JP2008117204A - Intersection branch control method for automated guided vehicle and device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intersection branch control method for an automated guided vehicle, for controlling a travel direction at low cost. <P>SOLUTION: In this intersection branch control method for the automated guided vehicle, the automated guided vehicle has: a counter counting when passing the intersection; and a controller 8 comprising a control means 8b controlling the travel direction when carrying. The control means stores an intersection corresponding to each count and the travel direction in each the intersection, reads the travel direction of the intersection to be next passed by the automated guided vehicle corresponding to the value counted by the counter while the intersection is passed (S8), and controls the travel direction of the automated guided vehicle such that the automated guided vehicle travels along a track guiding the travel direction of the automated guided vehicle according to the read travel direction of the intersection to be next passed after passing the current intersection. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an intersection branching control method and apparatus for an automated guided vehicle.

  In automatic guided vehicles introduced for the purpose of logistics automation in production factories, drive units with built-in motors, track sensors that read travel tracks configured by laying magnetic tape, etc., and to recognize intersections Patent Document 1 discloses an automatic guided vehicle having a configuration including an intersection marker sensor that detects an intersection marker arranged in front of an intersection.

  In this technology, the automatic guided vehicle is controlled so as to travel without deviating on the traveling track by determining the traveling direction based on the output signal of the track sensor and turning the vehicle straight and turning right or left. .

Also, in order to perform the branching operation at the intersection, based on the output of the intersection marker sensor, grasp the intersection number to pass next, set the traveling direction of the automated guided vehicle from the intersection number, and then according to the output of the track sensor The trajectory tracking control performed in this way is switched from the normal mode to the intersection branching mode, and control is performed so that the intersection travels in the designated direction.
JP 2004-192058 A

  However, in the above-described conventional automatic branching vehicle intersection branching control, it is necessary to install an intersection marker for each intersection in order to grasp the intersection, and the automated guided vehicle needs an intersection marker sensor for detecting the intersection marker. Thus, there is a problem that costs increase.

  Accordingly, an object of the present invention is to provide an intersection branching control method for an automated guided vehicle that reliably travels an intersection along a track in a predetermined direction without using an intersection marker and an intersection marker sensor in an intersection branching control of an automated guided vehicle. It is to provide such a device.

  The present invention relates to an automatic guided vehicle including a counter that counts a count number while passing through an intersection of a transport route and a controller that controls a traveling direction during transport. The controller includes a transport route corresponding to each count number. And the advancing direction at each intersection are stored, and the advancing direction of the intersection where the automated guided vehicle passes next corresponding to the count number counted by the counter while the automated guided vehicle passes the intersection is read. The traveling direction of the automatic guided vehicle is set so as to travel along a track that guides the traveling direction of the automatic guided vehicle in accordance with the traveling direction of the next passing intersection that has been read after passing through the currently passing intersection. It is an intersection branching control method for an automatic guided vehicle characterized by controlling.

  In the present invention, in the intersection branching control of the automated guided vehicle, the traveling direction at the intersection of the automated guided vehicle can be reliably controlled without using the intersection marker or the intersection marker sensor.

  FIG. 1 is an external view of an automatic guided vehicle to which the present invention is applied, and FIG. 2 is a configuration diagram of a mounting portion of a track detection sensor 6. The automatic guided vehicle 1 has a so-called cart-like appearance, and in addition to the front and rear wheels 2 and 3, drive wheels 5 connected to drive motors 4 a and 4 b as drive sources of the automatic guided vehicle are substantially omitted. It is installed in the center. The drive wheels are composed of left and right drive wheels 5a and 5b, and each drive wheel 5a and 5b is individually connected to an individual drive motor 4a and 4b, and is unmannedly conveyed according to the rotational speed of each drive motor 4a and 4b. The traveling direction and traveling speed of the vehicle 1 are controlled. That is, if the left and right drive motors 4a and 4b have the same rotational speed, the vehicle travels straight. Thus, the turning radius is controlled according to the magnitude of the rotational speed difference.

  In addition, as shown in FIG. 2, the automatic guided vehicle 1 includes trajectory detection sensors 6 a to 6 c for detecting the track 7 that guides the traveling direction of the automatic guided vehicle 1 so as to be orthogonal to the longitudinal direction of the track 7. Three are arranged in parallel. For example, the track 7 is made of a magnetic material, and the track sensors 6a to 6c are made of sensors that determine the magnetic material.

  Further, the automatic guided vehicle 1 receives output signals detected by the track detection sensors 6a to 6c, and controls the rotational speed difference and the rotational speed of the drive motors 4a and 4b to control the traveling direction of the automatic guided vehicle. A controller 8 for controlling the running state is provided.

  FIG. 3 is a control block diagram for explaining the input / output of the controller 8.

  The controller 8 includes a sensor input unit 8a to which the output signals of the trajectory detection sensors 6a to 6c are input, and a counter that counts the count number based on the input signal, and the intersection is identified and identified by the count number. A travel control unit 8b that stores the traveling direction of the intersection and sets the rotational speed of the drive motors 4a and 4b, and a motor that controls each drive motor 4a and 4b based on the drive motor rotational speed set by the travel control unit 8b And a driver 8c.

  The traveling control unit 8b wirelessly receives a control signal from the integrated control unit 100 that performs integrated control of the plurality of automatic guided vehicles 1 through the receiving unit 8d, and starts and stops traveling of the automatic guided vehicle 1 and conveys information. Obtain and remember. Here, the transport information includes information on the transport start point, the end point (destination), and the transport route such as the trajectory 7 passing from the start point to the end point, and each passing intersection. Further, each intersection passing through the transport route is distinguished by setting a predetermined number (count number), and the count number is sequentially set from 1 in order from the intersection closest to the start point, for example. . The information on the transport route includes information on an intersection at which the automatic guided vehicle 1 corresponding to the count number should travel, and information on the traveling direction and traveling speed at the intersection.

  In addition, the track detection sensors 6a to 6c provided in the automatic guided vehicle 1 have a predetermined output pattern, for example, an output pattern in which all the three track detection sensors 6a to 6c are turned on. The counter provided in the traveling control unit 8b counts the number of counts, and reads the traveling direction of the corresponding intersection according to the counted number.

  Next, an example of trajectory tracking control performed by intersection branching control will be described with reference to FIGS.

  FIG. 4 is a plan view showing a state in which the automatic guided vehicle 1 whose direction of travel is controlled by the controller 8 turns right at a predetermined intersection, and tracks 7a to 7c extending in the right and left turn directions and straight directions, and the intersections. A change in the combination of output signals of the trajectory detection sensors 6a to 6c when turning right according to an instruction from the controller 8 is shown.

  FIG. 5 shows an output pattern composed of a combination of output signals of the trajectory detection sensors 6a to 6c when turning right at the intersection, and a traveling state of the automatic guided vehicle 1 corresponding to the combination of the output signals, that is, straight ahead, left turn and right turn. The travel control unit 8b of the controller 8 stores in advance the output patterns of the output signals of the trajectory detection sensors 6a to 6c for straight travel and for left / right turn, and combinations of output signals for each output pattern. The driving state corresponding to is stored.

  In FIG. 4, the automatic guided vehicle 1 travels from the lower side to the upper side of the drawing and enters an intersection. The automatic guided vehicle 1 controlled by the controller 8 so as to make a right turn at the next intersection goes straight on the straight track 7b and enters the intersection (time t1) until it confirms the approach of the intersection. In the figure, t1 to t7 indicate time.

  Here, the automatic guided vehicle 1 sets the traveling state of the automatic guided vehicle 1 by the combination of output signals of the track detection sensors 6a to 6c, and the combination of the output signals is only the central track detection sensor 6b as shown in FIG. If is on, the vehicle travels while maintaining a straight traveling state based on a combination of output signals from the trajectory detection sensors 6a to 6c when turning right at the intersection as shown in FIG. For example, when the center and right sensors 6b and 6c are in the ON state, the automatic guided vehicle 1 is in a right turn running state.

  The automatic guided vehicle 1 enters the intersection, and the left-side track detection sensor 6a detects the left-turn track 7a at time t2. Here, since the combination of the output signals of the trajectory detection sensors 6a to 6c is instructed to turn right at the intersection even if the left and center sensors 6a and 6b are turned on, the automatic guided vehicle is based on the output pattern of FIG. 1 keeps going straight. Subsequently, all combinations of output signals of the trajectory detection sensors 6a to 6c are turned on at time t3, and the controller 8 recognizes that the automatic guided vehicle 1 has entered a predetermined intersection from the combination of output signals. The automatic guided vehicle 1 passing through the intersection starts a right turn to travel on the right turn track 7 c based on an instruction from the controller 8. Specifically, as shown in FIG. 5, the controller 8 controls the drive motors 4 a and 4 b by using combinations of output signals of the trajectory detection sensors 6 a to 6 c when turning right at the intersection and when all the combinations of the output signals are turned on. Then, the automatic guided vehicle 1 starts to turn right.

  The automatic guided vehicle 1 continues to turn right according to the combination of the output signals of the track detection sensors 6a to 6c from time t3 to time t5 so as to travel along the right turn track 7c. When the output signal combination is switched to the straight traveling combination at time t6, the controller 8 changes the traveling of the automatic guided vehicle 1 from a right turn to a straight traveling.

  As described above, according to the trajectory tracking control of the present invention, an output pattern composed of a combination of output signals of the trajectory detection sensors 6a to 6c for detecting the trajectory 7 is set for each traveling direction of the intersection passing through the output pattern. Since the advancing direction of the automatic guided vehicle 1 is controlled, the automatic guided vehicle 1 can travel on the track 7 in the set traveling direction without deviating from the track 7.

  Next, the case of straight traveling of the trajectory tracking control will be described with reference to FIGS.

  FIG. 6 is a plan view showing a state in which the automatic guided vehicle 1 whose traveling direction is controlled by the controller 8 goes straight through a predetermined intersection, and tracks 7a to 7c extending in the right / left turn direction and the straight traveling direction, and the intersections. A change in the combination of output signals of the trajectory detection sensors 6a to 6c when the vehicle travels straight according to an instruction from the controller 8 is shown.

  FIG. 7 shows an output pattern composed of a combination of output signals of the trajectory detection sensors 6a to 6c when traveling straight at the intersection, and a traveling state of the automatic guided vehicle 1 corresponding to the combination of the output signals, that is, straight travel, left turn and right turn. The travel control unit 8b of the controller 8 stores in advance the output patterns of the output signals of the trajectory detection sensors 6a to 6c for straight travel and for left / right turn, and combinations of output signals for each output pattern. The driving state corresponding to is stored.

  In FIG. 6, the automatic guided vehicle 1 travels from the lower side to the upper side of the drawing, and the automatic guided vehicle 1 that has received an instruction to go straight at the next intersection goes straight to the intersection according to an instruction from the controller 8 ( Time t1). In the figure, t1 to t6 indicate time.

  Here, the automatic guided vehicle 1 recognizes the traveling direction based on the combination of the output signals of the track detection sensors 6a to 6c, and if the combination of the output signals is only the center track detection sensor 6b as shown in FIG. As shown in FIG. 7, the vehicle travels while maintaining a straight traveling state.

  Even if the automatic guided vehicle 1 enters the intersection, and the combination of the output signals of the trajectory detection sensors 6a to 6c is turned on at the time t2, the left and center sensors 6a and 6b are kept straight. Subsequently, all combinations of output signals of the trajectory detection sensors 6a to 6c are turned on at time t3, and the controller 8 recognizes that the automatic guided vehicle 1 has entered a predetermined intersection from the combination of output signals. The automatic guided vehicle 1 passing through the intersection maintains a straight traveling so as to travel on the straight track 7 b based on an instruction from the controller 8.

  The automatic guided vehicle 1 continues traveling straight according to the combination of the output signals of the track detection sensors 6a to 6c from time t3 to time t6 in order to travel along the straight track 7b.

  Even when the automated guided vehicle 1 turns left at the intersection, the content of the intersection branching control can be performed in the same way as when turning right or going straight, and FIG. 8 shows the output signals of the track detection sensors 6a to 6c when turning left. An output pattern composed of combinations is shown.

  In addition, the attachment interval of each of the track detection sensors 6a to 6c is set according to the width of the tracks 7a to 7c. As described above, when entering the intersection, all of the track detection sensors 6a to 6c are temporarily turned on. Is set to be When the automated guided vehicle 1 travels along one track, the track following control is performed so that the center sensor 6b of the track detection sensors 6a to 6c travels along the center of the track 7.

  FIG. 9 is a flowchart of intersection branching control performed by the travel control unit 8b of the controller 8 of the present embodiment.

  First, the count number set for each intersection in step S <b> 1 is read and set as an initial value according to the current position of the automatic guided vehicle 1. The controller 8 stores the count number of the intersection branching control counter at the end of the previous conveyance, and reads the stored count number as the count number corresponding to the current position of the automatic guided vehicle 1.

  In step S2, the intersection passing after the start of traveling is grasped from the read count number, and the traveling direction at this intersection is read from the traveling direction data corresponding to the count number stored in advance. In subsequent step S3, output patterns of output signals of the trajectory detection sensors 6a to 6c are set according to the read traveling direction.

  In step S4, the automatic guided vehicle 1 starts running, and in step S5, output signals from the trajectory detection sensors 6a to 6c are read.

  In a succeeding step S6, it is determined whether or not the operation state of the timer provided in the controller 8 is in operation. Here, the timer starts counting when the output signals of the trajectory detection sensors 6a to 6c at the time of entering the intersection are in a predetermined condition, for example, when all are turned on, and counts for a predetermined time. This predetermined time is set to a time required for the automatic guided vehicle 1 to pass through the intersection. That is, when the timer is operating, it is determined that the automatic guided vehicle 1 is passing the intersection.

  In step 6, if the timer is operating, the process proceeds to step S13, and if not, the process proceeds to step S7.

  In step S7, it is determined whether or not a predetermined time counted by the timer has elapsed. If YES, the process proceeds to step S8, and if NO, the process proceeds to step S10.

  In step S8, since it can be determined that the vehicle has just passed through the intersection, the traveling direction at the next intersection after the passing intersection is read based on the count set in step S11, and the traveling direction of the next intersection in step S9. The output patterns of the output signals of the trajectory detection sensors 6a to 6c according to the above are set, and the process proceeds to step S13.

  On the other hand, in step S10, the output signals of the trajectory detection sensors 6a to 6c are read to determine whether all the output signals are on. If it is ON, it is determined that the automatic guided vehicle 1 is passing through the intersection, and the process proceeds to step S11 to increment the count set for each intersection by one. In step S12, the timer starts counting, and the process proceeds to step S13.

  In step S13, the trajectory tracking control as shown in FIGS. 4 and 5 is performed, and the last count number set for each intersection by the automatic guided vehicle 1 in step S14 is recognized. It is determined whether or not the ground (end point) has been reached. If the destination has been reached, this control is terminated. If not, the process returns to step S5 to repeat the intersection branching control.

  As described above, in the present embodiment, the controller 8 that controls the traveling of the automatic guided vehicle gives the count number to the intersection passing through the conveyance route, and stores the traveling direction at each intersection corresponding to the count number. In addition, when the trajectory detection sensors 6a to 6c indicate an output pattern of a predetermined output signal, the count number is counted and read based on the count number obtained by counting the advancing direction of the next passing intersection. Controls the direction of travel at the next intersection. By adopting such a control method, the existing trajectory detection sensors 6a to 6 can be used without using the trajectory marker laid before the intersection on the trajectory 7 provided in the prior art and the trajectory marker sensor for reading the trajectory marker. Intersection branching control can be performed using only 6c, and the cost can be reduced.

  Next, another example of output patterns of output signals of the trajectory detection sensors 6a to 6c for trajectory tracking control will be described with reference to FIGS.

  First, FIG. 10 shows a traveling state when the automatic guided vehicle 1 turns right at the intersection using the output patterns of the output signals of the trajectory detection sensors 6a to 6c shown in FIG. The difference from the case shown in FIG. 4 is the traveling speed of the automatic guided vehicle 1, and the traveling state in the case of FIG. 10 is higher when the traveling speed is higher than in the case of FIG.

  First, until the time t2, the automatic guided vehicle 1 goes straight along the straight track 7b. At this time, as described above, the track following control is performed so that the center of the track 7b and the center of the automatic guided vehicle 1 coincide with each other. That is, only the center sensor 6b among the trajectory detection sensors 6a to 6c is turned on. Thereafter, at time t4, all the output signals are turned on, the approach to the intersection is recognized, and the automatic guided vehicle 1 starts a right turn.

  However, since the traveling speed of the automatic guided vehicle 1 is high, it is not sufficient to follow the right turn track 7c. Although the right turn output pattern is shown at time t6, the right turn track is shown at time t6. Deviating from 7c, the output pattern becomes an output pattern indicating straight travel, and at the subsequent time t7, the output pattern becomes a left turn, and the automatic guided vehicle 1 travels along the straight track 7b. Therefore, although the right turn track following control is performed, the traveling speed of the automatic guided vehicle 1 is high, and thus the track following control cannot be completely followed, and the automatic guided vehicle 1 may go straight.

  When the traveling speed of the automatic guided vehicle 1 is high, output patterns of output signals of the track detection sensors 6a to 6c as shown in FIG. 12 are used. This output pattern shows an output pattern for a right turn as an example, and a position where the center line of the track 7 is offset to the left with respect to the center line of the automatic guided vehicle 1 when traveling straight ahead as compared with the output pattern shown in FIG. The output pattern is as follows. When the track following control for turning the automatic guided vehicle 1 to the right at the intersection is performed with this output pattern, the control is performed so that the center line of the track 7 is shifted to the left with respect to the central line of the automatic guided vehicle 1 when traveling straight.

  Specifically, the automatic guided vehicle 1 is assumed to go straight when the left and center sensors 6a and 6b of the trajectory detection sensors are on, and the output pattern of turning right when only the center sensor 6b is on. is there.

  By setting it as such an output pattern, as shown in FIG. 11, the frequency with which the combination of the output signals of the trajectory detection sensors 6a to 6c becomes a combination instructing a right turn can be increased, and the automatic guided vehicle 1 travels. Even when the speed is high, the predetermined trajectory can be accurately followed.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

It is an external view of the automatic guided vehicle to which the present invention is applied. It is a block diagram of the attaching part of a track detection sensor. It is a block diagram of a controller. It is a conceptual diagram explaining the track following control in an intersection (at the time of a right turn). It is a figure which shows the output pattern of the output signal of a track | orbit detection sensor, and a driving | running | working state (at the time of a right turn). It is a key map explaining trajectory tracking control at an intersection (at the time of going straight). It is a figure which shows the output pattern and driving state of the output signal of a track detection sensor (at the time of straight ahead). It is a figure which shows the output pattern of the output signal of a track | orbit detection sensor, and a driving | running | working state (at the time of a left turn). It is a flowchart explaining the content of orbital branch control. It is a conceptual diagram explaining the trajectory tracking control at an intersection (at the time of high-speed right turn, before countermeasures). It is a conceptual diagram explaining the trajectory tracking control at an intersection (at the time of high-speed right turn, after countermeasures). It is a figure which shows the output pattern of the output signal of a track detection sensor, and a driving | running | working state (after countermeasures at the time of a high-speed right turn).

Explanation of symbols

1: automatic guided vehicle 2: front wheel 3: rear wheels 4a, 4b: drive motors 5a, 5b: drive wheels 6a-6c: track detection sensors 7a-7c: track 8: controller 8a: sensor input unit 8b: travel control unit 8c : Motor driver 8d: Receiver 100: Integrated controller

Claims (7)

A counter that counts the count while passing the intersection of the transport route;
In an automatic guided vehicle including a controller composed of a control unit that controls a traveling direction during transportation,
The control means includes
Store the intersection of the transport route corresponding to each count number and the traveling direction at each intersection,
Read the traveling direction of the intersection where the automatic guided vehicle passes next, corresponding to the count number counted by the counter while the automatic guided vehicle passes the intersection,
Controls the traveling direction of the automated guided vehicle so that it travels along a track that guides the traveling direction of the automated guided vehicle according to the traveling direction of the next passing intersection that has been read after passing through the currently passing intersection. An intersection branching control method for an automatic guided vehicle.   The determination as to whether or not the automatic guided vehicle is passing an intersection is made based on output states of a plurality of track detection means for detecting a track that guides the traveling direction of the automatic guided vehicle, and the counter detects the track detection 2. The intersection branching control method for an automatic guided vehicle according to claim 1, wherein the number of counts is counted when it is determined that the vehicle is passing the intersection according to the output state of the means.   If it is determined that the automatic guided vehicle is passing the intersection, and a predetermined time has elapsed, it is determined that the automatic guided vehicle has passed the intersection, and according to the traveling direction of the intersection read corresponding to the count number, The method of controlling an intersection branching of the automatic guided vehicle according to claim 2, wherein the traveling direction of the automatic guided vehicle is controlled so as to travel along a track.   The control means stores an output pattern composed of a combination of a plurality of output signals of the trajectory detection means, and the automatic guided vehicle travels along the predetermined trajectory according to the combination. The method for controlling the intersection branching of an automatic guided vehicle according to claim 1, wherein the vehicle is controlled to go straight or turn.   5. The intersection branching control method for an automatic guided vehicle according to claim 4, wherein the output pattern is provided for each traveling direction of the intersection.   A plurality of the trajectory detection means are arranged perpendicular to the longitudinal direction of the trajectory so that the center of the trajectory detection means is offset from the center of the trajectory toward the traveling direction side of the next passing intersection. The method for controlling the intersection branching of the automatic guided vehicle according to claim 2, further comprising: controlling a traveling direction of the automatic guided vehicle before passing through the intersection. A counter that counts the count while passing the intersection of the transport route;
In an automatic guided vehicle including a controller composed of a control unit that controls a traveling direction during transportation,
The control means includes
Storage means for storing the intersection of the transport route corresponding to each count number, and the traveling direction at each intersection;
Travel direction setting means for reading the travel direction of the intersection where the automatic guided vehicle passes next, corresponding to the count number counted by the counter while the automatic guided vehicle passes the intersection;
Controls the advancing direction of the automated guided vehicle so that it travels along a track that guides the advancing direction of the automated guided vehicle according to the set traveling direction of the next passing intersection after passing through the currently passing intersection. An intersection branching control device for an automatic guided vehicle comprising: an advancing direction control means.