Method for transporting and placing goods by means of automated forklift

Abstract

Such an automatic forklift (1) comprises:-a lifting member (2) which can be moved at least vertically,-a drive system (6) for moving the forklift,-a first non-contact detection device (9) which is fixed relative to the forklift and which can detect an obstacle located in front of the forklift, and-a control unit (8) which can control the forklift in accordance with information from the first detection device, and the movement of the lifting member (2) can be controlled. The forklift further comprises a second non-contact detection device (11), which is fixed with respect to the forklift (1), is arranged above the first detection device (9), and is capable of detecting an obstacle located in front of the forklift (1). The control unit (8) is capable of controlling the forklift truck (1) on the basis of information from the second non-contact detection device (11).

Description

Technical Field

[0001] The present invention relates to the field of autonomous vehicles for the 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, transport and position goods at height without human intervention.

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

[0005] In this work environment, personal safety is of paramount importance, so specific procedures need to be put in place.

[0006] For example, in order to limit the risk of collisions, automated forklifts are often equipped with devices for contactless detection of obstacles.

[0007] This non-contact detection device is fixed to the forklift and emits a beam pointing forward to detect the presence of obstacles in its detection field. When an obstacle is detected, the automated forklift will slow down or even make an emergency stop.

[0008] During the unloading phase, the forklift approaches the storage structure until it reaches the unloading position allowing the unloading operation. When the forklift approaches, the detection field of the non-contact detection device must be deactivated so that the structure is not detected and the unloading position is not hindered.

[0009] Therefore, there is a risk of pedestrians being crushed between the cargo carried by the forklift and the structure. Summary of the invention

[0010] Therefore, in view of the above situation, an object of the present invention is to propose an automatic forklift capable of improving the safety level of the operation of unloading cargo.

[0011] The present invention relates to an automatic forklift, comprising: a lifting member, which can be moved at least vertically and is equipped with at least two arms for lifting goods; a drive system, which is used to move the forklift; a first non-contact detection device, which is fixed relative to the forklift and can emit a first light beam with a main emission direction, which is horizontally oriented towards the front of the forklift to detect obstacles located in front of the forklift.

[0012] According to one general feature, the forklift further includes a control unit that can receive information indicating the presence of an obstacle from the first non-contact detection device, can control the operation of the drive system to automatically guide the forklift based on the information from the first non-contact detection device, and can control the movement of the lifting member.

[0013] According to another general feature, the forklift further comprises a second non-contact detection device, which is fixed relative to the forklift and arranged above the first non-contact detection device. The second non-contact detection device can emit a second light beam having a main emission direction, which is horizontally oriented toward the front of the forklift to detect obstacles located in front of the forklift.

[0014] According to another general feature, the control unit receives information indicating the presence of an obstacle from a second contactless detection device.

[0015] According to another general feature, the control unit may control the operation of the drive system based on information from the second non-contact detection device to automatically guide the forklift.

[0016] This autonomous forklift can ensure that the vehicle approaches the structure designed to receive the goods without the risk of pedestrians being crushed during the operation of unloading the goods.

[0017] Advantageously, the second non-contact detection device is fixed to the forklift at a constant height between 150 mm and 2000 mm relative to the ground. This is because the Applicant has observed that the risk of pedestrians being crushed increases as storage structures fall within this height range.

[0018] Advantageously, the second non-contact detection device is fixed to the forklift at a height between 300 mm and 1100 mm (preferably between 700 mm and 900 mm) relative to the ground. As an indication, the second non-contact detection device can be fixed to the forklift at a height equal to 830 mm relative to the ground. The automated forklift comprises an on-board locator device configured to acquire data related to the position of the forklift and to communicate with the control unit. Preferably, the first and second non-contact detection devices are different from the locator device.

[0019] According to a particular configuration, the light beam emitted by each of the first and second detection means sweeps over at least one predetermined planar detection area. The planar detection area may be defined by four different points defining a rectangle or by three different points defining a triangle. The first and / or second detection means may be provided with light beams having different planar shapes, such as circular, elliptical, etc.

[0020] In a first embodiment, the lifting member is equipped with a front fork which is vertically movable and comprises the two arms.

[0021] In this case, the second non-contact detection device may be offset relative to the two arms towards the rear of the forklift.

[0022] The front fork of the lifting member may further comprise at least two uprights, each upright carrying one of the two arms.The second non-contact detection device may then be offset relative to the uprights towards the rear of the forklift.

[0023] The two arms of the front fork can move between a highest position and a lowest position corresponding to the operating position. Preferably, the first non-contact detection device is fixed below the lowest position of the two arms.

[0024] In an alternative second embodiment, the lifting member is equipped with a clamp, which can be vertically movable, can be rotated and includes the two arms. In this case, the second non-contact detection device can be offset towards the rear of the forklift relative to the two arms.

[0025] According to another aspect, the present invention relates to a method for transporting and unloading cargo using an automated forklift as described above.

[0026] Transportation and unloading methods include:

[0027] - a step of positioning a forklift relative to a structure intended to carry goods in a close position relative to said structure, the first contactless detection means being active during the step of positioning the forklift,

[0028] - a step of raising the arm of the lifting member above the second contactless detection device when the forklift has reached the access position, and a step of deactivating the first contactless detection device,

[0029] - after the step of raising the arm of the lifting member of the forklift, a step of activating the second contactless detection means,

[0030] - after the step of activating the second detection device, if the second non-contact detection device does not detect an obstacle, the step of advancing the automated forklift to the unloading position,

[0031] - a step of deactivating the second contactless detection means after the automated forklift has reached the unloading position, and

[0032] - After or simultaneously with the step of deactivating the second contactless detection device, a step of lowering the arm of the lifting member of the forklift in order to unload the cargo to the unloading position.

[0033] This method of unloading improves the safety of operators working or who may be near the storage structure by being able to check that there are no operators between the automated forklift transporting the cargo to be unloaded and the storage structure when the forklift approaches the structure during the unloading operation.

[0034] Preferably, the step of deactivating the first contactless detection device is performed after the step of lifting the arm of the lifting member above the second light beam of the second contactless detection device when the forklift has reached the access position.

[0035] As an alternative, the step of deactivating the first non-contact detection device may be performed before the step of lifting the arm of the lifting member above the second light beam of the second non-contact detection device. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Other objects, features and advantages of the present invention will become apparent on reading the following description given by way of non-limiting example only and with reference to the accompanying drawings, in which:

[0037] [ Figure 1 ] is a perspective view of an automatic forklift according to a first exemplary embodiment of the present invention;

[0038] [ Figure 2 ]、[ Figure 3 ]、[ Figure 4 ]and[ Figure 5 ] schematically shows a method according to an embodiment of the present invention Figure 1 The use of forklifts in the method of transporting and unloading goods;

[0039] [ Figure 6 ] shows a flow chart of a method for transporting and unloading cargo according to one embodiment of the present invention; and

[0040] [ Figure 7 ] is a perspective view of an automatic forklift according to a second exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0041] Figure 1 The main elements of an automated forklift 1 according to one embodiment of the invention are depicted.

[0042] The structure of the forklift 1 is given by way of example and does not limit the invention to the solely presented structural configuration. It must be understood that the invention also relates to a forklift designed to operate in manual mode and which has been adapted to enable a second operating mode in automatic mode.

[0043] Figure 1The automatic forklift 1 shown comprises a lifting member 2, which comprises a carriage 3 and is equipped with a front fork 4, which comprises two arms 4a, 4b spaced laterally apart and extending towards the front of the forklift. The front fork 4 also comprises two uprights 4'a, 4'b, each upright carrying one of the arms 4a, 4b.

[0044] The arms 4a, 4b of the front fork are usually intended to be inserted into an entry opening provided in a transport pallet carrying the cargo to be lifted. The uprights 4'a, 4'b allow the arms 4a, 4b to be raised so that a pallet or some other type of cargo to be transported can be raised and the pallet or some other type of cargo can be positioned or collected at a high place.

[0045] The front fork 4 can translate along the vertical mast 5 of the forklift in a vertical plane V defined by the bracket 3. The uprights 4'a, 4'b can slide along the mast 5. The arms 4a, 4b of the front fork can be moved in a vertical plane V defined by the bracket 3. Figure 1 and Figure 2 4a, 4b is located at a certain distance from the ground.

[0046] 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 preferably also movable transversely relative to each other.

[0047] As a variant, the arms of the front fork 4 may also be telescopic or retractable and / or be capable of being angularly oriented about its longitudinal axis.

[0048] As is known, the forklift 1 is equipped with a drive system 6 capable of moving the forklift 1. The drive system comprises at least one electric motor or internal combustion engine (not shown) providing drive to the wheels of the forklift 1.

[0049] The forklift 1 is also equipped with an onboard locator device 7 and an onboard control unit 8 ( Figure 2 ) to automatically control the movement of the forklift.

[0050] The control unit 8 comprises hardware and software for controlling the operation of the drive system 6 based on information received from the positioner device 7. The control unit 8 may also control automatic movement of the lifting member 2.

[0051] The forklift 1 is equipped with a first non-contact detection device 9, which is fixed to the forklift 1 and cannot move relative to the forklift. The non-contact detection device 9 is fixed at a constant height relative to the ground. The non-contact detection device 9 is located below the lowest position of the arms 4a, 4b of the lifting member 2. The non-contact detection device 9 is fixed to the forklift 1. The non-contact detection device 9 is fixed to the forklift 1 and cannot move relative to the forklift in translation. The non-contact detection device 9 is located below the mast 5 and is offset towards the rear of the forklift relative to the arms 4a, 4b and relative to the columns 4'a, 4'b.

[0052] The forklift 1 is further equipped with a second non-contact detection device 11, which is also fixed to the forklift 1. The non-contact detection device 11 is fixed to the forklift 1 and cannot move relatively in translation relative to the forklift. The non-contact detection device 11 is fixed at a constant height relative to the ground. The non-contact detection device 11 is arranged above the non-contact detection device 9. The non-contact detection devices 9, 11 form a lower detection device and an upper detection device, respectively. The detection devices 9, 11 are different from each other. The detection devices 9, 11 are also different from the locator device 7. The detection devices 9, 11 can be, for example, lidar laser sensors.

[0053] The non-contact detection device 11 is located above the lowest position of the arms 4a, 4b of the lifting member 2. The non-contact detection device 11 is fixed to the mast 5. The non-contact detection device 11 is offset towards the rear of the forklift relative to the arms 4a, 4b and relative to the uprights 4'a, 4'b.

[0054] The second non-contact detection device 11 is arranged at a constant height relative to the ground, which may be, for example, between 150 mm and 2000 mm, preferably between 300 mm and 1100 mm, even more preferably between 700 mm and 900 mm. The second non-contact detection device 11 may be arranged, for example, at a height equal to 830 mm.

[0055] As will be described in more detail below, the detection devices 9, 11 may each emit a light beam having a main emission direction which is oriented horizontally towards the front of the forklift 1 in order to detect obstacles located in front of the forklift. The light beams emitted by the detection devices 9, 11 are different.

[0056] The detection devices 9, 11 are configured to acquire data related to the presence of an obstacle and to send information indicating that the presence of an obstacle is detected in at least one predefined detection area to the control unit 8. Based on the received information, the control unit 8 then controls the operation of the drive system 6 and the vertical movement of the lifting member 2. The control unit 8 can also control the activation state or deactivation state of each of the detection devices 9, 11.

[0057] Reference Figures 2 to 5 The operating principle of the automatic forklift 1 for unloading cargo 12 onto the structure 13 will now be described as well as Figure 6 The related uninstallation method 20 is shown.

[0058] The method 20 starts with a step 21 of positioning the forklift 1 in a predefined access position relative to a structure 13 intended to carry cargo.

[0059] In this initial phase, the control unit 8 controls the operation of the forklift 1 based on the data from the locator device 7 and the information from the detection device 9, so as to bring it closer to the structure 13. This locating step 21 is performed in the activated state of the first non-contact detection device 9, which emits a first light beam 10 oriented horizontally towards the front of the forklift 1. If the detection device 9 detects the presence of an obstacle located in front of the forklift 1, the control unit 8 controls the forklift 1 to make an emergency stop and puts the forklift 1 in a standby state so that the operator can re-establish correct operation (step 21').

[0060] On the contrary, if the first non-contact detection device 9 does not detect any obstacle, the control unit 8 continues to move the forklift 1 forward until it reaches the approach position.

[0061] When the forklift 1 reaches the access position, the method 20 continues with step 22 of lifting the arms and step 23 of deactivating the contactless detection device 9. To this end, the control unit 8 issues a command to deactivate the contactless detection device 9 and to lift the arms 4a, 4b.

[0062] In step 22, the movement of the arm is controlled by the control unit 8 so that it is located above the non-contact detection device 11, such as Figure 3 shown.

[0063] Preferably, the step 23 of deactivating the contactless detection means 9 is performed after the step 22 of lifting the arms 4a, 4b of the lifting member. Alternatively, the deactivation step 23 may be performed before or simultaneously with the step 22 of lifting the arms.

[0064] The method 20 continues with a step 24 of activating the contactless detection device 11. To this end, the control unit 8 issues a command to activate the contactless detection device 11, which then emits a second light beam 14 ( Figure 3 ). The light beam 14 is located below the arms 4a, 4b of the lifting member. Figure 3 In FIG. 1 , the light beam 14 is located above the structure 13 .

[0065] After step 24 of activating the detection device 11 , the method 20 continues with step 25 of advancing the forklift 1 to a predetermined unloading position.

[0066] If the non-contact detection device 11 detects an obstacle, the control unit 8 controls the forklift 1 to perform an emergency stop and puts the forklift 1 into a standby state so that the operator can re-establish correct operation (step 25').

[0067] On the contrary, if the second non-contact detection device 11 does not detect any obstacle, the control unit 8 continues to move the forklift 1 forward until it reaches the predetermined unloading position.

[0068] When the forklift 1 reaches the unloading position, the method 20 continues with step 26 of deactivating the contactless detection device 11. To this end, the control unit 8 issues a command to deactivate the contactless detection device 11.

[0069] The method 20 continues with step 27 of lowering the arms 4a, 4b of the lifting member to unload the cargo to the unloading position. Step 27 may be performed after step 26 of deactivating the contactless detection device 11 or simultaneously with this step.

[0070] In this step 27, the control unit 8 controls the lowering of the arms 4a, 4b of the lifting member until the load 12 is placed in contact with the portion of the structure 13 intended to receive it. The control unit 8 then continues to lower the arms 4a, 4b, producing a relative vertical movement between the arms 4a, 4b and the load 12, which means that the load is no longer in contact with the arms 4a, 4b and rests completely on the structure 13.

[0071] In the exemplary embodiment described, the lifting member of the forklift is equipped with a front fork which is vertically movable and is equipped with two arms 4a, 4b.

[0072] If the forklift is equipped with a clamp 30 instead of the front fork 4, as Figure 7 The forklift clamp 30 is vertically movable along the mast 5, is rotatable about a horizontal axis 31 and is equipped with two arms 32 that can grip the load to be unloaded. Figure 7 Only one of the two arms is visible.

[0073] As is known, the clamp 30 is equipped with a slide 33 that can slide along the mast 5 and carries the arm 32. The arm 32 of the clamp can move between a highest position and a lowest position corresponding to the operating position. In the lowest position, the arm 32 is located at a certain distance from the ground.

[0074] In this case, the positioning of the detection means 9, 11 is similar to that described above.

[0075] The non-contact detection device 9 is fixed to the forklift 1 in a similar manner to the first exemplary embodiment. The non-contact detection device 9 is located below the lowest operating position of the arm 32 of the clamp. The non-contact detection device 9 is located below the mast 5 and is offset toward the rear of the forklift relative to the arm 32 and relative to the slide 33.

[0076] The non-contact detection device 11 is also fixed to the forklift 1 in a similar manner to the first exemplary embodiment. The non-contact detection device 11 is arranged above the non-contact detection device 9. The non-contact detection device 11 is located above the lowest operating position of the arm 32 of the clamp. The non-contact detection device 11 is fixed to the mast 5. The non-contact detection device 11 is offset toward the rear of the forklift relative to the arm 32 of the clamp and relative to the slide 33.

Claims

1. A method (20) for transporting and unloading cargo (12) using an automated forklift (1), comprising: - a lifting member (2) which is at least vertically movable and is equipped with at least two arms (4a, 4b) for lifting goods; 32)， - a drive system (6) for moving the forklift (1), a first contactless detection device (9) fixed relative to the forklift and capable of emitting a first light beam (10) having a main emission direction oriented horizontally towards the front of the forklift in order to detect obstacles located in front of the forklift, a control unit (8) capable of receiving information indicating the presence of an obstacle from the first non-contact detection device (9), capable of controlling the operation of the drive system (6) to automatically guide the forklift based on the information from the first non-contact detection device (9), and capable of controlling the movement of the lifting member, and a second non-contact detection device (11), which is fixed relative to the forklift (1) and arranged above the first non-contact detection device (9), The method is characterized in that the method comprises the following steps: - a step (21) of positioning the forklift (1) relative to a structure (13) intended to carry goods in a close position relative to said structure, the first contactless detection device (9) being active during the step of positioning the forklift (1), - when the forklift (1) reaches the access position, a step (22) of raising the arms (4a, 4b) of the lifting member (2) above the second non-contact detection device (11), and a step (23) of deactivating the first non-contact detection device (9), - after a step (22) of lifting the arms (4a, 4b) of the lifting member (2) of the forklift (1), a step (24) of activating the second contactless detection device (11), - after the step (24) of activating the second non-contact detection device (11), if the second non-contact detection device (11) does not detect an obstacle, a step (25) of advancing the automatic forklift (1) to the unloading position, - a step (26) of deactivating the second contactless detection device (11) after the automated forklift (1) has reached the unloading position, and - After or simultaneously with the step (26) of deactivating the second contactless detection device (11), a step (27) of lowering the arms (4a, 4b) of the lifting member (2) of the forklift (1) in order to unload the cargo to the unloading position.

2. The method according to claim 1, wherein: When the forklift (1) has reached the approach position, after a step (22) of lifting the arm (4a, 4b) of the lifting member (2) above the second light beam (14) of the second non-contact detection device (11), a step (23) of deactivating the first non-contact detection device (9) is performed.

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