JP2022137662A - Cargo handling vehicle and determination program - Google Patents

Abstract

To enhance work efficiency of cargo handling operation.SOLUTION: A fork lift 1 comprises: a vehicle body 11 capable of traveling; a fork 12 provided on the vehicle body 11 in an elevating/lowering manner, and holding a pallet 30; a distance sensor 24 capable of acquiring depth information of a prescribed floor surface area R at a front side of a vehicle body; and a control part 27. The control part 27 determines whether or not the pallet 30 can be placed in a pallet ground contact area GA at the front side of the vehicle body on the basis of the depth information of the floor surface area R acquired by the distance sensor 24.SELECTED DRAWING: Figure 3

Description

The present invention relates to a cargo handling vehicle and a determination program.

Conventionally, in a cargo handling operation using a cargo handling vehicle such as a forklift, a driver visually confirms whether or not a pallet (load) can be placed on the floor surface (ground) in front of the vehicle. In particular, when temporarily placing a pallet in a place where the cargo is not originally placed, it is necessary to check the place carefully.
However, for example, when a large load is loaded on the forks, the driver's line of sight is blocked, making it difficult to visually recognize the floor surface and the cargo bed surface in front. In such a case, it becomes necessary for the driver to confirm the state of the place in advance before entering the place, which reduces work efficiency.

In response to such a problem, for example, a technology has been proposed to prevent the load from collapsing by maintaining the horizontality of the load in consideration of the inclination of the vehicle body when placing the load (see, for example, Patent Document 1). No technique has been proposed for evaluating the soundness of a place where a load is placed to improve work efficiency.

Japanese Patent No. 5921183

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the working efficiency of cargo handling work.

The cargo handling vehicle according to the present invention is
a drivable vehicle; and
a fork that is provided on the vehicle body so as to be able to move up and down and holds a pallet;
a measuring means capable of acquiring depth information of a predetermined surface area in front of the vehicle body;
determination means for determining whether or not the pallet can be placed on the pallet contact area in front of the vehicle body based on the depth information of the surface area acquired by the measurement means;
It was configured to include

A determination program according to the present invention is
A computer for a cargo handling vehicle comprising a vehicle body that can travel, a fork that is provided on the vehicle body so that it can be raised and lowered to hold a pallet, and a measuring means capable of acquiring depth information of a predetermined surface area in front of the vehicle body,
Determination means for determining whether or not the pallet can be placed on the pallet contact area in front of the vehicle body based on the depth information of the surface area acquired by the measurement means;
It was assumed to function as

ADVANTAGE OF THE INVENTION According to this invention, the work efficiency of cargo handling work can be improved.

1 is a side view showing the appearance of a forklift according to an embodiment; FIG. 1 is a block diagram showing a schematic control configuration of a forklift according to an embodiment; FIG. 7 is a flow chart showing the flow of flat placement propriety determination processing according to the embodiment. FIG. 10 is a diagram for explaining flat placement propriety determination processing according to the embodiment; FIG. 10 is a diagram for explaining flat placement propriety determination processing according to the embodiment; It is a figure for demonstrating the other example of the distance sensor which concerns on embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Forklift configuration]
FIG. 1 is a side view showing the appearance of a forklift 1 according to this embodiment.
A forklift 1 according to this embodiment is an example of a cargo handling vehicle according to the present invention, and includes a vehicle body 11 , forks 12 , an elevating body (lift) 13 , a mast 14 and wheels 15 . The mast 14 is provided in front of the vehicle body 11 and is driven by a drive source (not shown) to tilt forward and backward relative to the vehicle body 11 . The elevating body 13 is driven by a drive source (not shown) and ascends and descends along the mast 14 . A pair of left and right forks 12 for holding a load L, a pallet 30, and the like are attached to the lifting body 13 . The pair of forks 12 can be tilted and lifted with respect to the vehicle body 11 by driving the mast 14 and the lifting body 13 .
The pallet 30 is a receiving table on which the load L is placed. The pallet 30 is shaped like a short rectangular plate and has two holes (fork pockets) 32 into which the pair of forks 12 are inserted.

FIG. 2 is a block diagram showing a schematic control configuration of the forklift 1. As shown in FIG.
As shown in this figure, in addition to the above configuration, the forklift 1 includes a drive unit 21, an operation unit 22, a display unit 23, a distance sensor 24, an inertial measurement unit (IMU) 25, a storage unit 26, and a control unit. 27.

The drive unit 21 includes a travel motor, a steering motor, and a cargo handling motor (all of which are not shown), which are various drive sources of the forklift 1 . The travel motor drives drive wheels of the wheels 15 . The steering motor rotates (steers) the steered wheels of the wheels 15 . The cargo-handling motor is a driving source for raising and lowering the lifting body 13 and tilting the mast 14 .

The operation unit 22 is operation means for the driver to perform various operations. The operation unit 22 includes, for example, a handle, a pedal, a lever, various buttons, and the like, and outputs an operation signal to the control unit 27 according to the content of these operations.
The display unit 23 is, for example, a liquid crystal display, an organic electroluminescence display, or another display, and displays various information based on display signals input from the control unit 27 . Note that the display unit 23 may be a touch panel that also serves as a part of the operation unit 22 .

The distance sensor 24 can acquire distance information (depth information) of a predetermined surface area (floor surface area R described later) in front of the vehicle body, and outputs the acquired information to the control unit 27 . The distance sensor 24 is an example of measuring means according to the present invention, and is a TOF sensor (depth sensor) capable of acquiring three-dimensional information including depth information in this embodiment.
The distance sensor 24 of the present embodiment is installed in the front portion of the vehicle body 11 and in the center portion in the width direction, facing forward and obliquely downward, and measures the floor area R in front of the vehicle body (FIGS. 1 and 4A). reference).

The inertial measurement device 25 measures the three-dimensional acceleration and angular velocity of the forklift 1 and outputs the results to the controller 27 . However, the inertial measurement device 25 of this embodiment only needs to be able to detect at least the vertical direction (gravitational direction).

The storage unit 26 is a memory configured by RAM (Random Access Memory), ROM (Read Only Memory), etc., stores various programs and data, and also functions as a work area for the control unit 27 . The storage unit 26 of the present embodiment stores in advance a flat placement propriety determination program 260 for executing a flat placement propriety determination process (see FIG. 3), which will be described later.
The control section 27 controls the operation of each section of the forklift 1 . Specifically, the control unit 27 operates the driving unit 21 based on the operation content of the operation unit 22, develops a program stored in advance in the storage unit 26, and cooperates with the developed program to perform various operations. perform processing. In addition, the control unit 27 can acquire information (other than those described above) regarding the vehicle state such as the traveling distance, speed, position, etc. of the forklift 1 by means of sensors (not shown).

[Flat placement propriety determination process]
Next, the operation of the forklift 1 during cargo handling when executing the flat placement permission/inhibition determination process will be described.
FIG. 3 is a flow chart showing the flow of flat placement propriety determination processing, and FIGS. 4 and 5 are diagrams for explaining the flat placement propriety determination processing.

The horizontal placement propriety determination process is a process in which the forklift 1 determines whether or not the pallet 30 can be laid flat on the floor and notifies the worker (driver). This horizontal placement permission/inhibition determination process is executed by the control unit 27 of the forklift 1 reading out the horizontal placement permission/inhibition determination program 260 from the storage unit 26 and developing it.

As shown in FIG. 3, when the horizontal placement propriety determination process is executed, the control unit 27 first sets the pallet grounding area GA (step S1).
The pallet grounding area GA is the grounding position (relative position to the forklift 1) and grounding range when the pallet 30 held by the forks 12 is lowered and placed on the floor (Fig. 4(b) reference). The pallet grounding area GA is a position and its range on a plane in this embodiment, but may be a three-dimensional position and its range. The “plane” in this case is a horizontal plane in this embodiment, but may be a plane parallel to the ground surface of the forklift 1 as will be described later.

In this step S1, the control unit 27 acquires the shape information of the pallet 30 based on the user's operation, and obtains and sets the position and range (size) of the pallet grounding area GA based on the shape information. The pallet grounding area GA is set as an area slightly larger than the area where the pallet 30 actually grounds. In acquiring the shape information of the pallet 30, the user may input the necessary related dimensions (dimensions related to grounding) of the pallet 30, or may directly input the position and range of the pallet grounding area GA. Of these, the input of the related dimensions of the pallet 30 by the user may be replaced with the input of the type of pallet to be used. In that case, the related dimensions of the type corresponding to the pallet type may be read from the pallet shape database. . The pallet shape database may be stored in the storage unit 26 (or a terminal or the like with which the forklift 1 can communicate).
It should be noted that the setting of the pallet grounding area GA in this step may be performed in advance before execution of the flat placement propriety determination process.

Next, when the forklift 1 is started to travel by the user's operation (step S2), the control unit 27 starts measuring the floor surface in front of the vehicle body by the distance sensor 24 (step S3). Here, it is assumed that the forklift 1 is traveling with the pallet 30 held by the forks 12 (the forks 12 are inserted into the holes 32 and lifted).
In this step S3, as shown in FIG. 4A, the distance sensor 24 measures the floor area R in front of the vehicle body. Since the field of view of the distance sensor 24 widens as the distance increases, the floor area R measured by the distance sensor 24 has a substantially trapezoidal shape.
Since this measurement is performed while the forklift 1 is traveling, the measurement data of a plurality of floor areas R along the traveling direction are continuously (or intermittently) obtained. The acquired measurement data is stored in the storage unit 26 .

Next, the control unit 27 generates three-dimensional point cloud data from the measurement data acquired in step S3 (step S4). That is, here, three-dimensional point cloud data included in the floor area R measured in step S3 is extracted as depth information.

Next, the control unit 27 extracts point cloud data of the pallet grounding area GA (step S5).
In this step, as shown in FIG. 4B, the control unit 27 generates point cloud data for a plurality of (four in the example of FIG. 4) floor areas R that include the pallet grounding area GA in plan view. is accumulated (integrated). A plurality of floor areas R are areas that are continuously (or intermittently) measured as the forklift 1 travels, and each point cloud data is acquired by performing the processing of steps S3 and S4 for each. be done.
Further, the control unit 27 causes the storage unit 26 to store the obtained point cloud data of the pallet grounding area GA. At this time, measurement data including point group data other than the pallet grounding area GA may be erased. Thereby, the amount of memory used in the storage unit 26 can be suppressed.
Note that the integration interval P and the total integration amount S when integrating the point cloud data of a plurality of floor areas R are set so as to properly include the pallet ground area GA (for example, the minimum ), and is preferably changed and adjusted as appropriate according to the travel speed (travel distance) of the forklift 1 . As a result, for example, useless memory usage due to acquiring a large amount of data at a short integration interval P at low speed can be suppressed.

Next, based on the point cloud data of the pallet grounding area GA, the control unit 27 calculates the inclination angle (tilt degree) and flatness of the pallet grounding area GA (step S6).
In this step, the control unit 27 first obtains a representative plane TP of the pallet contact area GA by fitting a plane to the point group data of the pallet contact area GA extracted in step S5. Then, as shown in FIG. 5A, the control unit 27 calculates the inclination angle θ of the representative plane TP from the ideal plane (horizontal plane H in this embodiment). As for the direction of the horizontal plane H, the direction of gravity may be obtained from the inertial measurement device 25 . In addition, as shown in FIG. 5(b), the control unit 27 calculates the flatness of the representative plane TP as the maximum value (or the average value or the like) of variations in the measurement data from the representative plane TP.

Next, the control unit 27 determines whether both the inclination angle θ and the flatness of the pallet grounding area GA are within a predetermined normal range (step S7). (step S7; Yes), the process proceeds to step S9, which will be described later. That is, in this step S7, it is determined whether or not the pallet 30 can be placed on the pallet grounding area GA.
Each normal range of the inclination angle θ and the flatness is preset and stored in the storage unit 26 . This normal range may correspond to the shape, area, etc. of the ground surface of the pallet 30 .
The operator (driver) may be notified that the determination result is within the normal range.

If it is determined in step S7 that at least one of the inclination angle θ and the flatness of the pallet grounding area GA is not within the normal range (step S7; No), that is, if it is determined that the pallet 30 cannot be placed on the pallet grounding area GA, The control unit 27 notifies the driver of the determination result (step S8).
The notification mode in this case is not particularly limited, and a warning may be displayed on the display unit 23, or a warning sound may be output from a speaker (not shown). At this time, the inclination angle θ and the flatness of the pallet grounding area GA illustrated in FIG. , and these may be combined as appropriate.

Next, the control unit 27 determines whether or not to end the flat placement permission/inhibition determination process (step S9), and when it is determined not to end (step S9; No), the process proceeds to step S3 described above. to continue measuring.
Then, when it is determined that the horizontal placement permission/inhibition determination process should be terminated due to, for example, the end of cargo handling work (step S9; Yes), the control section 27 terminates the horizontal placement determination process.

As described above, in the horizontal placement propriety determination processing of the present embodiment, by measuring the floor surface with the distance sensor 24 while the forklift 1 is running, it is determined at any time whether the pallet can be laid flat in the pallet grounding area GA at that time. be.
The data such as the determination results regarding the passed pallet grounding area GA may be erased from the storage unit 26, or the determination results may be associated with the position information and accumulated so that they can be reused.

[Technical effect of the present embodiment]
As described above, according to the present embodiment, based on the depth information of the floor area R acquired by the distance sensor 24, it is determined whether or not the pallet 30 can be placed on the pallet contact area GA in front of the vehicle body.
As a result, it is automatically determined whether or not the pallet 30 can be grounded to the pallet grounding area GA, unlike the conventional system in which the driver visually confirms the location of the pallet. Therefore, it is possible to improve the working efficiency of the cargo handling work as compared with the conventional art. As a result, it is possible to prevent the load from collapsing or collapsing, and the cargo handling work can be carried out safely.

Further, according to the present embodiment, the pallet contact area GA is an area included in the range of a plurality of floor surface areas R continuously or intermittently acquired by the distance sensor 24 while the forklift 1 is traveling. The depth information of the floor area R is integrated to obtain the depth information of the pallet grounding area GA.
As a result, even the distance sensor 24 that has a relatively narrow viewing angle and cannot capture the pallet grounding area GA within the viewing angle at once can be preferably used.

Further, according to the present embodiment, when acquiring the depth information of the pallet grounding area GA by integrating the depth information of the plurality of floor areas R, the integration interval P and the total integration amount S correspond to the speed of the forklift 1. is changed (adjusted) by
As a result, the depth information of the pallet grounding area GA can be preferably acquired while suppressing unnecessary memory usage of the storage unit 26 .

Further, according to the present embodiment, when it is determined that the pallet cannot be placed on the pallet grounding area GA, the determination result is notified to the driver. As a result, the driver can be quickly notified of the situation.
Further, according to this embodiment, when it is determined that the pallet cannot be placed on the pallet grounding area GA, the lowering motion of the forks 12 is restricted. As a result, it is possible to more reliably prevent the pallet 30 from being accidentally placed on the pallet grounding area GA.

[others]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments (including modifications).
For example, in the above embodiment, a TOF sensor (area sensor) is used as the distance sensor 24 . However, the distance sensor 24 may be any sensor that can acquire distance information (depth information) of a predetermined surface area in front of the vehicle body. For example, as shown in FIG. Ra) (for example, two-dimensional LiDAR (LASER Imaging Detection and Ranging)).
In this case, unlike the above embodiment, the measurement area of the distance sensor 24 is the line area Ra. However, as shown in FIG. Depth information of the contact area GA can be obtained.

Further, in the horizontal placement propriety determination process of the above embodiment, the inclination angle and flatness of (the representative plane TP of) the pallet grounding area GA are obtained and evaluated/determined in steps S6 and S7. However, instead of this determination method, the dispersion of the point cloud data of the pallet grounding area GA from the ideal plane may be evaluated without determining the inclination angle and flatness.
In the above embodiment, the ideal plane, which is the criterion for determining the inclination angle, is the horizontal plane. In this case, the inclination (orientation) of the forklift 1 may be obtained from the inertia measurement device 25 . As a result, it is possible to cope with the case where the pallet 30 is placed on an inclined surface such as a slope.

Further, in the horizontal placement propriety determination processing of the above embodiment, the processing of steps S3 to S9 is repeated while the forklift 1 is running. It may be performed only when a trigger is detected. This execution trigger may be, for example, an input operation by the driver, or may be a stop of the forklift 1, an up/down operation of the fork 12, a tilt operation, or the like.

Also, the distance sensor 24 may capture the pallet grounding area GA within its viewing angle (that is, the pallet grounding area GA is included in one floor surface area R). In this case, the point cloud data of the floor region R need not be integrated.
Moreover, in the above-described embodiment, the case where the measurement data of the plurality of floor surface regions R to be integrated is obtained while the forklift 1 is traveling straight is exemplified. However, even when the forklift 1 is traveling other than going straight (for example, turning right or left, going backwards, or turning), the relative positions of the plurality of floor areas R are acquired from the inertial measurement device 25, and the pallet contact area GA is included. Integrate so that

Further, the place (height) where the forklift 1 places the pallet 30 is not limited to the floor surface (ground), and may be a high (or low) position such as a shelf. However, in this case, it is necessary to provide the distance sensor 24 at a high position (or provide it on the lifting body 13 so that it can move up and down) so that this high (or low) position can be measured.
In addition, the cargo handling vehicle according to the present invention is not limited to a forklift as long as it can travel while holding a load with a fork. (including forklifts)) and the like.
Moreover, the cargo handling vehicle according to the present invention may directly hold the cargo with the forks without using the pallet.

Further, the pallet according to the present invention broadly includes a load-receiving table on which a load is placed and which is held by a fork (for example, a gridiron). In this case, the pallet grounding area may include only the grounding portion.
In addition, the details shown in the above embodiments can be changed as appropriate without departing from the scope of the invention.

1 Forklift (cargo handling vehicle)
11 vehicle body 12 fork 23 display unit (informing means)
24 distance sensor (measuring means)
25 Inertial measurement device 26 Storage unit 27 Control unit (judgment means, notification means, regulation means)
30 pallet 32 hole 260 flat placement propriety determination program (determination program)
L Load R Floor area (surface area)
Ra Line area P Integration interval S Total integration amount GA Pallet contact area TP Representative plane H Horizontal plane θ Tilt angle

Claims (8)

a drivable vehicle; and
a fork that is provided on the vehicle body so as to be able to move up and down and holds a pallet;
a measuring means capable of acquiring depth information of a predetermined surface area in front of the vehicle body;
determination means for determining whether or not the pallet can be placed on the pallet contact area in front of the vehicle body based on the depth information of the surface area acquired by the measurement means;
cargo handling vehicle. The depth information is distance information from the measuring means in the surface area,
A cargo handling vehicle according to claim 1 . The determination means is
calculating the degree of inclination and the degree of flatness of the pallet contact area based on the depth information of the surface area;
Determining whether the pallet can be placed on the pallet grounding area based on the degree of inclination and flatness of the pallet grounding area;
A cargo handling vehicle according to claim 1 or claim 2. The pallet contact area is included in the range of a plurality of surface areas continuously or intermittently acquired by the measuring means while the cargo handling vehicle is traveling,
The determining means acquires depth information of the pallet grounding area by integrating depth information of the plurality of surface areas.
A cargo handling vehicle according to any one of claims 1 to 3. When the depth information of the pallet contact area is acquired by integrating the depth information of the plurality of surface areas, the determination means changes the integration interval and the total integration amount according to the speed of the cargo handling vehicle.
The cargo handling vehicle according to claim 4. Informing means for informing a driver of the judgment result when the judging means judges that the pallet cannot be placed on the pallet grounding area,
A cargo handling vehicle according to any one of claims 1 to 5. a restricting means for restricting the lowering operation of the fork when the determining means determines that the pallet cannot be placed on the pallet grounding area;
A cargo handling vehicle according to any one of claims 1 to 6. A computer for a cargo handling vehicle comprising a vehicle body that can travel, a fork that is provided on the vehicle body so that it can be raised and lowered to hold a pallet, and a measuring means capable of acquiring depth information of a predetermined surface area in front of the vehicle body,
Determination means for determining whether or not the pallet can be placed on the pallet contact area in front of the vehicle body based on the depth information of the surface area acquired by the measurement means;
Judgment program that functions as

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