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

Abstract

TITLE: Method for gripping a container, and container gripping device. The invention relates to a method for gripping a container (2) by means of 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: Deployment of the gripping means (1) aimed at reaching an initial stroke value (Ci), During deployment, measurement, by means of the sensor (4), of a distance profile (9) between said gripping means (1) and the container (2), Comparison of 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), Correction of 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 scope of this disclosure is that of warehouse logistics and in particular the handling and transport of objects such as parts or products in containers, including bins, stored in racks.

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

[0003] This disclosure also relates to a container gripping device, intended to implement the process according to this disclosure.

[0004] This disclosure also relates to a computer program product comprising instructions configured to implement said process. Prior art

[0005] In product storage warehouses, it is known to use robots, or vehicles, to retrieve containers, particularly bins or trays, containing specific products stored on racking shelves and transport them to another location, for example, an order picking station. These robots are equipped with motorized means enabling them to move horizontally on the floor, but also vertically along the racking structure, for example, on racks or belts. These robots are also equipped with gripping means, the function of which is to grasp and place a container on a shelf or at an order picking station.

[0006] These gripping means may consist of a telescopic fork deployed by the robot to grasp the containers. However, these containers then end up cantilevered during transport, which can unbalance the robot during its movement.

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

[0008] Finally, document EP3638607B1 proposed using a motorized trolley, comprising climbing means configured to cooperate with the racking, particularly its vertical uprights, to allow said trolley to rise along the racking and thus reach the height of the container to be picked up. Once facing The forklift deploys a movable gripping device relative to the forklift's chassis. The gripping device is equipped with means, such as fingers or lugs, to engage with notches on the underside of the container. The device retracts, taking the container with it. The forklift can then move, carrying the container vertically above its chassis, to its drop-off location. 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 presents drawbacks related to the alignment of the cooperating parts of the gripping means and the container. In particular, a misalignment of position in the plane of the lower surface of the container can result in a failure of the gripping operation.

[0010] A first type of centering solution using mechanical means exists. In these solutions, determining the exact position between the cooperating parts is typically achieved by mechanical centering means based on the relative placement of the two cooperating parts. For example, the mechanical centering means can be sloping surfaces, such as conical surfaces forming an angle with the vertical, arranged in complementary positions on the cooperating parts. As illustrated in [Fig. 3], this known solution allows for the absorption of a slight relative offset between the two parts, where one part forces the other to move.

[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] Moreover, as already mentioned, this type of solution only allows for the correction of a small decentering, for example on the order of a few millimeters.

[0013] Furthermore, there is another type of centering solution which uses optical sensors.

[0014] An example of such a centering solution is disclosed in document CN113998626. Optical sensors, including 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, so that the gripping fingers of the gripping means are positioned opposite the notches on the underside of the container.

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

[0017] It is also possible to locate the notches on the underside of the container by detecting the edges of the container as the gripping means moves under the container. However, this technique has the drawback of becoming unusable if two containers are touching on the racking. Such a situation occurs relatively frequently in warehouses.

[0018] The purpose of this disclosure is therefore to mitigate at least in part the disadvantages of the prior art mentioned above.

[0019] In particular, one objective of this disclosure is to propose a solution that ensures robust and easy-to-implement centralization of the cooperating parties, notably by using minimal data to process. Finally, this disclosure aims to propose a solution with reduced cost and simple components, thereby minimizing its environmental impact. Summary

[0020] According to a first aspect, the present disclosure relates to a method for gripping a container by means of a deployable gripping means, the gripping means being mobile along a deployment direction from a chassis of a device such as a vehicle, and being equipped with a distance sensor, and comprising a gripping means configured to cooperate with a gripping zone of a container to be grasped, said gripping zone being arranged on a gripping surface of the container and defining at least one relief variation of said gripping surface, the method comprising: - / A / The deployment of the gripping means from said chassis in the direction from an area opposite said gripping surface of the container to be grasped, the deployment aims to reach an initial stroke value, - / B / During the deployment of the gripping means, the measurement, using 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 responding to at least one variation in the relief of the gripping surface until a target stroke value is determined, enabling 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 and said gripping zone said container - / F / Retraction of the gripping device that gripped said container, up 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 reliably and easily implemented.

[0022] In addition, the use of a distance sensor, instead of 3D optical sensors, and the processing of a 2D profile of measurement points in two dimensions, are 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 realization of a distance profile.

[0024] The features described in the following paragraphs may optionally be implemented independently of each other or in combination with each other:

[0025] According to examples, the distance profile can be obtained by linking 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 at each acquisition of a new measurement point.

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

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

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

[0029] According to examples, the cooperation between said gripping means with said gripping zone of said container can be achieved 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 mobile in a first and a second direction along said deployment direction on one side and the other of said chassis.

[0031] In examples, said deployable gripping means may include 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 on which the gripping means is deployed acquires 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

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[0041] container opposite the gripping means. In examples, the process may include triggering an error mode and retracting the gripping means if the comparison of the distance profile and the reference profile did not allow the determination of a target stroke value while the gripping means reached the initial stroke value. In examples, in / B / , the measurement of the distance profile may include the acquisition of a plurality of distance points measured by said sensor, said measurements being associated respectively with stroke values ​​of the gripping means. According to a second aspect, this disclosure concerns a container seizure 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 relief variation 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 process according to the first aspect. According to examples, said sensor could be a non-contact linear distance sensor. In some examples, the sensor can be oriented on the gripping means along a detection direction substantially perpendicular to said deployment direction of the gripping means. In some examples, said sensor may be positioned in front of said gripping means in the direction of chassis deployment towards the container. In some examples, said gripping means may be fingers configured to fit at least partially into recesses arranged on said container. In examples, the deployable gripping means may be mobile in a first and second direction along said deployment direction on one side and the other of said chassis. In examples, said deployable gripping means may include a first and a second distance sensor, each positioned at one end of the gripping means, the two ends being opposite in the deployment direction, the first sensor configured to implement / B / when the means gripping is deployed in the first direction, the second sensor configured to put in / 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 grasped is placed.

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

[0044] Other features, details and advantages will become apparent from reading the detailed description below and from analyzing the accompanying drawings, in which: Fig. 1

[0045] [Fig.1] shows a schematic representation of a transport vehicle comprising a prior art gripping means. Fig. 2

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

[0047] [Fig.3] shows a bottom view of a container of the prior art having gripping area suitable for cooperating with the gripping means of a gripping means. Fig. 4

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

[0049] [Fig.5] shows a schematic longitudinal sectional representation of an example of a container gripping device 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 process of this disclosure. Fig. 7

[0051] [Fig. 7] shows a schematic representation of a container transport vehicle V in which the gripping means is equipped with two sensors, and the means The gripping device is deployable and mobile in two directions along the deployment direction. Description of the implementation methods

[0052] The drawings and description below contain, essentially, elements of a definite nature. They may therefore not only serve to better explain this disclosure, but also contribute to its definition, if necessary.

[0053] In the various figures, the same reference numerals designate identical or similar elements. For the sake of brevity, only the elements that are useful for understanding the described embodiment 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 "front," "back," "top," "bottom," "left," "right," etc., or relative position qualifiers, such as "above," "below," "superior," "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 automated transport vehicle in its normal operating position. Furthermore, the term "approximately" is to be interpreted as indicating that the result obtained is as precise as the known method for measuring it.

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

[0056] A vehicle V of the prior art is represented, comprising a means of Gripper 1 deployable from a chassis 3 along a deployment direction Dp. The gripper 1 is configured to assist in grasping 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 capable of moving across the warehouse floor from one rack to another. The vehicle also includes climbing means Gr, enabling the vehicle V to ascend the vertical uprights 101 of a warehouse rack 100 (also called a "rack"), as shown in [Fig. 2], in order to access the shelf 102 on which the container 2 to be retrieved is located. The climbing means Gr may typically include motorized sprockets 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, of which there are four 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 "mean of "gripping" and "gripping zone" can designate one or more portions capable of cooperating respectively with each other so as to drive the container 2 with the deployment movement of the gripping means 1.

[0059] The gripping means are arranged in particular 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 in an identical distribution. The distribution of the gripping zones 6 on the container 2 can be planar. 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 as such for clarity, but can be freely interchanged 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 protrusion capable of inserting into a complementary gripping zone 6. Either shape of the means and the gripping 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 recess.

[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 hinders the cooperation of the latter with the gripping areas 6.

[0065] Figure 4 represents a prior art centering technique which does not give Complete satisfaction.

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

[0067] Indeed, the vehicle V of the type described above, comprises a chassis 3, from which a gripping means 1 is deployed The gripping means is foldable. The gripping means is mobile along a deployment direction Dp from the chassis 3 of the vehicle V. The gripping means 1 is equipped with a distance sensor 4, arranged on a support surface 11 of the gripping means 1. The gripping means 1 includes 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 areas 7 of the container 2 include protrusions configured to cooperate with the recesses.

[0069] The relief variation 8 is defined as 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, particularly due to flatness imperfections on the molded surfaces during container manufacturing. The distance measured at a relief variation zone may exhibit a variation at least greater than the manufacturing tolerances, for example, by 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 method makes it possible to reliably center the cooperation parts without being affected by disturbances related to other variations, for example, 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 can be delimited by a rear side 12 and a front side 13. The sensor can typically be positioned at the front side 13. The sensor 4 can 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 such that, during its deployment, the gripping means 1 first passes over a front edge 21 of the container and then over a rear edge 22 of the container. The gripping surface 7 is delimited in particular by the front edge 21 and the rear edge 22, as well as by lateral edges 23.

[0072] Figure 5 shows an example in which the gripping means 1 is deployed in a direction marked by an arrow, parallel to the deployment direction Dp. The gripping means 1 can also be deployed in both directions, forward and backward, along the deployment direction Dp. These embodiments can be used to grasp two containers stored on either side of vehicle V without the latter having to move vertically, for example in a 100 racking configuration as shown in [Fig.2], in which vehicle V is positioned between two 100 racks.

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

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

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

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

[0078] The area opposite the gripping surface 7 is, in the example shown in [Fig. 5], the area located directly below 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 opposite one of the lateral edges 23. In such examples, said area is the volume formed by extending 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 stationary. For example, the vehicle V can position itself at a height allowing the gripping means to deploy, along 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 container 2, so as to ignore any lack of parallelism between the deployment direction Dp and the gripping surface 7.

[0080] The seizure process 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 such as shown in [Fig. 6], the distance profile 9 can be obtained as a curve connecting points defined by an abscissa and an ordinate. The abscissa represents the actual stroke values ​​of the deployment means, for example, obtained by the stroke sensor, and the ordinate represents 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, for example, over a given range of stroke values. It is also possible to interchange the type of value displayed 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 deployment speed of the gripping means 1 by the controller.

[0083] In examples, two measurement phases, P1 and P2, can be distinguished. In phase P1, the gripping means has not yet sufficiently extended, and the sensor 4 has not yet reached the area opposite the gripping surface 7. The distance measurements acquired during this phase P1 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 performed a first measurement in the area opposite the gripping surface 7. It can 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 can, in particular, reduce the amount of data to be processed for the implementation of the gripping method according to this disclosure.

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

[0085] In one example, the acquisition of points based on distance measurements is carried out periodically, according to an acquisition rate. The acquisition rate, in one example, can be on the order of one point per millimeter traveled by the gripping means 1. Other acquisition rates can be considered, or may These settings can be adjusted by the controller according to the application. For example, the acquisition speed of the distance sensor 4 can be the same as the acquisition speed of the stroke sensor. In some examples, the acquisitions of the distance sensor 4 and the stroke sensor are simultaneous.

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

[0087] In examples, the profile can be realized 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 linked to the previous point to continue the realization of the distance profile 9.

[0088] In examples, the reference profile 10 can be a predetermined curve stored in the memory connected to the controller. The reference profile 10 can be selected by the controller from a database of profiles that can, 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 in such a way 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 at least one gripping means 5 with 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 considered direction of deployment of the gripping means, 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 position x-Dg / 2 when it is desired to align 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 position x-Dz-Dg / 2, in a case where it is desired to align 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 seizure process also includes: - / D / Correction of the initial stroke Ci of said gripping means 1 by the target race value Ce. - / E / Cooperation between at least one means of gripping 5 with at least one seizing zone 6 of said container 2

[0093] Thus, the gripping means has a 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 some examples, cooperation between the gripping means 5 and the gripping zones 6 is achieved 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 some examples, cooperation between the gripping means 5 and the gripping zones 6 is achieved by vertical displacement of the gripping means 5, or by upward deployment of the gripping means 5. For example, once the correction along / D / has been performed, engagement between the gripping means 5 and the gripping zones 6 can be achieved by moving the vehicle in the vertical direction, by actuating the climbing means, and over a limited stroke. Such a movement can engage the gripping means 5 and the gripping zones 6, or even 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 can be movable elements between a retracted position, at least partly under the support surface 11, and a deployment position in which the gripping means protrudes from the support surface 11, thus being able to penetrate the corresponding gripping zone 6.

[0096] The seizure process also includes: - / F / Retraction of the gripping means 1 that gripped said container 2, up to the vehicle chassis

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

[0098] The distance sensor 4 can preferably be a non-contact linear distance sensor. Such sensors can have the advantage of being able to perform measurements very quickly, which is particularly relevant in warehouses where the speed of robot movement is paramount. However, it is possible to use other types of sensors known to those skilled in the art.

[0099] The detection of the sensor 4 can be carried out along a detection direction substantially perpendicular to the deployment direction Dp of the gripping means 1.

[0100] In examples, particularly in the example shown in [Fig. 5], the sensor 4 is positioned sufficiently forward of the front gripping means 5.1. For example, the sensor 4 is positioned 20 mm forward of the front gripping means 5.1. For example, the sensor 4 is positioned at least 15 mm forward of the front gripping means 5.1. In this way, the deployment of the gripping means 1 in / 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, as the gripping means would already have deployed beyond the target stroke value Ce.It may then be necessary to interrupt the stroke of the gripping means 1 and then retract it to the target stroke Ce. This can lead to a loss of efficiency in the gripping operation, and especially a loss of time. In an example such as that 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 it reaches its new target, 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 even though 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 event of an error mode being triggered, it 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 process. or to implement other corrective measures.

[0102] In an example, notably shown 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 small distance measurement compared to the initial measurements of the 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 an initial distance below a threshold value reveals the presence of the container 2 opposite the gripping means 1. In an example where 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 small value.

[0103] In an example shown in [Fig.7], the deployable gripping means 1 is mobile 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 grasp either 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 along the deployment direction Dp. During acquisition in / B / , only the sensor 4 positioned at the end on the side from which the gripping means 1 is deployed acquires the plurality of distance measurement points. In the example shown in [Fig. 7], the gripping means 1 (solid line) is deployed to the left, the gripping means (dashed line) representing the position it could also occupy if deployed to the right. In the case of deployment to the left as in this example, it is the sensor 4.2 at the end on the left side that acquires the measurement points, the other sensor 4.1 being able to be deactivated or to participate in other operations

Claims

Demands

1. A method for grasping a container (2) by means of 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 equipped 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 grasped, 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 grasping means (1) from said chassis (3) towards an area opposite said gripping surface (7) of the container (2) to be gripped, the deployment aimed at reaching an initial stroke value (Ci), - / 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), - / C / Comparison of said distance profile (9) with a profile of reference (10) corresponding to at least one variation in relief (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 gripping zone (6) of said container (2) - / F / Retraction of the grasping means (1) that had gripped said container (2), up to the vehicle chassis

2. A method according to the preceding claim, wherein the distance profile (9) is obtained by linking 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 measurement point.

3. A method according to any 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) being carried out along a detection direction substantially perpendicular to said deployment direction (Dp) of the gripping means (1).

5. Method according to any one of the preceding claims, the deployment of the gripping means (1) in / 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 effected by means of a movement of the chassis in a direction substantially perpendicular to the direction of deployment.

7. A method according to any one of the preceding claims, 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 chassis (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 along the deployment direction (Dp), only the sensor (4) positioned at the end on the side on which the gripping means (1) is deployed acquires the plurality of distance measurement points.

9. A method according to any one of the preceding claims, comprising the detection of 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 one of the preceding claims, 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 enabled the determination of a target stroke value (Ce) while the gripping means (1) has reached the initial stroke value (Ci).

11. A method according to any 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.

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16.

17.

18. of distance points measured by said sensor (4), said measurements being associated respectively with stroke values ​​(C) of the gripping means. Container gripping device (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 any 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 any one of claims 12 to 15, said gripping means (5) being fingers configured to insert at least partially into hollows arranged on said container (2). Device according to any one of claims 12 to 16, wherein the deployable gripping means (1) is mobile in a first and a second direction along said deployment direction (Dp) on one side and the other of said chassis (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 along the deployment direction (Dp), the first sensor (4) configured to implement / B / when the gripping means is deployed in the first direction, the second sensor configured to put in / B / when the gripping means is deployed in the second direction.

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

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

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