Automatic forklift for transporting goods and related method

Abstract

This automatic forklift (1) comprises:-a front fork (4) which can be moved vertically provided with at least two arms (4a, 4b) for lifting goods,-a drive system (7) for moving the forklift (1), and-a control unit which can control the operation of the drive system (7) in order to automatically guide the forklift and can control the vertical movement of the front fork. The forklift further comprises a device (10) for the contactless detection of goods that can be moved together with the front fork (4), said device (10) being arranged above the arms (4a, 4b) of the front fork. The detection device (10) is capable of emitting a light beam that sweeps over at least one predefined planar detection area located above the arms (4a, 4b) in order to detect the presence or absence of the cargo. The forklift further comprises means for determining the movement of the forklift.

Description

Technical Field

[0001] The present invention relates to the field of autonomous vehicles for autonomous transport of goods, such as autonomous forklifts. Background Art

[0002] Autonomous vehicles for transporting goods are increasingly being used to increase productivity and improve logistics management in factories or warehouses.

[0003] An example of such a vehicle is an autonomous forklift, which can, for example, load and transport goods and position them at height without human intervention.

[0004] However, in environments such as factories or warehouses, human intervention is still necessary in addition to automated operations, for example in order to check that these operations are carried out correctly or to perform tasks that machines cannot perform alone. Therefore, these environments are shared between humans and autonomous machines.

[0005] In this work environment, the safety of personnel is of paramount importance, so specific procedures need to be implemented.

[0006] For example, in order to limit the risk of falling of the transported goods, forklifts are usually provided with mechanical sensors arranged on the vertical uprights of the front forks used for lifting, transporting and unloading these goods.

[0007] Such a mechanical sensor is in the form of a stop that pivots between an extended position corresponding to the absence of cargo or out of contact with the stop and a retracted position corresponding to the cargo being in contact with the stop.

[0008] However, these mechanical sensors mounted on the bottom of the carriage cannot ensure that the placement on the storage rack is correctly performed during unloading of goods, or that the extraction of goods from the rack is also correctly performed during extraction.

[0009] This creates the risk of accidents.

[0010] Specifically, after unloading the goods on the rack, if the arms of the front forks are not correctly retracted relative to the pallet carrying the goods and remain in contact with the pallet, there is a great risk of the goods falling during the forklift's reverse movement.

[0011] This risk of falling also exists during the extraction of goods from the rack if the arms of the forklift's front forks are not correctly positioned relative to the goods, so that the goods may be pushed off the rack as the forklift advances. Summary of the invention

[0012] In view of the above, an object of the present invention is therefore to propose an automatic forklift capable of increasing the reliability and safety of the unloading operation and the operation of extracting goods from the storage rack.

[0013] The subject of the invention is an automatic forklift comprising: a front fork which can be moved vertically and is provided with at least two arms for lifting goods; a drive system for moving the forklift; and a control unit capable of initiating the operation of the drive system in order to automatically guide the forklift and capable of initiating the vertical movement of the front fork.

[0014] According to a general feature, the forklift also includes a non-contact cargo detection device, which can move with the front fork and is arranged above the arm of the front fork. The non-contact detection device is capable of emitting a light beam that sweeps across at least one predefined planar detection area located above the arm to detect the presence or absence of cargo.

[0015] According to another general characteristic, the forklift also comprises means for determining the movement of the forklift. The determining means are capable of acquiring information representative of the movement of the forklift from a position where the forklift unloads or extracts the cargo and which is stored by the control unit.

[0016] According to another general feature, the control unit receives representative information output by the determination device and information output by the contactless detection device indicating the presence or absence of goods in said predefined planar detection area.

[0017] According to another general feature, the control unit is able to initiate the operation of the drive system and the vertical movement of the front fork based on this information.

[0018] With this automated forklift, it is now possible to ensure that after unloading the goods on the storage racks, the vehicle reverses without any risk of the unloaded goods falling.

[0019] It is now also possible to ensure that during the retrieval of goods from the storage racks, the vehicle moves forward without any risk of the goods being pushed and thus falling.

[0020] Furthermore, incorporating such a contactless detection device makes it possible to perform remote detection of any type of cargo.

[0021] Advantageously, the determination device comprises at least one rotary encoder which is able to measure a rotation of at least one wheel of the forklift.

[0022] Incorporating such a rotary encoder facilitates achieving high-precision control of the forklift's movements.

[0023] Advantageously, said predefined planar detection area swept by the light beam emitted by the contactless detection device is horizontal.

[0024] Preferably, the predefined planar detection area swept by the light beam emitted by the contactless detection device is located above the two arms. In this case, the planar detection area can at least partially extend laterally beyond the lateral space requirement of the arms of the front fork.

[0025] In a variant, the contactless detection device may sweep over two separate planar detection areas, namely a first predefined planar detection area located above a first arm of the front fork and a second predefined planar detection area located above a second arm of the front fork different from the first arm.

[0026] According to another feature, the front fork comprises at least two uprights supporting the arms, and the contactless detection device is arranged on one of the uprights.

[0027] The automatic forklift comprises an onboard positioning device configured to obtain the forklift position data and communicate with the control unit. Preferably, the non-contact detection device is separated from the positioning device.

[0028] Preferably, the determining means are separate from the positioning means.Alternatively, however, it is conceivable that the positioning means forms the determining means.

[0029] In a particular embodiment, the automated guided forklift can also include a stopper, arranged on each upright of the front fork and mounted to pivot between an extended position corresponding to the absence of cargo or not in contact with said stopper and a retracted position corresponding to cargo in contact with said stopper, the contactless detection device arranged on said upright being located above the relevant stopper. Alternatively, the forklift can still be without these stops.

[0030] According to another aspect, the subject of the invention is a method for transporting and unloading goods using an automated forklift as described above.

[0031] Methods used for transport and unloading include:

[0032] - a step of unloading the cargo, wherein the forklift has reached a position for unloading the cargo,

[0033] - a step of recording the position of the forklift in said position for unloading the cargo as a reference position,

[0034] - a step of performing a cargo detection step in at least one predefined planar detection area by a contactless detection device,

[0035] - if the cargo is not detected in the detecting step, a step of reversing the forklift at a predetermined reversing distance, wherein the predetermined reversing distance is controlled via information output by the determining device,

[0036] - after the step of reversing the forklift truck at a predetermined reversing distance, a step of performing cargo detection by the non-contact detection device in at least one predefined plane detection area adjacent to the previous plane detection area, the at least one predefined plane detection area being located on the opposite side of the non-contact detection device relative to the previous plane detection area and having a lateral dimension equal to the value of the reversing of the forklift truck performed in the reversing step,

[0037] - if the cargo was not detected in the immediately preceding detection step, repeating the reversing step and the detection step until the cargo is detected in at least one predefined planar clearance area relative to the free end of the arm of the front fork, and

[0038] - A step of moving the forklift, the step being triggered at least based on the presence or absence of cargo in said predefined planar gap area.

[0039] With this method for unloading, safety is increased by being able to check during unloading of the goods onto the storage rack that the goods remain in position on the rack and that the goods are not carried by the forklift when the forklift is reversing.

[0040] For example, the predefined planar clearance area may be located in front of the free ends of the arms of the front fork.

[0041] Alternatively, the predefined planar gap area may be located behind the free end of the arm of the front fork and the step of moving the forklift is triggered if the absence of cargo in said gap area is detected and if the sum of the values ​​of reversing the forklift performed from the unloading position is greater than the distance between the free end of the arm of the front fork and the part of said detection area located beside the detection device in the step.

[0042] Advantageously, the reversing of the forklift performed during the reversing step has a constant value. Alternatively, a variable reversing value may still be provided.

[0043] In a particular embodiment, the step of reversing the forklift is performed continuously without stopping, the detection device activating the detection area and the clearance area successively according to a constant reversing value of the forklift.

[0044] In another embodiment, the step of reversing the forklift can be performed stepwise, with a stop phase between two consecutive reversing steps.

[0045] A further subject of the invention is a method for lifting and transporting loads using an automated forklift as described above.

[0046] Methods used for lifting and transport include:

[0047] - a step of positioning the arm of the front fork relative to the load to be lifted in a position for extracting the load,

[0048] - a step of carrying out a detection of the goods by means of a contactless detection device in at least one predefined planar detection zone relative to the free end of the arm of the front fork,

[0049] - if the cargo is detected in the detecting step, a step of recording the position of the forklift in said position for detecting the cargo as a reference position,

[0050] - a step of causing the forklift to advance by a predetermined advance distance, the predetermined advance distance being controlled via information output by the determination device,

[0051] - after the step of advancing the forklift by a predetermined advancement distance, a step of detecting the cargo by means of a non-contact detection device in at least one predefined planar detection area, said at least one predefined planar detection area being adjacent to the previous planar detection area, being located beside the non-contact detection device relative to the previous planar detection area and having a lateral dimension equal to the value of the advancement of the forklift performed in the advancement step,

[0052] - if cargo is detected in the previous detection step, repeating the advancing step and the detection step until cargo is detected in at least one predefined plane extraction area,

[0053] - a step of lifting the cargo if the cargo is detected in said predefined plane extraction area, and

[0054] -After the lifting step, the step of moving the forklift and transporting the goods.

[0055] With this method for lifting, safety is improved by being able to check during retrieval of goods from the storage rack that the goods remain in position on the rack and are not pushed by the forklift as it advances.

[0056] Preferably, the advancement of the forklift performed during the advancement step has a constant value. Alternatively, a variable advancement value may still be provided.

[0057] In a particular embodiment, the step of advancing the forklift is performed continuously without stopping, the detection device activating said detection zone and said extraction zone successively according to a constant advancement value of the forklift.

[0058] In another embodiment, the step of advancing the forklift can be performed stepwise, with a stop phase between two consecutive advances.

[0059] According to one feature, the predefined plane detection area is defined by four points defining a rectangle.

[0060] In one embodiment, the step of detecting cargo is performed in a planar detection area common to the arms of the fork.

[0061] In another embodiment, the step of detecting the goods is performed in two separate planar detection areas, each belonging to one of the two arms of the front fork. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Other objects, features and advantages of the present invention will become apparent from a reading of the following description given by way of non-limiting example only and with reference to the accompanying drawings, in which:

[0063] [ Figure 1 ] is a perspective view of an automatic forklift according to an exemplary embodiment of the present invention;

[0064] [ Figure 2 ] schematically shows Figure 1 The condition of the forklift when in use;

[0065] [ Figure 3 ]yes Figure 1 A partial top view of a forklift, wherein a first cargo detection area is schematically shown;

[0066] [ Figure 4 ] shows a flow chart of a method for transporting and unloading cargo according to one embodiment of the present invention;

[0067] [ Figure 5 ]yes Figure 1 A partial top view of a forklift truck schematically showing Figure 3 A cargo inspection area adjacent to a previous cargo inspection area shown in ;

[0068] [ Fig. 6A ]、[ Figure 6B ]、[ Figure 6C ]、[ Fig.6D ]、[ Fig. 6E ]、[ Fig. 6F ]、[ Figure 6G ]yes Figure 1 A partial top view of a forklift truck, schematically showing Figure 4 The continuous and contiguous cargo detection areas used in the method shown;

[0069] [ Figure 6H ]yes Figure 1 A partial top view of a forklift truck, schematically showing Figure 4 The gap area used in the method shown;

[0070] [ Figure 7 ] shows a flow chart of a method for lifting and transporting cargo according to one embodiment of the present invention; and

[0071] [ Fig. 8A ]、[ Figure 8B ]、[ Figure 8C ]、[ Fig.8D ]、[ Fig. 8E ]、[ Fig.8F ]、[ Figure 8G ]、[ Figure 8H ]、[ Figure 8I ]yes Figure 1 A partial top view of a forklift truck, schematically showing Figure 7 A continuous and contiguous cargo inspection area used in the method shown; and

[0072] [ Figure 8J ]yes Figure 1 A partial top view of a forklift truck, schematically showing Figure 7 The cargo extraction area used in the method shown. DETAILED DESCRIPTION

[0073] Figure 1 The main elements of an automated forklift 1 according to one embodiment of the present invention are shown.

[0074] The architecture of the forklift 1 is given by way of example and does not limit the invention to only the configuration of the architecture presented. It should be understood that the invention also relates to a forklift intended to operate in manual mode and which has been designed to allow a second automatic operating mode.

[0075] Figure 1 The automatic forklift 1 shown comprises a front fork bracket 3 provided with a front fork 4, the front fork 4 comprising two arms 4a, 4b spaced laterally apart and extending forward. The front fork 4 further comprises two uprights 4'a, 4'b, each upright supporting one of the arms 4a, 4b.

[0076] The arms 4a, 4b of the front fork are usually used to be inserted into insertion channels provided in a transport pallet supporting the cargo to be lifted. The uprights 4'a, 4'b can raise the arms 4a, 4b so that the pallet or some other type of cargo to be transported can be raised and the pallet or some other type of cargo can be placed or grasped at a height.

[0077] The front fork 4 is able to translate along the vertical mast 5 of the forklift in a vertical plane V defined by the front fork bracket 3. The uprights 4'a, 4'b can slide along the mast 5. The longitudinal axes of the arms 4a, 4b of the front fork 4 are parallel. These longitudinal axes are oriented parallel to the horizontal axis X and define a horizontal plane H called the lifting plane. The arms 4a, 4b of the front fork 4 are perpendicular to the vertical plane V. The arms 4a, 4b of the front fork are also preferably movable laterally relative to each other.

[0078] In variants, the arms of the front fork 4 may be telescopic or retractable and / or capable of being angularly oriented about their longitudinal axis.

[0079] As is known, the forklift 1 is equipped with a drive system 7 for moving the forklift 1. The drive system comprises at least one electric motor or internal combustion engine (not shown) for driving the wheels 18 of the forklift 1.

[0080] The forklift 1 is also equipped with a vehicle-mounted positioning device 8 and a vehicle-mounted control unit 9 ( Figure 2 ), the on-board control unit 9 receives the information output by the positioning device 8 so as to automatically start the movement of the forklift.

[0081] The control unit 9 comprises hardware and software for initiating the operation of the drive system 7 based on the information received from the positioning device 8. The control unit 9 may also initiate automatic movement of the front fork 4.

[0082] The forklift 1 is also equipped with means 11 for determining the movement of the forklift 1, which are configured to acquire information representative of the movement of the forklift 1 and transmit it to the control unit 9. In a preferred embodiment, the determination means 11 comprises at least one rotary encoder capable of measuring the rotation of at least one wheel 18 of the forklift 1. The encoder is capable of determining the movement value of the forklift 1 based on the number of rotations of the relevant wheel 18 detected.

[0083] The forklift 1 is also equipped with a non-contact detection device 10 arranged above the arms 4a, 4b of the front fork 4. The detection device 10 is fixed to the column 4'a of the front fork and is located above the arms 4a, 4b. The non-contact detection device 10 can move together with the column 4'a of the front fork. The detection device 10 is separated from the positioning device 8 and the determination device 11.

[0084] As will be described in more detail below, the detection device 10 is capable of emitting a light beam that sweeps across at least one predefined planar detection area above the arms 4a, 4b so as to detect the presence of cargo to be lifted via intersection of the light beam with the cargo within the predefined planar detection area.

[0085] The detection device 10 is configured to acquire position data of the cargo to be lifted and transmit information indicating the presence or absence of the detected cargo within the predefined planar detection area to the control unit 9. Based on the received information, the control unit 9 then initiates the operation of the drive system 7 and the vertical movement of the front fork 4. The detection device 10 may be, for example, a laser sensor of the LiDAR type.

[0086] Now refer to Figure 2 and Figure 3 The operating principle of the automatic forklift 1 for detecting the presence or absence of goods 12 to be unloaded on the rack 13 is described.

[0087] In the initial stage, the control unit 9 starts the operation of the forklift 1 so as to move it toward the rack 13 and raise the arm of the front fork 4 carrying the goods to be unloaded so as to position the goods relative to the rack 13. The forklift 1 is started by the control unit 9 based on the data output by the positioning device 8. When the forklift moves, the forklift 1 is kept at a minimum safety distance d relative to the rack 13. During the initial stage, the forklift 1 is kept at a minimum horizontal safety distance between the overhanging end of the arm of the front fork 4 and the rack 13 so as to allow the arm of the front fork 4 to pass safely over the rack 13.

[0088] In addition to the data output by the positioning device 8 , the control unit 9 can use the information transmitted by the determination device 11 to precisely control the movement of the forklift 1 .

[0089] After this initial phase, the detection device 10 emits a light beam 14 which sweeps at least one predefined planar detection area 15a located above the arms 4a, 4b of the front fork. The vertical projection of the detection area 15 covers the arms 4a, 4b of the front fork and the lateral space between them.

[0090] In the exemplary embodiment shown, the detection area 15a is defined by four different points defining a rectangle, e.g. Figure 3 Point A schematically represents the emission point of the light beam 14 leaving the device 10. In this case, the detection area 15a is horizontal. Alternatively, an area 15a inclined relative to the horizontal direction can be provided.

[0091] The long side of the rectangle defined by points B, C, D and E has a length y greater than the lateral space requirement of the arms 4a, 4b of the front fork, and the detection area 15a is centered relative to these arms. In other words, the planar detection area 15a extends laterally beyond the lateral space requirement of the arms 4a, 4b of the front fork. As an indication, the width w of the short side of the rectangle defined by points B, C, D and E and therefore the depth of the detection area 15a may be equal to 50 mm.

[0092] The detection device 10 is configured to detect whether the cargo 12 is located in the detection area 15a. When the cargo 12 intersects the light beam 14 and is located in the first detection area 15, the presence of the cargo 12 is detected by the device 10. The detection device 10 can detect that the cargo is located in the first detection area 15 by distance measurement.

[0093] If the light beam 14 emitted by the device 10 does not intersect the cargo, or if there is such an intersection, but the detection device 10 detects that the light beam 14 is separated from the cargo 12 by a distance outside the predefined planar detection area 15, the device 10 detects that there is no cargo 12 in the detection area.

[0094] A method 20 of unloading cargo using the automated forklift 1 will now be described. Figure 4 Method 20 is shown in FIG.

[0095] The method 20 starts with a step 21 of unloading the goods 12, during which the control unit 9 manipulates the forklift 1 to go to the position for unloading the goods. Once the forklift 1 has reached the position for unloading the goods, the control unit 9 manipulates the movement of the arms 4a, 4b relative to the shelf 13 in order to unload the goods 12 thereon. During this phase, the control unit 9 manipulates the goods 12 to be lowered above the shelf 13 until the goods 12 are in contact with the portion of the shelf 13 intended to receive the goods 12. The control unit 9 then continues to lower the arms 4a, 4b, causing a relative vertical movement between the arms 4a, 4b and the goods 12, which means that the goods are no longer in contact with the arms 4a, 4b and are completely resting on the shelf 13.

[0096] The method 20 continues with step 22 of recording the position of the forklift 1 in the position for unloading the load as a reference position.

[0097] During the subsequent goods detection step 23, the device 10 detects whether the goods 12 are not in the predefined plane detection area 15a ( Figure 3 ).

[0098] If the presence of goods in the area 15a is detected, the control unit 9 stops the forklift 1 in step 23' to allow the operator to rearrange.

[0099] If it is detected that there is no cargo in the area 15a, the method continues with a reversing step 24. During this step 24, the control unit 9 steers the forklift 1 so that it reverses away from the shelf 13 and the cargo 12 by a predetermined reversing distance. The reversing distance has a predetermined value and can be equal to 50 mm, for example. The control unit 9 controls the reversing of the forklift 1 via the information output by the determination device 11.

[0100] In a variant, the method 20 may include an additional reversing step performed before the detection step 23 .

[0101] After step 24 of reversing the forklift 1 by a predetermined reversing distance, the method continues with a cargo detection step 25, in which the device 10 detects the cargo in a new predefined plane detection area 15b ( Figure 5 ), the new predefined plane detection area is adjacent to the previous plane detection area 15a relative to the elongation axis of the arms 4a, 4b of the front forks. The predefined plane detection area 15b is located on the opposite side of the detection device 10 relative to the previous plane detection area 15a and has a transverse dimension w equal to the value of the forklift 1 reversing performed in the reversing step 24. Figure 5 In the example, the predefined plane detection area 15b corresponds to the rectangle CCb D b D. Given the adjacency of area 15b relative to area 15a, rectangles BCDE and CC b D b D share one of their longer sides, side CD.

[0102] If the presence of goods in the area 15b is detected in step 25, the control unit 9 stops the forklift 1 in step 25' to allow the operator to rearrange.

[0103] If no cargo is present in the area 15b in the cargo detection step 25, the method 20 continues to repeat 26 the reversing step 24 and the detection step 25 until the detection device 10 detects a predefined planar clearance area 16 ( Figure 6H ) in the goods.

[0104] In the exemplary embodiment shown, the clearance area 16 corresponds to a predetermined area located in front of the arms 4a, 4b of the front fork and defined as a clearance position of the front fork relative to the load 12, in which there is no risk of interference. Figure 6H In FIG. 1 , the clearance area 16 is defined by four points F, G, H, I, which define a rectangle located in front of the arms 4a, 4b of the front fork.

[0105] In a variant, another clearance area 16 may be defined relative to the free ends of the fork arms 4a, 4b, for example an area further away from the free ends of the fork arms 4a, 4b, or an area having a different width w.

[0106] As described above, if it is detected in the cargo detection step 25 that no cargo is present in the area 15 b , the method 20 continues by repeating the backing step and the detection step.

[0107] Therefore, after the forklift 1 operated by the control unit 9 performs a new reversing with a reversing distance equal to the value in step 24, a new predefined plane detection area 15c ( Fig. 6A The predefined plane detection area 15c is located on the opposite side of the detection device 10 relative to the previous plane detection area 15b and has a lateral dimension w equal to the value of the forklift 1 reversing just performed.

[0108] If the presence of cargo in the area 15c is detected, the control unit 9 stops the forklift 1 to allow the operator to rearrange. If the presence of cargo in the area 15c is detected, the method 20 continues.

[0109] For the detection area 15d ( Figure 6B ) to 15i( Figure 6G ), the repetition of the reversing step and the detection step continues in the same manner until the plane gap area 16 ( Figure 6H ).

[0110] The reversing step of the forklift 1 is performed continuously without stopping. The detection device 10 activates the detection areas 15a to 15i and the clearance area 16 successively according to the constant reversing value of the forklift.

[0111] When a cargo detection is performed in this area 16 , if no cargo is present in the gap interval 16 , the method proceeds to step 27 of moving the forklift 1 , which can then be assigned to a different task.

[0112] On the other hand, if during this detection there is cargo in the gap area 16, the control unit 9 stops the forklift 1 in a step 26' in order to allow the operator to rearrange.

[0113] In another embodiment, if cargo is present in the clearance region 16 when cargo detection is performed in the region 16, the method may proceed to step 27. For this embodiment, it is preferred to provide a greater spacing between the free ends of the arms 4a, 4b of the front fork and the region 16.

[0114] In the described embodiment, the method 20 comprises a cargo detection step in a clearance area 16 located in front of the arms 4a, 4b of the front fork. As mentioned above, another clearance area 16 may be defined.

[0115] For example, the clearance area 16 can be defined as the rear of the free ends of the arms 4a, 4b of the front fork. In this case, the vertical projection of the clearance area 16 is located on the arms 4a, 4b of the front fork.

[0116] If, for a clearance area 16 defined in this way, no cargo is present in this area 16 and if the sum of the values ​​of reversing the forklift performed from the unloading position is greater than the distance between the free ends of the arms 4a, 4b of the front forks and the long side BE of the rectangle of the detection area 15a, the method proceeds to step 27 of moving the forklift.

[0117] In the embodiment, a single step of recording the position of the forklift in the position for unloading the cargo as the reference position, i.e., the reference step, is provided. In a variant, a step of referencing the position of the forklift after each reverse at a predetermined reverse distance may also be provided.

[0118] A method 30 of lifting and transporting cargo using the automated forklift 1 will now be described. Figure 7 Method 30 is shown in FIG.

[0119] The method 30 starts with a positioning step 31 during which the control unit 9 operates the forklift 1 to position the arms 4a, 4b relative to the shelf 13 in a position for extracting the goods 12. Before and during this step, the goods 12 rest on the shelf.

[0120] Method 30 continues by performing the following steps in the predefined plane detection area 17a ( Fig. 8A ) in step 32 of performing cargo detection by the detection device 10. In the exemplary embodiment shown, the area 17a corresponds to a predetermined area located in front of the arms 4a, 4b of the front fork. Fig. 8A In FIG. 1 , the area 17a is defined by four points J, K, L and M, which define a rectangle located in front of the arms 4a, 4b of the front fork.

[0121] If no cargo is detected in the plane detection area 17a, then in step 32' the control unit 9 stops the forklift 1 to allow the operator to rearrange.

[0122] If the presence of cargo is detected in the area 17 a , the method 30 continues with step 33 , which records the position of the forklift 1 in the position for detecting cargo 12 as a reference position, followed by a forwarding step 34 .

[0123] During the advancement step 34 , the control unit 9 steers the forklift 1 to advance a predetermined advancement distance towards the rack and the goods. The advancement has a predetermined value and may be equal to 50 mm, for example. The control unit 9 controls the advancement of the forklift 1 via the information output by the determination device 11 .

[0124] In a variant, the method 30 may include an additional forwarding step performed before the reference step 33 .

[0125] After the step 34 of advancing the forklift 1 by the predetermined reversing distance, the method 30 proceeds to the cargo detection step 35, in which the detection device 10 detects the cargo in a new predefined planar detection area 17b ( 17a ) adjacent to the previous planar detection area 17a relative to the elongation axis of the arms 4a, 4b of the front forks. Figure 8B ) is performed in the cargo detection. The predefined plane detection area 17b is located next to the detection device 10 relative to the previous plane detection area 17a and has a transverse dimension w equal to the value of the advancement of the forklift 1 performed in the advancement step 34. Figure 8B In the example, the predefined plane detection area 17b corresponds to the rectangle J b JMM b Given the adjacency of region 17b relative to region 17a, rectangle J b JMM b and JKLM share one of their long sides, namely side JM.

[0126] If it is detected that no goods are present in the area 17b, the control unit 9 stops the forklift 1 in step 35' to allow the operator to rearrange.

[0127] If the presence of goods is detected in the area 17b, the method 30 continues to repeat 36 the advance step 34 and the detection step 35 until the detection device 10 is relative to the Figure 8J The cargo is detected in the predefined planar extraction area 18 of the vertical upright of the front fork as shown.

[0128] In the exemplary embodiment shown, the extraction area 18 corresponds to a predetermined area that is located beside the vertical upright of the front fork and is defined as a safe location for extracting cargo. Figure 8J In FIG. 1 , the extraction area 18 is defined by four points P, R, S and Q, which define a rectangle located beside the vertical upright of the front fork.

[0129] As described above, if the presence of cargo in the area 17b is detected in the cargo detecting step 35, the method 30 continues by repeating the advancing step and the detecting step.

[0130] Therefore, after the forklift 1 operated by the control unit 9 newly advances the advancing distance having the same value as the advancing distance in step 34, the new predefined plane detection area 17c ( Figure 8C ) A new detection step is performed in the predefined plane detection area 17c which is located beside the detection device 10 relative to the previous plane detection area 17b and has a transverse dimension w which is equal to the value of the forklift 1 advancement just performed.

[0131] If it is detected that no cargo is present in the area 17c, the control unit 9 stops the forklift 1 to allow the operator to rearrange. If it is detected that cargo is present in the area 17c, the method 30 continues.

[0132] For area 17d( Fig.8D ) to 17i( Figure 8I ), the forward step and the detection step are repeated in the same manner until the region 18 is extracted, as shown in FIG. Figure 8J shown.

[0133] The step of advancing the forklift 1 is performed continuously without stopping. The detection device 10 activates the detection areas 17a to 17i and the extraction area 18 successively according to the constant advancement value of the forklift.

[0134] If no cargo is present in the extraction zone 18 when the cargo detection is performed in the zone 18 , the control unit 9 stops the forklift 1 in step 36 ′ in order to allow the operator to rearrange.

[0135] On the other hand, if cargo is present in the extraction area 18 during this detection, the method proceeds to step 37, in which the control unit 9 implements the lifting of the cargo by issuing a lifting command.

[0136] After the freight 12 has been lifted, the method 30 continues with step 38 of moving the forklift and transporting the freight 12 .

[0137] In the embodiment, a single step of recording the position of the forklift in the position for detecting the cargo as a reference position, ie, a reference step, is provided. In a variant, a step of referencing the position of the forklift after each advance of a predetermined advance distance may also be provided.

[0138] In each of the embodiments described, the detection step is performed using detection zones of the detection device, each detection zone being common to the arms 4a and 4b of the front fork.

[0139] In a variant, in each detection step and for each of the arms 4a, 4b of the front fork, a detection zone belonging thereto can be provided. In this case, in each detection step, the detection device emits a light beam that sweeps over the detection zone belonging to the arm 4a of the front fork and located above it, and sweeps over the zone belonging to the arm 4b, located above it and separated from the detection zone belonging to the arm 4a.

Claims

1. An automatic forklift (1), comprising: - a front fork (4) which is vertically movable and provided with at least two arms (4a, 4b) for lifting cargo, - a drive system (7) for moving the forklift (1), and - a control unit (9) capable of initiating the operation of the drive system (7) in order to automatically guide the forklift and capable of initiating the vertical movement of the front fork (4), characterized in that the forklift (1) also comprises: - a contactless cargo detection device (10) movable with the front fork (4) and arranged above the arms (4a, 4b) of the front fork, the contactless detection device (10) being capable of emitting a light beam (14) which sweeps across at least one predefined planar detection area located above the arms (4a, 4b) in order to detect the presence or absence of cargo, and - means (11) for determining the movement of the forklift (1), said determining means (11) being able to obtain information representing the movement of the forklift (1) from the positions of the forklift (1) unloading or picking up the goods stored in the control unit (9), - The control unit (9) receives information indicating the movement of the forklift (1) output by the determination device (11) and information indicating the presence or absence of cargo in the predefined plane detection area output by the non-contact detection device (10), and is able to start the operation of the drive system (7) and the vertical movement of the front fork (4) based on the information.

2. The automatic forklift according to claim 1, wherein: The determination device (11) comprises at least one rotary encoder which is capable of measuring the rotation of at least one wheel (18) of the forklift.

3. The automatic forklift according to claim 1 or 2, wherein: The predefined planar detection area swept by the light beam (14) emitted by the non-contact detection device (10) is horizontal.

4. An automated forklift according to any one of the preceding claims, wherein: The front fork (4) comprises at least two uprights (4'a, 4'b) supporting arm portions (4a, 4b), and a non-contact detection device (10) is arranged on one of the uprights (4'a, 4'b).

5. The automatic forklift according to any one of the preceding claims, comprising an on-board positioning device (8) configured to obtain forklift position data and communicate with a control unit (9), and the non-contact detection device (10) is separated from the positioning device (8).

6. The automatic forklift according to claim 5, wherein: The determining device (11) is separated from the positioning device (8).

7. A method (20) for transporting and unloading goods (12) using an automated forklift (1) according to any one of the preceding claims, characterized in that include: -a) a step (21) of unloading the cargo (12), wherein the forklift has reached a position for unloading the cargo, - b) a step (22) of recording the position of the forklift (1) in said position for unloading the cargo as a reference position, -c) a step (23) of detecting the goods by means of a non-contact detection device (10) in at least one predefined planar detection area (15a), -d) if the cargo is not detected in the detection step (23), a step (24) of causing the forklift (1) to reverse at a predetermined reversing distance, wherein the predetermined reversing distance is controlled via information output by the determination device (11), -e) after the step (24) of reversing the forklift (1) at a predetermined reversing distance, a step (25) of performing cargo detection by the non-contact detection device (10) in at least one predefined plane detection area (15b) adjacent to the previous plane detection area (15a), the at least one predefined plane detection area (15b) being located on the opposite side of the non-contact detection device (10) relative to the previous plane detection area (15a) and having a lateral dimension equal to the value of the reversing of the forklift (1) performed in the reversing step (24), -f) if no cargo is detected in the immediately preceding detection step (25), repeating (26) the reversing step (24) and the detection step (25) until cargo is detected in at least one predefined planar clearance area (16) relative to the free ends of the arms (4a, 4b) of the front forks, and -g) a step (27) of moving a forklift, said step being triggered at least based on the presence or absence of cargo in said predefined planar clearance area (16).

8. The method according to claim 7, wherein: The predefined planar clearance area (16) is located in front of the free ends of the arms (4a, 4b) of the front fork.

9. The method according to claim 7, wherein: The predefined plane gap area (16) is located behind the free ends of the arms (4a, 4b) of the front forks, and if it is detected that no cargo is present in the gap area (16) and if the sum of the values ​​of reversing the forklift from the unloading position is greater than the distance between the free ends of the arms (4a, 4b) of the front forks and the part of the detection area (15a) located next to the detection device (10) in step (23), a step (27) of moving the forklift is triggered.

10. The method according to any one of claims 7 to 9, wherein: The reversing of the forklift performed during the reversing step (24) has a constant value.

11. The method according to claim 10, wherein: The step (24) of reversing the forklift is performed continuously without stopping, and the detection device (10) activates the detection areas (15a, 15b) and the clearance area (16) successively according to a constant reversing value of the forklift.

12. A method (30) for lifting and transporting goods (12) using an automated forklift (1) according to any one of claims 1 to 6, characterized in that include: a) a step (31) of positioning the arms (4a, 4b) of the front fork (4) relative to the load (12) to be lifted in a position for picking up the load, b) a step (32) of detecting the presence of goods in at least one predefined planar detection area (17a) relative to the free end of the arm (4a, 4b) of the front fork by means of a contactless detection device (10), c) if the cargo is detected in the detecting step (32), a step (33) of recording the position of the forklift (1) in the position for detecting the cargo as a reference position, d) a step (34) of causing the forklift (1) to advance by a predetermined advance distance, wherein the predetermined advance distance is controlled by information output by the determination device (11), e) after the step (34) of advancing the forklift (1) by a predetermined advancing distance, a step (35) of detecting the cargo in at least one predefined plane detection area (17b) by means of the non-contact detection device (10), the at least one predefined plane detection area (17b) being adjacent to the previous plane detection area (17a), being located next to the non-contact detection device (10) relative to the previous plane detection area (17a), and having a lateral dimension equal to the value of advancing the forklift (1) performed in the advancing step (34), f) if cargo is detected in the previous detection step (35), repeating (36) the advancing step (34) and the detection step (35) until cargo is detected in at least one predefined plane extraction area (18), g) if cargo is detected in said predefined plane extraction area (18), a step of lifting cargo (37), and h) After the lifting step (37), a step of moving the forklift and transporting the goods (38).

13. The method according to claim 12, wherein: The advancement of the forklift performed during the advancement step (34) has a constant value.

14. The method according to claim 13, wherein: The step (34) of advancing the forklift is continuously performed without stopping, and the detection device (10) successively activates the detection area (17a, 17b) and the extraction area (18) according to the constant advancement value of the forklift.

15. The method according to any one of claims 7 to 14, wherein: The predefined plane detection area is defined by four points defining a rectangle.

16. The method according to any one of claims 7 to 15, wherein: The step of detecting the goods is performed in the plane detection area common to the two arms (4a, 4b) of the front fork.

17. The method according to any one of claims 7 to 15, wherein: The step of detecting the goods is performed in two planar detection areas, each belonging to one of the two arms (4a, 4b) of the front fork.

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