JP2019197349A - System to control stop position of spin turn and method to control spin turn rotation angle for unmanned carrier - Google Patents

Abstract

To provide a spin turn stop position control system for unmanned carrier which can accurately stop at a prescribed stop position after the carrier spin turns.SOLUTION: A system for controlling a stop position when an unmanned carrier 1 spin turns a prescribed angle PA while the carrier 1 is guidance controlled by guiding means A and tracklessly self-propelled along a prescribed travel route B, comprises a two dimensional code E2 at a position a prescribed distance apart from a turnabout reference center position T that is in ground side and coincides with the spin turn end position Q of the carrier 1. The unmanned carrier 1 comprises a two dimensional code reader sensor S2 that reads the two dimensional code E2. After the unmanned carrier begins spin turn, the carrier reads the two dimensional code E2 in ground side with the two dimensional code reader S2 and stops at the spin turn end position Q.SELECTED DRAWING: Figure 5B

Description

  The present invention relates to a stop position control system in a spin turn of an automatic guided vehicle that is guided and controlled by using a guiding means and travels in a trackless manner along a predetermined travel route, and a rotation angle control method in the spin turn of the automatic guided vehicle About.

  An automated guided vehicle (AGV) that runs on a trackless track has a free wheel (a caster wheel) that receives a load in order to be able to travel along a curved traveling path in addition to a driving wheel that travels. For example, the vehicle travels along the travel route while being guided by a guide line installed along a predetermined travel route (see, for example, Patent Document 1).

When such an automatic guided vehicle changes direction in a narrow passage or the like, a spin turn (for example, a 90 ° spin turn or a 180 ° spin turn) that rotates about the center of the vehicle body is often used (for example, Patent Document 1).
In order to spin-turn the automatic guided vehicle and stop it at a predetermined position, the stop position is controlled by reading a guide wire installed on the ground by a sensor provided in the automatic guided vehicle. Alternatively, the amount of rotation of the drive wheel after the start of the spin turn is detected by the encoder from the spin turn start position, and the drive wheel is controlled to stop when the number of encoder pulses reaches a set value corresponding to the required angle. (Hereinafter referred to as “rotation angle control by an encoder”).

In addition, some automatic guided vehicles include a lifting table on which a conveyed product is placed (see, for example, Patent Document 2).
The automatic guided vehicle (movable drive unit 20) of Patent Document 2 sinks under the transported object (stock holder 30) in a state where the lifting table (coupling head 110) is lowered, and lifts the lifting table to move the transported object. Move to a designated point in the work space in the lifted state.

Japanese Patent Laid-Open No. 7-114414 Japanese Patent Laying-Open No. 2006-222465

  When a guided vehicle installed on the ground is read by a sensor provided in the automated guided vehicle and the stop position is controlled when the automated guided vehicle performs a spin turn as in Patent Document 1, a one-dimensional position is included in the guided line. Since only information is recorded, it is difficult to stop at a predetermined position after the spin turn.

  In addition, when the rotation angle control by the encoder is performed when the automatic guided vehicle performs a spin turn, the setting value of the number of pulses of the encoder is based on the diameter of the driving wheel in a state where it is not worn. When worn, the amount of rotation is insufficient even if the number of pulses of the encoder reaches the set value. Therefore, since it becomes impossible to stop at a predetermined position after the spin turn, the stop position accuracy is deteriorated.

  If the automatic guided vehicle cannot stop at a predetermined stop position with high accuracy after performing a spin turn, it is placed on the ground using an automatic guided vehicle equipped with a lifting table on which a transported object is placed as in Patent Document 2, for example. When the lifted table is lifted and received after the spin turn, the transported object and the lift table may be out of phase, so that the transported object may not be received by the lift table. In particular, a positioning means for positioning the conveyed product with respect to the lifting table so as to eliminate transfer defects cannot be positioned by the positioning means.

  In view of the above-described background, the present invention provides a stop position control system in a spin turn of an automatic guided vehicle and rotation in the spin turn of an automatic guided vehicle that can be stopped at a predetermined stop position with high accuracy after the automatic guided vehicle has made a spin turn. An object is to provide an angle control method.

The stop position control system in the spin turn of the automatic guided vehicle according to the present invention,
In an automated guided vehicle that is guided and controlled using a guiding means and travels in a trackless manner along a predetermined traveling route,
A system for controlling a stop position when the automatic guided vehicle performs a spin turn of a predetermined angle,
On the ground side of the spin turn end position of the automatic guided vehicle, a two-dimensional code is provided at a position separated from the turning point by a predetermined distance,
The automatic guided vehicle is
A two-dimensional code reading sensor for reading the two-dimensional code;
After starting the spin turn, the two-dimensional code reading sensor reads the two-dimensional code on the ground side and stops at the spin turn end position.

In such a configuration, since the two-dimensional code is provided at a position separated by a predetermined distance from the turning point on the ground side of the spin turn end position of the automatic guided vehicle, it is far from the spin turn rotation center of the automatic guided vehicle. A two-dimensional code is installed at the position.
In addition, a two-dimensional code reading sensor for reading a two-dimensional code provided in the automatic guided vehicle is also at a position far from the spin turn rotation center.
Therefore, compared with the case where a two-dimensional code is installed at or near the spin turn rotation center of the automatic guided vehicle, the rotation angle in the spin turn can be read to a fine angle, so that the automatic guided vehicle can be rotated with high accuracy. The angle can be controlled.

In addition, the automatic guided vehicle starts a spin turn, and the automatic guided vehicle stops by reading the two-dimensional code provided on the ground side at the spin turn end position of the automatic guided vehicle by the two-dimensional code reading sensor.
As a result, when the automatic guided vehicle performs a spin turn, the stop position accuracy is not deteriorated due to wear of the drive wheels as in the case where the rotation angle control is performed by the encoder.

The rotation angle control method in the spin turn of the automatic guided vehicle according to the present invention,
In an automated guided vehicle that is guided and controlled using a guiding means and travels in a trackless manner along a predetermined traveling route,
A method for controlling a rotation angle of the automatic guided vehicle when the automatic guided vehicle performs a spin turn of a predetermined angle,
On the ground side of the spin turn start position of the automatic guided vehicle,
The first two-dimensional code is provided at a position separated by a predetermined distance from the turning point,
On the ground side of the spin turn end position of the automatic guided vehicle,
A second two-dimensional code is provided at a position separated from the turning point by the predetermined distance,
The automatic guided vehicle includes a two-dimensional code reading sensor that reads the two-dimensional code,
The control device for the automatic guided vehicle includes:
Obtaining coordinate data of the spin turn start position from information obtained by reading the first two-dimensional code by the two-dimensional code reading sensor at the spin turn start position;
Obtaining coordinate data of a target stop position for rotating the predetermined angle from the coordinate data of the spin turn start position;
Starting the spin turn of the automatic guided vehicle, reading the second two-dimensional code by the two-dimensional code reading sensor, and stopping the automatic guided vehicle when the coordinate data of the target stop position is read;
(Claim 2).

In such a configuration, the first two-dimensional code is provided at a position separated by a predetermined distance from the turning point on the ground side of the spin turn start position of the automatic guided vehicle, and the spin turn end position of the automatic guided vehicle is provided. The second two-dimensional code is provided at a position on the ground side that is a predetermined distance away from the turning point.
Therefore, the first two-dimensional code and the second two-dimensional code are installed at a position far from the spin turn rotation center of the automatic guided vehicle.
In addition, a two-dimensional code reading sensor for reading a two-dimensional code provided in the automatic guided vehicle is also at a position far from the spin turn rotation center.
Therefore, compared with the case where a two-dimensional code is installed at or near the spin turn rotation center of the automatic guided vehicle, the rotation angle in the spin turn can be read to a fine angle, so that the automatic guided vehicle can be rotated with high accuracy. The angle can be controlled.

In addition, the control device of the automatic guided vehicle obtains the coordinate data of the spin turn start position from the information obtained by reading the first two-dimensional code by the two-dimensional code reading sensor at the spin turn start position. The coordinate data of the target stop position that rotates at a predetermined angle is obtained, the spin turn is started, the second two-dimensional code is read by the two-dimensional code reading sensor, and the coordinate is stopped when the coordinate data of the target stop position is read. .
As a result, when the automatic guided vehicle performs a spin turn, the stop position accuracy is not deteriorated due to wear of the drive wheels as in the case where the rotation angle control is performed by the encoder.

Here, the automatic guided vehicle includes an elevating table for placing a transported object,
The control device for the automatic guided vehicle includes:
Moving the automatic guided vehicle so as to transport the transported object placed on the lifting table to an unloading position;
Lowering the elevating table to place the transported object on the ground at the unloading position;
Obtaining coordinate data of the spin turn start position from information obtained by reading the first two-dimensional code by the two-dimensional code reading sensor at the spin turn start position at the unloading position;
Obtaining coordinate data of a target stop position for rotating the predetermined angle from the coordinate data of the spin turn start position;
Starting the spin turn of the automatic guided vehicle, reading the second two-dimensional code by the two-dimensional code reading sensor, and stopping the automatic guided vehicle when the coordinate data of the target stop position is read;
Raising the elevating table and placing the conveyed product on the elevating table;
Is a preferred embodiment (claim 3).

In such a configuration, the coordinate data of the spin turn start position is obtained at the spin turn start position at the unloading position where the lift table is lowered and the object is placed on the ground, and rotation is performed at a predetermined angle from this coordinate data. Find the coordinate data of the target stop position.
As a result, the automatic guided vehicle performs a spin turn by itself, rotates at a predetermined angle with high accuracy, and stops at a spin turn end position. The automatic guided vehicle places the conveyed product on the lifting table with respect to the conveyed product. It is in the proper position to do.
Therefore, it is possible to prevent a transfer failure of the conveyed product when the lift table is raised at the spin turn end position and the conveyed product is placed on the lift table.

In addition, the automatic guided vehicle includes a lifting table on which a transported object is placed,
The control device for the automatic guided vehicle includes:
A step of moving the automatic guided vehicle to a mounting position for mounting the transported object placed on the ground on the lifting table;
Obtaining the spin-turn start position coordinate data from the information obtained by reading the first two-dimensional code by the two-dimensional code reading sensor at the spin-turn start position at the placement position;
From the coordinate data of the spin turn start position and the position data of the transported object received from the ground side control device, a predetermined for moving the transported object to an appropriate position for placing it on the lifting table at the spin turn end position Obtaining coordinate data of an angle and a target stop position for performing rotation of the predetermined angle;
Starting the spin turn of the automatic guided vehicle, reading the second two-dimensional code by the two-dimensional code reading sensor, and stopping the automatic guided vehicle when the coordinate data of the target stop position is read;
Raising the elevating table and placing the conveyed product on the elevating table;
It is also a preferred embodiment that includes (Claim 4).

In such a configuration, the coordinate data of the spin turn start position is obtained at the spin turn start position at the placement position where the transported object is placed, and the coordinate data and the placement data received from the ground side control device are placed at the placement position. From the position data of the transported object, the predetermined angle for moving the transported object to the proper position for placing it on the lifting table at the spin turn end position, and the coordinate data of the target stop position for rotating the predetermined angle Ask.
As a result, the automatic guided vehicle performs a spin turn by itself, rotates at a predetermined angle with high accuracy, and stops at a spin turn end position. The automatic guided vehicle places the conveyed product on the lifting table with respect to the conveyed product. It is in the proper position to do.
Therefore, it is possible to prevent a transfer failure of the conveyed product when the lift table is raised at the spin turn end position and the conveyed product is placed on the lift table.

Furthermore, the lifting table of the automatic guided vehicle includes a positioning pin,
The transported object includes a receiving part,
In a more preferred embodiment, the positioning pin is engaged with the receiving portion in a state where the lifting table is raised and the conveyed product is placed on the lifting table.

In the invention according to claim 3 or 4, in a spin turn that the automatic guided vehicle performs alone with respect to the transported object, it is possible to accurately rotate the predetermined angle with respect to the transported object. Positioning means for engaging can be provided. That is, when the automatic guided vehicle performs a spin turn by itself and rotates at a predetermined angle with high accuracy and stops, the positioning pin is used to lift the lifting table and place the transported object on the lifting table. Engage the receiving part securely.
Therefore, when the lift table of the automatic guided vehicle is raised and the transported object is placed on the lift table, the positioning pin of the lift table engages the receiving part of the transported object. Since the conveyed product does not shift, the conveyed product can be conveyed stably and reliably by the automatic guided vehicle.

  Furthermore, the coordinate data of the spin turn start position and the coordinate data of the target stop position may include only an angle (claim 6).

  For example, when the automatic guided vehicle performs a spin turn, if it can be rotated with the spin turn rotation center fixed, it can be accurately stopped at the target stop position.

  In a more preferred embodiment, the coordinate data of the spin turn start position and the coordinate data of the target stop position include an angle and a translation position (Claim 7).

  As a result, when the automatic guided vehicle performs a spin turn, it can be accurately stopped at the target stop position even if it cannot rotate while the spin turn rotation center is fixed.

As described above, according to the stop position control system in the spin turn of the automatic guided vehicle according to the present invention and the rotation angle control method in the spin turn of the automatic guided vehicle according to the present invention, the following effects are mainly provided. Play.
(1) Since the rotation angle in the spin turn can be read to a fine angle, the rotation angle of the automatic guided vehicle can be controlled with high accuracy.
(2) The stop position accuracy is not deteriorated due to wear of the drive wheels as in the case of controlling the rotation angle by the encoder.

It is a perspective view of the automatic guided vehicle concerning an embodiment of the invention. It is a schematic plan view which similarly shows the principal part of an automatic guided vehicle. Similarly, it is a schematic plan view and shows a state in which the automatic guided vehicle performs a spin turn. It is a partial longitudinal cross-section front view which shows the state (state which the raising / lowering table lowered | hung) which the positioning pin provided in the raising / lowering table of the automatic guided vehicle and the receiving part provided in the conveyed product are not engaging. It is a partial longitudinal cross-section front view which shows the state (state which the raising / lowering table raised) where the said positioning pin and the said receiving part are engaging. It is a schematic plan view which shows the receiving part which receives the said positioning pin in a conveyed product. It is a schematic plan view which shows the movement of the automatic guided vehicle from the upstream of a direction change path | route to a spin turn start position. It is a schematic plan view which shows the spin turn of the automatic guided vehicle from a spin turn start position to a spin turn end position. It is a schematic plan view which shows the state which the automatic guided vehicle which mounted the conveyed product is moving toward the unloading position. It is a schematic plan view which shows the state which the automatic guided vehicle which mounted the conveyed product stopped in the unloading position. It is a schematic top view which shows the state in the middle of the automatic guided vehicle performing the spin turn in the state which put the conveyed product on the ground in the unloading position. It is a schematic plan view which shows the state which the automatic guided vehicle performed the spin turn and stopped at the target stop position. It is a schematic plan view which shows the state which the automatic guided vehicle is moving toward the mounting position. It is a schematic plan view which shows the state which the automatic guided vehicle stopped in the mounting position. It is a schematic plan view which shows the state which the automatic guided vehicle performed the spin turn and stopped at the target stop position.

Embodiments according to the present invention will be described below with reference to the drawings.
In the following embodiments, the guidance direction is controlled using guidance means, and the traveling direction (direction of the arrow in FIG. 2A) of the automatic guided vehicle that self-runs along a predetermined traveling path is assumed to be forward and forward. The front, back, left and right are defined in the state, and the view seen from the right is the front view.

<Automated guided vehicle>
As shown in the perspective view of FIG. 1, the schematic plan view of FIG. 2A, and the partial longitudinal sectional front view of FIG. 3A, the automatic guided vehicle 1 according to the embodiment of the present invention includes 2 and left and right drive wheels 3 and 3 and a lifting table 4 on which the object D is placed.
The elevating table 4 includes positioning pins 5 and 5 diagonally projecting from the upper surface of the elevating table 4 as the elevating table 4 rises.
A transport object D placed on the lifting table 4 is a carriage 6 having front, rear, left and right wheels 7, 7,... And a luggage W on the carriage 6. In addition, the automatic guided vehicle 1 may transport the empty cart 6 with the load W unloaded.

As shown in the schematic plan view of FIG. 2A, the automatic guided vehicle 1 includes a travel drive device (not shown) of the drive wheels 3 and 3, a lift drive device (not shown) of the lift table 4, magnetic sensors S1 and S1, and a two-dimensional code. A reading sensor S2 and a control device (not shown) are provided.
The spin turn rotation center O shown in FIG. 2A is a vertical axis that is located at the center of the lifting table 4 and passes through the center in the left-right direction on the rotation axis of the left and right drive wheels 3, 3.
The magnetic sensors S1 and S1 are provided in front of and behind the spin turn rotation center O of the automatic guided vehicle 1, and the two-dimensional code reading sensor S2 is provided at a position as far as possible from the spin turn rotation center O, for example, on the right front side.

  The magnetic sensor S1 detects a magnetic tape (for example, the magnetic tape A in FIG. 5A) that is guiding means installed on the ground (for example, the floor surface FL in FIG. 3A), and detects the amount of displacement in the width direction with respect to the center position. To detect. Based on the detection information, the control device controls traveling so that the rotation speed of the left and right drive wheels 3 and 3 is changed so that the automatic guided vehicle 1 can travel along the center of the magnetic tape.

In the present embodiment, the guiding means used for guiding control is a magnetic tape that is a guiding wire, that is, a magnetic guiding type. Such an induction wire may be a magnetic induction type such as a magnetic wire, an electromagnetic induction type using an induction current from an electric wire, or an optical induction type using an optical tape or a drawn line. Also good.
Alternatively, without using guide lines, grasp the shape of the surrounding environment from information obtained by various sensors, estimate the self-location of the automated guided vehicle 1 based on the shape data, and make a map while correcting it Autonomous guidance such as moving SLAM (Simultaneously Localization And Mapping) may be used.

  However, by using a guide wire as the guide means, the automatic guided vehicle 1 travels while being guided by the guide wire installed along the travel route, so that the positional accuracy in the direction orthogonal to the traveling direction of the automatic guided vehicle 1 is improved. it can. In addition, in a direction orthogonal to the traveling direction of the automatic guided vehicle 1 in stop position control in which the automatic guided vehicle 1 is controlled to stop at a direction changing point (for example, see T in FIG. 5A) on a direction changing path described later. Stop position accuracy can be improved.

The two-dimensional code reading sensor S2 is, for example, a two-dimensional vision sensor, and recognizes a two-dimensional code (for example, the two-dimensional code E1, E2 in FIG. 5A) installed on the ground. Based on the recognition information, for example, the control device controls traveling so as to stop at the target stop position while measuring the distance in the traveling direction from the two-dimensional code.
Alternatively, the control device obtains the coordinate data of the automatic guided vehicle 1 from the information obtained by reading the two-dimensional code by the two-dimensional code reading sensor S2, and based on the coordinate data, the coordinates of the target stop position of another two-dimensional code. The data is set and stopped when the two-dimensional code reading sensor S2 reads the coordinate data of the target stop position.

The automatic guided vehicle 1 can be easily spin-turned around the spin-turn rotation center O by rotating the left and right drive wheels 3 and 3 in the reverse direction at a constant speed by the traveling drive device. For example, the schematic plan view of FIG. 2B shows a state in which a 90 ° spin turn is performed clockwise in plan view.
Such a spin turn may be configured not to rotate the left and right drive wheels 3 and 3 in the reverse direction at a constant speed but to steer the front, rear, left and right drive wheels.

The elevating table 4 of the automatic guided vehicle 1 can be moved up and down between a lowered position shown in the partial vertical sectional front view of FIG. 3A and an elevated position shown in the partial vertical sectional front view of FIG. 3B. 5 is provided on the diagonal.
Further, as shown in the schematic plan view of FIG. 4, the carriage 6 includes receiving portions G, G,... That receive the positioning pins 5, 5 at four locations, and the receiving portions G, G,. (4-fold rotational symmetry).
Since the positioning pins 5 and 5 raised by raising the lifting table 4 as shown in FIG. 3B are inserted into the receiving portions G and G of the carriage 6, the transported object D ( Since the carriage 6 and the luggage W) do not shift, the unmanned transport vehicle 1 can transport the transported object D stably and reliably.

A state in which the unmanned transport vehicle 1 transports the transported material D, lowers the lifting table 4 and lowers the transported material D, and then the unmanned transport vehicle 1 is rotated 90 ° clockwise or counterclockwise in plan view. However, if the accuracy of the rotation angle of the 90 ° spin turn is good, the receiving portions G, G,... Are 90 ° rotationally symmetric. It is inserted into the receiving parts G and G.
Similarly, after the transported object D is transported by the automatic guided vehicle 1 and the lift table 4 is lowered to lower the transported material D, the automatic guided vehicle 1 is rotated 180 ° clockwise or counterclockwise in plan view. Even if the accuracy of the rotation angle of the 180 ° spin turn is good, the receiving portions G, G,... Are 90 ° rotationally symmetric. It is inserted into the receiving parts G, G of the carriage 6.

<Stop position control system for spin turn of automated guided vehicles>
Hereinafter, the stop position control system in the spin turn of the automatic guided vehicle 1 according to the embodiment of the present invention will be described mainly with reference to the schematic plan views of FIGS. 5A and 5B.
The operation of FIGS. 5A and 5B shows an example in which the unmanned automated guided vehicle 1 performs a spin turn at a predetermined location on the travel route. In the travel route B, the magnetic tape A is installed on the ground, and the travel route B includes a direction changing route C in which the automatic guided vehicle 1 performs a spin turn.

A first two-dimensional code E1 is provided at a position spaced apart from the turn point T on the ground side of the spin turn start position P of the automatic guided vehicle 1 by a predetermined distance.
In addition, a second two-dimensional code E2 is provided at a position separated from the turning point T by a predetermined distance on the ground side of the spin turn end position Q of the automatic guided vehicle 1.

The positions of the first two-dimensional code E1 and the second two-dimensional code E2 will be described with reference to the schematic plan view of FIG. 6A.
Since the two-dimensional code E1, E2 on the ground side is read by the two-dimensional code reading sensor S2 of the automatic guided vehicle 1, the two-dimensional code reading sensor S2 is provided at a position as far as possible from the spin turn rotation center O. Correspondingly, it is installed at a position separated from the turning point T by a predetermined distance.

The two-dimensional codes E1 and E2 are installed at the positions shown in FIG. 6A, for example, with the local coordinate systems X and Y set as described in the figure.
The distance from the turning point T of the two-dimensional code E1 and the distance from the turning point T of the two-dimensional code E2 are both (α ² + β ² ) ^1/2 .

An example of the spin turn performed by the automatic guided vehicle 1 will be described with reference to the schematic plan views of FIGS. 5A and 5B.
As shown in FIG. 5A, the automatic guided vehicle 1 travels from the upstream side of the direction change path C toward the direction change point T, and stops at a position where, for example, the spin turn rotation center O substantially overlaps the direction change point T. .

When performing such traveling, as described above, the magnetic sensor S1 of the automatic guided vehicle 1 detects the magnetic tape A on the ground, detects the amount of deviation in the width direction with respect to the center position, and detects the detection information. Originally, traveling control is performed so that the automatic guided vehicle 1 can travel along the center of the magnetic tape A.
When the two-dimensional code reading sensor S2 of the automatic guided vehicle 1 recognizes the two-dimensional code E1 on the ground, as described above, the stop at the target stop position is performed while measuring the distance in the traveling direction from the two-dimensional code E1. Travel control is performed as is done.

Next, as shown in FIG. 5B, the automatic guided vehicle 1 is spin-turned from the spin turn start position P to the spin turn end position Q by a predetermined angle PA (PA = 90 ° in this example) clockwise in plan view. .
In this spin turn, after starting the spin turn from the spin turn start position P, the two-dimensional code reading sensor S2 reads the two-dimensional code E2 on the ground side and stops at the spin turn end position Q.

In such a configuration, since the two-dimensional code E2 is provided at a position separated by a predetermined distance from the turning point T on the ground side of the spin turn end position Q of the automatic guided vehicle 1, the spin of the automatic guided vehicle 1 is provided. A two-dimensional code E2 is installed at a position far from the turn rotation center O.
Further, the two-dimensional code reading sensor S2 for reading the two-dimensional code E2 provided in the automatic guided vehicle 1 is also at a position far from the spin turn rotation center O.
Therefore, compared with the case where the two-dimensional code is installed at or near the spin turn rotation center O of the automatic guided vehicle 1, the rotational angle in the spin turn can be read to a fine angle, so the automatic guided vehicle can be read with high accuracy. The rotation angle of 1 can be controlled.

In addition, the automatic guided vehicle 1 starts a spin turn, the two-dimensional code E2 provided on the ground side of the spin turn end position Q of the automatic guided vehicle 1 is read by the two-dimensional code reading sensor S2, and the automatic guided vehicle 1 stops. To do.
Thereby, when the automatic guided vehicle 1 performs a spin turn, the stop position accuracy is not deteriorated due to wear of the drive wheels 3 and 3 as in the case of performing the rotation angle control by the encoder.

<Rotation angle control method in spin turn of automated guided vehicle>
Hereinafter, a rotation angle control method in the spin turn of the automatic guided vehicle 1 according to the embodiment of the present invention will be described with reference to the schematic plan views of FIGS. 6A to 6D and the schematic plan views of FIGS. 7A to 7C. To do.

  6A to 6D, the unmanned transport vehicle 1 transports the transported article D placed on the lifting table 4 to the unloading position P1, and places the transported article D on the ground at the unloading position P1. Only the spin turn is performed, and then, an example is shown in which the conveyed product D is placed on the lifting table 4 and moved.

As shown in FIG. 6A, the automatic guided vehicle 1 on which the conveyed product D is placed travels from the upstream side of the direction change path C toward the direction change point T, and stops at the position of FIG. 6B, for example.
In this example of the stop position, the spin turn rotation center O of the automated guided vehicle 1 is slightly shifted from the ground side turning point T, and the conveyed object D and the automated guided vehicle 1 are rotated clockwise by an angle F around the vertical axis. It is off.

In the unloading position P1 in FIG. 6B, the control device of the automatic guided vehicle 1 lowers the lifting table 4 and places the transported object D on the ground.
At the unloading position P1, there are cases where a load is unloaded from the cart 6 as the transported object D, a load is loaded onto the cart 6, a load is unloaded from the cart 6, and a new load is loaded.

From the information obtained by reading the first two-dimensional code E1 by the two-dimensional code reading sensor S2 at the spin turn start position P at the unloading position P1, the control device reads the coordinate data of the automatic guided vehicle 1 at the spin turn start position P. Get.
From the coordinate data of the automatic guided vehicle 1 at the spin turn start position P, the control device obtains coordinate data of a target stop position that rotates at a predetermined angle PA (PA = 90 °, see FIG. 6D).

In this case, the control device performs coordinate conversion in the following procedure.
(1) The position (translation position, angle) in the local coordinate system of the two-dimensional code E1 read from the first two-dimensional code E1 by the two-dimensional code reading sensor S2 is converted into the world coordinate system.
(2) The target stop position after the rotation of the predetermined angle PA = 90 ° in the world coordinate system is obtained.
(3) The target stop position of the world coordinate system is converted into the local coordinate system of the second two-dimensional code E2, and the target stop position (translation position, angle) of the local coordinate system of the two-dimensional code E2 is obtained.

Next, the control device starts the spin turn as shown in FIG. 6C from the spin turn start position P, reads the second two-dimensional code E2 by the two-dimensional code reading sensor S2, and obtains 2 as described above. When the coordinate data of the target stop position in the local coordinate system of the dimension code E2 is read, the automatic guided vehicle 1 is stopped as shown in FIG. 6D.
In this way, the control device stops the automatic guided vehicle 1 by reading the coordinate data of the target stop position of the local coordinate system of the two-dimensional code E2 by the two-dimensional code reading sensor S2, so that the rotation angle control by the encoder is performed. As in the case, the stop position accuracy is not deteriorated due to wear of the drive wheels.

In the spin turn end position Q of FIG. 6D in which the automatic guided vehicle 1 has made a spin turn as described above, the automatic guided vehicle 1 is suitable for placing the conveyed product D on the lifting table 4 with respect to the conveyed product D. In position. That is, the positions of the diagonal positioning pins 5 and 5 of the lifting table 4 are aligned with the positions of the diagonal receiving portions G and G of the conveyed product D.
Thereby, when the control device raises the lifting table 4 and places the conveyed product D on the lifting table 4, the positioning pins 5, 5 of the lifting table 4 are securely attached to the receiving portions G, G of the conveyed product D. Engage with.
Therefore, since the conveyed product D does not shift from the lifting table 4 of the automatic guided vehicle 1, the automatic guided vehicle 1 can convey the conveyed product D stably and reliably.

  7A to 7C, the automatic guided vehicle 1 moves to the placement position P2 where the transported object D placed on the ground is placed on the lifting table 4, and only the automatic guided vehicle 1 spins, The example which moves the conveyed product D by mounting on the raising / lowering table 4 is shown.

The transport object D is placed on the ground at the mounting position P2, and the position data of the transport object D is, for example, based on information from another automatic guided vehicle that transports the transport object D to the mounting position P2. The controller knows.
There are cases where the transported object D at the placement position P2 is loaded with a load on the carriage 6 or only the carriage 6 is used.

As shown in FIG. 7A, the unmanned automated guided vehicle 1 travels from the upstream side of the direction change path C toward the direction change point T, and stops at, for example, the position shown in FIG. 7B.
In this example of the stop position, the automatic guided vehicle 1 is stopped at a position where the spin turn rotation center O substantially overlaps the direction turning point T, and there is no angular deviation around the vertical axis. However, as in the example of the stop position in FIG. 6B, there may be a case where there is a deviation between the spin turn rotation center O of the automatic guided vehicle 1 and the ground direction turning point T and an angular deviation about the vertical axis. The procedure in that case is the same as the following.

The control device of the automatic guided vehicle 1 performs the automatic transfer at the spin turn start position P from the information obtained by reading the first two-dimensional code E1 by the two-dimensional code reading sensor S2 at the spin turn start position P at the placement position P2. The coordinate data of the car 1 is obtained.
The control device places the transport object D on the lift table 4 at the spin turn end position Q from the coordinate data of the automatic guided vehicle 1 at the spin turn start position P and the position data of the transport object D received from the ground side control device. A predetermined angle for moving to an appropriate position to be placed and coordinate data of a target stop position for performing the rotation of the predetermined angle are obtained.

In this case, the control device performs coordinate conversion in the following procedure.
(1) The position (translation position, angle) in the local coordinate system of the two-dimensional code E1 read from the first two-dimensional code E1 by the two-dimensional code reading sensor S2 is converted into the world coordinate system.
(2A) When the position data of the conveyed product D received from the ground side control device is a position (translation position, angle) of the two-dimensional code E1 in the local coordinate system, the position is converted into the world coordinate system.
(2B) When the position data of the conveyed product D received from the ground side control device is in the world coordinate system, the data is held as it is.
(3) From the position data of the world coordinate system of the transport object D and the position data of the world coordinate system of the automatic guided vehicle 1 at the spin turn start position P, the transport object D is placed on the lift table 4 at the spin turn end position Q. Coordinate data for a predetermined angle for moving to an appropriate position and a target stop position for rotating the predetermined angle in the world coordinate system are obtained.
(4) The target stop position of the world coordinate system is converted into the local coordinate system of the second two-dimensional code E2, and the target stop position (translation position, angle) of the local coordinate system of the two-dimensional code E2 is obtained.

Next, the control device starts the spin turn from the spin turn start position P, reads the second two-dimensional code E2 by the two-dimensional code reading sensor S2, and determines the local coordinates of the two-dimensional code E2 obtained as described above. When the coordinate data of the target stop position of the system is read, the automatic guided vehicle 1 is stopped as shown in FIG. 7C.
In this way, the control device stops the automatic guided vehicle 1 by reading the coordinate data of the target stop position of the local coordinate system of the two-dimensional code E2 by the two-dimensional code reading sensor S2, so that the rotation angle control by the encoder is performed. As in the case, the stop position accuracy is not deteriorated due to wear of the drive wheels.

At the spin turn end position Q of FIG. 7C where the automatic guided vehicle 1 has made a spin turn as described above, the automatic guided vehicle 1 is suitable for placing the conveyed product D on the lifting table 4 with respect to the conveyed product D. In position. That is, the positions of the diagonal positioning pins 5 and 5 of the lifting table 4 are aligned with the positions of the diagonal receiving portions G and G of the conveyed product D.
Thereby, when the control device raises the lifting table 4 and places the conveyed product D on the lifting table 4, the positioning pins 5, 5 of the lifting table 4 are securely attached to the receiving portions G, G of the conveyed product D. Engage with.
Therefore, since the conveyed product D does not shift from the lifting table 4 of the automatic guided vehicle 1, the automatic guided vehicle 1 can convey the conveyed product D stably and reliably.

In the above embodiment, the coordinate data of the spin turn start position P and the coordinate data of the target stop position, which is the spin turn end position Q, more preferably include the translation position (x, y) and the angle (θ). This is a preferred embodiment.
Accordingly, when the automatic guided vehicle 1 performs a spin turn, it is possible to detect a deviation from the rotation center when the rotation cannot be performed with the spin turn rotation center fixed. Alternatively, when the detected deviation from the center of rotation is a certain value or more, the correction operation can be performed after the spin turn.
However, when the deviation from the rotation center does not need to be severely considered, the coordinate data may be only the angle (θ).

  All the description of the above embodiment is an illustration, and is not limited to this. Various improvements and modifications can be made without departing from the scope of the invention.

DESCRIPTION OF SYMBOLS 1 Automatic guided vehicle 2 Swivel wheel 3 Drive wheel 4 Lifting table 5 Positioning pin 6 Carriage 7 Wheel A Magnetic tape (guidance means)
B Travel route C Direction change route D Conveyed objects E1, E2 Two-dimensional code FL Floor (ground)
G receiving portion O spin turn rotation center P spin turn start position P1 unloading position P2 placement position PA predetermined angle Q spin turn end position S1 magnetic sensor S2 two-dimensional code reading sensor T turning point W luggage

Claims (7)

In an automated guided vehicle that is guided and controlled using a guiding means and travels without a track along a predetermined traveling route,
A system for controlling a stop position when the automatic guided vehicle performs a spin turn of a predetermined angle,
On the ground side of the spin turn end position of the automatic guided vehicle, a two-dimensional code is provided at a position separated by a predetermined distance from a turning point,
The automatic guided vehicle is
A two-dimensional code reading sensor for reading the two-dimensional code;
After starting the spin turn, the two-dimensional code reading sensor reads the two-dimensional code on the ground side and stops at the spin turn end position,
Stop position control system for spin turn of automated guided vehicles. In an automated guided vehicle that is guided and controlled using a guiding means and travels in a trackless manner along a predetermined traveling route,
A method for controlling a rotation angle of the automatic guided vehicle when the automatic guided vehicle performs a spin turn of a predetermined angle,
On the ground side of the spin turn start position of the automatic guided vehicle,
The first two-dimensional code is provided at a position separated by a predetermined distance from the turning point,
On the ground side of the spin turn end position of the automatic guided vehicle,
A second two-dimensional code is provided at a position separated from the turning point by the predetermined distance,
The automatic guided vehicle includes a two-dimensional code reading sensor that reads the two-dimensional code,
The control device for the automatic guided vehicle includes:
Obtaining coordinate data of the spin turn start position from information obtained by reading the first two-dimensional code by the two-dimensional code reading sensor at the spin turn start position;
Obtaining coordinate data of a target stop position for rotating the predetermined angle from the coordinate data of the spin turn start position;
Starting the spin turn of the automatic guided vehicle, reading the second two-dimensional code by the two-dimensional code reading sensor, and stopping the automatic guided vehicle when the coordinate data of the target stop position is read;
Including,
A rotation angle control method in a spin turn of an automated guided vehicle. The automatic guided vehicle includes an elevating table for placing a transported object,
The control device for the automatic guided vehicle includes:
Moving the automatic guided vehicle so as to transport the transported object placed on the lifting table to an unloading position;
Lowering the elevating table to place the transported object on the ground at the unloading position;
Obtaining coordinate data of the spin turn start position from information obtained by reading the first two-dimensional code by the two-dimensional code reading sensor at the spin turn start position at the unloading position;
Obtaining coordinate data of a target stop position for rotating the predetermined angle from the coordinate data of the spin turn start position;
Starting the spin turn of the automatic guided vehicle, reading the second two-dimensional code by the two-dimensional code reading sensor, and stopping the automatic guided vehicle when the coordinate data of the target stop position is read;
Raising the elevating table and placing the conveyed product on the elevating table;
including,
The rotation angle control method in the spin turn of the automatic guided vehicle according to claim 2. The automatic guided vehicle includes an elevating table for placing a transported object,
The control device for the automatic guided vehicle includes:
A step of moving the automatic guided vehicle to a mounting position for mounting the transported object placed on the ground on the lifting table;
Obtaining the spin-turn start position coordinate data from the information obtained by reading the first two-dimensional code by the two-dimensional code reading sensor at the spin-turn start position at the placement position;
From the coordinate data of the spin turn start position and the position data of the transported object received from the ground side control device, a predetermined for moving the transported object to an appropriate position for placing it on the lifting table at the spin turn end position Obtaining coordinate data of an angle and a target stop position for performing rotation of the predetermined angle;
Starting the spin turn of the automatic guided vehicle, reading the second two-dimensional code by the two-dimensional code reading sensor, and stopping the automatic guided vehicle when the coordinate data of the target stop position is read;
Raising the elevating table and placing the conveyed product on the elevating table;
including,
The rotation angle control method in the spin turn of the automatic guided vehicle according to claim 2. The lifting table of the automatic guided vehicle includes a positioning pin,
The transported object includes a receiving part,
The positioning pin engages with the receiving portion in a state where the lift table is raised and the conveyed product is placed on the lift table.
The rotation angle control method in the spin turn of the automatic guided vehicle according to claim 3 or 4. The coordinate data of the spin turn start position and the coordinate data of the target stop position include only angles.
The rotation angle control method in the spin turn of the automatic guided vehicle according to any one of claims 2 to 5. The coordinate data of the spin turn start position and the coordinate data of the target stop position include an angle and a translation position.
The rotation angle control method in the spin turn of the automatic guided vehicle according to any one of claims 2 to 5.

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