JP7166051B2 - automated guided vehicle - Google Patents

Description

The present disclosure relates to automated guided vehicles.

2. Description of the Related Art Conventionally, automated guided vehicles (AGVs) are known that are used to transport heavy objects in factories and distribution warehouses that produce industrial products.

For example, Patent Literature 1 describes a trackless automatic guided vehicle that travels along a predetermined travel route, and imaging means for imaging a plurality of optical marks regularly arranged along the travel route. a running position detecting means for detecting the current running position of the vehicle body based on the positional relationship between each optical mark included in the image captured by the imaging means and the reference optical mark; An unmanned guided vehicle is disclosed that includes travel control means for performing travel control of a vehicle body based on an optical mark whose positional relationship is determined with respect to the optical mark.

Japanese Patent Application Laid-Open No. 2008-210416

By the way, even in the field of agriculture, where farms and facility horticulture farms (hereinafter referred to as farms) are the work stages, the use of automatic guided vehicles is desired because there are many opportunities to transport heavy objects, but they are still not widespread due to the following reasons. It's hard to say. In other words, many cultivation benches are often arranged side by side in order to increase the yield per unit area in farms, etc. However, it is costly and undesirable to attach an expensive guide line such as a magnetic tape, which is commonly used in the above industrial field, to the entire route.
In this respect, the automatic guided vehicle described in Patent Document 1 adopts an optical guidance system that does not rely on magnetic tape, but is mainly intended for use in facilities such as clean rooms, and is placed on the floor. It is configured to detect the vent as a plurality of optical marks. Therefore, it cannot be said to be suitable for use in farms and the like where there are no regularly arranged optical marks such as vents. In addition, Patent Document 1 describes detection of the position of an automatic guided vehicle, but does not disclose any guidance method or the like when the automatic guided vehicle turns.

In view of the above problems, it is an object of at least one embodiment of the present invention to realize an unmanned guided vehicle that can travel over a wide range at low cost.

(1) An automatic guided vehicle according to at least one embodiment of the present invention,
An automatic guided vehicle capable of moving along a guide line including a first line along the direction of travel and a second line intersecting the first line,
a vehicle body;
at least two wheels rotatably mounted on the vehicle body;
at least one drive for applying rotational force to at least two of said wheels;
at least one imaging device for obtaining a first image of a road surface below the front portion of the vehicle body and a second image of a road surface below the rear portion of the vehicle body;
a control unit that controls the driving unit to guide the vehicle body along the first line based on the first line included in the first image;
a detection unit mounted on a lower portion of the vehicle body for detecting a mark arranged at an intersection of the first line and the second line and transmitting a detection signal to the control unit;
with
Based on the detection signal, the control unit controls the driving unit so as to start a turning operation for turning the vehicle body from a state along the first line to a state along the second line, and controls the second driving unit. The drive unit is configured to end the turning motion based on a determination result that the second line is included in a determination region that is at least a partial region within an image.

According to the above configuration (1), the vehicle body can be guided using the optical guidance method based on the first image obtained by imaging the road surface at least in the lower front portion of the vehicle body. As a result, without the need for expensive infrastructure equipment such as magnetic tape, guided driving can be achieved with a simple configuration that uses inexpensive tape, paint, etc. to draw identifiable guidance lines in optically acquired images. Therefore, an automatic guided vehicle that can travel over a wide range can be realized at low cost.
In addition, if the road surface is slippery, for example, using an encoder or the like to determine the position, orientation, and attitude of the vehicle body from the number of rotations of the wheels will cause errors due to slippage, resulting in low accuracy. According to the configuration of 1), even if the wheel slips due to falling objects, rain, dew, etc. on the road surface, the mark arranged at the intersection of the first line and the second line is detected by the detector, the turning motion can be started. In addition, since the completion of the turning operation can be reliably grasped in real time by the presence or absence of the second line in the second image, it is possible to reliably determine whether or not the vehicle body has completely turned. Furthermore, it is possible to reduce the convergence time required from the start of turning to the completion of turning by suppressing insufficient turning and excessive turning as much as possible.
In this specification, the "front part/rear part" of the vehicle body refers to the parts of the vehicle body that are on the front side/rear side in the traveling direction of the center of the vehicle body in the front-rear direction.
In addition, the "first line" and the "second line" refer to lines extending in the front-rear direction and in the left-right direction crossing the vehicle body, respectively, and are included in the image acquired by the imaging device. In this case, when the upper part of the screen is the direction of travel, the lines along the top and bottom are called the first lines, and the lines in the left and right directions intersecting with the first lines are called the second lines.
Further, the direction "along the second line" may be either left or right direction suitable for reaching the preset target position.

(2) In some embodiments, in the configuration described in (1) above,
The at least one imaging device comprises:
a first imaging device that is arranged in front of the turning center of the turning motion and acquires the first image;
A second imaging device that is arranged at a rear portion of the vehicle body relative to the turning center and acquires the second image may be included.

With configuration (2) above, the first image and the second image can be captured by separate imaging devices. Thereby, each image can be acquired by imaging from directly above the road surface on which the vehicle is traveling, for example. That is, since the images of the road surface on which the front and rear parts of the vehicle body are traveling can be clearly captured from a short distance while suppressing the influence of shadows, the image quality of the first image and the second image can be improved. can. Therefore, the reliability and stability of guided travel along the guide line can be improved.
Furthermore, by providing the second image pickup device, for example, if the control unit is configured to guide the vehicle body along the guide line included in the second image, the vehicle can move forward in the traveling direction (reversing direction) when reversing. The vehicle body can be guided based on the second image corresponding to the image of the subordinates.

(3) In some embodiments, in the configuration described in (2) above,
The control unit performs the turning based on the second line included in the image acquired by the imaging device arranged at a position farther from the center of turning than the first imaging device and the second imaging device. It may be configured to determine the end of the operation.

According to the above configuration (3), the control unit determines whether or not the turning motion is completed based on the image acquired by the imaging device arranged at a position farther from the turning center. It is possible to improve the determination accuracy of the determination of the end of turning compared to the case of determining the end of turning based on an image acquired by an imaging device arranged at a position close to. Therefore, the orientation of the vehicle body after the end of turning can be matched with high accuracy by the second line, which is the traveling direction after that, so that the reliability of guided travel can be improved.

(4) In some embodiments, in the configuration described in any one of (1) to (3) above,
The control unit terminates the turning operation when at least part of the second line included in the second image overlaps a center line of the second image along the longitudinal direction of the vehicle body in the second image. may be configured to determine the

According to the above configuration (4), the direction of travel after turning can be more aligned with the second line, so that the turning accuracy can be improved. Further, for example, if the control unit is configured to determine that the turning is completed when the center line in the width direction of the second line and the center line of the second image overlap, the turning accuracy can be further improved. .

(5) In some embodiments, in the configuration described in any one of (1) to (4) above,
The control section may be configured to control the drive section so as to perform the turning motion such that a turning center of the turning motion overlaps an intersection point between the first line and the second line. .

According to the configuration (5) above, since the vehicle body performs the turning motion so that the center of turning overlaps the intersection of the first line and the second line, the direction of movement becomes larger from the first line to the second line. The vehicle body can be turned so as to reliably follow the guide line at the changed right and left turn points. Therefore, even in a narrow passage in which a large number of cultivation benches are arranged side by side, the automatic guided vehicle can be accurately guided and traveled.

(6) In some embodiments, in the configuration described in any one of (2) to (5) above,
The controller determines whether the guide line is included in the second image when the guide line is not included in the first image, and determines whether the guide line is included in the second image. The drive unit may be controlled to guide the vehicle body according to the inclination of the guide line in the second image when it is determined that the guide line is included.

A guide line on the road surface, which is used as an index during forward running, may be partially hidden or blurred due to the influence of falling objects or adhesion, making it difficult to read by an imaging device.
In this regard, according to the above configuration (6), even if it is difficult to read the guide line in the first image below the front portion of the vehicle body, the guide line can be read in the second image below the rear portion of the vehicle body. If it can be read, it is possible to continuously guide the automatic guided vehicle along the guide line without stopping according to the inclination of the guide line in the second image obtained by the second imaging device. can. Therefore, it is possible to improve the working efficiency by improving the operation rate of the automatic guided vehicle. Also, the vehicle body can be appropriately guided with a simple configuration without requiring other complicated configurations.

(7) In some embodiments, in the configuration of (6) above,
The control unit is configured such that an image is captured by the first imaging device based on the inclination of the guide line in the second image and a preset distance between the first imaging device and the second imaging device. The position of the guide line in the first image may be predicted, and the drive unit may be controlled to guide the vehicle body based on the predicted position.

According to the above configuration (7), even if the first image picked up by the first imaging device arranged in the front part of the vehicle body does not include the guide line, the first image pickup device arranged in the rear part of the vehicle body When the guide line is included in the second image captured by the two imaging devices, the inclination of the guide line in the second image and the preset distance between the first imaging device and the second imaging device Based on this, the automatic guided vehicle can be continuously guided along the guide line without being stopped. Therefore, it is possible to improve the working efficiency by improving the operation rate of the automatic guided vehicle. Also, the vehicle body can be appropriately guided with a simple configuration without requiring other complicated configurations.

(8) In some embodiments, in the configuration described in any one of (1) to (7) above,
The driving unit is configured to independently apply driving force to at least two of the wheels,
The control section may be configured to control the driving section to rotate the at least two wheels in opposite directions to perform the turning motion.

According to the above configuration (8), one of the left and right wheels located inside the turn rotates in the opposite direction to the direction of rotation before the turn, so that the two wheels rotate in opposite directions and the super signal is transmitted. Can perform ground turns. Therefore, since the minimum turning radius can be kept as small as possible, it is possible to realize an unmanned guided vehicle that can easily turn in a small radius.

(9) In some embodiments, in the configuration described in any one of (2) to (8) above,
The wheels include a rear wheel that can be turned in any horizontal direction and a pair of left and right front wheels to which driving force is applied,
The imaging devices include the first imaging device, at least a part of which is arranged in front of the axle of the front wheels, and the second imaging device, at least a part of which is arranged behind the axle of the rear wheels. and at least one of.

With configuration (9) above, it is possible to secure a large distance between the first imaging device and the second imaging device, thereby improving the degree of freedom in the layout of the space between the two imaging devices.
In addition, when the configuration of (6) or (7) above is adopted, the configuration of (9) above can secure a large distance between the first imaging device and the second imaging device. For example, even if the first image does not include the first line and continues for a certain range (less than the distance between the first imaging device and the second imaging device), the image is acquired from the second imaging device. Based on the first line in the obtained second image, the automatic guided vehicle can be reliably guided along the first line.

(10) In some embodiments, in the configuration according to any one of (1) to (9) above, the automatic guided vehicle may include an agricultural automatic guided vehicle.

According to the configuration (10) above, it is possible to obtain an agricultural automatic guided vehicle capable of traveling in a farm or a house of a greenhouse farm. Therefore, it is possible to reduce the burden on workers and improve production efficiency by using automatic guided vehicles for agriculture.

(11) An unmanned guided vehicle system according to at least one embodiment of the present invention,
The automatic guided vehicle according to any one of (1) to (10) above;
the guide line including the first line along the traveling direction of the automatic guided vehicle and the second line intersecting the first line;
the mark arranged at the intersection of the first line and the second line;
Prepare.

According to the configuration (11) above, it is possible to realize an unmanned transport system capable of guiding the vehicle body using an optical guidance system at low cost without requiring expensive infrastructure such as a magnetic tape.

According to some embodiments of the present invention, an automatic guided vehicle that can travel over a wide range can be realized at low cost.

It is a figure showing a schematic structure of an unmanned carrier system concerning one embodiment. 1 is a schematic perspective view showing the appearance of an automatic guided vehicle according to one embodiment; FIG. It is a block diagram showing the configuration of a control system in the automatic guided vehicle according to one embodiment. It is a figure which shows roughly the guided driving|running|working by the automatic guided vehicle which concerns on one Embodiment. It is a flow chart which shows processing by an automatic guided vehicle concerning one embodiment. It is a schematic diagram showing a turning operation by the automatic guided vehicle according to one embodiment, (a) shows a state of reaching a turning position, (b) shows a turning state, and (c) shows a turning end state. It is a schematic diagram showing a second image in one embodiment, (a) is during turning, (b) is a state in which the guidance line is displayed in the second image, (c) is the center line in the second image It shows a state in which guidance lines are superimposed and displayed. It is a flow chart which shows processing by an automatic guided vehicle concerning other embodiments. FIG. 4 is a schematic diagram showing a first image and a second image in one embodiment; FIG. 4 is a conceptual diagram showing how a guidance line in a first image is estimated from the inclination of a guidance line in a second image in one embodiment; It is a perspective view showing a lower structure of an automatic guided vehicle according to one embodiment.

Several embodiments of the present invention will now be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, and are merely illustrative examples. do not have.
For example, expressions denoting relative or absolute arrangements such as "in a direction", "along a direction", "parallel", "perpendicular", "center", "concentric" or "coaxial" are strictly not only represents such an arrangement, but also represents a state of relative displacement with a tolerance or an angle or distance to the extent that the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous", which express that things are in the same state, not only express the state of being strictly equal, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
For example, expressions that express shapes such as squares and cylinders do not only represent shapes such as squares and cylinders in a geometrically strict sense, but also include irregularities and chamfers to the extent that the same effect can be obtained. The shape including the part etc. shall also be represented.
On the other hand, the expressions "comprising", "comprising", "having", "including", or "having" one component are not exclusive expressions excluding the presence of other components.

FIG. 1 is a diagram showing a schematic configuration of an unmanned guided vehicle system according to one embodiment. FIG. 2 is a schematic perspective view showing the appearance of an automatic guided vehicle according to one embodiment. FIG. 3 is a block diagram showing the configuration of the control system in the automatic guided vehicle according to one embodiment. FIG. 4 is a diagram schematically showing guided travel by an automatic guided vehicle according to one embodiment.
As shown in a non-limiting manner in FIG. 1, an automatic guided vehicle system 1 according to an embodiment includes an automatic guided vehicle 10, a first line 8A along the traveling direction of the automatic guided vehicle 10, and a crossing of the first line 8A. A guiding line 8 including a second line 8B to be drawn, and a mark 7 arranged at an intersection point P between the first line 8A and the second line 8B.

First, the configuration of the automatic guided vehicle 10 will be described.
As shown in FIGS. 1 to 4, an automatic guided vehicle 10 according to at least one embodiment of the present invention includes a first line 8A along the traveling direction and a second line 8B intersecting the first line 8A. It may be configured as an automated guided vehicle 10 movable along line 8 .
The automatic guided vehicle 10 includes a vehicle body 12, at least two wheels 20 rotatably attached to the vehicle body 12, at least one drive unit 24 that imparts rotational force to the at least two wheels 20, and at least A first image 43 (see FIGS. 4, 9 and 10) that captures the road surface 4 below the front portion of the vehicle body 12 (see FIG. 1) and a second image 43 that captures the road surface 4 below the rear portion of the vehicle body 12. At least one imaging device 40 for acquiring an image 44 (see FIGS. 7, 9 and 10) and a vehicle body along the first line 8A based on the first line 8A included in the first image 43 A control unit 70 configured to control the driving unit 24 to guide the vehicle 12, and a mark 7 mounted on the lower portion of the vehicle body 12 and arranged at the intersection point P between the first line 8A and the second line 8B. and a detection unit 17 that detects and transmits a detection signal to the control unit 70 .

The vehicle body 12 may include, for example, a box-shaped (rectangular) housing as shown in FIG. good too. Note that the mounting table 14 may adopt a shape such as a plate shape, a bowl shape, a tray shape, a box shape, or the like, which can appropriately transport the object to be transported according to the type and shape of the object to be transported.

The at least two wheels 20 can adopt respective diameters, widths, presence/absence of treads, tread patterns, etc., depending on the road surface conditions of the road surface 4 on which the automatic guided vehicle 10 travels. Each wheel 20 may be directly attached to the vehicle body 12 via a bearing portion, a shock absorbing mechanism, or the like (not shown), or may be arranged below the vehicle body 12 via a base or the like (not shown).

The drive unit 24 may be any device as long as it can apply rotational force to the wheels 20. As the drive unit 24, various power sources such as an electric motor and an internal combustion engine can be employed. In some embodiments, for example, as shown in FIGS. 3 and 4, the drive unit 24 may include motors (first motor 24A and second motor 24B).

The imaging device 40 is arranged so as to be able to image the lower side of the vehicle body 12 . The imaging device 40 converts the reflected light from the road surface 4 incident through a lens 46 (see FIG. 11) into a digital image with an image sensor such as a CCD (charge-coupled device) or a CMOS (complementary metal oxide semiconductor). and transmit the converted image data to the control unit 70 . In some embodiments, imaging device 40 may include a transparent lens cover 45 (see FIG. 11) below lens 46 .

In some embodiments, a single imaging device 40 may be configured so that the imaging range of the imaging device 40 can be switched between the lower front portion and the lower rear portion of the vehicle body 12 . The imaging range may be switched by switching the mounting angle of the imaging device 40 so that the orientation of the lens 46 can be switched between at least the lower front portion and the lower rear portion of the vehicle body 12, or by moving the imaging device 40 itself back and forth. A configuration in which the imaging range is switched by sliding or the like may be employed, and an actuator for performing these switching may be provided.

In some embodiments, the automatic guided vehicle 10 has a plurality of (eg, first The imaging device 40 may include two imaging devices 41 and 42 ).

The detection unit 17 may be, for example, an antenna such as an RFID reader capable of detecting an RFID tag when the RFID tag is used as the mark 7 . In another embodiment, for example, a bar code or a QR code (registered trademark) may be used as the mark 7 and a bar code reader or a QR code (registered trademark) reader may be used as the detector 17 .
In some embodiments, the detector 17 may be located between the wheels 20, 20, for example, connecting the wheels 20, 20 in plan view, as non-limitingly shown in FIG. It may be arranged on the axle 22 at a position approximately equal in distance from each wheel 20, 20 (that is, at the center of the line connecting each wheel 20, 20).

As illustrated in a non-limiting manner in FIG. 3, the control unit 70 is, for example, a computer, and includes a CPU 72 as a calculation unit that executes various processes, and a work area such as a development area for various programs executed by the CPU 72 and a calculation area. A RAM (Random Access Memory) 73 functioning as an area, a ROM (Read Only Memory) 74 as a storage unit for storing data such as programs and tables, and a communication interface (not shown) for connecting to a communication network. ), and an access portion (not shown) to which an external storage device is attached. All of these are electrically connected via bus 75 . The ROM 74 may store, for example, a guidance travel program 80 for guiding the automatic guided vehicle 10 based on images acquired by the imaging device 40 . Further, the control unit 70 includes, for example, an operation panel 76 having an input unit 77 including a keyboard, a mouse, etc., a display unit 78 including a liquid crystal display device for displaying various data, the imaging device 40 described above, and a driving unit. The (motor) 24 and the detector 17 may be connected.

Then, the control unit 70 in at least one embodiment of the present invention performs a turning operation for turning the vehicle body 12 from the state along the first line 8A to along the second line 8B based on the detection signal from the detection unit 17. and control the driving unit 24 to start the determination result that the second line 8B is included in the determination region R, which is at least a part of the second image 44 (for example, FIG. 7B) ) to control the drive unit 24 to end the turning motion.

The determination region R is, for example, the traveling direction of the automatic guided vehicle 10 (for example, the upward direction in FIGS. 4, 7 and 9 to 10) in the display region of the first image 43 or the second image 44. ), and may be defined to have predetermined widths to the left and right of the center line C, respectively. The predetermined width may be, for example, equal to the width of the guide line 8, or may be arbitrarily defined within the range of the display area.

Specifically, the control unit 70 reads the guidance running program 80 stored in the ROM 74 by the CPU 72, develops it in the RAM 73, and executes it, so that, for example, guidance along the guidance line 8 as illustrated in FIGS. can realize running.

FIG. 5 is a flowchart showing processing by an automatic guided vehicle according to one embodiment. 6A and 6B are schematic diagrams showing a turning operation by an automatic guided vehicle according to an embodiment, in which (a) shows a state in which a turning position has been reached, (b) shows a state during turning, and (c) shows a state in which turning is completed. . FIG. 7 is a schematic diagram showing a second image in one embodiment, (a) is during turning, (b) is a state in which the guidance line is displayed in the second image, and (c) is in the second image. Indicates a state in which the guidance line is superimposed on the center line of the .
Guided travel and turning motions of an automatic guided vehicle 10 according to at least one embodiment of the present invention will be described below with reference to FIGS. 1 to 7. FIG.

As non-limitingly illustrated in FIG. 5, the control unit 70 turns on the imaging device 40 ( Step S1) Acquire the first image 43 (Step S2). Then, when the guide line 8 (more specifically, the first line 8A) is included in the first image 43 (see, for example, the dashed frame A in FIG. 4), the automatic guided vehicle 10 moves along the guide line 8. A drive signal is transmitted to the drive unit 24 so as to execute guided travel (step S3). Guided travel based on the guide line 8 in the first image 43 is driven in a direction in which the centers of gravity of the first image 43 and the center of gravity of the guide line 8 included in the first image 43 overlap, for example. It may be realized by driving the unit 24 .
In addition, the drive unit 24 is driven so that the automatic guided vehicle 10 moves along the guide line 8 according to the processing for identifying the guide line 8 in the first image 43 and the inclination of the identified guide line 8. A well-known technique can be applied to the processing for this, so a detailed description thereof is omitted here.

When the guided travel based on the guide line 8 is started, the CPU 72 places the mark 7 (for example, RFID tag) placed at the intersection point P between the first line 8A and the second line 8B at the turning center position of the unmanned guided vehicle 10. Detected by the detection unit 17 (for example, an RFID reader), it is determined whether or not the turning center 32 of the automatic guided vehicle 10 has reached the turning point (for example, the intersection point P between the first line 8A and the second line 8B). (step S4). If the CPU 72 does not determine that the turning center 32 has reached the turning point (step S4: NO), it repeats the process of step S4. On the other hand, for example, as illustrated in FIG. 6A, when it is determined that the turning center 32 of the automatic guided vehicle 10 has reached the turning point (for example, the intersection point P) (step S4: YES), the CPU 72 performs turning operation. is started (step S5).

With the start of the turning motion, the CPU 72 acquires the second image 44 via the imaging device 40 (step S6), and inserts the guide line 8 (more specifically, the second line 8B) is included (step S7), and control is executed to drive the drive unit 24 so as to rotate the automatic guided vehicle 10 in a predetermined clockwise or counterclockwise turning direction. . The predetermined turning direction may be determined, for example, based on a specified route pre-stored in a storage unit such as the ROM 74 or an external storage device (not shown), or an instruction input from the input unit 77 of the operation panel 76. may be determined based on

In step S7, for example, as can be seen with reference to FIGS. 6B and 7A, if the guide line 8 is not included in the determination region R of the second image 44 (step S7: NO), The CPU 72 repeatedly executes the process of step S7. On the other hand, for example, as can be seen with reference to FIG. 6(c) and FIG. 7(b) or FIG. The CPU 72 controls the drive unit 24 to end the turning operation (step S8), and then guides the unmanned guided vehicle 10 so that it moves along the guide line 8 in the second image 44. (step S9). More specifically, the CPU 72 switches the image acquired via the imaging device 40 from the second image 44 to the first image 43 upon completion of the turning motion, and the guide line 8 included in the first image 43 is displayed. Execute control to move along.
In this specification, for convenience of explanation, the guide line 8 that guides the automatic guided vehicle 10 before turning operation is referred to as a first line 8A, and the guide line 8 intersecting the first line 8A is referred to as a second line 8B. However, the guide line 8, which was the second line 8B before the turning operation, is newly treated as the first line 8A along the traveling direction (front-rear direction) of the automatic guided vehicle 10 after the completion of the turning operation. will be clear to those skilled in the art.

According to the above configuration, the vehicle body 12 can be guided using the optical guidance method based on the first image 43 that captures at least the road surface 4 below the front portion of the vehicle body 12 . As a result, without the need for expensive infrastructure equipment such as magnetic tape, guidance can be achieved with a simple configuration in which a guide line 8 that can be identified in an optically acquired image is drawn with, for example, inexpensive tape or paint. Since it can be realized, the automatic guided vehicle 10 that can travel over a wide range can be realized at low cost.
Further, if the road surface 4 is slippery, for example, a configuration in which the position, orientation, and attitude of the vehicle body 12 are determined from the number of rotations of the wheels using an encoder or the like will cause an error due to slippage, resulting in low accuracy. According to the above configuration, even if the wheel 20 slips due to falling objects, rain, dew, etc. on the road surface 4, the intersection point P between the first line 8A and the second line 8B can be By detecting the arranged mark 7 (RFID tag) with the detection unit 17 (RFID reader), the turning operation can be started. In addition, since the completion of the turning operation can be grasped in real time by the presence or absence of the second line 8B in the second image 44, it is possible to reliably determine whether or not the vehicle body 12 has completely turned. can be done. In addition, it is possible to reduce the convergence time required from the start of turning to the completion of turning by suppressing insufficient turning and excessive turning as much as possible.
It should be noted that, when turning 180 degrees (U-turn), the turning may be continued even after recognizing the second line 8B, and the turning operation may be finished by recognizing the first line 8A.
In some embodiments, for example, as shown in FIG. 11, a lighting device 50 that illuminates the imaging range of the imaging device 40, and a light shielding member that covers the surroundings of the imaging device 40 and the lighting device 50 to block external light. 60 may be located on the lower portion of the vehicle body 12 .

In some embodiments, at least one image pickup device 40 includes a first image pickup device 41 that is arranged in front of the turning center 32 of the turning movement to obtain a first image 43 and a vehicle main body that is located ahead of the turning center 32 . a second imaging device 42 positioned behind 12 to acquire a second image 44 (see, eg, FIGS. 4, 6 and 9).

FIG. 8 is a flow chart showing processing by an automatic guided vehicle according to another embodiment having the first imaging device 41 and the second imaging device 42 .
As non-limitingly illustrated in FIG. 8 , the control unit 70 turns on the first imaging device 41 when the guided traveling process is started based on an instruction to start guided traveling from the input unit 77 of the operation panel 76, for example. (step S11) to acquire the first image 43 (step S12). Then, when the guide line 8 (more specifically, the first line 8A) is included in the first image 43 (see FIG. 4), the drive unit 10 moves along the guide line 8. 24 to execute guided travel (step S13).

When the guidance traveling based on the guidance line 8 is started, the CPU 72 transmits by detecting the mark 7 (RFID tag) installed at the intersection of the first line 8A and the second line 8B by the detection unit 17 (RFID reader). Based on the detected signal, it is determined that the turning center 32 of the automatic guided vehicle 10 has reached the turning point (intersection point P) (step S14). When the CPU 72 does not determine that the turning center 32 has reached the turning point (step S14: NO), the CPU 72 repeatedly executes the process of step S14. On the other hand, for example, as illustrated in FIG. 6A, when it is determined that the turning center 32 of the automatic guided vehicle 10 has reached the turning point (for example, the intersection point P) (step S14: YES), the CPU 72 performs turning operation. is started (step S15).

With the start of the turning motion, the CPU 72 turns on the second imaging device 42 (step S16), acquires the second image 44 (step S17), and draws the guidance line in the determination region R in the second image 44. 8 (more specifically, the second line 8B) is included (step S18), and the drive unit 10 rotates the automatic guided vehicle 10 in a predetermined clockwise or counterclockwise turning direction. 24 is executed.

In step S18, for example, as can be seen with reference to FIGS. 6B and 7A, when the guide line 8 is not included in the determination region R of the second image 44 (step S18: NO), The CPU 72 repeatedly executes the process of step S18. On the other hand, for example, as can be seen with reference to FIG. 6(c) and FIG. 7(b) or FIG. The CPU 72 controls the drive unit 24 to end the turning operation (step S19), and then guides the unmanned guided vehicle 10 along the guide line 8 in the second image 44. (step S20). More specifically, the CPU 72 switches the image acquired via the imaging device 40 from the second image 44 to the first image 43 upon completion of the turning motion, and the guide line 8 included in the first image 43 is displayed. Execute control to move along.

According to the above configuration, the first image 43 and the second image 44 can be captured by separate imaging devices 40, ie, the first imaging device 41 and the second imaging device 42, respectively. Thereby, the images 43 and 44 can be obtained by imaging from right above the road surface 4, for example. That is, the image of the road surface 4 below the front portion and the rear portion of the vehicle body 12 can be clearly captured from a short distance while suppressing the influence of shadows and the like. can be improved. Therefore, the reliability and stability of guided travel along the guide line 8 can be improved.
Furthermore, by providing the second imaging device 42, for example, if the control unit 70 is configured to guide the vehicle main body 12 along the guide line 8 included in the second image 44, the travel direction ( In the backward direction), the vehicle body 12 can be guided based on the second image 44 corresponding to the image of the lower front portion.
Note that, in some embodiments, a first lighting device 51 and a second lighting device 50 are provided adjacent to the first imaging device 41 and the second imaging device 42 and serve as the lighting device 50 for illuminating the imaging range of each of the imaging devices 41 and 42 . Devices 52 may be arranged respectively (see FIGS. 3 and 11).

In some embodiments, the control unit 70 is included in the image acquired by the imaging device 40 arranged at a position farther from the turning center 32 than the first imaging device 41 or the second imaging device 42. It may be configured to determine the end of the turning motion based on the guide line 8 (more specifically, the second line 8B).
For example, as illustrated in a non-limiting manner in FIG. 32 to the lens of the second imaging device 42 is large (D1<D2: see FIG. 6B), the control unit 70 adjusts the second image 44 obtained from the second imaging device 42. When the guide line 8 is included in the determination area R, it is determined that the turning motion is finished. On the other hand, when the distance from the turning center 32 to the lens is greater in the first imaging device 41 than in the second imaging device 42 (D1>D2), the control unit 70 controls the first image obtained by the first imaging device 41 When the guide line 8 is included in the determination area R in 43, it is determined that the turning motion is finished.

Thus, according to the configuration for determining the end of turning based on the guidance line 8 included in the image acquired by the imaging device 40 arranged at a position further away from the turning center 32 , the control unit 70 controls the turning center 32 It is possible to improve the determination accuracy of the determination of the end of turning compared to the case of determining the end of turning based on the image acquired by the imaging device 40 arranged at a position close to. Therefore, the orientation of the vehicle body 12 after the turn is completed can be matched with high accuracy by the second line 8B, which is the traveling direction after that, so that the reliability of guided travel can be improved.

In some embodiments, the control unit 70 controls that at least part of the second line 8</b>B included in the second image 44 is aligned with the center line C of the second image 44 along the longitudinal direction of the vehicle body 12 within the second image 44 . (see, for example, FIG. 7(c)), it may be configured to determine the end of the turning motion. With this configuration, the direction of travel after turning can be more closely aligned with the second line 8B, so that the accuracy of turning can be improved. Further, for example, if the control unit 70 is configured to determine that the turning is completed when the center line in the width direction of the second line 8B and the center line C of the second image 44 overlap, the turning accuracy is further improved. can be made

In some embodiments, the turning motion may be performed so that the turning center 32 of the turning motion overlaps the intersection point P between the first line 8A and the second line 8B. For example, when the two wheels 20, 20 are rotated in opposite directions to perform a super pivot turn, the middle point of the rotation center line connecting the rotation centers of the wheels 20 serving as the drive wheels in the vehicle width direction is the turning center 32. Therefore, the turning operation may be performed so that the intersection point P is positioned below the middle point of each wheel 20,20.

According to the above configuration, the vehicle body 12 performs the turning operation so that the turning center 32 of the turning operation overlaps the intersection point P of the first line 8A and the second line 8B. The vehicle body 12 can be turned so as to reliably follow the guide line 8 at the right/left turn point where the traveling direction is greatly changed to 8B. Therefore, even in a narrow passage where many collection and delivery points 6 (see FIG. 1) are arranged side by side, the guided travel of the automatic guided vehicle 10 can be realized accurately.

FIG. 9 is a schematic diagram showing a first image and a second image in one embodiment.
As non-limitingly illustrated in FIG. 9 , in some embodiments, the control unit 70 may cause the guide line 8 to be included in the second image 44 when the guide line 8 is not included in the first image 43 . When it is determined that the guide line 8 is included in the second image 44, the vehicle body 12 is driven to guide according to the inclination of the guide line 8 in the second image 44. It may be configured to control the unit 24 .

The guide line 8 (more specifically, the first line 8A) on the travel road surface 4, which is used as an index during forward travel, is partially hidden due to the influence of fallen objects such as fallen leaves and foreign matter 9 such as adhesion. It may be difficult to read by the imaging device 40 due to blurring or blurring (for example, see FIG. 9).
In this respect, with the above configuration, even if it is difficult to read the guide line 8 in the first image 43 below the front portion of the vehicle body 12, it is possible to read the second image 44 below the rear portion of the vehicle body 12. If the guide line 8 can be read, the automatic guided vehicle 10 is stopped along the guide line 8 according to the inclination of the guide line 8 in the second image 44 obtained by the second imaging device 42. It can be guided continuously. Therefore, it is possible to improve the working efficiency by improving the operation rate of the automatic guided vehicle 10 . Further, the vehicle body 12 can be appropriately guided with a simple configuration without requiring any other complicated configuration.

FIG. 10 is a conceptual diagram showing how a guidance line in the first image is estimated from the inclination of the guidance line in the second image in one embodiment.
As non-limitingly illustrated in FIG. 10 , in some embodiments, the control unit 70 controls the inclination of the guide line 8 in the second image 44 and the preset first imaging device 41 and second imaging device. Based on the distance D3 from the device 42, the position of the guide line 8 in the first image 43 that will be captured by the first imaging device 41 is predicted, and the vehicle body 12 is guided based on the predicted position. It may be configured to control the drive unit 24 as follows.

With this configuration, even if the guide line 8 is not included in the first image 43 picked up by the first imaging device 41 arranged in the front part of the vehicle body 12, it is arranged in the rear part of the vehicle body 12. When the guide line 8 is included in the second image 44 captured by the second imaging device 42, the inclination of the guide line 8 in the second image 44, the preset first imaging device 41 and the first Based on the distance between the two imaging devices 42, the automatic guided vehicle 10 can be continuously guided along the guide line 8 without being stopped. Therefore, it is possible to improve the working efficiency by improving the operation rate of the automatic guided vehicle 10 . Further, the vehicle body 12 can be appropriately guided with a simple configuration without requiring any other complicated configuration.

In some embodiments, the drive unit 24 is configured to independently apply a driving force to at least two wheels 20, and the control unit 70 rotates the at least two wheels 20 in opposite directions to turn. It may be configured to control the drive unit 24 to perform an operation.
Specifically, for example, when it is determined in step S4 or step S14 described above that the turning center 32 has reached the intersection point P between the first line 8A and the second line 8B (step S4: YES, or step S14 : YES), the CPU 72 controls the driving section 24 so as to rotate the wheels 20, 20 in opposite directions to perform a turning motion.

According to the above configuration, one of the left and right wheels 20 positioned inside the turn rotates in the opposite direction to the rotation direction before turning, so that the automatic guided vehicle 10 can perform a so-called super pivot turn. . Therefore, since the minimum turning radius can be kept as small as possible, the unmanned guided vehicle 10 that can easily turn in a small radius can be realized.

In some embodiments, the wheels 20 include any horizontally steerable rear wheels (e.g., casters 26) and a pair of left and right front wheels (e.g., wheels 20) to which driving force is applied, and the imaging device Reference numeral 40 designates a first imaging device 41 at least partly arranged in front of the axle 22 of the front wheels and a second imaging device 42 at least partly arranged behind the axle 22 of the rear wheels. At least one of them may be included (for example, see FIG. 9).

According to the above configuration, it is possible to secure a large distance between the first imaging device 41 and the second imaging device 42 and improve the degree of freedom in the layout of the space between the two imaging devices 40 .
Further, when a configuration is adopted in which the vehicle body 12 is guided according to the inclination of the guide line 8 in the second image 44 when the guide line 8 is not included in the first image 43, the above-described With this configuration, a large distance can be secured between the first image pickup device 41 and the second image pickup device 42. Therefore, for example, the first image 43 does not include the guide line 8, and the vehicle can travel within a certain range (the second image pickup device 42). (Less than the distance D3 between the first imaging device 41 and the second imaging device 42). By doing so, the automatic guided vehicle 10 can be reliably guided.

In some embodiments, AGV 10 may comprise an agricultural AGV.
In this case, for example, the automatic guided vehicle 10 moves along a guide line 8 installed on the traveling road surface 4 on which a large number of collection and delivery points 6 are arranged at predetermined intervals, It may be configured such that an object to be transported (object to be transported) can be transported between the collection site 5 and the delivery point 6 . That is, the unmanned guided vehicle 10 in some embodiments can be configured as an autonomously traveling guided vehicle capable of moving outdoors, inside a house, or the like, for example, in a farm, a facility horticulture farm, or the like (farm, etc.). The collection and delivery point 6 (see FIG. 1) in this case may be, for example, a cultivation bench or shelf.

According to the above configuration, it is possible to obtain the automatic guided vehicle 10 for agriculture that can travel in a house of a farm or a greenhouse farm. Therefore, the unmanned guided vehicle 10 can be used for agriculture to reduce the burden on workers and improve production efficiency. In addition, for example, by setting the size of the vehicle body 12 according to the width of the passage, etc., it is possible to appropriately assist the transport work associated with picking and harvesting performed in relatively narrow passages, thereby greatly reducing the burden on workers. can do.

According to the configuration described above, the automatic guided vehicle 10 that can travel over a wide range can be realized at low cost.
It should be noted that the automatic guided vehicle 10 to which the present invention is applied, which has been described in the above-described several embodiments, can be used in facilities other than farms as described above (for example, flat maintenance surfaces such as concrete, asphalt, and wood). is also possible.

The present invention is not limited to the above-described embodiments, and includes modifications of the above-described embodiments and combinations of these embodiments.

1 Unmanned transport system 4 Driving surface 5 Collection area 6 Collection and delivery point (shelf/cultivation bench)
7 Mark (RFID tag)
8 Guidance line 8A First line 8B Second line 9 Foreign matter (fallen leaves)
10 Automated Guided Vehicle 12 Vehicle Body 14 Mounting Table 17 Detector (RFID Reader/Antenna)
20 wheels (front wheels/drive wheels)
22 axle 24 drive unit (motor)
24A First motor 24B Second motor 26 Caster (rear wheel/driven wheel)
32 Turning center 40 Imaging device 41 First imaging device (front camera)
42 Second imaging device (rear camera)
43 First image 44 Second image 45 Lens cover 46 Lens 50 Lighting device 51 First lighting device 52 Second lighting device 60 Light blocking member 70 Control unit 72 CPU
73 RAM
74 ROMs
75 Bus 76 Operation panel 77 Input unit 78 Display unit 80 Guidance running program C Center line P Intersection R Judgment area

Claims (9)

An automatic guided vehicle capable of moving along a guide line including a first line along the direction of travel and a second line intersecting the first line,
a vehicle body;
at least two wheels rotatably mounted on the vehicle body;
at least one drive for applying rotational force to at least two of said wheels;
A first imaging device that acquires a first image of the road surface below the front portion of the vehicle body, and a second imaging device that acquires a second image of the road surface below the rear portion of the vehicle body. an imaging device;
a control unit that controls the driving unit to guide the vehicle body along the first line based on the first line included in the first image;
a detection unit mounted on a lower portion of the vehicle body for detecting a mark arranged at an intersection of the first line and the second line and transmitting a detection signal to the control unit;
with
The at least two wheels include a pair of rear wheels, which are a pair of left and right casters capable of turning in any horizontal direction, and a pair of left and right front wheels to which driving force is applied,
At least part of the first imaging device is arranged forward of the axle of the front wheel,
At least part of the second imaging device is arranged between the pair of rear wheels,
At least part of the detection unit is arranged to overlap the axle of the front wheel in a plan view ,
Based on the detection signal, the control unit controls the driving unit to start a turning operation for turning the vehicle body from a state along the first line to a state along the second line, and the turning operation. The first imaging device arranged in front of the turning center of the vehicle body, and the second imaging device arranged in the rear part of the vehicle body on the side opposite to the turning center with respect to the center of the vehicle body in the longitudinal direction. The turning motion is ended based on a determination result that the second line is included in a determination region that is at least a partial region in the second image acquired by the second imaging device among the imaging devices. An unmanned guided vehicle characterized by being configured to control the drive unit so as to The control unit determines that the turning is completed when at least part of the second line included in the second image overlaps a center line of the second image along the longitudinal direction of the vehicle body in the second image. The automatic guided vehicle according to claim 1, characterized in that it is configured to determine that. The control unit is configured to control the drive unit so as to perform the turning operation such that the turning center of the turning operation overlaps the intersection of the first line and the second line. 3. The automatic guided vehicle according to claim 1 or 2. The controller determines whether the guide line is included in the second image when the guide line is not included in the first image, and determines whether the guide line is included in the second image. 4. The driving unit is configured to guide the vehicle body in accordance with the inclination of the guide line in the second image when it is determined that the guide line is included in the second image. The automatic guided vehicle according to any one of 1. The control unit is configured such that an image is captured by the first imaging device based on the inclination of the guide line in the second image and a preset distance between the first imaging device and the second imaging device. 4. The driving unit is configured to predict the position of the guide line in the first image, and control the drive unit to guide the vehicle body based on the predicted position. The automatic guided vehicle described in . The driving unit is configured to independently apply driving force to at least two of the wheels,
6. The controller according to any one of claims 1 to 5, wherein the control unit is configured to control the drive unit so as to rotate at least two of the wheels in opposite directions to perform the turning motion. Automatic guided vehicle described in paragraph. 7. The automatic guided vehicle according to any one of claims 1 to 6, wherein a part of said second imaging device is arranged behind an axle of said rear wheel. The automatic guided vehicle according to any one of claims 1 to 7, wherein the automatic guided vehicle includes an agricultural automatic guided vehicle. An automatic guided vehicle according to any one of claims 1 to 8;
the guide line including the first line along the traveling direction of the automatic guided vehicle and the second line intersecting the first line;
the mark arranged at the intersection of the first line and the second line;
An unmanned carrier system comprising:

Images