Method for gripping a container, and device for gripping a container.

Abstract

TITLE: Method for gripping a container, and device for gripping a container. The invention relates to a method for gripping a container (2) by a deployable gripping means (1), comprising a distance sensor (4) and a gripping means (5) configured to cooperate with a gripping zone (6) defining a relief variation (8) on the container, comprising: Deploying the gripping means (1) aiming to reach an initial stroke value (Ci),During deployment, measuring, by means of the sensor (4), a distance profile (9) between said gripping means (1) and the container (2), Comparing said distance profile (9) with a reference profile (10) corresponding to the relief variation (8) until a target stroke value is determined allowing the cooperation of said gripping means (5) with said gripping zone (6),Correcting the initial stroke (Ci) by the target stroke value (Cc).Cooperation between said gripping means (5) with said gripping zone (6) Figure 5.

Description

Title of the invention: Method for gripping a container, and device for gripping a container. Technical field

[0001] The field of the present disclosure is that of warehouse logistics and in particular the handling and transport of objects such as parts or products in containers, in particular bins, stored in shelves.

[0002] More specifically, the present disclosure relates to a method of gripping a container, for example placed in a shelf of a warehouse.

[0003] The present disclosure also relates to a device for gripping a container, intended to implement the method according to the present disclosure.

[0004] The present disclosure also relates to a computer program product comprising instructions configured to implement said method. Prior art

[0005] In product storage warehouses, it is known to use robots, or vehicles, to pick up containers, in particular bins or trays, containing specific products, stored in shelving units and transport them to another location, for example an order preparation station. These robots are in particular equipped with motorized means allowing them to move on the ground, horizontally, but also vertically, along the structure of the shelving, for example on racks or on belts. These robots are also equipped with gripping means, the function of which is to pick up and place a container on a shelf or at an order preparation station.

[0006] These gripping means may consist of a telescopic fork deployed by the robot to grip the containers. But these then end up in overhang during their transport, which can unbalance the robot during its movement.

[0007] It is also known to use telescopic arms which extend on the lateral sides of the container, the arms being provided with means for pulling the container by cooperating for example with lugs or notches. But it is then necessary to provide a space on the sides of the containers to allow the arms to pass, which then reduces the density of stored containers.

[0008] Finally, document EP3638607B1 proposed using a motorized trolley, comprising climbing means configured to cooperate with the shelving, in particular with its vertical uprights, to allow said trolley to rise along the shelving and thus reach the height of the container to be gripped. Once in front of said container, the trolley deploys a gripping device movable relative to a chassis of the trolley. The gripping device being provided with means, such as fingers or lugs, to cooperate with notches on a lower face of said container, the device retracts, taking the container with it. The trolley can then move, carrying the container vertically above its chassis, towards its drop-off destination. This solution is illustrated in Figures 1 and 2.

[0009] This solution is satisfactory with regard to the gripping and transport operation. However, such a solution has drawbacks linked to the alignment of the cooperating parts of the gripping means and the container. An off-center position, in the plane of the lower surface of the container, can in particular result in a failure of the gripping.

[0010] There is a first type of centering solutions using mechanical means. In these solutions, the location of the exact position between these cooperating parts is typically achieved by mechanical centering means, which are based on the relative placement of the two cooperating parts. For example, the mechanical centering means may be sloping surfaces, for example conical surfaces forming an angle with the vertical, arranged in a complementary manner on the cooperating parts. As illustrated in [Fig.3], this known solution makes it possible to absorb a slight relative offset between the two parts, one of the two parts forcing the displacement of the other.

[0011] On the other hand, this type of solution requires a precise machining operation to obtain two perfectly complementary shapes, at the risk of making the cooperation unstable.

[0012] Furthermore, as already mentioned, this type of solution only allows for the correction of a small offset, for example of the order of a few millimeters.

[0013] Furthermore, there is another type of centering solutions which this time use optical sensors.

[0014] An example of such a centering solution is disclosed in document CN113998626. Optical sensors, in particular 3D cameras, are used to locate in space the exact position of the container notches.

[0015] The information is then transmitted to the actuator of the gripping means and / or the robot to correct their position, such that the hooking fingers of the gripping means are positioned opposite the notches on the lower face of the container.

[0016] However, the optical sensors required for acquiring the position data of the notches in the form of point clouds, or 3D reconstructions, are for example stereo cameras or cameras operating on the “time-of-flight” principle, or “time-of-flight (TOF) cameras”, which process a large quantity information. These solutions are therefore very cumbersome to implement and consume a relatively large amount of energy.

[0017] It is also possible to locate the notches on the lower surface of the container by detecting the edges of the container as the gripping means moves under the container. However, this technique has the disadvantage of no longer being usable if two containers touch on the shelf. However, such a situation occurs relatively commonly in warehouses.

[0018] The present disclosure therefore aims to at least partially overcome the drawbacks of the state of the art cited above.

[0019] In particular, an objective of the present disclosure is to propose a solution which ensures a centering of the cooperation parties which is robust, and simple to implement in particular in that it uses little data to be processed. The present disclosure finally aims to propose a solution which has a reduced cost, and simple components which thus have a reduced environmental impact. Summary

[0020] According to a first aspect, the present disclosure relates to a method of gripping a container by a deployable gripping means, the gripping means being movable along a deployment direction from a chassis of a device such as a vehicle, and being provided with a distance sensor, and comprising gripping means configured to cooperate with a gripping zone of a container to be gripped, said gripping zone being arranged on a gripping surface of the container and defining at least one variation in relief of said gripping surface, the method comprising: - / A / The deployment of the gripping means from said chassis in the direction of an area opposite said gripping surface of the container to be grasped, the deployment aiming to reach an initial stroke value, - / B / During the deployment of the gripping means, the measurement, by means of the sensor, of a distance profile between said gripping means and the gripping surface of said container, - / C / Comparison of said distance profile with a reference profile cor corresponding to at least one variation in relief of the gripping surface until a target stroke value is determined allowing the cooperation of said gripping means with said gripping zone of said container, - / D / Correction of the initial stroke of said gripping means by the value of target race. - / E / Cooperation between said gripping means with said gripping zone of the said container - / F / Retraction of the gripping means having gripped said container, to the vehicle chassis

[0021] Thus, in a particularly effective manner, the alignment of said gripping means of the gripping means with said gripping zone of the container is ensured in a reliable and simple manner to implement.

[0022] Furthermore, the use of a distance sensor, instead of 3D optical sensors, and the processing of a 2D profile of two-dimensional measurement points, is of great economic and ecological interest.

[0023] The measurement, carried out by the sensor in / B / , can also be considered as an acquisition or a detection, for example followed or preceded by a calculation operation, allowing the creation of a distance profile.

[0024] The features set out in the following paragraphs may, optionally, be implemented, independently of one another or in combination with one another:

[0025] According to examples, the distance profile can be obtained by connecting a plurality of distance measurement points between the gripping means and the gripping surface of the container, the comparison of said distance profile and the reference profile being carried out each time a new measurement point is acquired.

[0026] According to examples, said sensor may be a non-contact linear distance sensor.

[0027] According to examples, the measurement of the sensor can be carried out in a measurement direction substantially perpendicular to said direction of deployment of the gripping means.

[0028] According to examples, the deployment of the gripping means at / A / and / D / to the target stroke value may be an uninterrupted movement.

[0029] According to examples, the cooperation between said gripping means with said gripping zone of said container can be carried out by means of a movement of the chassis in a direction substantially perpendicular to the direction of deployment.

[0030] In examples, the deployable gripping means may be movable in a first and a second direction along said deployment direction on either side of said frame.

[0031] In examples, said deployable gripping means may comprise a first and a second distance sensor each positioned at one end of the gripping means, the two ends being opposite in the direction of deployment, only the sensor positioned at the end on the side of which the gripping means deploys carries out the acquisition of the plurality of distance measurement points.

[0032] In examples, the method may include detecting the container by measuring a first distance less than a threshold value revealing the presence of the

[0033]

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041] container opposite the gripping means. In examples, the method may include triggering an error mode and retracting the gripping means if comparing the distance profile and the reference profile fails to determine a target stroke value after the gripping means has reached the initial stroke value. In examples, in / B / , the measurement of the distance profile may comprise the acquisition of a plurality of distance points measured by said sensor, said measurements being respectively associated with stroke values ​​of the gripping means. According to a second aspect, the present disclosure relates to a container gripping device comprising: - A chassis, - A gripping means deployable along a deployment direction from said chassis and set in motion by at least one actuator, the gripping means comprising a gripping means configured to cooperate with a gripping zone arranged on a gripping surface of the container to be gripped and defining at least one variation in relief of said gripping surface, - A distance sensor, positioned on said gripping means, - A controller comprising a processor, a memory, and an instruction set configured to implement the method according to the first aspect. According to examples, said sensor may be a non-contact linear distance sensor. In examples, the sensor may be oriented on the gripping means in a detection direction substantially perpendicular to said direction of deployment of the gripping means. In examples, said sensor may be positioned in front of said gripping means in the direction of deployment of the chassis towards the container. In examples, said gripping means may be fingers configured to at least partially fit into recesses arranged on said container. In examples, the deployable gripping means may be movable in a first and second direction along said deployment direction on either side of said frame. In examples, said deployable gripping means may comprise a first and a second distance sensor each positioned at one end of the gripping means, the two ends being opposite according to the direction of deployment, the first sensor configured to implement / B / when the gripping means gripping means is deployed in the first direction, the second sensor configured to set / B / when the gripping means is deployed in the second direction.

[0042] In examples, said chassis may be at least part of a container transport vehicle equipped with climbing means configured to move along a rack on which the container to be picked up is placed.

[0043] According to a third aspect, the present disclosure relates to a computer program product comprising instructions which, when executed by a processor connected to a memory, are configured to implement the method according to the first aspect. Brief description of the drawings

[0044] Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the attached drawings, in which: Fig.l

[0045] [Fig.l] shows a schematic representation of a transport vehicle comprising a gripping means of the state of the art. Fig. 2

[0046] [Fig.2] shows a schematic representation of a container transport vehicle of the state of the art, moving between two racks on which container receiving shelves are provided, the vehicle being shown with its gripping means deployed under a container to be gripped. Fig. 3

[0047] [Fig.3] shows a bottom view of a container of the state of the art having a gripping zone capable of cooperating with the gripping means of a gripping means. Fig. 4

[0048] [Fig.4] shows a longitudinal section of mechanical means used by a state-of-the-art centering technique. Fig. 5

[0049] [Fig.5] shows a schematic representation in longitudinal section of an exemplary device for gripping a container according to the present disclosure. Fig. 6

[0050] [Fig.6] shows a graphical representation of a distance measurement profile to be compared with a reference profile according to operations / B / and / C / of the input method of the present disclosure. Fig. 7

[0051] [Fig.7] shows a schematic representation of a container transport vehicle V in which the gripping means is provided with two sensors, and the means gripping is deployable movable in two directions along the deployment direction. Description of the embodiments

[0052] The drawings and the description below contain, for the most part, elements of a certain character. They may therefore not only serve to better understand the present disclosure, but also contribute to its definition, where appropriate.

[0053] In the various figures, the same references designate identical or similar elements. For the sake of brevity, only the elements which are useful for understanding the embodiment described are shown in the figures and are described in detail below.

[0054] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "upper", "lower", etc., or to orientation qualifiers, such as "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures or of an automatic transport vehicle in its normal position of use. Furthermore, the term "substantially" is to be interpreted as indicating that the result obtained is as precisely as the known method for measuring it.

[0055] Reference is now made to Figures 1, 2 and 3.

[0056] A vehicle V of the state of the art is shown, comprising a means of gripping means 1 deployable from a chassis 3 along a deployment direction Dp. The gripping means 1 is configured to contribute to the gripping of a container 2 such as a bin, or a tray, or any other object stored in a warehouse, which may or may not contain other objects.

[0057] The vehicle V is typically controlled by an automatic guidance system, and is able to move on the floor of a warehouse to go from one rack to another. The vehicle further comprises climbing means Gr, able to allow the vehicle V to rise along the vertical uprights 101 of a warehouse rack 100 (otherwise called a “rack”), as shown in [Fig.2], so as to access the shelf 102 on which the container 2 to be picked up is located. The climbing means Gr may typically comprise motorized pinions cooperating with the teeth of racks or roller chains, fixed along the uprights 101 of the rack 100.

[0058] The gripping means 1 comprises several gripping means 5.1, 5.2, 5.3, 5.4, which are four in number in this example. In other examples, it is possible to provide any number of gripping means, for example one, two, three, or more gripping means 5. Generally, the terms “gripping means” "seizing" and "seizing zone" may designate one or more portions capable of cooperating with each other respectively so as to drive the container 2 with the deployment movement of the gripping means 1.

[0059] The gripping means are in particular arranged opposite a gripping surface 7 of the container. In this example, this surface is the lower surface of the container 2, and the gripping means 1 is deployed in an area opposite the gripping surface 7, i.e. below the container 2.

[0060] The gripping means 5 are configured to cooperate with gripping zones 6.1, 6.2, 6.3, 6.4 of the container 2, arranged on the gripping surface 7 of the container 2. The gripping zones 6 and the gripping means 5 are configured to cooperate with each other, and are therefore arranged according to an identical distribution. The distribution of the gripping zones 6 on the container 2 may be flat. In this example, the distribution of the gripping zones 6 forms a rectangle identical to that formed by the distribution of the gripping means 5.

[0061] The distribution of the gripping zones 6 and the gripping means 5 can form any pattern as long as they are at least partly identical so as to cooperate with each other.

[0062] The gripping zones and gripping means are named thus for the sake of clarity, but can be freely swapped and interchanged, arranged either on the container 2 or on the gripping means 1, as long as they are able to cooperate with each other.

[0063] The gripping means 5 are, in this example, fingers or lugs each forming a protuberance capable of being inserted into a complementary gripping zone 6. One or other of the shapes of the gripping means and zones 5, 6 can be interchanged, as long as each constitutes a pair of complementary shapes, or shapes capable of cooperating with each other, such as a finger and a hollow.

[0064] The gripping means 5, in the example of [Fig. 1], are typically protrusions which are higher than any other element of the gripping means which may be located opposite the gripping surface 7 of the container 2 during its deployment, such that no other element comes into contact with the container before the gripping means 5 and does not hinder the cooperation of the latter with the gripping zones 6.

[0065] [Fig.4] represents a centering technique according to the prior art which does not give complete satisfaction.

[0066] Reference is now made to [Fig.5], which shows a schematic view of an input device and an input method according to the present disclosure.

[0067] In fact, the vehicle V of the type of that of the state of the art described above, comprises a chassis 3, from which a gripping means 1 is deployed. foldable. The gripping means is movable along a deployment direction Dp from the chassis 3 of the vehicle V. The gripping means 1 is provided with a distance sensor 4, arranged on a support surface 11 of the gripping means 1. The gripping means 1 comprises at least one gripping means 5 configured to cooperate with at least one gripping zone 6 of a container 2 to be gripped. The at least one gripping zone 6 is arranged on a gripping surface 7 of the container 2 and defines at least one relief variation 8 of said gripping surface 7.

[0068] In this example, the relief variation 8 constitutes at least one hollow, or a recess entering into the gripping surface 7. But it is also possible to provide that such recesses are provided on the gripping means 1, and that the gripping zones 7 of the container 2 comprise protuberances configured to cooperate with the recesses.

[0069] The relief variation 8 is defined in that it corresponds to a variation in the distance measured by the sensor 4 between the support surface 11 of the gripping means 1 and the gripping surface 7. For example, the distance between the support surface 11 and the gripping surface 7 measured by the sensor 4 may vary outside the relief variation zones, in particular due to flatness imperfections on the surfaces obtained by molding during the manufacture of the containers. The distance measured at a relief variation zone may have a variation at least greater than those of the manufacturing tolerances, for example at least 10 mm, for example between 20 and 60 mm, of the distance between the support surface 11 and the gripping surface 7.Such a detection mode makes it possible to reliably center the cooperation parts without suffering disturbances linked to other variations, for example, to a possible lack of parallelism between the deployment direction Dp and the gripping surface 7 of the container, or to the manufacturing tolerances of the container.

[0070] The support surface 11 of the gripping means may be delimited by a rear side 12 and a front side 13. The sensor may typically be positioned at the front side 13. The sensor 4 may be positioned closer to the front side 13 than to the rear side 12.

[0071] The deployment direction Dp of the gripping means 1 is defined in such a way that the gripping means 1, during its deployment, first exceeds a front edge 21 of the container and then a rear edge 22 of the container. The gripping surface 7 is in particular delimited by the front edge 21 and the rear edge 22, as well as by lateral edges 23.

[0072] [Fig. 5] shows an example in which the gripping means 1 is deployed in a direction marked with an arrow, parallel to the deployment direction Dp. The gripping means 1 can also be deployed in both directions, front and rear, along the deployment direction Dp. These embodiments can make it possible to grip two containers stored on either side of the vehicle V without the latter having to move in height, for example in a racking configuration 100 as shown in [Fig.2], in which the vehicle V is positioned between two racks 100.

[0073] The seizure method comprises: - / A / The deployment of the gripping means 1 from said chassis 3 in direction of an area opposite said gripping surface 7 of the container 2 to be grasped, the deployment aiming to reach an initial stroke value Ci.

[0074] The deployment can be carried out using at least one actuator, for example an electric motor, or a cylinder. The deployment can be carried out using at least one transmission element, for example pulleys, belts, and / or racks. The at least one actuator can be controlled by a controller. The controller can be connected to a memory, itself connected to the distance sensor 4.

[0075] The at least one actuator and / or the at least one transmission element may be equipped with a travel sensor, for example of the encoder type. The travel sensor may, throughout the operation of deploying the gripping means, associate a distance measurement value acquired by the distance sensor 4 with an actual travel value of the gripping means 1.

[0076] The controller is connected to the memory, which itself can be connected, if necessary, to the stroke sensor of the actuator or of the transmission element of the gripping means 1.

[0077] The initial stroke value Ci may typically be a sufficient value to allow the distance sensor 4 to exceed the rear edge 22 of the container, unless otherwise commanded to stop or retract.

[0078] The area facing the gripping surface 7 is, in the example shown in [Fig. 5], the area located directly under the gripping surface, delimited by a downward extension of the lateral edges 23 and the front and rear edges 21, 22 of the container. In other examples, the gripping surface may be the outer surfaces of the lateral edges 23, the gripping means 1 then having two support surfaces 11, each being deployed in an area facing one of the lateral edges 23. In such examples, said area being the volume formed by extension of the peripheral contour of the respective lateral edge 23, in a direction normal to a plane formed by said lateral edge 23.

[0079] In one example, when the gripping surface 7 is the lower surface of the container 2, the deployment of the gripping means 1 is carried out in the area opposite the gripping surface 7 while the vehicle is static. For example, the vehicle V can be positioned at a height allowing the gripping means to deploy, according to the deployment direction Dp, at an average distance of approximately 30 mm below the gripping surface. Such a distance can be measured for example at the front edge 21 of the container 2, so as to ignore a lack of parallelism between the deployment direction Dp and the gripping surface 7.

[0080] The input method also includes: - / B / During the deployment of the gripping means 1, the measurement, by means of the sensor 4, of a distance profile 9 between said gripping means 1 and the gripping surface 7 of said container 2.

[0081] According to an example as shown [Fig.6], the distance profile 9 can be obtained in the form of a curve connecting points defined by an abscissa and an ordinate, the abscissa comprising the actual stroke values ​​of the deployment means, for example obtained by the stroke sensor, and the ordinate comprising the distance measurement values ​​obtained by the distance sensor 4 and stored in the memory connected to the controller. The distance profile is a curve obtained by connecting each of the points or at least some of the points together, for example over a given range of stroke values. It is also possible to swap the type of value reported on the abscissa and the ordinate.

[0082] In other examples, the abscissa values ​​may be time values. Each of the time values ​​is calculated as a function of the speed of deployment of the gripping means 1 by the controller.

[0083] In examples, two measurement phases PI, P2 can be distinguished. In phase PI, the gripping means has not yet been sufficiently deployed, and the sensor 4 has not yet reached the area opposite the gripping surface 7. The distance measurements acquired during this phase PI are therefore not representative of the actual distance between the gripping surface 7 and the gripping means 1. Phase P2 begins when the sensor 4 has made a first measurement in the area opposite the gripping surface 7. It may be provided that only the distance measurements acquired by the sensor 4 during this phase are compared during operation / C / with the reference profile 10. This may in particular make it possible to reduce the quantity of data to be processed for the implementation of the capture method according to the present disclosure.

[0084] It may also be provided to associate with each of the measurement phases, a specific deployment speed. For example, the deployment speed during phase PI may be greater than the deployment speed during phase P2 by at least 200%.

[0085] In one example, the acquisition of points based on distance measurements is performed periodically, according to an acquisition speed. The acquisition speed, according to one example, may be of the order of one point per millimeter traveled by the gripping means 1. Other acquisition speeds may be envisaged, or may be set according to the application cases by the controller. According to examples, the acquisition speed of the distance sensor 4 may be identical to the acquisition speed of the stroke sensor. In examples, the acquisitions of the distance sensor 4 and the stroke sensor are simultaneous.

[0086] The input method also includes: - / C / Comparison of said distance profile 9 with a reference profile 10 cor corresponding to the at least one variation of relief 8 of the gripping surface 7 until a target stroke value is determined allowing the cooperation of the at least one gripping means 5 with the at least one gripping zone 6 of said container 2,

[0087] In examples, the profile can be produced as the gripping means 1 is deployed. In other words, from the acquisition of a first distance measurement point, as soon as a new distance measurement point is recorded, it is connected to the previous point to continue producing the distance profile 9.

[0088] In examples, the reference profile 10 may be a predetermined curve recorded in the memory connected to the controller. The reference profile 10 may be selected by the controller from a profile base which may, for example, correspond to different types of containers 2.

[0089] In examples, the distance profile 9 is compared to the reference profile by the controller at each new measurement point acquired by the sensor 4. At the very least, the controller preferably compares the distance profile 9 to the reference profile 10, periodically, during the deployment of the gripping means 1, and preferably so as to obtain a positive comparison (i.e. with determination of a correspondence with the reference profile), before the gripping means 5 exceed the gripping zones 6. Less preferably, it is possible to compare the distance profile 9 to the reference profile 10, only once the deployment of the gripping means has reached the initial stroke Ci.

[0090] In examples, as soon as the relief variations 8 highlighted by the distance profile 9 are identified on the reference profile 10, the controller is configured to deduce a target stroke value Ce corresponding to the alignment of the at least one gripping means 5 with the at least one gripping zone 6. To this end, the controller can, according to examples, take into account the position of the sensor 4 on the gripping means 1 relative to at least one of the gripping means 5 of the gripping means.

[0091] For example, by placing oneself on an axis X parallel to the direction Dp, positive in the direction considered for deployment of the gripping means, by noting Dz the distance between the centers of the gripping zones, Dg the distance between the centers of the gripping means, and x the position of the center of the targeted gripping zone (with x=0 the center of the vehicle V), the center of the gripping means is placed at the position x-Dg / 2 when it is desired to match the front gripping means 5.1 with the front gripping zone 6.1. It is also possible, according to examples, to place the center of the gripping means at the position x-Dz-Dg / 2, in a case where it is desired to match the front gripping means 5.1 with the rear gripping zone 6.2. The center of the gripping means 1 is for example considered to be equidistant from the gripping means 5.1, 5.2.

[0092] The input method also includes: - / D / Correction of the initial stroke Ci of said gripping means 1 by the target stroke value Ce. - / E / Cooperation between the at least one gripping means 5 with the at least one seizure zone 6 of said container 2

[0093] Thus, the gripping means has the new objective of reaching the target stroke Ce, which corresponds to the stroke value for which the gripping means 5 and the gripping zones 6 are able to cooperate.

[0094] In examples, the cooperation between the gripping means 5 and the gripping zones 6 is obtained by a movement of the chassis 3 in a direction substantially perpendicular to the deployment direction Dp. In one example shown [Fig.5], this is an upward movement of the chassis.

[0095] In examples, the cooperation between the gripping means 5 and the gripping zones 6 is obtained by vertical displacement of the gripping means 5, or even upward deployment of the gripping means 5. For example, once the correction according to / D / has been carried out, the engagement between the gripping means 5 and the gripping zones 6 can be obtained by a movement of the vehicle in the vertical direction, by actuation of the climbing means, and according to a limited stroke. Such a movement can make it possible to engage the gripping means 5 and the gripping zones 6, or even to lift the container, over a short stroke, from the support surface of the shelf on which it rests.According to another example, the gripping means may be elements movable between a retracted position, at least partly under the support surface 11, and a deployed position in which the gripping means protrudes from the support surface 11, then being able to penetrate into the corresponding gripping zone 6.

[0096] The input method also includes: - / F / Retraction of the gripping means 1 having gripped said container 2, to the vehicle chassis

[0097] In examples, the gripping means 5 and the gripping zones 6 may be configured to cooperate at least by contact between two complementary surfaces 51, 61. In examples, these surfaces may be substantially perpendicular. to the deployment direction Dp. In this way, the retraction movement of the gripping means 1 carries with it the container 2 by contact between the complementary surfaces 51, 61.

[0098] The distance sensor 4 may preferably be a non-contact linear distance sensor. Such sensors may have the advantage of being able to carry out measurements very quickly, which is particularly the case in storage warehouses where the speed of movement of the robots is essential. It is however possible to provide other types of sensor known to those skilled in the art.

[0099] The detection of the sensor 4 can take place in a detection direction substantially perpendicular to the deployment direction Dp of the gripping means 1.

[0100] In examples, in particular in an example shown in [Fig.5], the sensor 4 is positioned sufficiently in front of the front gripping means 5.1. For example, the sensor 4 is positioned 20mm in front of the front gripping means 5.1. For example, the sensor 4 is positioned at least 15mm in front of the front gripping means 5.1. In this way, the deployment of the gripping means 1 at / A / and / D / up to the target stroke value Ce is an uninterrupted movement: it allows a positive comparison with the reference profile, before the gripping means reach the gripping zones. Conversely, if the sensor 4 were too close to the front gripping means 5.1, the correspondence between the distance profile 9 and the reference profile 10 could be determined too late, the gripping means having already deployed beyond the target stroke value Ce.It may then be necessary to interrupt the stroke of the gripping means 1, then to retract it to the target stroke Ce. This may cause a loss of efficiency in the gripping operation, and above all a loss of time. In an example as shown [Fig. 5], the sensor 4 is deployed opposite the last gripping zone 6.1 sufficiently in advance of the gripping means 5.1, so that the latter has not yet passed opposite the gripping zone 6.1 when the determination of the correspondence between the distance profile 9 and the reference profile 10 is carried out. This allows the gripping means 1 to continue its stroke, for example unchanged, until its new objective which is the target stroke value Ce.

[0101] In examples, an error mode may be provided. This mode may be triggered in particular when the measured distance profile 9 still does not correspond to the reference profile 10 while the gripping means has reached its initial stroke Ci, or when the comparison of the distance profile 9 and the reference profile 10 has not allowed the determination of a target stroke value Ce. In the case of triggering of the error mode, this may initiate the retraction of the gripping means 1 from the target stroke Ci towards the chassis 3. It may then be possible to correct the height of the vehicle V and to restart the execution of the gripping method, or to take other corrective action.

[0102] In an example notably represented in [Fig.6], the sensor 4 can detect that the gripping means 1 has reached the area opposite the gripping surface 7 by acquiring a relatively low distance measurement compared to the first measurements of this same distance. The first measurement points then correspond to the distance measurement between the sensor and an obstacle located further above. For example, the measurement of a first distance less than a threshold value reveals the presence of the container 2 opposite the gripping means 1. In an example in which two acquisition phases P1 and P2 are distinguished, the transition from one to the other can be defined by the acquisition of this first relatively low value.

[0103] In an example shown in [Fig.7], the deployable gripping means 1 is movable in a first and a second direction along said deployment direction Dp on one side and the other of said chassis 3. The vehicle V is then able to grip one or the other of two containers 2 located on two racks 100 (not shown) on either side of the vehicle V.

[0104] Said deployable gripping means 1 comprises a first and a second distance sensor 4.1, 4.2 positioned at each end of the gripping means 1. The two ends are opposite in the direction of deployment Dp. During the acquisition in / B / , only the sensor 4 positioned at the end of the side on which the gripping means 1 is deployed carries out the acquisition of the plurality of distance measurement points. In the example shown in [Fig.7], the gripping means 1 in solid line is deployed to the left, the gripping means in dotted line representing the position that it could also occupy if it were deployed to the right. In the case of deployment to the left according to this example, it is the sensor 4.2 at the end of the left side which carries out the acquisition of the measurement points, the other sensor 4.1 being able to be deactivated, or being able to participate in other operations

Claims

Claims

1. A method of gripping a container (2) by a deployable gripping means (1), the gripping means (1) being movable along a deployment direction (Dp) from a chassis (3) of a device such as a vehicle (V), and being provided with a distance sensor (4), and comprising a gripping means (5) configured to cooperate with a gripping zone (6) of a container (2) to be gripped, said gripping zone (6) being arranged on a gripping surface (7) of the container (2) and defining at least one relief variation (8) of said gripping surface (7), the method comprising: - / A / The deployment of the gripping means (1) from said chassis (3) towards an area opposite said gripping surface (7) of the container (2) to be gripped, the deployment aiming to reach an initial stroke value (Ci), - / B / During the deployment of the gripping means (1), the measuring, by means of the sensor (4), a distance profile (9) between said gripping means (1) and the gripping surface (7) of said container (2), - / C / Comparison of said distance profile (9) with a profile of reference (10) corresponding to at least one relief variation (8) of the gripping surface (7) until a target stroke value is determined allowing the cooperation of said gripping means (5) with said gripping zone (6) of said container (2), - / D / Correction of the initial stroke (Ci) of said means of grip (1) by the target stroke value (Ce). - / E / Cooperation between said gripping means (5) with said seizure zone (6) of said container (2) - / F / Retraction of the gripping means (1) having gripped said container (2), up to the chassis of the vehicle

2. Method according to the preceding claim, in which the distance profile (9) is obtained by connecting a plurality of distance measurement points between the gripping means (1) and the gripping surface (7) of the container (2), the comparison of said distance profile (9) and the reference profile (10) being carried out at each acquisition of a new measuring point.

3. Method according to one of the preceding claims, said sensor (4) being a non-contact linear distance sensor.

4. Method according to any one of the preceding claims, the detection of the sensor (4) taking place in a detection direction substantially perpendicular to said direction of deployment (Dp) of the gripping means (1).

5. Method according to any one of the preceding claims, the deployment of the gripping means (1) at / A / and / D / up to the target stroke value (Ce) being an uninterrupted movement.

6. Method according to any one of the preceding claims, the cooperation between said gripping means (5) with said gripping zone (6) of said container being carried out by means of a movement of the chassis in a direction substantially perpendicular to the direction of deployment.

7. A method according to any preceding claim, wherein the deployable gripping means (1) is movable in a first and a second direction along said deployment direction (Dp) on either side of said frame (3).

8. Method according to the preceding claim, said deployable gripping means (1) comprising a first and a second distance sensor (4) each positioned at one end of the gripping means (1), the two ends being opposite in the direction of deployment (Dp), only the sensor (4) positioned at the end on the side of which the gripping means (1) is deployed carries out the acquisition of the plurality of distance measurement points.

9. Method according to any one of the preceding claims, comprising detecting the container (2) by measuring a first distance less than a threshold value revealing the presence of the container (2) opposite the gripping means (1).

10. A method according to any preceding claim, comprising triggering an error mode and retracting the gripping means (1) if the comparison of the distance profile (9) and the reference profile (10) has not allowed the determination of a target stroke value (Ce) while the gripping means (1) has reached the initial stroke value (Ci).

11. Method according to one of claims 1 to 10, wherein in / B / the measurement of the distance profile (9) comprises the acquisition of a plurality

12.

13.

14.

15.

16.

17.

18. of distance points measured by said sensor (4), said measurements being associated respectively with stroke values ​​(C) of the gripping means. Device for gripping a container (2) comprising: - A chassis (3), - A gripping means (1) deployable along a deployment direction (Dp) from said chassis (3) and set in motion by at least one actuator, the gripping means (1) comprising a gripping means (5) configured to cooperate with a gripping zone (6) arranged on a gripping surface (7) of the container (2) to be gripped and defining at least one relief variation (8) of said gripping surface (7), - A distance sensor (4), positioned on said gripping means (1), - A controller comprising a processor, a memory, and an instruction set configured to implement the method according to any one of the preceding claims. Device according to the preceding claim, said sensor (4) being a non-contact linear distance sensor. Device according to one of claims 12 or 13, the sensor (4) being oriented on the gripping means (1) in a detection direction substantially perpendicular to said deployment direction (Dp) of the gripping means (1). Device according to one of claims 12 to 14, said sensor (4) being positioned in front of said gripping means (5) in the direction of deployment of the chassis (3) towards the container (2). Device according to one of claims 12 to 15, said gripping means (5) being fingers configured to be inserted at least partially into hollows arranged on said container (2). Device according to one of claims 12 to 16, wherein the deployable gripping means (1) is movable in a first and a second direction along said deployment direction (Dp) on one side and the other of said frame (3). Device according to the preceding claim, said deployable gripping means (1) comprising a first and a second sensor (4) of distance each positioned at one end of the gripping means (1), the two ends being opposite according to the direction of deployment (Dp), the first sensor (4) configured to implement / B / when the gripping means is deployed in the first direction, the second sensor configured to implement / B / when the gripping means is deployed in the second direction.

19. Device according to one of claims 12 to 18, said chassis (3) being at least part of a vehicle (V) for transporting a container (2) equipped with climbing means (Gr) configured to move along a shelf (100) on which the container (2) to be gripped is placed.

20. A computer program product comprising instructions which, when executed by a processor connected to a memory, are configured to implement the method according to any one of claims 1 to 11.

Images