Device and method for achieving displacements along a rectilinear trajectory

Abstract

A device (46) configured to move along a straight path, the device comprising a chassis (50); a motorized movement means (52) configured to move the chassis along the straight path; a panel (54) with a reference position (76), the panel acting as a receiver for a light emitter (48) directed towards the device; an optical sensor (56) comprising a field of view including at least the reference position (76); and a processor configured to: detect a light pattern (49) in the field of view of the optical sensor (56); compare the position of the light pattern (49) on the panel (54) with the reference position (76); and control the motorized movement means (52) to correct a deviation between the position of the light pattern (49) and the reference position (76). Figure 3

Description

Title of the invention: Device and method for achieving displacements along a rectilinear trajectory technical field

[0001] The present disclosure falls within the domain of displacement and guidance techniques for achieving rectilinear displacements. Previous technique

[0002] Straight-line movement is typically necessary for creating floor markings, for example, in a warehouse. These floor markings subsequently enable autonomous vehicles used to retrieve items stored in the warehouse to navigate. The autonomous vehicles can follow the floor markings and measure the distance traveled to determine their position within the warehouse. Since the autonomous vehicles may navigate through narrow passages between the uprights of the storage racks, the markings must be sufficiently precise to prevent the autonomous vehicles from hitting the uprights.

[0003] Traditionally, floor marking is carried out manually by an operator, for example by applying adhesive tape or paint. Floor marking can also be applied by following a line projected by a laser, or by using a ruler positioned successively on the floor.

[0004] However, such a manual application is imprecise. The operator must navigate a complex environment, with narrow passages formed between the uprights of the storage racks and obstacles to overcome. The resulting marking is not precise enough to be followed by an autonomous vehicle.

[0005] Document FR 3138453 A1 describes a device for applying ground markings comprising a linear optical sensor adapted to detect a plane laser. The plane laser emits along a vertical plane, and the linear optical sensor is configured to detect the plane of the laser. The linear optical sensor can detect the vertical plane of the laser regardless of the flatness of the ground. The device can thus follow the plane laser to apply the marking along a straight path, independent of any unevenness in the ground.

[0006] However, it has been observed that beyond twenty meters between the plane laser emitter and the device, the divergence of the light beam emitted by the plane laser no longer allows the linear optical sensor to detect variations in trajectory, so that the device no longer has a reference point to guide its movement. Furthermore, the relatively small size of the linear optical sensor regularly results in the plane laser being lost by this sensor. Therefore, the device described in the document FR 3138453 Al is not suitable for ground marking over distances greater than twenty meters. Summary

[0007] A device is proposed that is configured to move along a straight trajectory, the device comprising: - a chassis; - a motorized means of transport, mounted on the chassis, the means of transport being configured to move the chassis along a straight trajectory; - a panel, mounted on the chassis, the panel acting as a receiver of a light emitter directed towards the device; - an optical sensor comprising a field of view, said field of view comprising at least a portion of the panel surface, said portion comprising a reference position; and - a processor configured for: • detect a light pattern from a light emitter in the field of view of the optical sensor; • compare the position of the light pattern on the panel relative to the reference position; • to control the motorized means of movement to correct a deviation between the position of the light pattern and the reference position.

[0008] Thus, the device can be guided by the light pattern intercepted by the panel. The device can follow the fixed reference of the light pattern over distances of up to several tens of meters.

[0009] Optionally, the reference position may correspond to the center of a marker on the panel. In particular, the marker is formed by the four corners of a rectangle.

[0010] Optionally, the field of view of the optical sensor may include a panel surface width greater than 100 mm, preferably greater than 140 mm, and a panel surface length greater than 100 mm, preferably greater than 150 mm. The light pattern detection area is sufficiently large so that the light pattern is not lost sight of the device during movement, even when the floor has surface irregularities. The risk of the device losing sight of the light pattern is reduced.

[0011] Optionally, the device may further include a marking means mounted on the chassis, the marking means being configured to apply a marking to the ground, and the sign being mounted on the chassis in the vicinity of the marking means. This avoids a delay between the detection of a deviation from the rectilinear trajectory defined by the projection of the light pattern and the application of the marking. This allows any deviation of the device to be corrected before the ground marking is affected.

[0012] The term "in the vicinity of the marking means" means that the panel is arranged, along a longitudinal axis of the frame, at a distance from the marking means less than half the length of the frame along said longitudinal axis, for example at a distance from the marking means less than one third of the length of the frame.

[0013] Optionally, the motorized propulsion means may include: a steering gear mounted on a first end of the chassis and adapted to control the direction of movement of the device, and a drive means mounted on a second end of the chassis, opposite the first end and configured to move the device. The steering gear may form the front of the device to control its direction by pivoting around the drive means. A position error of the light pattern relative to the reference position may be converted into a rotation error around the pivot point, ensuring that the device continuously follows a straight path.

[0014] Optionally, the advancement means and the marking means may include a single applicator roller configured both to apply an adhesive strip to the floor and to move the device. The applicator roller allows both the device to advance along the straight path and to apply the adhesive strip by applying pressure to the adhesive strip against the floor during the device's movement. The applied adhesive strip does not deviate from the straight path, thus enabling precise marking.

[0015] Optionally, the device may include an indicator configured to show when the light pattern is projected onto the reference position on the panel. Thus, a user can position the device in an initial position in which the light pattern is projected onto the reference position of the panel. It is also possible for an operator to monitor the drift of the operating vehicle.

[0016] According to another aspect, a linear guidance assembly is proposed comprising: - the above-mentioned device, and - a transmitter configured to emit a light pattern, the transmitter being positioned at a distance from the device.

[0017] The emitter provides the light pattern which allows the movement of the device to be guided along the rectilinear trajectory.

[0018] Optionally, the emitter can be a laser emitter, in particular a point laser emitting a disc-shaped light pattern. The light pattern is then easy to detect on the panel and does not require complex image processing by the processor.

[0019] Optionally, the transmitter can transmit over a distance greater than 20 meters. The device can move over relatively long distances, for example to make floor markings in a warehouse.

[0020] According to another aspect, a method for performing rectilinear displacements is proposed comprising: - to place, by a user, the above device at a distance from a light emitter, so as to project a light pattern onto the reference position on the device's panel; - to control, via the processor, the motorized means of movement to drive the movement of the device; - detect, by the optical sensor, the light pattern in the field of vision of the optical sensor; - compare, by the processor, the position of the light pattern on the panel relative to the reference position on the panel; - to control, via the processor, the motorized means of movement to correct a deviation between the position of the light pattern and the reference position.

[0021] Thus, the device can be guided by the light pattern intercepted by the panel. The device can follow the fixed reference of the light pattern over distances of up to several tens of meters.

[0022] Optionally, the movement means may include a forwarding means comprising an applicator roller, and the movement of the device may include the rotation of the applicator roller to move the device and, simultaneously, apply an adhesive strip to the floor. The applicator roller allows both the progression of the device along the straight path and the application of the adhesive strip, by applying pressure to the adhesive strip against the floor during the movement of the device. The applied adhesive strip cannot deviate from the straight path, allowing for precise marking.

[0023] Optionally, the motorized means of movement may include a steering gear adapted to control the direction of movement of the device; and the control of the means of movement to correct the deviation may include: activating the steering gear to bring the position of the light pattern on the panel closer to the reference position on the panel. The steering gear allows control of the direction of the device, ensuring that the device continuously follows the light pattern.

[0024] Optionally, placing the device may include positioning the device until an indicator on the device shows that the light pattern is projected onto the reference position on the panel. This ensures that the device is correctly positioned initially by a user.

[0025] According to another aspect, it is proposed to use the device, or the assembly, or even the method, for the application of linear floor marking, in particular adhesive tape, used for guiding automated guided vehicles in storage warehouses. Brief description of the drawings

[0026] Other features, details and advantages will become apparent from reading the detailed description below and from analyzing the accompanying drawings, in which: Fig. 1

[0027] [Fig.1] schematically illustrates an automated storage and retrieval system (ASRS) according to one embodiment. Fig. 2

[0028] [Fig.2] schematically illustrates an autonomous vehicle that can be implemented in the ASRS of [Fig.1] according to one embodiment. Fig. 3

[0029] [Fig.3] schematically illustrates a linear guidance system that can be implemented in the ASRS of [Fig.1] according to one embodiment. Fig. 4

[0030] [Fig.4] schematically illustrates a perspective view of a device configured to move along a straight trajectory that can be implemented throughout [Fig.3] according to one embodiment. Fig. 5

[0031] [Fig.5] schematically illustrates a view from a different perspective of the device of [Fig.4] according to one embodiment. Fig. 6

[0032] [Fig.6] schematically illustrates a front view of the device of [Fig.4] according to one embodiment. Fig. 7A and Fig. 7B

[0033] [Fig.7A] and [Fig.7B] schematically illustrate a front view of a device configured to move along a straight trajectory, when implemented in the whole of [Fig.3] according to one embodiment. Fig. 8

[0034] [Fig. 8] schematically illustrates a perspective view of the device of [Fig. 7A] during its implementation in the whole of [Fig. 3] according to one embodiment. Fig. 9

[0035] [Fig.9] shows a flowchart of a method for achieving straight trajectories according to an embodiment. Description of the implementation methods

[0036] Fig. 1 schematically illustrates an ASRS 10 automated storage and retrieval system. Such a system 10 is used in warehouses for storing items.

[0037] The ASRS 10 includes, in particular, at least two, and especially several, storage racks 12, which may also be referred to as "shelves", intended to receive articles for storage. The storage racks 12 advantageously extend vertically (in the vertical Z direction) to a maximum height of 10 m or more, in particular 12 m or more, and preferably 14 m or more.

[0038] Each of the storage racks 12 comprises consecutive columns 14 of compartments, the compartments 16 of each column of compartments 14 being stacked on several levels along the vertical direction Z between a lower level and an upper level. In particular, each of the compartments 16 defines a storage location intended to receive a bin 42 containing one or more items.

[0039] The storage racks 12 are arranged to form at least one circulation aisle 18 between the respective storage racks 12. More specifically, at least one circulation aisle 18, preferably several circulation aisles 18, extend along a longitudinal direction XI between two respective storage racks 12. In addition, at least one circulation aisle 18, preferably several circulation aisles 18, extend along a transverse direction X2 between two respective storage racks 12. The circulation aisles 18 allow autonomous vehicles 20 and / or operators to move within the ASRS 10 to retrieve items stored therein. The circulation aisles 18 may, for example, have a width between two storage racks of 800 mm, 600 mm, or even 400 mm.

[0040] In one example, each column 14 of cells 16 may include free spaces 23 extending vertically between the floor level of the ASRS 10 and a cell 16 at a lower level of the column 14 of cells, near the floor. The storage racks 12 thus include passages 13 extending at floor level, each passage 13 passing through the free space 23 of one of the columns 14 of each storage rack 12. These passages 13 allow the autonomous vehicle 20 to access a specific position in a traffic aisle 18 more directly, without the vehicle 20 having to move along said traffic aisle 18.

[0041] As illustrated in [Fig. 1], the floor of the ASRS includes a marking 11. The marking 11 may, for example, be adhesive strips applied to the floor. Here, the marking 11 is formed by a plurality of first parallel straight lines extending along the longitudinal direction XI and a plurality of second parallel straight lines extending along the transverse direction X2. The marking thus forms a grid on the warehouse floor. The straight lines of the marking 11 may extend over a distance greater than 40 m, greater than 60 m, or even greater than 80 m. Straight lines may extend into the traffic aisles 18 of the ASRS 10 and / or pass through the free spaces 23 under the storage racks 12.

[0042] The ASRS 10 may further comprise at least one autonomous vehicle 20, preferably a plurality of vehicles 20. The vehicle 20 may be an AGV, the acronym AGV standing for "Automated Guided Vehicle". In the embodiment of [Fig. 1], each autonomous vehicle 20 moves within the ASRS 10 on the floor and in the vertical direction Z to retrieve and / or deposit the bins 42 stored in the slots 16 of the storage racks 12. The autonomous vehicle 20 may, in particular, move on the floor of the ASRS 10 by means of the marking 11 on the floor.

[0043] As more clearly seen in [Fig. 2], the autonomous vehicle 20 comprises a chassis 26, typically parallelepiped in shape, and motorized means 28 mounted on the chassis 26. The means 28 enable the autonomous vehicle 20 to move on the floor. The means 28 allow the autonomous vehicle 20 to move on the warehouse floor, in particular in the traffic aisles 18 and / or in the passages 13 between the floor and the lower-level storage bays 16. In particular, the autonomous vehicle 20 can move by following the marking 11 applied to the floor of the ASRS. The autonomous vehicle 20 can follow the marking 11 and measure the distance traveled to determine its position in the warehouse.

[0044] The autonomous vehicle 20 also includes climbing means 34 (in the retracted position shown in [Fig. 2]) adapted to cooperate with uprights of the storage racks 12 adjoining said column 14 of storage cells. The climbing means 34 are, for example, arranged at the four corners of the chassis 26. The climbing means 34 enable movement along the vertical direction Z of the vehicle 20 along the storage racks 12, typically by cooperating with climbing elements arranged on the uprights. The autonomous vehicle 20 can thus access all the cells 16 of the column of storage cells 14 in order to place or retrieve a bin 42 from the cell 16.

[0045] The autonomous vehicle 20 further includes retractable loading means 36 (in retracted position on the [Fig.2]) adapted to extract and insert bins 42 into the slots 16 of the storage rack 12, and to position them on the chassis 26 of the autonomous vehicle 20.

[0046] The ASRS 10 may further include a container loading and / or unloading station such as a bin 42. This station may include an unloading system which is configured to unload a bin 42 from the autonomous vehicle 20, for delivery, and a loading system which is configured to load the bin 42 onto the autonomous vehicle 20 for transfer of the bin 42 to a storage rack 12, during replenishment.

[0047] The ASRS may further include an order preparation station 19 at which an operator or a robotic arm picks an item from an order from a bin brought by an autonomous vehicle.

[0048] Fig. 3 shows a linear guide assembly 44. The linear guide assembly 44 is, for example, suitable for making ground markings along straight lines, for example for making markings 11 used for precise navigation of the autonomous vehicle 20 in the ASRS 10.

[0049] The linear guidance assembly 44 includes a device 46 configured to move along a straight path and an emitter 48 configured to emit a light pattern 49 on a surface such as a panel, the light pattern being adapted to guide the device 46. By "straight path" is meant a path which would deviate by only plus or minus 1.5 millimeters from a perfect straight line over a distance of one hundred meters.

[0050] For the purpose of following the straight trajectory, the device 46 essentially comprises a chassis 50, a motorized means 52, a panel 54, an optical sensor 56, and a processor (not visible). When the device 46 is adapted for making ground markings, the device 46 further comprises a marking means 70.

[0051] The chassis 50 here takes the form of a substantially flat plate. The chassis 50 can, for example, be a metal or plastic plate, laser-cut. The chassis 50 allows the assembly of the device 46, by forming a mounting surface.

[0052] The motorized means of transport 52 comprises a steering train 58 and a forward means 60, mounted on the chassis 50.

[0053] The advancement means 60 here comprises a roller 62. The roller 62 is mounted on a first end of the frame 50 intended to form the rear of the device 46 when the device 46 moves. The roller 62 is in particular a cylindrical part driven in rotation by a motor 64. The roller can be connected to an output shaft 63 of the motor 64 by a belt 65 ([Fig. 5]). The roller 62 ensures the forward movement of the device 46. According to an embodiment described in more detail later, when the device 46 is adapted for applying markings to the ground, in particular in the form of adhesive tape 68, the roller 62 is an applicator roller 66 which, in conjunction with the movement of the device 46, applies pressure to an adhesive tape 68 supplied between the ground and the applicator roller 66.

[0054] The steering gear 58 is mounted on a second end of the chassis 50 opposite the first end on which the drive means 60 is mounted. The steering gear 58 is intended to form the front of the device 46 when the device 46 moves. The steering gear 58 is configured to control the direction of the device 46 from the front of the device 46. Therefore, a position error of the device 46 can to be converted into a rotation to be carried out around the pivot point, here defined by the roller 62. The roller 62 being behind the steering train 58 when the device 46 moves, the position correction can be smoothed during the movement of the device 46. A sudden change of direction of the moving device 46 is avoided.

[0055] The steering train 58 here comprises two steerable wheels 72 arranged on either side of the chassis 50. The device 46 is a tripod, with three points of contact on the ground, namely the roller 62 and each of the steerable wheels 72. The tripod configuration gives the device 46 isostatic equilibrium. The orientation of the steerable wheels 72 is controlled by means of a motor.

[0056] Here, the distance between the drive means 60 and the steering train 58 is between 500 mm and 600 mm, preferably 550 mm. The distance between the two steerable wheels 72 is, for example, between 300 mm and 400 mm, preferably 330 mm. Such wheelbases make it possible to compensate for uneven ground and to guarantee a straight trajectory of the device 46 with a deviation of less than 1.5 mm over a straight line of more than 100 m.

[0057] The panel 54 is here a plate of opaque material, for example a plate of plastic material. The panel 54 is adapted to intercept the light pattern 49 emitted by the emitter 48 positioned at a distance from the device 46. The light pattern 49 can, for example, be a disc of light. The disc of light can be intercepted by the panel 54 to allow the device 46 to detect any deviation from the straight trajectory.

[0058] The panel 54 is positioned, in particular, on the end of the frame 50 carrying the marking means 70, specifically the applicator roller 66, when the device 46 is adapted for applying the marking 11 to the ground in the form of adhesive tape 68. Any deviation of the device 46 from its straight trajectory can be detected at the time of application of the marking to the ground. There is no delay between the detection of the deviation and the application of the marking. The trajectory of the device 46 can be corrected to avoid deviation of the applied marking. In the example shown in Figures 4 to 6, the panel 54 is positioned at the rear of the device 46 when the device 46 is moving. Alternatively, as illustrated in Figures 7 and 8, the panel 54 could be positioned on one end of the frame 50 intended to form the front of the device 46 when the device 46 is moving, so as to face the emitter 48.

[0059] The panel 54 includes a reference position 76. The detection of any deviation of the device 46 from the straight path can be achieved by comparing the position of the light pattern 49 on the panel 54 with the reference position 76, as will be described in more detail later. The reference position 76 can, for example, be the center of a rectangle. The perimeter of the rectangle or the four corners of the rectangle can be marked or otherwise engraved on the panel 54.

[0060] The optical sensor 56 can be any type of sensor suitable for acquiring images of the light pattern 49 on the panel 54. The optical sensor 56 is, for example, a camera. The optical sensor 56 is mounted on the chassis 50 so that a field of view of the optical sensor 56 includes at least a portion of the surface of the panel 54, in particular a portion of the panel containing the reference position 76. The field of view can, for example, be a rectangle whose center coincides with the center of the rectangle forming the reference position 76. The rectangle of the field of view can, for example, have a length of 154 mm and a width of 140 mm. The optical sensor 56 can detect the light pattern 49 on the panel 54 even when a significant deviation exists between the center of the panel 54 and the position of the light pattern 49. This prevents the device 46 from losing sight of the light pattern 49 during its movement.

[0061] For example, the camera resolution can be between 10 and 15 million pixels, preferably 12 million pixels. The images acquired by the camera can have a pixel density of between 20 and 50 pixels / mm, preferably approximately 30 pixels / mm. The panel 54 has 4600 pixels in width and 2600 pixels in height. The frame rate (fps) can be at least 15 fps to avoid a delay between the deflection of the device 46 and the detection of said deflection.

[0062] The processor is, for example, mounted on the chassis 50. The processor is configured to process the images acquired by the optical sensor 56 to detect any deviation between the reference position 76 and the position of the light pattern 49 on the panel 54, as described in more detail later. Based on the comparison, the processor can control the movement means 52, in particular the directional train 58, to bring the position of the light pattern 49 closer to the reference position 76.

[0063] The device 46 may further include indicators 78, in particular visual or audible indicators. The indicators 78 may light up or emit a sound when the position of the light pattern 49 and the position of the reference position 76 coincide on the panel 54. The indicators 78 are here two diodes placed on either side of the device 46, in particular at the front of the device 46 when it is moving, in particular in the vicinity of each of the wheels 72 of the steering train 58. A first left diode may, for example, be used to indicate a deviation to the right and a second right diode may, for example, be used to indicate a deviation to the left of the position of the light pattern 49 relative to the reference position 76.These indicators 78 can enable an operator to place the device 46 in an initial position facing the emitter 48 in which the light pattern 49 is intercepted on the reference position 76 of the panel 54, and to control the movement of the device 46.

[0064] Where device 46 is adapted for floor marking, the marking means 70 can, for example, be adapted for applying adhesive tape 68 to the floor. Such marking is unlikely to bleed and is therefore particularly suitable for guiding automated vehicles 20 within the warehouse. For example, the roller 62 of the movement means is an applicator roller 66 adapted to simultaneously move device 46 and apply the adhesive tape to the floor. The marking means 70 further comprises a feed reel 82, a guide piece 84, at least one tensioning drum 86, and optionally a retrieval reel 88.

[0065] The supply reel 82 is mounted on the frame 50. The supply reel 82 is cylindrical with a rim. A roll of adhesive tape 90 can be mounted on the supply reel 82. The marking 11 on the ground is formed by adhesive strips 68 unwound from the supply reel 82 to the applicator roller 66. The roll 90 of adhesive tape 68 is cantilevered over the supply reel 82. The roll 90 is thus accessible (there is no housing around the roll), so that it is easy to replace the roll 90 when the adhesive tape 68 on the roll is used up.

[0066] The guide piece 84 forms an insertion guide for the unrolled adhesive strip 68 between the applicator roller 66 and the floor. The guide piece 84 ensures proper positioning of the unrolled adhesive strip 68 between the applicator roller 66 and the floor, thus ensuring precise positioning of the unrolled adhesive strip 68 on the floor.

[0067] The tensioning drum 86 is rotatably mounted on the frame 50. The tensioning drum 86 is mounted substantially above the applicator roller 66, to form an inflection point of the adhesive strip 68 when the adhesive strip 68 is unwound from the feed reel 82. Thus, the unwound adhesive strip 68, extending between the feed reel 82 and the applicator roller 66, is tensioned by the tensioning drum 86 and can be pressed against the guide piece 84. The adhesive strip 68 can be unwound from the feed reel 82, tensioned by the tensioning drum 86, pressed against the guide piece 84 before being applied under pressure against the ground by the applicator roller 66.

[0068] The tensioning drum 86 is driven in rotation by the motor 64, which also drives the roller 62, in particular the applicator roller 66. The tensioning drum 86 can be connected to the output shaft 63 of the motor 64 by the belt 65. Thus, the tensioning drum 86 drives the adhesive strip 86 from the supply reel 86 to the applicator roller 66 in conjunction with the advancement of the device 46.

[0069] The recovery coil 88 is rotatably mounted on the frame 50. The recovery coil 88 is a hollow cylindrical part whose rotation is driven by the motor 64, which also drives the applicator roller 66. The coil of The recovery reel 88 can be connected to the output shaft 63 of the motor 64 by the belt 65. A coating of the adhesive strip 68 can be wound around the recovery reel 88 by rotation of the recovery reel 88, in conjunction with the advancement of the device 46. The recovery reel 88 is particularly suitable for the embodiment where the adhesive surface of the adhesive strip 68 is covered by the coating, i.e. a plastic film protecting the adhesive surface.

[0070] The device 46 can be powered by a battery 89 mounted on the chassis 50. In addition, the control electronics, including the processor, can be mounted on the chassis 50, for example in a housing 91.

[0071] The emitter 48 can emit any type of light pattern 49 suitable for being intercepted by the panel 54. Here, the emitter 48 is a laser emitter, in particular a point laser emitter. Thus, the light pattern 49 intercepted by the panel 54 is a disk of light. The emitter 48 is placed at a distance from the device 46, for example, at a distance greater than 20 m, to guide the device 46. The emitter 48 forms a fixed reference for the device 46, allowing the device 46 to be guided during its movement.

[0072] A method for carrying out displacements along a rectilinear trajectory is subsequently described. The displacement is notably carried out by the device 46 described above.

[0073] The method includes E100 placing the device 46 at a distance from the emitter 48 by a user. Placing the device may include positioning the device 46 at a distance from the emitter 48, for example, at a distance greater than 20 m. Placing the device may further include aligning the light pattern 49 projected onto the panel 54 by the emitter 48 with the reference position 76 on the panel 54. The device 46 is placed when the light pattern 49 is projected onto the reference position 76. Placing the device is carried out, for example, until the indicator 78 of the device 46 shows that the light pattern 49 coincides with the reference position 76.

[0074] The method includes E200 controlling the motorized drive means 52 to drive the movement of the device 46. In particular, the advancement means 60 in the form of a roller 62 is driven in rotation by the motor 64, activated by the processor. Here, the roller 62 is an applicator roller 66, and the movement of the device 46 includes, in conjunction with the rotation of the applicator roller 66, the application of the adhesive strip 68 to the floor.

[0075] The method includes E300 detecting the light pattern 49 on the panel 54, in particular during the movement of the device 46. Detecting the light pattern 49 includes, in particular, acquiring images of the portion of the panel within the camera's field of view, the portion of the panel comprising the reference position. The images can, for example, be acquired at least every 4 ms. This avoids thus delaying the detection of a deviation of device 46 from the straight trajectory.

[0076] The method includes E400 comparing, by means of the processor, the position of the light pattern 49 on the panel 54 relative to the reference position 76. Comparison may include processing the images captured by the optical sensor 56 to detect the light pattern 49 on each image. Processing the images to detect the light pattern on each image may, for example, be carried out by colorimetry and / or grain size analysis. Comparison may further include determining a deviation between the reference position 76 and the light pattern 49. The comparison may, for example, determine that the light pattern 49 is shifted to the left relative to the reference position 76, indicating that the device 46 is deviating to the right. Conversely, the comparison may determine that the light pattern 76 is shifted to the right relative to the reference position 76, indicating that the device 46 is deviating to the left.Any vertical deviation may be related to irregularities in the ground and can be ignored.

[0077] When the deviation is established, the method includes E500 controlling, via the processor, the motorized movement means 52, in particular the directional gear 58, to bring the light pattern 49 closer to the reference position 76. When the device 46 has deviated to the left, the directional gear 58 can be controlled to rotate the device 46 to the right. Conversely, when the device 46 has deviated to the right, the directional gear 58 can be controlled to rotate the device 46 to the left.

[0078] In addition, when the deviation is established, the method may include E600 an activation of the visual or audible indicator, so as to indicate to the operator that the deviation has been detected.

[0079] The command, detect and compare steps E200, E300, E400, E500 are carried out until the device 46 reaches the transmitter 48. When the device 46 applies an adhesive strip 68 to the floor, at the end of the process, a straight line of adhesive strip 68 is applied to the floor between the initial position of the device 46 and the transmitter 48.

Claims

Demands

1. A device (46) configured to move along a rectilinear path, the device comprising: - a chassis (50); - a motorized movement means (52) mounted on the chassis, the movement means being configured to move the chassis along the rectilinear path; - a panel (54) mounted on the chassis (50), the panel acting as a receiver of a light emitter (48) directed towards the device (46); - an optical sensor (56) comprising a field of view, said field of view comprising at least a portion of the surface of the panel (54), said portion comprising a reference position (76); and - a processor configured to: • detect a light pattern (49) in the field of view of the optical sensor (56); • compare the position of the light pattern (49) on the panel (54) with respect to the reference position (76);• to control the motorized means of movement (52) to correct a deviation between the position of the light pattern (49) and the reference position (76).

2. Device (46) according to claim 1, wherein the reference position (76) corresponds to the center of a marker on the panel (54), in particular the marker being formed by four corners of a rectangle.

3. Device (46) according to any one of the preceding claims, further comprising a marking means (70) mounted on the chassis (50), the marking means (70) being configured to apply a marking to the ground, and the panel (54) being mounted on the chassis (50) in the vicinity of the marking means (70).

4. Device (46) according to any one of the preceding claims, wherein the motorized means of movement (52) comprises: - a steering train (58) mounted on a first end of the chassis (50) and adapted to control the direction of movement of the device (46); - a means of advancement (60) mounted on a second end of the chassis (50), opposite to the first end and configured to ensure the movement of the device (46).

5. Device (46) according to claims 3 and 4, wherein the advancement means (60) and the marking means (70) comprise the same applicator roller (66) configured both to apply an adhesive strip (68) to the ground and to ensure the movement of the device (46).

6. Device (46) according to any one of the preceding claims, comprising an indicator (78) configured to indicate when the light pattern (49) is projected onto the reference position (76) on the panel (54).

7. Linear guidance assembly (44) comprising: - the device (46) according to any one of the preceding claims, and - an emitter (48) configured to emit a light pattern (49), the emitter being positioned at a distance from the device.

8. Assembly (44) according to claim 7, wherein the emitter (48) is a laser emitter, in particular a point laser emitting a disc-shaped light pattern.

9. Linear guidance assembly (44) according to claim 7 or 8, wherein the transmitter (48) is configured to transmit over a distance greater than 20 meters.

10. A method for performing rectilinear movements comprising: - placing, by a user, a device (46) according to any one of claims 1 to 6 at a distance from a light emitter (48), so as to project a light pattern (49) onto the reference position (76) on the panel (54) of the device (46); - controlling, by the processor, the motorized movement means (52) to drive the movement of the device (46); - detecting, by the optical sensor (56), the light pattern (49) in the field of vision of the optical sensor; - comparing, by the processor, the position of the light pattern (49) on the panel (54) with respect to the reference position (76) on the panel (54); - controlling, by the processor, the motorized movement means (52) to correct a deviation between the position of the light pattern (49) and the reference position (76).

11. A method for carrying out rectilinear displacements according to claim 10, wherein the displacement means (52) comprises an advancement means (60) comprising an applicator roller (66), and the displacement of the device (46) comprises the rotation of the applicator roller (66) to move the device (46) and, concurrently, apply an adhesive strip (48) to the ground.

12. A method for carrying out rectilinear movements according to claim 10 or 11, wherein the motorized movement means (52) includes a steering train (58) adapted to control the direction of movement of the device (46); and the control of the movement means (52) to correct the deviation includes: an activation of the steering train (58) to bring the position of the light pattern (49) on the panel (54) closer to the reference position (76) on the panel (54).

13. A method for carrying out rectilinear displacements according to any one of claims 10 to 12, wherein placing the device (46) comprises positioning the device until an indicator (78) of the device (46) indicates that the light pattern (49) is projected onto the reference position (76) on the panel (54).

14. Use of the device (46) according to any one of claims 1 to 6, or of the assembly according to any one of claims 7 to 9, or of the method according to claims 10 to 13, for the application of linear floor marking, in particular adhesive tape, used for guiding automated guided vehicles in storage warehouses.