FR2814578A1 - DEVICE FOR CONTROLLING ACCESS USED BY MOTOR VEHICLES - Google Patents

Abstract

It comprises a rail (2) movable between first and second positions in which it bars and releases access, respectively, a reading terminal (6) of an access authorization title placed in front of the rail ( 2), first (8) and second means for detecting the presence of a vehicle at the terminal (6) and the boom, respectively, and means (7) supplied by signals emitted by the terminal ( 6) and the detection means, for controlling the movements of the arm (2). The second detection means (9, 10) are photosensitive means illuminated by a light brush passing through the access to be controlled and the control means (7) pass the arm (2) from its second position to an intermediate position between this and its first position, when the detection means (8) signal the presence of another vehicle at the terminal (6).

Description

The present invention relates to an access control device

  borrowed by motor vehicles and, more particularly, to such a device comprising a movable beam between at least first and second positions in which it bars and releases, respectively, said access, a terminal for reading an authorization title d access placed in front of said arm, first and second means for detecting the presence of a vehicle at said terminal and said arm, respectively, and means supplied by signals emitted by said terminal and said means detection, to control the movements of

said smooth.

  Motor vehicle parking lots are commonly equipped with such devices, to control the entry and / or exit of vehicles. As shown diagrammatically in FIG. 1 (plan view) and FIG. 2 (elevation view) of the appended drawing, an access control device commonly comprises a barrier consisting of a box 1 for supporting a heddle 2, the box comprising a motor 3 making it possible to selectively rotate the arm 2 around one of its ends. In a first position, shown in solid lines in FIG. 2, the other end of the heddle rests on a support 4, in a horizontal position, so as to bar an access path 5 constituting an entry or exit from a fleet of parking. In a second position, shown in broken lines in FIG. 2, the heddle 2 is vertical and

  clears the access route 5 to authorize the passage of a vehicle.

  The opening of the barrier is controlled by reading, in a terminal 6, a ticket (card, ticket, etc.) presented by the driver parking in front of this terminal to present this ticket at the terminal. A control logic 7, arranged for example in the box 1, organizes the

  reading of the title and the control of the motor 3 for actuating the arm 2.

  To do this, the logic 7 receives (see FIG. 2) a logic signal B emitted by the terminal 6, representative of the valid or invalid character of the ticket presented, a signal Dl emitted by first means 8 for detecting the presence or the absence of a vehicle at terminal 6 and another signal emitted by second means for detecting the presence or

  the absence of a vehicle under the arm.

  These first and second detection means are commonly constituted each by an inductive "loop" consisting of one or more turns of a metallic conductor embedded under the surface of the access path 5. The loop is supplied by a high current frequency (19 kHz for example). A variation in this frequency, induced by the presence of a metallic mass (that of a motor vehicle) above said loop, is detected by suitable electronic means forming the

  signal Di sent to the control unit 7.

  Thus when this logic is informed by this signal of the presence of a vehicle in front of the terminal 6 for reading the title, the logic 7 authorizes the reading of this title by the terminal 6 and, in the event of validity of the title, controls the lifting of the arm 2 to allow the vehicle to pass under this arm. As soon as the detection means placed under the arm indicate that the vehicle has exceeded it, the logic 7 controls the

  return of the arm to the closed position.

  It has been observed that the device described above authorizes fraud.

  Indeed, if, during the passage under the beam of a first vehicle, a second vehicle closely follows the first, this second vehicle can take advantage of the authorization to pass given to the first vehicle to pass under the beam immediately after it without have previously presented a valid access ticket to the terminal. When this title is chargeable, this results in obvious damage to the operator of the fleet of

parking.

  The present invention therefore aims to provide a device for controlling an access taken by motor vehicles, designed so as to prevent fraudulent passage of vehicles through this access, in

  "little train", according to the expression used.

  This object of the invention is achieved with a device of the type described in

  preamble to this description, including in particular first

  and second means for detecting the presence of a vehicle at the terminal and the arm respectively, and means supplied by signals emitted by said terminal and said detection means for controlling the movements of said arm, this device being remarkable in that said second detection means are photosensitive means illuminated by a beam of light passing through the access to be controlled and in that said control means cause the beam to pass from its second position to an intermediate position between it and its first position, when said photosensitive detection means cease to signal the presence of a vehicle at said beam while said first detection means signal the presence of a

  another vehicle at said terminal.

  As will be seen further on, in its intermediate position, the heald sufficiently blocks the access to prevent the passage of a next vehicle in a "small train", a first vehicle normally authorized to

  pass, unlike the driver of the next vehicle.

  According to another characteristic of the device according to the invention, this further comprises third detection means for forming a signal representative of the passage of a vehicle beyond the arm, the control means triggering the return of the arm to its first

position in response to this signal.

  According to yet another characteristic of the device according to the invention, it further comprises alarm means for the driver of the vehicle signaled at the terminal, actuated by the control means. The alarm means display a message ordering a stop

of this vehicle.

  Other features and advantages of the present invention

  will appear on reading the description which follows and on examining the

  appended drawing in which: - Figures 1 and 2 schematically show, in plan and elevation respectively, a preferred embodiment of a device according to the present invention, already partially described in the preamble to

this description, and

  - Figures 3 and 4 show timing diagrams useful for explaining the operation of the device according to the present invention. Reference is made to FIG. 1 of the accompanying drawing to complete the

  description of the structure of the device according to the invention. Besides the

  elements or organs 1 to 8 already described, the device comprises photosensitive detection means 9,10 arranged, in plan view, at the level of the heddle 2 or in its immediate vicinity, these means comprising an emitter 9 of a fine brush of electromagnetic radiation, fixed for example on the support 4 of the heddle, and a photosensitive receiver or cell mounted on the box 1 for example, on the axis of the brush emitted by the transmitter 9, this brush cutting transversely l 'access 5, as

  shown in broken lines in Figure 1.

  The cell 10 delivers to the control logic a logic signal C which is in the high state when the cell is not lit by the radiation brush (i.e. when a vehicle cuts this brush while passing under the

  smooth) and which is low otherwise.

  The device according to the invention also comprises third detection means 11, of the type of those of which the loop 8 is part, described above. The loops 8 and 11 thus deliver logic signals Di and D2 respectively, to the control logic 7, these signals being in the high state when the corresponding loop detects the presence of a

  vehicle above it, and low otherwise.

  We now refer to the timing diagrams of Figures 1 and 2 for

  describe the operation of the device according to the invention.

  The timing diagrams in Figure 1 correspond to a normal crossing of the barrier by a motor vehicle, in the direction of arrow F (see Figure 1). Initially, the driver stops his vehicle at the instant tt in front of terminal 6, in order to be able to present his pass for access. The signal Di then goes high and the control logic activates the ticket reading means placed in the terminal 6. At time t2, the driver presents his ticket to these means which read the ticket and transmit, if the title is valid, a signal B delivered to the logic 7 which reacts to this signal by commanding the activation of the motor 3 to move the arm 2 from its first position (closing) to its second position (raised to 90) in which it authorizes the passage of the vehicle in the access. The vehicle then starts and comes to cut, at time ts, the radiation brush leaving the transmitter 9. The height of the brush above the ground should correspond to the average height of the underbody of motor vehicles, so that this brush is cut as soon as the most advanced part of the vehicle is at the right of the cell and the boom. For this purpose, it is possible to choose a height h of this brush such that h = 630 mm, this value being given by way of illustrative example and not

restrictive only.

  The vehicle continuing to advance begins to pass right of the barrier and comes to be detected, from time t4, by the loop 11 placed downstream of the barrier. The signal D2 emitted by this loop then goes high. Advantageously, a safety mechanism is then activated by logic 7 to lock the heald 2 in its raised position.

  throughout the duration of the passage of the vehicle under this beam.

  At time t, this vehicle, having completely crossed the barrier, ceases to be detected by cell 10, the output signal C of which then drops to the low state. At this instant tU, the control logic 7 examines the level of the signal Di emitted by the loop 8. If the latter has then returned to a low level, as shown in FIG. 3, the logic deduces that none

  no other vehicle overlooks loop 8.

  The logic 7 then controls the return of the arm 2 to its low, horizontal position (marked 0 in FIG. 3) as soon as, at the instant te, the loop 11 ceases to detect the presence of the vehicle in front of the arm 2 (D2 returns to the low state), this being then sufficiently spaced from it

  so that it can be folded down without risk of collision with the vehicle.

  The device is then returned to its initial state, ready to process a

  new access request from the driver of another vehicle.

  The vehicle passage scenario illustrated by the timing diagrams of FIG. 4 repeats the initial steps of that illustrated by FIG. 3,

until time t2.

  At time t3, where cell 10 detects the arrival of a vehicle under the rail 2, the reading of the signal Di by the control logic 7 reveals that at this time another vehicle is located at the terminal 6 (Di in the high state), even though the first vehicle has just left this

terminal to pass under the arm 2.

  In this case, according to the present invention, as soon as the signal C returns to the low state (instant t%), significant that the first vehicle has crossed the barrier, the logic 7 commands a rapid passage of the arm 2 of its raised position at an intermediate position between it and its position

  low, intermediate position marked I in Figure 2.

  In this intermediate position I, the rail 2 obstructs the access sufficiently so that a vehicle driver attempting to fraudulently pass the barrier in a "small train", immediately following a preceding vehicle, is dissuaded from continuing his advance to avoid a

  shock between the barrier and its vehicle.

  This attempt can generate a pulse Ci of the signal C, between the instant when the front of this second vehicle is detected by the cell 10 and the instant when this detection ceases because the second vehicle reverses towards terminal 6, after to have been dissuaded from continuing its advance by the inclined beam. Throughout the duration of Ci, the loop 11, close to the cell 10, detects the presence of the second vehicle, which keeps D2 in the high state until the loop 11 ceases to detect one and / or the other

of the two vehicles.

  Tests have shown that, in its intermediate position I, a

  smooth inclined at 45 on the horizontal sufficiently obstructs the passage.

  This inclination is given for information only and is not limitative

only.

  The stringer 2 should also very quickly reach this intermediate obstruction position, barely giving the fraudulent driver enough time to pass under the stringer before it has reached

this position.

  Tests have shown that a passage time of the beam from its raised position to its intermediate position, of about 0.6 seconds, is suitable in the application described above of the device according to the invention. Such a fast passage time can be obtained with a commercial gear motor, the choice of which enters into the normal activities of those skilled in the art. The latter will thus be able to choose a reversible bevel gear unit with bevel torque mounted directly on the shaft which rotates the arm, and a three-phase asynchronous brake motor controlled by a

  programmable frequency converter.

  To reinforce the deterrent effect provided by the partial lowering of the boom, the barrier can be fitted with a panel 11 (see Figure 2) visual and / or audible alarm. This alarm can thus consist of a flashing of a message such as the word STOP, on panel 11, ordering the halt of a vehicle by fraud, before any risk of collision.

  between this vehicle and the barrier rail of the device according to the invention.

  The excitation of this alarm then intervenes from the moment tg, preferably.

  It will be noted in FIG. 4 that at the instant t4 intermediate between the instants ta and ti, the vehicle lawfully crossing the barrier

  begins to be detected by loop 1 1 (signal D2 goes high).

  As soon as this signal D2 returns to the low state, at the instant t6 after ta, it can be considered that this vehicle, and a possible fraudulent vehicle as we saw above, are sufficiently distant from the barrier so that the arm can be returned to its closed position (0) without risk of collision with these vehicles. The logic 7 then controls the return of the barrier to this position, from its intermediate position I. This return can take place less quickly, in about 1.2 seconds for example, than the passage of the arm to position I. The choice of the distances 1 and L of the loops 1 1 and 8 to the stringer 2 (see FIG. 1) clearly falls within the normal activities of the skilled person. By way of illustrative and nonlimiting example only, one can choose

1 = lm and L = 2.5m.

  It will be noted that the use, in the device according to the invention, of a fine radiation brush to detect the passage of a vehicle in front of the arm 2 in the raised position, makes it possible to detect the instant of the end of this passage with great precision and therefore very quickly bring the boom to its intermediate position I. This is necessary given the proximity of the rear of this vehicle and the front of another vehicle trying to pass the barrier in "small train". Such precision is not possible with an electromagnetic induction loop detector. Of course, the invention is not limited to the embodiment described and shown which has been given only by way of example. Thus the heald could consist of two or more articulated arms, the intermediate position of such an articulated heald then being chosen so that these arms are sufficiently obstructing for a vehicle trying to pass

in fraud.

  Similarly, the photosensitive detection means could comprise several emitter / cell pairs arranged at different heights, to take account of the differences in geometry of the bottoms

  bodywork of motor vehicles.

Claims (8)

  1. Device for controlling an access taken by motor vehicles, comprising a heald (2) movable between at least first and second positions in which it bars and releases, respectively, said access, a reading terminal (6) d '' an access authorization title placed in front of said beam, first (8) and second means for detecting the presence of a vehicle at said terminal (6) and said beam, respectively, and means (7) supplied by signals emitted by said terminal (6) and said detection means, for controlling the movements of said beam (2), characterized in that said second detection means (9, 10) are photosensitive means illuminated by a light brush passing through the access to be controlled and in that said control means (7) pass the beam (2) from its second position to a position (J) intermediate between it and its first position, when said first s detection means (8) signal the presence of another   vehicle at said terminal (6).   2. Device according to claim 1, characterized in that it comprises third detection means (11) for forming a signal (D2) representative of the passage of a vehicle beyond said beam (2), said means control triggering the return of said beam (2) to its   first position in response to said signal (D2).   3. Device according to any one of claims I and 2,   characterized in that it comprises alarm means (11) of the driver of said other vehicle, actuated by said control means (7) when, on detection of said first vehicle by said photosensitive means (9,10), said first detection means (8) signal the   presence of said other vehicle at said terminal (6).   4. Device according to claim 3, characterized in that said alarm means displays a message (STOP) ordering the stopping of said other vehicle.   5. Device according to any one of claims 2 to 4,   characterized in that it comprises a safety mechanism for locking said stringer (2) in its second position during the passage of said   vehicle at said third detection means (11).   6. Device according to any one of claims 2 to 5,   characterized in that said first (8) and third (11) detection means are of the inductive loop type.   7. Device according to any one of claims 1 to 6,   characterized in that the said heald (2) is actuated by an electric motor (3) capable of moving it from its second position to its position   intermediate (I) in about 0.6 seconds.   8. Device according to any one of claims 1 to 7,   characterized in that in said intermediate position (I), said heald (2)   is oriented at 45 from the horizontal, approximately.