to a conventional usage of the vehicle, when the user kills the starter contact, the receiver module  11  is not activated any longer and the microprocessor  12  cuts off automatically the starter circuit  15  by means of the power output  14  to put the anti-starting system into service. 
   Putting the anti-starting system into service may be accompanied by a control signal of the light-indicator  7  (for example a short steady light of the order of a few tenths of a second); also, such activation of the anti-starting system may be signalled by the flashing lights  20 ,  21  and the buzzer  17  (for example transmission of a short luminous signal accompanied by a sound beep) . The switch  6  of the transmitting means  1  may be placed in the off position since the receiver module  11  cannot receive the HF signal transmitted any longer. 
   According to the management mode which has just been described, when the vehicle is en operation, if the user walks away after leaving the seat, without cutting off the motorisation, as soon as the receiver module  11  does not receive the HF signal transmitted by the transmitting means  1  any longer, the microprocessor  12  activates the power output  14  to cut off the ignition circuit  15 . The vehicle cannot then start until the carrier of the transmitting means  1  activates the starter contact. 
   In case of theft or intrusion, with the engine on, the presence sensor  22  is deactivated when the standard user leaves his seat, then it is re-activated when the intruder takes possession of the vehicle. 
   If the receiver module  11  does not receive the HF signal transmitted by the transmitting means  1  any longer by the end of the safety time-period (which can be denominated identification range triggered by the intruder sitting down, the microprocessor  12  activates the power output  14  to cut off the ignition circuit  15  in order to stop the vehicle upon completion of identification range, the intruder may drive away with the vehicle, but the starter circuit  15  will open during the next change of state of the sensor to render the vehicle unusable. 
   As a variation, the power output  14  may be placed on the starter circuit of the vehicle; still according to another variation, this power output  14  may control an electro-mechanical system placed on the fuel incoming circuit. 
   More generally, the switching system  14  managed by the microprocessor  12  may control any member necessary to the correct operation of the vehicle. 
   It should also be noted that in addition to the control of the power outputs  14  and  16 , the microprocessor  12  may also manage one or several additional power output(s) entrusted with activating or deactivating other functions of the vehicle. Thus, several members necessary to the correct operation of the vehicle may be managed simultaneously (ignition circuit, starter function, or fuel incoming circuit. 
   It should further be noted that the seat sensor  22  described in relation with the embodiment above, may be replaced with a system for detecting when a gear has been selected, by a system for detecting when a threshold of a given engine duty has been exceeded (for example 2000 rpm.), or other suitable means, while adhering to the same general operation principle. 
   The latter case evoked (system for detecting when a threshold of a given engine duty has been exceeded), may in particular be quite suitable to an application of the anti-theft safety device to a vehicle such as a scooter. 
   Within the framework of an application of an anti-theft safety device similar to an automotive vehicle (conventional car or truck, notably), the presence detection means may be composed of a closure/opening sensor of the driver&#39;s door, of a safety belt fastening sensor, of an infrared sensor placed in the body of the car, or other suitable means. 
   On the other hand, putting into service the receiver module may in such a case be performed by an infrared sensor placed close to the driver&#39;s door, for example on the rear-mirror or the handle. 
   The principle according to this invention for neutralising the transmitting/receiving means by presence detection means enables to make the overall operation of the anti-theft device secure and reliable. 
   The same principle may be used in very different fields for example for accessing premises, for controlling access to a microcomputer (the presence sensor corresponding here to a piece of information regarding the use of key on a keyboard, of a game joystick, of the mouse or other suitable means.