A method for setting a safety threshold that triggers the sending, by an acceleration or movement sensor device ( 20 ), of a safety signal that causes a safety movement of a motorised screen ( 11 ) used as a closure or as a sunshade or for privacy, said method comprising the following steps:
       manual shaking of the screen,   recording of a signal produced by a sensor means ( 33 ) during the manual shaking step, and   determination of the safety threshold from this recording.

BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to a method for setting a safety threshold that triggers the sending, by an acceleration or movement sensor device, of a safety signal that causes a safety movement of a motorized screen used as a closure or as a sunshade or for privacy. The invention also relates to an acceleration or movement sensor device for implementing such a method. 
       DESCRIPTION OF THE PRIOR ART 
       [0002]    It is known practice to use a vibration sensor comprising, for example, an accelerometer, to detect movements caused by the wind on a mobile structure such as an awning. The sensor is mounted on the mobile structure at a point where the wind effects are particularly important. It also includes a device that analyzes the signals produced by the accelerometer and a radio transmitter to send to a motor control unit a command to wind the awning up when the vibration level exceeds a predetermined threshold. 
         [0003]    Such a device is known for example from application FR 2 811 431. 
         [0004]    Document EP 1 659 256 describes a similar sensor for detecting the presence of wind and controlling a sunshade installation accordingly. 
         [0005]    One problem with this type of sensor is how to set adjustment thresholds (to adjust the degree of sensitivity of the sensor), because it is important that the sensor should have a completely watertight housing since the mobile structure, which is sensitive to wind action, is also exposed to weather, moisture and salt fogs. The means for setting the threshold or thresholds can only be got at after the housing has been disassembled, which usually means removing the sensor from the structure. 
         [0006]    Furthermore, setting a preset potentiometer contained in a closed housing is a difficult task. But on the other hand, making the control of the potentiometer accessible from the outside significantly increases the cost, because of the need for water tightness. 
         [0007]    It is an object of the invention to provide a method for setting a sensor device that overcomes the drawbacks cited above and improves the known setting methods of the prior art. In particular, the invention proposes a simple setting method that limits the work on the sensor device. The invention further relates to a sensor device for implementing such a setting method. 
       SUMMARY OF THE INVENTION 
       [0008]    The setting method according to the invention is defined in claim  1 . 
         [0009]    Various embodiments of the setting method are defined in claims  2 - 8 . 
         [0010]    The sensor device according to the invention is defined in claim  9 . 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0011]    The appended drawing shows, by way of example, an embodiment of a sensor device according to the invention and a way of carrying out a method of setting a sensor device according to the invention. 
           [0012]      FIG. 1  is a diagram of an installation comprising a sensor device according to the invention. 
           [0013]      FIG. 2  is an exploded diagram of a sensor device according to the invention. 
           [0014]      FIG. 3  is an electrical diagram of a sensor device according to the invention. 
           [0015]      FIG. 4  is a flow chart showing one way of carrying out a method for setting a sensor device according to the invention. 
           [0016]      FIG. 5  is a flow chart showing one way of carrying out the first step of the setting method. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]      FIG. 1  shows an installation  10  comprising a motorized awning in which the fabric  11  is attached by a fixing  12  to a load bar  13 . The fabric is wound onto a motorized tube  18 . When the motor winds the fabric onto the winding tube, the fabric moves the load bar  13  in direction X 1 , and, to a lesser extent, in direction Y 2 . A plurality of spring-loaded hinged arms  14  apply a force to the load bar  13  in direction X 2  and, to a lesser extent, in direction Y 1  so as to keep the fabric taut. The hinged arm  14  is connected to the load bar by a first hinge  15 . The hinged arm comprises other hinges, in particular a second hinge  16  connecting it to the fixed structure  17  of the installation, which comprises the motorized winding tube. Load bar, fabric and jointed arms constitute the mobile structure. 
         [0018]    The installation  10  also comprises a sensor device  20  mounted on the load bar  13 . The sensor device  20  could be located anywhere such that the wind (represented by a solid arrow WND) acting on the fabric  11  causes the mobile structure, and in particular the location where the sensor device is situated, to move about. The sensor device  20  transmits a safety signal to a control unit  19 . This control unit generates the commands which control the motorized tube. The unit comprises a radiofrequency receiver with an antenna, and optionally some sort of weather sensor. 
         [0019]      FIG. 2  details the components comprised in the sensor device  20 . In the preferred embodiment, the sensor device comprises a base  22  mounted on the mobile structure, and a removable part  23  forming a cover and comprising the electronic components of the sensor device. 
         [0020]    The cover  23  comprises clips  24  for quick attachment of the cover  23  to the base  22  in recesses  25 . The base is mounted rigidly on the load bar  13  by mounting means  26  represented by circles. These may simply be fastening screws. The base also includes a primary element  27  for detecting the closure of the housing, for example a magnet, a reflective patch or a pin designed to operate a switch. The base and the cover form the housing of the sensor device. 
         [0021]    The sensor device  20  also comprises an electronic circuit  30 . The components are mounted on a printed circuit  31  fixed to the cover  23  by means of fixing pins  28 . These components comprise a secondary element  32  for detecting the closure of the housing, such as a reed switch controlled by a magnet, an optocoupler or a single switch. The secondary element acts in conjunction with the primary element, as shown by a curved dashed line, to deliver an electrical state representing the state of closure of the housing. 
         [0022]    Also mounted on the printed circuit is a vibration sensor means  33 , e.g. an accelerometer or a ball and contact inertial sensor, or any device for detecting movement. 
         [0023]    A logical processing unit  34 , such as a microcontroller, a radio transmitter  35  and its antenna, and a battery  36  are also inserted into the printed circuit  31  of the sensor device. 
         [0024]    The connections between these components are detailed in  FIG. 3 . 
         [0025]    The logic processing unit includes among other things software means for controlling the operation of the sensor device during its setting by the setting method to which the invention relates, one way of carrying this out being described in detail later. In particular, these software means comprise computer programs. 
         [0026]    The logic processing unit  34  is powered by the battery  36 , as is the vibration sensor means  33  if a controlled switch  37  is closed. The signals produced by the vibration sensor means  33  are transmitted to a first input ACC of the logic processing unit. The output of the secondary housing-closing element  32  is connected to a second input CLS of the logic processing unit. This input is in the low logic state while the housing is closed. In this case, the signals produced by the vibration sensor means are processed, and, if they exceed one or more predetermined threshold(s), a control signal is then transmitted from a first output SGNL of the logic processing unit to an input RFI of the radio transmitter  34 , of which an output RFO supplies a radiofrequency antenna, which then transmits a safety signal “wind”. 
         [0027]    Alternatively, the first and second elements detect not the opening of the housing but its mounting at a predetermined location of the mobile structure. For example, a magnet acts as the primary element and is located at a point of the mobile structure, while a reed sensor acts as the secondary element. The primary element may also be a simple U-shaped ferromagnetic part mounted on a mobile structure, while the magnet and the reed sensor are positioned inside the housing. When the housing is placed near the ferromagnetic part, the latter channels the magnetic flux of the magnet and returns it to the reed sensor. 
         [0028]    To allow interchangeability of housings in the event that a defective element needs replacing, all primary elements are able to interact with all secondary elements where the elements are of the same type. 
         [0029]    If the logic input CLS changes to the high state, the logic processing unit ignores the signal produced by the vibration sensor means. In the embodiment shown in  FIG. 3 , a controlled opening switch  37  is controlled by an inhibiting output INH of the logic processing unit  34 , the effect of which is to stop the supply to the vibration sensor means  33 , and therefore stop any signal produced by the latter. Alternatively, the logic processing unit  34  may simply stop analyzing the signals present at its input ACC, or temporarily block the sending of a signal transmission command to the radio transmitter  35 , or temporarily interrupt the power to the radio transmitter  35  by a means similar to the control switch  37 , or by using the same control switch  37  to cut off the power to the vibration sensor means and to the radio transmitter. 
         [0030]    Once the sensor device has been configured, its operation is such that, when movements or vibrations exceed a predetermined safety threshold, the sensor device transmits a safety signal that triggers a safety movement of the screen, for example winding it up in the case of an awning supported by arms. 
         [0031]    One way of carrying out the setting method according to the invention is described in detail below with reference to  FIG. 4 . 
         [0032]    In the first step E 11 , the sensor device is put in an setting mode. This can be done in various ways. For example, if the sensor device has wireless signal receiving means, a signal to enter the setting mode can be sent to it from a remote control with which it is paired. Alternatively, the sensor device may have a special switch for putting it in the setting mode when activated. Also, if the sensor device is of the type described above, it is possible that it can be triggered to enter the setting mode by a sequence of actions of removing and/or opening and fitting and/or closing the housing of the sensor device in compliance with a specified time sequence. For example, opening the housing and then closing it again less than 10 seconds after opening it may put the sensor device into setting mode as detailed below. 
         [0033]    In the second step E 12 , the installer shakes the screen with the sensor device mounted on it. The movement and/or vibrations introduced by the installer by applying forces to the screen will be those which are decisive in defining a safety threshold above which the sensor device will transmit a signal, once completely configured. By construction, an awning is capable of withstanding quite violent gusts of wind, but the user perceives the shaking of the structure as alarming. It is therefore desirable for the installer to give the awning a shaking movement corresponding to what the user would regard as alarming, rather than what the awning could actually cope with. 
         [0034]    In the third step E 13 , which takes place simultaneously with step E 12 , the signal produced by the vibration sensor means is recorded. This recording step has a predetermined duration T 1  of for example between 30 seconds and 3 minutes. This duration is counted from the instant the unit enters setting mode. The data defining the signal are stored in a memory MEM of the logic processing unit  34 . These data may for example be values sampled from the signal produced by the vibration sensor means. 
         [0035]    At the end of step E 13 , in the fourth step E 14 , one or more safety threshold values are calculated from the above recording, using algorithms or empirical rules. For this purpose the logic processing unit  34  contains a calculating program stored in memory MEM enabling it to process the values previously stored in its memory. 
         [0036]    For example, a safety threshold may be determined from the highest measured value, or from the mean of the ten highest values. Alternatively, a first safety threshold may be determined for a high oscillation frequency (or for a pulsed mode) and a second threshold may be determined for a low oscillation frequency. 
         [0037]    These determinations of values can be done automatically as described in the above three paragraphs by an automatic sequencing of the steps. 
         [0038]    Alternatively, step E 13  may be stopped by an action of the installer, such as pressing a button on a remote control (e.g. pressing the stop button causing the actuator to stop when it is operating). 
         [0039]    Lastly, steps E 13  and E 14  can be combined into a single step in which a value determined by the signal produced by the vibration sensor is continually updated. For example, this can be done by a peak detector which keeps the maximum value of the signal in memory. The most recent value obtained at the end of the step is for example the safety threshold value. 
         [0040]    In the fifth step E 15 , the safety threshold value or values are recorded in the memory MEM. 
         [0041]    In the sixth step E 16 , at the end of the preceding step, the sensor device automatically switches to the operating mode, termed the monitoring mode. The sensor device is now operational. 
         [0042]    In an optional seventh step (not shown) the sensor device may tell the installer that one or more safety thresholds have been recorded and that the sensor device is operational. 
         [0043]      FIG. 5  details an embodiment of the first step E 11  of the setting method, allowing the device to enter the setting mode. 
         [0044]    In the first substep E 21  of the step of putting the device in the setting mode, the installer opens the housing or removes it, after first opening the awning at least partially. This is detected by the detection means. 
         [0045]    In the second substep E 22 , the wind safety signal is inhibited. This is to ensure that the awning does not retract automatically in response to the movements applied to the housing by the user. 
         [0046]    In the third substep E 23 , a second time period T 2  of short duration, for example between 2 and 10 seconds, is triggered. 
         [0047]    In the fourth substep E 24 , the device tests to see whether the removal and/or opening of the housing (detected in the first substep E 21 ) is maintained during the duration of the second time period. If it is not, and the housing has been closed again or put back in position during the duration of the second time period, then the setting mode is activated and the first step E 11  is completed. 
         [0048]    An installer who wishes to adjust the sensitivity thresholds of the sensor-transmitter must therefore carry out a very simple operation: remove the sensor-transmitter housing from its support, and put it back in place after a few seconds, alternatively open and then re-close the housing. This operation is performed while the awning is at least partly extended. 
         [0049]    If this embodiment is used, permission to transmit the wind safety signal is re-established at the end of the sixth step E 16 . 
         [0050]    The entry into the setting step may be confirmed to the user by a sensory signal: for example, an audible beep emitted by the sensor-transmitter, or preferably by the control unit  19  after the latter has received a radio message from the sensor-transmitter informing it that the setting step has begun. 
         [0051]    The method according to the invention is applicable to screens other than awnings. It is particularly applicable to a roller awning or to a door.