JP5689278B2 - Control method of automatic guided vehicle - Google Patents

Description

  The present invention relates to a control method for an automatic transport vehicle that automatically travels along a predetermined route to transport articles and the like.

  Conventionally, for example, an automated guided vehicle that travels along a preset route in a factory is known. The automatic transport vehicle includes a drive motor, a battery, and the like, and a detection sensor for detecting a conducting wire such as a magnetic tape laid on the floor surface. If a workpiece is loaded on such an automatic conveyance vehicle, the workpiece can be unmannedly conveyed along a predetermined route on which a conducting wire is laid.

  Furthermore, for example, an automatic transport vehicle that enables transfer between different conductors has been proposed so that various routes according to transport needs in the factory can be widely handled (see, for example, Patent Document 1). Here, the crossing between the two conductors is enabled by laying a transverse conductor for traversing the automated guided vehicle in the gap between the two conductors laid in parallel. Further, as a device for preventing the automatic guided vehicle from being derailed when moving from advancing to traversing, a technique is disclosed in which an oblique conducting wire is laid before the traversing conducting wire or is temporarily stopped when moving to the traversing conducting wire.

  However, the conventional automated guided vehicle has the following problems. In other words, if the installation side is complicated, such as laying a slanting conductor in front of the transverse conductor, or if it is stopped once when changing to the transverse conductor, the smooth running of the automated guided vehicle will be hindered, and the workpiece will be quickly There is a risk that it cannot be transported.

JP 2009-223561 A

  The present invention has been made in view of the above-described conventional problems, and is a control method for shifting the automatic transport vehicle to a follow-up state with respect to a new conducting wire after traversing or skewing. An object of the present invention is to provide a method for controlling an automatic guided vehicle capable of shortening the time required for shifting to a follow-up state by smoothly transferring to a conducting wire.

The present invention has two front and rear drive units in which two sets of drive wheels that are driven individually are arranged coaxially and are turned and steered according to the rotational difference between the two sets of drive wheels. And a detection sensor attached to the front side of the drive unit in order to detect a conductor having a predetermined width laid along the path, and an automatic guided vehicle traversing or skewing to a new conductor A control method for approaching and shifting to a follow-up state,
A first traveling step in which the automatic conveyance vehicle approaches the new conductor by traversing or skewing by moving the drive unit forward at an approach angle a with respect to the new conductor;
After the detection sensor of at least one of the drive units detects the new conducting wire, the second traveling advances the drive unit at the entry angle a until the detection sensor again detects the new conducting wire. Steps,
After the second traveling step, a third traveling step for steering the drive unit so that the new conducting wire can be redetected by the detection sensor;
The drive unit is made to enter the oblique direction with respect to the new conductor, and after the new conductor is re-detected by the detection sensor, the drive unit is steered so as to follow the new conductor. A transition step for performing switching to follow-up running control,
The detection sensor includes a detection area extending in a direction orthogonal to the traveling direction of the drive unit, and not only whether or not the conductor is detected, which part of the detection area detects the conductor. It is possible to detect which part is not detected, and to detect the conductor edge forming the edges on both sides in the width direction of the conductor according to the combination of the detection part and the non-detection part in the detection area Is possible,
In the transition step, switching to the following traveling control is not performed only by the detection sensor detecting the new conductor, and after the detection sensor detects a new conductor, the conductors on both sides of the conductor in the width direction are detected. In the control method of the automatic guided vehicle , the switching to the following traveling control is executed when the lead edge on the forward direction side of the drive unit is detected among the edges .

  In the control method for the automatic guided vehicle according to the present invention, when the automatic guided vehicle is shifted to the following state with respect to the new conducting wire, the detection sensor detects the new conducting wire as in the second traveling step. There is no immediate switch to follow-up running control. First, the drive unit is moved forward and passed until the detection sensor again detects the new conductor. Thereafter, the drive unit is steered so that the new conductor can be detected again.

In the transition step, the driving unit enters the new conducting wire from an oblique direction. For example, when entering from the left side of the conducting wire, the conducting wire starts to be detected from the right side of the detection area. If switching to the follow-up running control at this time when left steering is originally required, reverse right steering may occur so that the conductor detected on the right side of the detection area can be detected at the center. On the other hand, if switching to the follow-up running control is performed when the conductor edge on the forward direction side of the drive unit is detected as described above, steering in the left direction is appropriately performed so as not to deviate from the conductor. Can be generated. If switching to the following traveling control is executed when a lead wire edge on the forward direction side of the drive unit is detected, the reverse steering as described above can be avoided, and the automatic conveyance at the time of switching to the following traveling control is performed. Car behavior can be stabilized.
In this invention, it is preferable that the approach angle of the said drive unit with respect to the said new conducting wire in the said transition step is the approach angle b smaller than the said approach angle a (Claim 2).
In this control method, the drive unit is re-approached to the new conducting wire at the approach angle b smaller than the approach angle a via the steering of the drive unit as described above. Then, switching to the following traveling control is executed in response to the re-detection of the new conductor by the detection sensor. If the approach angle b approaches the new conductor and switches to the follow-up running control, the lead wire is compared with the approach angle a approach to the new conductor and the follow-up running control. The risk of derailment that deviates from can be suppressed.

  According to the control method of the present invention, after traversing or skewing, at least one of the drive units is controlled so as to pass the new conducting wire, so that the new angle at an approaching angle or speed at which derailment is inherently caused. It is possible to access to a simple lead wire. Thereafter, if the approach angle is suppressed and the new conductor is re-approached, it is possible to switch to the following traveling control while suppressing the possibility that the automatic guided vehicle will derail.

  As described above, according to the control method of the automatic guided vehicle of the present invention, it is possible to smoothly shift to the following state of the new conductor, and it is possible to shorten the time required for the transition.

  In the present invention, the number of executions of the first traveling step to the third traveling step may be one or may be two or more. For example, if the number of executions is two, the drive unit is controlled to meander on both sides of the new conductor. For example, if the approach angle is large or the speed of the drive unit is high, it is preferable to generate the meandering as described above by making the number of executions a plurality of times. If such meandering is controlled to gradually converge, the transition to the follow-up state for the new conductor can be performed with high reliability.

  Further, the approach angle is an angle formed by a first direction in which the automatic transport vehicle travels by traversing or skewing and a second direction in which the automatic transport vehicle travels following the new conductor. I mean. When the automatic transport vehicle traverses, this approach angle is about 90 degrees. As this approach angle becomes smaller than 90 degrees, the transfer to the new conductor becomes easier. On the other hand, when the approach angle exceeds 90 degrees, a direction component opposite to the second direction is included in the first direction. Therefore, as the approach angle exceeds 90 degrees, the difficulty of transferring to the new conductor increases.

The detection sensor includes a detection area extending in a direction orthogonal to the traveling direction of the drive unit, and not only whether or not the conductor is detected, but also a portion of the detection area detects the conductor. It is possible to detect which part is detected and which part is not detected, and it is possible to detect the conductor edge that forms the edge of the conductor according to the combination of the detection part and the non-detection part in the detection area. Yes,
In the transition step, switching to the follow-up running control is not performed only by detecting the new conducting wire by the detection sensor, and then the follow-up running control is performed when a conducting wire edge on the forward direction side is detected. Switching is performed .

  In the transition step, the driving unit enters the new conducting wire from an oblique direction. For example, when entering from the left side of the conducting wire, the conducting wire starts to be detected from the right side of the detection area. If the control is switched to the follow-up running control at this time, the right steering in the reverse direction may occur so that the conductor can be detected at the center of the detection area, even though the left steering is originally required. There is. On the other hand, if switching to the follow-up running control is performed when the conductor edge on the forward direction side of the drive unit is detected as described above, steering in the left direction is appropriately performed so as not to deviate from the conductor. Can be generated. If reverse steering as described above can be avoided, the behavior of the automatic guided vehicle at the time of switching to the follow-up traveling control can be stabilized.

In addition, the automatic transport vehicle includes autonomous navigation means that enables autonomous traveling by autonomous navigation,
The third traveling step is preferably a step in which the automatic guided vehicle performs autonomous traveling (claim 3).
In this case, it is not necessary to lay a conductor for advancing the drive unit at the approach angle b.

In addition, the automatic transport vehicle includes autonomous navigation means that enables autonomous traveling by autonomous navigation,
The first and second traveling steps are preferably steps in which the automatic guided vehicle performs autonomous traveling.
In this case, it is not necessary to lay a conducting wire for traversing or skewing between the conducting wire followed by the automated guided vehicle and the new conducting wire. Therefore, it is possible to realize a highly versatile automatic transfer system that can easily change the layout of the route on which the automatic guided vehicle travels.

Moreover, it is preferable that the control target value of the approach angle a in the first traveling step is 90 degrees. (Claim 5).
If the control target value of the approach angle a is set to 90 degrees, the automatic guided vehicle can be brought close to the new conductor. If the automatic transport vehicle is traversed, the travel distance in the front-rear direction of the automatic transport vehicle in the first travel step can be reduced to zero. In this case, there is a merit that the route on which the automated guided vehicle travels can be designed very compactly in the front-rear direction in accordance with the execution of the first travel step.

  However, if the drive unit that has entered the new lead wire at the approach angle a of about 90 degrees is immediately switched to the follow-up running control without being stopped, the control difficulty becomes too high. The demerit that the possibility becomes extremely low occurs. Therefore, as in the present invention, after passing the drive unit so as to cross the approach angle a and the new conductor, the effect of the present invention is to approach the new conductor at a smaller approach angle b. Especially effective.

Further, it is preferable that the first to third travel steps and the transition step are executed for the two front and rear drive units, respectively.
In this case, by performing the same control for the two front and rear drive units, the automatic guided vehicle can be transferred to the new conductor with a very smooth operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 3 is a top view schematically showing the automatic guided vehicle in the first embodiment. Explanatory drawing explaining the detection area of a line sensor in Example 1. FIG. 1 is a block diagram showing a system configuration of an automated guided vehicle in Embodiment 1. FIG. Explanatory drawing which shows the driving | running route of the automatic conveyance vehicle at the time of shifting to the follow-up state to the new guideline in Example 1. FIG. Explanatory drawing which shows the locus | trajectory of the detection area at the time of shifting to the follow-up state to a new guideline in Example 1. FIG. Explanatory drawing which shows the outline | summary of the other automatic conveyance system in Example 1. FIG. Explanatory drawing which shows the outline | summary of the other automatic conveyance system in Example 1. FIG. Explanatory drawing which shows the outline | summary of the automatic conveyance system in Example 2. FIG. Explanatory drawing which shows the driving | running route of the automatic conveyance vehicle at the time of shifting to the follow-up state to the new guideline in Example 2. FIG. Explanatory drawing which shows the locus | trajectory of the detection area at the time of shifting to the follow-up state to a new guideline in Example 2. FIG.

The embodiment of the present invention will be specifically described with reference to the following examples.
Example 1
This example relates to a control method for automatically running the automatic guided vehicle 2 along a predetermined route. The contents of this example will be described with reference to FIGS.

  In this example, as shown in FIGS. 1 and 2, two sets of front and rear drive units 3 in which a set of two drive wheels 331 to be individually driven are coaxially arranged, and a predetermined width laid along the path. Control method for the automatic guided vehicle 2 having a line sensor 351 (detection sensor) for detecting the guideline (conducting wire) 11 and 12 to shift to a follow-up state for the new guideline 12 (transfer) It is an example regarding.

The control method of the automatic transport vehicle 2 includes a first traveling step in which the automatic transport vehicle 2 is traversing and approaches the guideline 12;
After the line sensor 351 of the drive unit 3 detects the guideline 12, a second traveling step of moving the drive unit 3 forward until it does not detect the guideline 12 again;
After this second traveling step, a third traveling step for steering the drive unit 3 so that the guideline 12 can be detected again by the line sensor 351;
A transition step of switching to follow-up running control in which the drive unit 3 is steered to run following the guideline 12 in response to the re-detection of the guideline 12 by the line sensor 351.
Hereinafter, this content will be described in detail.

  As shown in FIG. 1, the automatic conveyance system 1 of this example is an unmanned conveyance system introduced into an assembly factory such as an automobile. A highly efficient transfer system can be realized by introducing an automatic transfer system 1 that automatically moves the automatic transfer vehicle 2 between work stations that serve as bases for loading or unloading workpieces such as automobile parts. In particular, the automatic conveyance system 1 of this example is configured to include an autonomous traveling section in which the automatic guided vehicle 2 autonomously travels regardless of the guidelines.

  First, the automatic conveyance vehicle 2 applied to the automatic conveyance system 1 of this example is demonstrated. As shown in FIG. 2, the automatic transport vehicle 2 includes a vehicle body 20 that is long in the front-rear direction including a loading platform (not shown) on which a workpiece such as an automobile part is loaded. The size of the vehicle body 20 is about 1.4 m in the front-rear direction and the width is about 0.5 m. The vehicle body 20 is provided with a drive unit 3 at two locations in the front-rear direction, and a control unit 50 (FIG. 4) and a battery (not shown). Auxiliary wheels (not shown) made up of free wheels are attached to the left and right sides of the bottom surface corresponding to the middle of the two drive units 3 in the front-rear direction.

  As shown in FIGS. 1 to 4, the drive unit 3 corresponds to a set of two drive wheels 331 arranged in parallel on the same axis, and each of these drive wheels 331, and can be independently controlled for rotation. And a basic drive motor 310. The drive unit 3 is steered according to the rotational difference between the drive wheels 331 on both sides that are individually driven. In the drive unit 3 of this example, the steering range is set so that the entire circumference of 360 degrees can be covered.

  In the front portion of the drive unit 3, the line sensor 351 is disposed at the center, and the marker sensor 352 is disposed at a position offset from the line sensor 351. These sensors are always attached so as to rotate together with the steering of the drive unit 3 so as to be positioned in front of the drive unit 3 on the forward side.

The line sensor 351 is a detection sensor that detects magnetism of the guide lines 11 and 12 that are magnetic tapes. The line sensor 351 of this example is a sensor in which a plurality of small magnetic detection elements 360 are arranged in the horizontal direction (see FIG. 3), and the detection area 36 having a wide width of about 8 cm in a direction perpendicular to the traveling direction of the drive unit 3. It has. The line sensor 351 can individually detect whether or not magnetism is detected for each magnetic detection element 360 in the detection area 36. According to the line sensor 351 of this example, it is possible to detect the edge of the guide line (conductive wire edge) according to the combination of which magnetic detection element 360 detects the guide line and which is not detected.
The marker sensor 352 is a sensor that reads address information and the like from guide markers that are appropriately arranged on the floor surface.

  The internal system of the automatic guided vehicle 2 is configured as shown in FIG. For the control unit 50 of the automatic guided vehicle 2, in addition to the two drive units 3, a bumper switch 220, an obstacle sensor 26, an emergency stop switch 231, an operation switch 232, a display lamp 233, an LED display 234, a speaker 235, the communication unit 25, the angular velocity sensor 281 and the like are electrically connected.

  The internal configuration of the drive unit 3 includes a drive unit 31 that drives the drive wheel 331 (FIG. 2) based on a control signal received from the control unit 50, and a detection that receives detection signals from various sensors and transmits them to the control unit. And section 35. The drive unit 31 includes a drive motor 310 and a motor driver 315 that controls the drive motor 310. The motor driver 315 controls the rotation of the drive motor 310 based on the control signal received from the control unit 50. The motor driver 315 can grasp the traveling speed of the corresponding drive wheel 331 based on the control value of the drive motor 310.

  In addition to detection means such as a line sensor 351, a marker sensor 352, a steering angle detection unit 350 that detects a steering angle, the detection unit 35 is an I / F that serves as an interface when transmitting a detection signal to the control unit 50. A circuit 38 is provided.

  The control unit 50 is a unit including an I / F circuit 55 that is an interface for exchanging signals with various switches and the like, and a main control circuit 51 that outputs various control signals to the drive unit 3. is there. The main control circuit 51 functions as a travel control means 510 for controlling the travel of the automatic transport vehicle 2, a control switching means 512 for switching the travel control mode, and a positioning means 513 for calculating positioning information such as the position of the automatic transport vehicle 2. It has.

  The travel control means 510 is a control means capable of executing follow-up travel control for the guidelines 11 and 12 and autonomous travel control. In the following traveling control of this example, the front and rear drive units 3 are individually controlled. On the other hand, the autonomous traveling control is a control for traveling along a route taught in advance for the autonomous traveling section. In this autonomous traveling control, each drive unit 3 is controlled by autonomous navigation based on positioning information by the positioning means 513.

In the autonomous traveling control of this example, the control content is different between when the automatic guided vehicle 2 is skewed and when it is traversing. In the skewed autonomous traveling control, the steering directions of the front and rear drive units 2 are controlled in phase . On the other hand, in the transverse autonomous traveling control, the steering direction of the front and rear drive units 2 is maintained at about 90 degrees, while the posture of the automatic guided vehicle 2 is controlled by adjusting the speed of the drive wheels 331 of each drive unit 3.

  The positioning means 513 is a means for calculating positioning information such as the position and posture of the automated guided vehicle 2 necessary for autonomous navigation. The positioning means 513 constitutes the autonomous navigation means 28 together with the angular velocity sensor 281 that detects the angular velocity and the motor driver 315 that detects the traveling speed of the drive wheel 331. The positioning means 513 calculates positioning information based on the angular velocity detected by the angular velocity sensor 281, the traveling speed by the motor driver 315, and the like. The calculated positioning information becomes an input value for autonomous traveling control by the traveling control means 510.

Next, the specification of the route in the automatic conveyance system 1 will be described. The route includes a follow-up section and an autonomous travel section.
As shown in FIG. 1, the following section is a section in which guide lines 11 and 12 made of magnetic tape having a width of about 2.5 cm are laid along the path. In the automatic conveyance system 1 of this example, the guide line 11 of the first follow-up section and the guide line 12 of the second follow-up section are laid in parallel through the autonomous traveling section. A guide marker 115 indicating the address information is arranged at the end point of the first follow-up section that is continuous with the autonomous travel section.

  The autonomous traveling section is a section where no guide line is laid, and the section where the automatic guided vehicle 2 autonomously travels by autonomous navigation. In the autonomous traveling section of this example, a traversing route that travels across the guide lines 11 and 12 is taught in advance as a route for the automatic guided vehicle 2 to travel.

The traveling operation of the automatic transport vehicle 2 in each section of the automatic transport system 1 configured as described above will be described.
<First follow-up section>
In the first follow-up section, the automatic guided vehicle 2 is controlled so as to follow the guideline 11 and travel. In the first following section, the following traveling control in which the two drive units 3 are individually controlled is applied. Each drive unit 3 is steered so that the guide line 11 can be detected at the center of the detection area 36 of each line sensor 351. For example, when the guideline 11 is detected by shifting to the left side of the detection area 36 of the line sensor 351, the steering is performed in the left direction. When the guideline 11 is shifted to the right side, the steering is performed in the right direction. Further, when the guide marker 115 in the first follow-up section is detected, the automatic guided vehicle 2 stops moving forward, starts traversing, and leaves the guideline 11.

<Autonomous driving section>
In the autonomous traveling section, the automated guided vehicle 2 autonomously travels by autonomous navigation while maintaining the posture when the automated guided vehicle leaves the guideline 11.
<Second follow-up section>
In the second follow-up section, the automatic guided vehicle 2 is controlled so as to follow the guideline 12 and travel. In the second follow-up section, the drive unit 3 is controlled similarly to the first follow-up section.

As shown in FIG. 5, the characteristic of the control method of the automatic guided vehicle 2 in this example is transition control when shifting from the autonomous traveling section to the second tracking section. In this transition control, the first to third travel steps and the transition step are applied to each drive unit 3.
(1) First traveling step In this step, each drive unit 3 is controlled so as to approach the guideline 12 at an approach angle a = about 90 degrees, and the automatic guided vehicle 2 traverses. In this step, the transverse autonomous traveling control is applied, and the steering angle of each drive unit 3 is about 90 degrees. This first traveling step corresponds to the traveling period to the detection area 36A in FIG. 6 in which the magnetic detection element 360 in the detection state is indicated by a black circle.

(2) Second traveling step This step maintains the steering angle of the drive unit 3 until each line sensor 351 again detects the guideline 12 after the line sensor 351 detects the guideline 12. As in the first traveling step, traversing autonomous traveling control is applied. In the autonomous traveling section as described above, the automatic guided vehicle 2 autonomously travels by autonomous navigation while receiving posture control so that the guideline 12 can be reached with the posture when the guideline 11 is left. Therefore, the arrival timing of each drive unit 3 to the guideline 12 is almost the same. This second traveling step corresponds to the traveling period from the detection area 36A to the detection area 36B in FIG.

(3) Third Traveling Step This step is a step in which the drive unit 3 is steered so that the guideline 12 can be detected again by the line sensor 351 after the second traveling step. In this step, the vehicle is steered so as to follow the travel route of FIG. 5 by autonomous navigation. The third traveling step corresponds to a traveling period from the detection area 36B to the detection area 36C in FIG. In this third traveling step, the oblique autonomous traveling control is applied, and the front and rear drive units 3 are controlled in phase .

(4) Transition step This step is a step in which the automatic transport vehicle 2 is skewed so that each drive unit 3 approaches the guideline 12 at the approach angle b = about 45 degrees, and then the control is switched to follow-up running control to the guideline 12. It is. When the automatic guided vehicle 2 is skewed as described above, the guideline 12 starts to be detected from the left side as in the detection area 36D in FIG. In the transition control of this example, even if the guideline 12 is detected in this way, the skew is maintained without being immediately switched to the follow-up running control. When the guideline 12 starts to be detected from the left side of the detection area 36 and is switched to the follow-up running control, the guideline 12 should be steered rightward in order to follow the guideline 12. This is because reverse steering (reverse steer) in the left direction is generated in order to detect this.

  If the skew is maintained as described above, the guideline 12 is not detected from the left side as in the detection area 36E in FIG. 6, and thus the edge 121 on the forward direction side can be detected. In the transition step of this example, when the edge 121 of the guideline 12 is detected in this way, switching to the following traveling control is executed. If the switching to the follow-up running control is executed at such timing, the steering is appropriately performed in the right direction so as not to deviate to the left of the guideline 12, and as shown in FIG. Can be migrated to. This transition step corresponds to the traveling period from the detection area 36C in FIG. 6 to the detection area 36E.

  In the automatic conveyance system 1 of the present example configured as described above, when the vehicle moves from the autonomous traveling by traversing to the guideline 12, the automatic transport vehicle 2 temporarily traverses the guideline 12 and then skews and guides the guideline. 12 again approaches to the follow-up state. In the transition control to such a follow-up state, the automatic guided vehicle 2 may not be temporarily stopped when traversing and reaching the guideline 12. In the automatic conveyance system 1 of this example, the automatic conveyance vehicle 2 is deliberately deviated from the guideline 12, and then autonomously travels so as to reapproach the guideline 12, thereby realizing a smooth and quick transfer to the guideline 12. ing.

  As described above, according to the control method of the automatic guided vehicle 2 of the present example for causing the automatic guided vehicle 2 to traverse and then shifting to a follow-up state with respect to the new guideline 12, smooth transfer to the new guideline 12 is achieved. This can be realized and the time required for transfer can be shortened.

  In the automatic conveyance system 1 of this example, the original guideline 11 and the guideline 12 to be transferred are parallel. Instead, as shown in FIG. 7, the guideline 12 to be transferred to the original guideline 11 can be laid diagonally. In the case of the figure, the drive unit 3 on the rear side of the traveling automatic transport vehicle 2 reaches the guideline 12 first. When the rear drive unit 3 reaches the guideline 12, the posture control is canceled and the rear drive unit 3 is stopped. Thereafter, the first to third travel steps and the transition are performed only for the front drive unit 3. Transition control consisting of steps may be applied. Alternatively, the same transition control as that of the front drive unit 3 may be applied to the rear drive unit 3.

  In this example, a transverse section between the first following section and the second following section is set as the autonomous traveling section. Instead, as shown in FIG. 8, a guideline 13 for traversing the automatic guided vehicle 2 may be provided between the guideline 11 in the first follow-up section and the guideline 12 in the second follow-up section. In this case, the following traveling control is applied to the first traveling step and the second traveling step in the transition control, and the autonomous traveling control is applied to the third traveling step. . If each drive unit 3 is controlled so as to pass through the guideline 12, it is not necessary to temporarily stop the automatic guided vehicle 2 that has traversed following the guideline 13 on the guideline 12, and the transfer to the guideline 12 is smooth and quick. realizable.

  In this example, the approach angles a and b are set to about 90 degrees and about 45 degrees, respectively. These numerical values are merely examples, and the setting of the approach angle can be changed as appropriate. The approach angle should be appropriately selected according to the travel characteristics, control specifications, approach speed, and the like of the automatic guided vehicle 2 as long as the relationship of the approach angle a> the approach angle b is maintained.

(Example 2)
This example is an example in which the traveling pattern in the autonomous traveling section is changed to skew based on the first embodiment. The contents will be described with reference to FIGS.
In the automatic conveyance system 1 of this example, the automatic conveyance vehicle 2 autonomously travels obliquely between the guideline 11 and the guideline 12 laid so as to be parallel to each other. The angle formed by the skew direction and the guideline 12, that is, the approach angle a of the automatic guided vehicle 2 with respect to the guideline 12 is about 45 degrees. Moreover, the approach angle b when changing to the guideline 12 is about 22.5 degrees. In this example, the approach speed with respect to the guideline 12 is set faster than that in the first embodiment, and therefore, the difficulty of transferring to the guideline 12 at the approach angle a is higher than that in the first embodiment.

In this example, as shown in FIGS. 10 and 11, the traveling period up to the detection area 36A corresponds to the first traveling step. The travel period from the detection area 36A to the detection area 36B corresponds to the second travel step. The travel period from the detection area 36B to the detection area 36C corresponds to the third travel step. Furthermore, the traveling period from the detection area 36C to the detection area 36E corresponds to the transition step.
Other configurations and operational effects are the same as those in the first embodiment.

  As mentioned above, although the specific example of this invention was demonstrated in detail like Example 1 and Example 2, these specific examples are only disclosing the example of the technique included by a claim. Needless to say, the scope of the claims should not be construed as limited by the configuration, numerical values, or the like of the specific examples. The scope of the claims includes techniques obtained by variously modifying or changing the specific examples using known techniques, knowledge of those skilled in the art, and the like.

1 Automatic transport system 11, 12 Guidelines (conductor)
121 Edge (conductor edge)
2 Automatic transport vehicle 20 Car body 28 Autonomous navigation means 281 Angular velocity sensor 3 Drive unit 331 Drive wheel 351 Line sensor (detection sensor)
352 Marker sensor 36 Detection area 360 Magnetic detection element 50 Control unit 510 Travel control means 512 Control switching means 513 Positioning means

Claims (6)

Two sets of drive wheels that are driven individually are arranged coaxially, and two drive units, front and rear, that are turned and steered according to the rotational difference between the two sets of drive wheels, and in the path A self-conveying vehicle equipped with a detection sensor attached to the front side of the drive unit for detecting a conducting wire of a predetermined width laid along the line approaches the new conducting wire by traversing or skewing. A control method for transitioning to a state,
A first traveling step in which the automatic conveyance vehicle approaches the new conductor by traversing or skewing by moving the drive unit forward at an approach angle a with respect to the new conductor;
After the detection sensor of at least one of the drive units detects the new conducting wire, the second traveling advances the drive unit at the entry angle a until the detection sensor again detects the new conducting wire. Steps,
After the second traveling step, a third traveling step for steering the drive unit so that the new conducting wire can be redetected by the detection sensor;
The drive unit is made to enter the oblique direction with respect to the new conductor, and after the new conductor is re-detected by the detection sensor, the drive unit is steered so as to follow the new conductor. A transition step for performing switching to follow-up running control,
The detection sensor includes a detection area extending in a direction orthogonal to the traveling direction of the drive unit, and not only whether or not the conductor is detected, which part of the detection area detects the conductor. It is possible to detect which part is not detected, and to detect the conductor edge forming the edges on both sides in the width direction of the conductor according to the combination of the detection part and the non-detection part in the detection area Is possible,
In the transition step, switching to the following traveling control is not performed only by the detection sensor detecting the new conductor, and after the detection sensor detects a new conductor, the conductors on both sides of the conductor in the width direction are detected. A control method for an automatic guided vehicle in which switching to the following traveling control is executed when a lead edge on the forward direction side of the drive unit is detected among the edges . The method for controlling an automatic guided vehicle according to claim 1 , wherein an approach angle of the drive unit with respect to the new conducting wire in the transition step is an approach angle b smaller than the approach angle a . The automated guided vehicle includes autonomous navigation means that enables autonomous traveling by autonomous navigation,
The method for controlling an automatic guided vehicle according to claim 1, wherein the third traveling step is a step in which the automatic guided vehicle performs autonomous traveling. The automated guided vehicle includes autonomous navigation means that enables autonomous traveling by autonomous navigation,
The method for controlling an automatic guided vehicle according to any one of claims 1 to 3, wherein the first and second traveling steps are steps in which the automatic guided vehicle performs autonomous traveling.   The control method of the automatic guided vehicle according to any one of claims 1 to 4, wherein a control target value of the approach angle a in the first traveling step is 90 degrees.   The method for controlling an automatic guided vehicle according to any one of claims 1 to 5, wherein the first to third travel steps and the transition step are executed for two front and rear drive units, respectively.

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