FR2476355A1 - SAFETY DEVICE FOR AVOIDING BACK BUFFING AND COLLISIONS ON HANDLING TROLLEYS EQUIPPED WITH SUCH A DEVICE - Google Patents

Abstract

A DEVICE TO AVOID REAR BUFFERS AND COLLISIONS ON HANDLING CARTS INCLUDES AT LEAST ONE TRANSMITTER 21, 22, 23, 24 AND AT LEAST ONE RECEIVER 25, 26, 27, 28 PLACED IN THE FRONT OR REAR OF THE VEHICLE, AS WELL AS FUNCTIONAL LINKS BETWEEN THE RECEIVERS AND THE DRIVE OF THE VEHICLE TO INTERRUPT THE LATTER BEFORE THE COLLISION. THE TRANSMITTERS EMIT RADIATION TO THE RECEIVERS. TRANSMITTERS AND RECEIVERS ARE CONSTITUTED BY OPTO-ELECTRONIC COMPONENTS, FOR EXAMPLE USING GA-AS DETECTORS OPERATING IN ALTERNATE LIGHT, AND ADVANTAGEY PHOTO-ELECTRIC BARRIERS WITH REFLECTED LIGHT OF THE GA-AS TYPE. THE TRANSMITTERS 21, 22, 23, 24 AND THE RECEIVERS 25, 26, 27, 28 ARE PREFERABLY AVAILABLE IN SUCH A WAY THAT THEY MAKE AN ANGLE WITH THE LONGITUDINAL AXLE OF THE TROLLEY.

Description

The invention relates to a device for avoiding rear bumps.

  and collisions on industrial trucks, comprising at least one transmitter and at least one receiver on the front and / or rear side, as well as functional links between the receivers and the vehicle drive, the transmitters emitting rays noticeable by receptors. The invention relates to a

handling cart comprising such a device.

  With such vehicles, in particular handling carts, for example stackers, it is desirable to provide a safety device to avoid rear bumps,

  especially in the form of collision protection.

  As a safety measure to avoid rear bumps, it is known to have transmitters which send strobe flashes in the direction of travel, the reflection of which is received and evaluated to form a signal to influence or stop the drive mechanism. this is

included in the invention.

On industrial trucks, for example the ger-

  beurs, such a safety device is independent of the fact that these are guided by rails or by induction in the aisles of shelving because this guidance is automatic or is done by a conductor, which is particularly important, because for a optimal use of shelf storage, it is essential that the trolleys follow each other as closely as possible. This requirement cannot be met by a driver, since for this driver, additional safety time must always be taken into account with regard to the reaction for controlling the drive. It is also possible, in the aisles of straight shelving, to embrace a route at a glance, but not in an installation with bends whose surveillance

  would require excessive attention from the driver.

  The functional links between receptors and entral-

  carriage take into account that in due time, before a safety distance determined by the braking stroke of the vehicle is reached, possibly also taking into account the load supported, a signal is sent to the carriage control to trigger the braking of the truck,

  in particular to also stop his training.

  The object of the invention is to ensure that, in

  a device or on a carriage of the aforementioned type, the remote

these collision are met reliably for

  avoid buffering, but also by avoiding the influence

  this stray radiation. The invention starts from the idea that it would be possible

  to use acoustic waves according to the principle of echoes

  probes or the Doppler effect. But this idea is not

  achievable because with this method innumerable

  brave reflections which alter the signal to the receiver, and it is not possible to achieve a narrow "lobe" using an acoustic coupler. In addition, the speed of propagation

  sound in the air is highly dependent on temperature.

  One can also imagine the use of a radar system. But it is not possible because of the price and

  lack of availability for mass production.

  This object is achieved, in accordance with the invention, in that

  that opto-electronic transmitters and receivers are used

  ques. The use of optoelectronic transmitters and receivers

  nics involves a specific wavelength and a focal

  sufficient reading, thanks to which the scattered rays

of external reflections are reduced enough to

  put a usable control. Advantageously, we use

  as opto-electronic transmitters and receivers of detectors

  reflectors of reflected light, which are produced using GaAs detectors for operation in alternating light

or pulsed. The reflected light detectors are characterized

feels that any object immersed in the path of the emitter's rays reflects the light emitted by the emitter and sends it to the receiver. This then emits a signal. With reflected light detectors, however, the control distances are limited to a maximum of two meters. This may be sufficient for different uses

  and constitutes a use of the invention.

  Such reflected light detectors are commercially available, for example under the trade name Leuze Elektronik RK 78 4 R and they have a transistor and relay output with increased insensitivity to light

  parasite. But we prefer to use light barriers

  reflected light electrics which are made in techno-

  gallium arsenide (Ga-As) for alternating light operation and which are commercially available under the name, for example of Leuze Elektronik RK 79,

also for a relatively large distance. The difference

The rence is that, in the case of photoelectric barriers with reflected light, a high-quality reflector is used as the reflecting object, which is fixed to the obstacle (vehicle or wall) at the desired height. We thus reach a

  relatively high directional accuracy.

  The two embodiments constitute a preferred use which already provides protection against collisions and security against bumps. The invention provides here that the direction of the rays is parallel to the longitudinal axis

  of the carriage and that the transmitters and receivers,

  the reflectors are arranged so that they face each other

suitable, next to one side of the cart, on a circular cart

butt in front or behind. But such an achievement presents

  -some drawbacks, especially with regard to

fouling, even when the distance is controlled by control or switching arrangements - which the invention also provides which are set to the threshold values of a reflected signal. Such threshold values, which are not excluded in the invention, can vary greatly due to external influences on the signals actually

received, for example, in the case of a quasi-rectilinear connection.

An essential point of the invention consists in eliminating

  these influences and to send a command signal to the central-

the carriage for a determined approach value,

  regardless of such influences.

  This object is achieved by the fact that at least the transmitters and the receivers are arranged at an angle with the longitudinal axis of the carriage. Thanks to this inclined arrangement, in particular by referring to a rectilinear path, there is always obtained a reflection incidence with a greatly increased threshold value when the transmitters and receivers arranged on different carriages, and possibly also reflectors, are parallel to each other and that their perpendicular bisectors coincide, that is to say when a well-determined distance is reached. This constitutes a particular embodiment of the invention, which is able, without additional means, to perceive a distance determined by the intensity of the signal, but which can perfectly be refined in its response precision, by checks of threshold values , With reflectors, the angular adjustment can be omitted if trihedron reflectors are used. In an advantageous embodiment, the transmitters and the receivers are arranged very close to each other

  and, with respect to the anterior and posterior sides of the cha-

  riots, in the vicinity of different lateral edges of the carriages; in this case, an angle y is each time an acute angle relative to the longitudinal axis of the carriage. This results in a

  diagonal signal including reflection, passing through the pro-

along the longitudinal axis and the direction of travel.

In an advantageous embodiment, the transmitters and receivers are provided spaced from each other on an anterior side and / or a posterior side of the carriage and making the same acute angle 6 with respect to the longitudinal axis

  carriage median. In this case, a reflector can be envisaged.

  It is possible to place a reflector for the opto-rays.

  electronic on at least one front side (front side

  and rear) of the carriage. This results in a measure of dis-

  defined tance, also in relation to an obstacle on which

a reflector is then provided.

  In an appropriate development, a reflector can be placed

  teur on the front side of the carriage remote from the side of the carriage on which a group of opto-electronic transmitters and receivers is provided; the reflector is placed in an appropriate angular position unless a trihedral reflector is used. If provision is made, in an advantageous embodiment, for transmitters and receivers arranged on each side of the middle of the carriage at an angle, it is possible to place

  in the central area on a front side of the carriage a reflective

  parallel to the front side of the carriage. Thanks to the inclined arrangement of the transmitters and receivers, we largely eliminate any external influence, such as

  as the temperature, the fouling.

  An advantageous development, in which the carriage comprises a steering motor mechanism, consists in that at least some of the parts, which include the receivers, the transmitters and possibly the reflectors, are pivotally mounted and are angularly adjustable with respect to the longitudinal axis of the carriage as a function of

  adjustment of the steering motor mechanism. Therefore, the agency

  cement described is also effective on short courses

  bes. The invention advantageously provides that the angular adjustment can be made around a vertical axis relative to

to the longitudinal axis of the carriage.

  In a preferred embodiment, an adjustable measuring device is provided around a transverse axis for measuring the tilt angle of the carriage and a mechanism

  adjustment drive for at least some of the

  ties including transmitters, receivers and reflectors

  tors around a horizontal axis. The goal is to ensure

  use when the carriage passes over thresholds, fran-

chit hollow areas or the like, this setting can

be adapted in an installation for each goal considered.

Since trolleys circulate at different speeds, which can in particular circulate towards one another, it is possible to provide, thanks to the angular adjustment relative to a reflector, or by a lateral offset, that the functional distance to carry out a command in the carriage drive when the carriages go towards each other, which is twice as large as when a carriage

approaches a wall.

The invention also relates to a handling trolley comprising an arrangement as described, that is to say transmitter-receiver-reflector arrangements, in particular on

the two front sides.

  The invention will be clearly understood on reading the

  detailed description given below by way of example only

  Lement, of embodiments shown schematically in the drawing, in which: - Figure 1 is a schematic top view of a shelf aisle with two carriages; - Figure 2 shows an improvement over Figure 1; - Figure 3 is a top view of a carriage arrangement having a particular configuration, in a shelf aisle; - Figure 4 shows an improvement, compared to Figure 2, of a variant of the installation; - Figure 5 is a schematic top view of a carriage to illustrate a specific type of control; - Figure 6 is a schematic top view of a shelf aisle with two carriages to illustrate a

another particular achievement.

  It should be noted that the invention relates to carriages which run on rails or are guided by induction, which

  are guided by a driver or commanded, or who move

cent automatically in an electro-controlled installation

fuck. Even when there is a driver, it must be taken into account that the driver, when the distances between carriages are small, does not always appreciate the safety distance to avoid a collision. The invention also envisages that the shelving installations to which the invention also relates for the use of trolleys, include dead-end passages whose ends

  must be able to be seen in time.

  In Figure 1, 1 designates a shelf aisle. In it are placed two carriages 2, 3 which for example comprise a control group structure 4 and a load-carrying unit 5. The aisle 1 can have 6 along the line

  in dashes an obstacle. The carriages 2, 3 are provided with respective

  on a front side near a side wall of a reflected light detector, which is constituted by a

  opto-electronic transceiver unit 7, 8 and 9, 10.

  Rays emitted in the direction of the arrow are reflected by an obstacle or by the front side of another carriage, which triggers a functional signal sent to the carriage's own drive. A particular security consists in that on the front side and on the rear side of a carriage are arranged the reflected light detectors 7 to 10, as well as

  photoelectric barriers of light reflected on different

  rent Sides of the carriage, so that they do not influence each other

mutually.

  Provision is made, in particular when using photoelectric barriers of reflected light, to place on the side

  anterior and posterior side, next to the other side longi-

  tudinal of the carriage, a reflector 11, 12 and 13, 14, and also for example on a front wall 15 of a shelf aisle

7 2476355

  at least on one side, a reflector 16 which responds to a

transceiver unit 17. The other transceiver units-

receivers are referenced in 18-20.

  Considerable security is already available here due to the focusing capacity of the photoelectric barriers of reflected light. But an improvement is obtained, according to Figures 3 and 4 by tilting them. In the embodiment of FIG. 1, the drawback is that the control is influenced by coefficients of the reflected object. In the embodiment of FIG. 2, this drawback is prevented to a certain extent, but here also the temperature, the fouling of the optics, etc., exert influences. On the other hand, the embodiments of FIGS. 3 and 4 have the advantage that if transmitters and

  receivers and reflectors with direct accuracy

  increased awareness can improve the perception of

  order tance. According to Figure 3, the transmitters 21, 22, 23, 24, on the one hand, and the receivers 25, 26, 27, 28 on the other hand are arranged next to the different side walls of the carriages on the front sides, however with the same

  angular position, namely so that their directions

  The main emission and reception positions cross at a predetermined distance and at an angle, which means that transmitters and receivers are respectively arranged at an angle 6 with the longitudinal axis of the carriage. In this embodiment, one can respectively have in the middle of the front sides of the carriage a reflector 29, 30 and 31, 32, provided that one starts from a straight shelving aisle 1. A signal radius from a transmitter and inclined from the angle ax reaches the associated receiver. On the obstacles as referenced at 6 in FIG. 1 and such that they can usually meet in service in a racking aisle, or else on the front wall of the racking aisle 15, a reflector is placed in the middle. appropriate 33 so that a warning signal or

  braking is also triggered on it.

  The described embodiment ensures that the control distance provided by angles a and B is unequivocal

and reproducible.

According to Figure 4, the groups of transmitters and receivers

teurs 34, 35, and 36, 37 are respectively placed on a front side of the carriage, however on different front sides; they are placed next to the longitudinal axis of the carriage at the angle 'Y with the longitudinal axis of the latter, in this case neighboring reflectors 38, 39 and 40, 41 are provided with the appropriate angular adjustment, or using trihedral reflectors on the front side of the cart. When the groups of transmitters and receivers 34-37, when approaching trolleys or a front aisle wall of shelving 15 provided with a reflector 42, arrive in a position such that a reflection in return is substantially on the same line as the main direction of transmission, there is an increase in the signal strength in the reception unit which is transmitted to the

drive control.

  Still taking account of the angle c, it can be seen in FIG. 4 that a signal specific to the control can be obtained at a distance 43, or b, between two carriages 2, 3, but also at a distance 44, or d, a front wall 15 of a shelf aisle. In this case, taking into account

of angle a, the lateral offset between transmitter and receiver

  tor, namely 34 and 35, with respect to the associated reflector 39 or 40, is equal to the distance a or c perpendicular to the longitudinal direction of the aisle of shelving. It is thus possible to adjust the control distance by choosing the angle of the transmitter and receiver group on the carriage, or the lateral offset of the reflector on the carriage. We thus have the following relation b = a / (tg a) and d = c / (tg a) We can obtain, by choosing the angle a, by measuring the lengths a or c, that the control distance 43 or 44, under specified conditions, in particular when two trolleys moving in opposite directions approach each other, that is to say twice as large as when a trolley approaches

of a wall 15.

Although the invention has so far been described only with reference to straight paths, it is understood,

with reference to a carriage 45 in FIG. 5, that the invention

  tion can also be used on curved routes. By

9 2476355

  example, the carriage 45 has four steerable wheels 46-49 which can be steered by a control or steering device not shown. For example, receivers 25 and 28 and transmitters 21 and 24 arranged on the front sides 51 or 52 according to the arrangement in FIG. 3 are coupled to the control 50 of the carriage by functional links 53, 54, so that their orientation is modified correspondingly when turning the wheels to take a turn. This is shown in Figure 5 only in relation to lateral pivoting, as is the case on a course

  plan. The pivot axes for transmitters and receivers

  In this case, the tors are referenced in 55, 56, 57, 58. These are vertical axes. It is understood that pivoting is also possible around horizontal axes when paths crossing thresholds,

bridges or the like are programmed.

  Although it has been mentioned that a stop is planned to avoid collisions, FIG. 6 illustrates with the example of FIG. 4 that it is also possible to consider switching the drive to very high speed. slow. If for example, according to FIG. 6, the transmission and reception device is oriented on the carriage 3 at an angle a and two reflectors 60, 61 are provided on the carriage 2 on the front side facing the preceding carriage the reflector 60 is supplied first to initiate very slow operation. If the approach continues and the reflector 61 is reached, the stop of the carriage drive can be triggered. The reflectors can also be oriented at an angle a unless trihedral reflectors are used, but in this case always place two adjacent reflectors to obtain an interruption between the different

reflections back in 60 and 61.

2476355-

Claims (16)

  1. Device for avoiding rear bumps and collisions on handling trucks, comprising at least one transmitter and at least one receiver on the front side and / or the rear side, as well as functional connections between the receivers and the vehicle drive, the transmitters emitting rays perceptible by the receivers teurs, characterized in that transmitters and opto-electronic receivers.   2. Device according to claim 1, characterized in that we use as transmitters and receivers opto- electronic reflected light detectors, which are real read as Ga-As detectors for operation in alternating light.   3. Device according to claim 1, characterized   in that we use as transmitters and receivers opto- electronic light barriers with reflected light shits, which are intended as Ga-As barriers for the alternating light operation.   4. Device according to one of claims 1 to 3,   characterized in that at least transmitters (21-24) and receivers (2528; 34-37,59) are arranged by making a angle with the longitudinal axis of the carriage.   5. Device according to claim 4, characterized in   what transmitters and receivers (34-37, 59) are available   posed very close to each other, and in relation to   front and rear sides of the carriages (2, 3), as shown sinage of different lateral edges of the carriages, the angle y   being each time an acute angle with respect to the longitudinal axis carriage end.   6. Device according to claim 4, characterized in that transmitters (21-24) and receivers (25-28) are provided distant from each other on an anterior side and / or a posterior side of the carriage and making the same acute angle with respect to the median longitudinal axis of the carriage.   7. Device according to any one of the claims   4 to 6, characterized in that on a front side of the carriage (front side and rear side) a reflector is placed   (29-32, 38-41) for opto-electronic departments.   8. Device according to claim 7, characterized in that a reflector (16, 33, 42) is placed on an obstacle, in particular on a front side of aisle of shelves (15).   9. Device according to claims 5 and 7, charac-   terized in that reflectors (28, 41) are arranged in the vicinity of groups of transmitters and receivers (34 -37) by making the same angle Y with the longitudinal axis of the carriage. 10. Device according to claim 7, characterized in that the reflector (38-41) is arranged on the front side of the carriage remote from the side of the carriage on which   provides a group of opto transmitters and receivers electronic (34, 37).   11. Device according to one of claims 7 and 10, characterized in that a reflector (29-32) is provided in the central area on a front side of the carriage, and on each side of the reflector transmitters (21-24) and receivers (25-28) arranged angularly. 12. Device according to any one of claims   1 to 11, in which the carriage comprises a steering motor mechanism, characterized in that at least some of the parts which include the transmitters (21-24) and the receivers (25-28) and the reflectors (38-41 ) are pivotally mounted and can be adjusted angularly with respect to the longitudinal axis of the carriage according to the adjustment of the mechanism steering motor (50). 13. Device according to claim 12, characterized in that the angular adjustment can be done around an axis   vertical (55-58) relative to the longitudinal axis of the carriage.   14. Device according to any one of claims 12 and 13, characterized in that there is an adjustable measuring device around a transverse axis for measuring the angle of inclination of the carriage and a drive mechanism adjustment of at least some of the compres-   emitting transmitters, receivers and reflectors around of a horizontal axis.   15. Device according to any one of claims 7, 8, 10 and 12 characterized in that one uses as reflec- of the trihedral reflectors.   16. Handling cart, characterized by a device according to one of claims 1 to 15;