JP2019120992A - AGV control system - Google Patents

Abstract

To measure the position of an automatic guided vehicle without laying down magnetic markers or passive tags near a traveling path, and use the obtained position information to control traveling of the automatic guided vehicle.SOLUTION: A traveling control system 12 includes zone designation means capable of designating a zone of an arbitrary width and shape in an arbitrary place, a first storage unit that stores the zone, a receiver 121 that receives a pulsating signal wirelessly transmitted from an active tag 111, position information production means 122 that regularly measures the position of the active tag 111 on the basis of the received pulsating signal, and produces position information, entry determination means that, when the produced position information meets a predetermined condition in relation to the zone stored in the first storage unit, determines that the active tag 111 has entered the zone, command production means that produces a command, which is sent to an automatic guided vehicle 11, on the basis of the determination by the entry determination means, and second communication means 124 that communicates with the automatic guided vehicle 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an AGV control system that controls traveling of an AGV (Automatic Guided Vehicle).

  2. Description of the Related Art Conventionally, as a physical distribution system for transferring articles in a factory or a warehouse, one using an automated guided vehicle (AGV) is known. In the conventional system, in general, there is a technology for guiding an unmanned transport vehicle by magnetic tape laid on the floor surface and grasping the position of the unmanned transport vehicle by a magnet type marker or passive tag laid on the floor surface as well. It is adopted (for example, patent documents 1, patent documents 2).

  However, in this method, when changing the traveling path, there is a problem that not only the magnetic tape but also the magnetic marker, the passive tag, etc. have to be changed. Moreover, although the position measurement system using an active tag is proposed by patent document 3, the technology which used an active tag in patent document 3 in order to prevent an unmanned carrier from colliding with an operator or a forklift is proposed. In the travel control of the automated guided vehicle itself, only a technique for measuring the position using a laser beam has been disclosed.

JP, 2016-170580, A JP 2004-94671 A JP, 2013-216476, A

  The present invention has been made in view of such circumstances, and measures the position of an unmanned transfer vehicle without laying a magnet type marker or a passive tag in the vicinity of a traveling path, and uses the obtained position information. It is an object of the present invention to provide a system for controlling the traveling of an unmanned transport vehicle.

  In order to solve the above problems, an AGV travel control system according to the present invention includes an unmanned transport vehicle and a travel control device for controlling the travel of the unmanned transport vehicle, wherein the unmanned transport vehicle has unique identification information Based on an instruction from the traveling control device, an active tag for wirelessly transmitting a pulse signal for positioning including a driving means, a driving means for automatically traveling itself, a first communication means for communicating with the traveling control device, and Drive control means for controlling the drive means, and the travel control device is set by zone setting means capable of setting zones of any size and any shape in any place, and the zone setting means The first storage unit for storing the zone, a receiving apparatus for receiving the pulse signal wirelessly transmitted from the active tag, and the pulse signal received by the receiving apparatus, Position information generating means for periodically measuring the position of the active tag and generating the position information, and for the zone in which the position information generated by the position information generating means is stored in the first storage unit Entry determination means for determining that the active tag has entered the zone when a predetermined condition is satisfied, command generation means for generating a command to the AGV based on the determination of the entry determination means, and And a second communication unit that communicates with the automated guided vehicle. A zone is a virtual zone.

  In travel control of the AGV, it is necessary to know the position of the AGV. However, the grasping of this position does not necessarily require a precision without any deviation, and in many cases, it is sufficient to know whether or not an unmanned transport vehicle exists within a predetermined range. For example, it is assumed that there is a case where it is desired to decelerate when the AGV passes a certain point while traveling on the traveling path. Passing this point often allows for an error of several tens of centimeters. In addition, also when stopping an unmanned carrier at a destination, it is often sufficient to stop within a section of a predetermined range.

  In this respect, according to the present invention, it is determined whether the active tag has entered a preset zone and the traveling of the AGV is controlled based on the determined information. Can be secured. Further, according to the present invention, since the zone can be freely set, it is only necessary to set the zone again even if the travel route, the traveling speed, and the destination are changed, and the equipment etc. for position measurement are installed. There is no need to do it again.

  On the other hand, errors occur in position measurement using an active tag. Even if the automatic guided vehicle travels in a predetermined direction, the time interval for generating the position information of the active tag, the speed of the automatic guided vehicle, and the measured position information of the active tag depending on the size of the error It does not necessarily follow, and the active tag may appear to move in the opposite direction to the AGV.

And if this happens just around the boundary of the zone, if the position information is used as it is, it may be recognized that the active tag is in or out of the zone, which is not convenient for control. It is.
In this respect, according to the present invention, for the set zone, it is determined that the active tag has entered the zone when the position information satisfies the predetermined condition, so that the treatment of the error is not complicated and unified. It is possible to make a clear determination based on the determination criteria.

  According to the present invention, it is possible to measure the position of an unmanned transfer vehicle without laying a magnet type marker or a passive tag in the vicinity of a traveling path, and to control the traveling of the unmanned transfer vehicle using the obtained position information. it can. Even when the traveling path is changed, it is not necessary to re-install equipment for position measurement.

It is an explanatory view showing an AGV control system typically. It is explanatory drawing which showed the unmanned carrier vehicle typically. It is an explanatory view showing a judgment standard of an approach judging means. It is an explanatory view showing another judgment standard of an approach judging means. It is an explanatory view showing another judgment standard of an approach judging means. It is explanatory drawing for showing the length of a required zone. It is explanatory drawing which shows the form of the zone which was not employ | adopted in an arrival point. It is explanatory drawing which shows the form of the zone in an arrival point. It is explanatory drawing which shows the installation method of the zone as guidance means. It is explanatory drawing which shows the method of installing a zone in an intersection as a guidance means.

  Hereinafter, although an embodiment embodying the AGV control system of the present invention will be described using the drawings, the technical scope of the present invention is of course not limited thereto. The detailed description of the well-known techniques is omitted.

(Embodiment)
First, the configuration of the AGV control system 1 according to the embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is an explanatory view schematically showing an AGV control system of the present embodiment, and FIG. 2 is an explanatory view schematically showing an unmanned transfer vehicle. Among them, FIG. 2 (a) is a side view, and FIG. 2 (b) is a bottom view. In addition, in FIG. 1, the unmanned conveyance vehicle 11, the zone, and the article storage shelf, the code etc. is attached only to the minimum necessary to explain.

  As shown in FIG. 1, the AGV control system 1 is, for example, a system introduced for the purpose of transporting parts, products and the like in a factory or a warehouse, and mainly includes a plurality of unmanned transport vehicles 11 and travel control. It comprises an apparatus 12.

  As shown in FIG. 2, the unmanned transport vehicle 11 mainly includes an active tag 111, a driving means (not shown battery, a not shown motor, a not shown motor, four driving wheels 112a, eight magnetic tape sensors 112b, a not shown gyroscope etc. The combination of the posture detection unit is the drive unit in the present invention), the drive control unit 113, and the first communication unit 114.

  The active tag 111 is an active RFID tag, and holds unique identification information. The active tag can freely output a 8.5 GHz to 9.5 GHz radio signal (pulse signal) of an ultra-wide band wireless (UWB) system as a positioning signal including identification information.

  The active tag 111 is attached upward to the upper end of a vertically extending post 115 provided at the front end of the automated guided vehicle 11. Although one active tag is mounted in the present embodiment, a plurality of active tags may be mounted, for example, one at each of the front end and the rear end of the vehicle body, and one at each of the four corners of the vehicle body. Although the cost is increased, the accuracy of the position measurement is improved. Moreover, the direction of the automatic guided vehicle 11 can be grasped.

  The unmanned transfer vehicle 11 is an AGV (Automatic Guided Vehicle). The unmanned transfer vehicle 11 is a four wheel drive vehicle of a Mecanum wheel, and is an automatic traveling vehicle in which four drive wheels 112a are driven by a motor (not shown) driven by the power of a battery (not shown). The drive system and the like use a well-known technology, and thus detailed description will be omitted. In addition, although the Mecanum wheel system was adopted in this embodiment, it is needless to say that it is not restricted to this.

The magnetic tape sensor 112 b is a guide sensor for causing the unmanned conveyance vehicle 11 to travel along the magnetic tape M laid on the traveling path, and is a known technique.
The magnetic tape sensor 112 b distinguishes between the N pole and the S pole. Further, as shown in FIG. 2, eight are mounted on the lower surface of the AGV main body at equal intervals in a circumferential shape coaxial with the centers of the four drive wheels 112 a. The diameter of the circle is larger than the width of the magnetic tape M. As a result, the magnetic tape M can be recognized regardless of the orientation of the unmanned transport vehicle 11 with respect to the magnetic tape M. The direction of the automated guided vehicle 11 with respect to the magnetic tape M can also be grasped. In addition, although it mounted in the circumferential shape in this embodiment, you may mount in the circumferential shape of a regular polygon, and a number may also be more than eight.

  The drive control means 113 is a computer in which a drive control program is implemented. The drive control means 113 uses the detection information of the attitude detection unit (not shown) and / or the magnetic tape sensor 112b depending on the travel command information from the travel control device 12, and the drive system of the unmanned transfer vehicle 11 The unmanned transfer vehicle 11 is made to travel automatically by controlling each component such as.

  The first communication unit 114 performs wireless communication for transmitting and receiving various information to and from the traveling control device 12.

In the unmanned transfer vehicle 11, an interferer sensor (not shown) that detects the presence of an interferer on the front side in the traveling direction, and a bumper sensor that detects that the interferer contacts the bumper of the unmanned transfer vehicle 11 (see FIG. Not shown). These sensors are all well known techniques.
When these sensors detect the presence or contact of an interferer, an emergency signal is sent to the drive control means 113, and the drive control means 113 makes the unmanned transfer vehicle 11 stop urgently. Thereby, the collision with the article storage rack, the worker, the forklift and the articles placed on the floor surface is prevented. The drive control means 113 transmits the information to the traveling control device 12 when the unmanned transfer vehicle 11 is urgently stopped.

  All unmanned carrier vehicles 11 are centrally managed by the travel control device 12.

  As shown in FIG. 1, the traveling control device 12 has a plurality of receiving devices 121, position information generating means 122, management device 123 (zone setting means in the present invention, first storage unit, entry determination means, command generation means And the second communication unit 124.

  As shown in FIG. 1, at the factory to which the AGV control system 1 is applied, a receiving area and an article storage rack are arranged, and a departure point SP near the receiving area, an arrival point AP near the article storage area, a departure point and an arrival A traveling path connecting the points (not shown for the traveling path and other boundaries) is provided. In the traveling path, a magnetic tape M as a guiding means for guiding the unmanned transfer vehicle 11 is laid in a portion shown by a solid line in the figure. The magnetic tape M is not laid in the other part. That is, a guiding means for guiding the AGV 11 is provided in a part of the traveling path, and no guiding means is provided in the other part.

The receiving device 121 is a device that receives an identification information signal wirelessly transmitted from the active tag 111 and a signal for position measurement. The receiving device 121 includes a plurality of receiving elements (not shown). A plurality of reception devices 121 are installed on the ceiling of the building. The receiving device 121 is arranged such that at least two receiving devices 121 can receive the signal of the active tag 111 regardless of the position of the active tag 111 in the measurement target area.
For example, in the present embodiment, six receiving devices 121 are provided as shown in FIG.

  The position information generation unit 122 is a computer mounted with a position information generation program. The positional information generation unit 122 receives a signal from the receiving device 121, measures the position of the active tag 111, and generates the positional information. The position information includes position coordinates. The position information generation unit 122 is configured to be able to communicate with the plurality of receiving devices 121 via a network device such as a hub. Further, it is configured to be communicable with the management device 123.

  The active tag 111 outputs a pulse signal as short as several nanoseconds, and the receiving device 121 measures the time lag for the signal to reach a plurality of receiving elements. Thus, a straight line indicating the direction of the active tag 111 as viewed from the receiving device 121 can be accurately determined. The receiving device 121 transmits the information on the straight line to the position information generating means 122.

  The position information generation unit 122 receives straight line information indicating the direction of the active tag 111 from at least two receiving devices 121, and obtains the intersection point of the straight line or the closest point, whereby the position of the active tag 111 in plan view is obtained. Calculate the coordinates. Although this may be used as position coordinates in position information, in the present embodiment, a plurality of position information (including position information) generated immediately before is stored, and calculation is performed using these position information and statistical methods. The position coordinates are corrected to generate position information.

  The position information generation unit 122 periodically (in the present embodiment, every 100 ms) executes position information generation processing for the active tag 111.

  The management device 123 is a computer on which various management programs are mounted. Although not shown, the management device 123 includes an operation unit and a storage unit, and further includes a display unit, a keyboard, a mouse, and the like as input / output devices. The management device 123 has the functions of zone setting means, first storage unit, entry determination means, and command generation means in the present invention.

The management device 123 has a function of zone setting means, and can set a virtual zone of any size and any shape at any place. The zones do not have to be set continuously, but may partially overlap. Also, it is possible to set a zone in the zone.
As a result, for example, it is possible to perform blockage management in continuous zones and to provide another zone for issuing a deceleration command and another zone for issuing a stop command.
Further, the management device 123 has a function of the first storage unit, and stores the set zone.

The management device 123 has a function as entry determination means, and determines that the active tag 111 has entered the zone when the position information satisfies a predetermined condition with respect to the stored zone.
Multiple pieces of position information are generated in a short time (in this embodiment, ten times per second). Since there is an error in the measurement of the position of the active tag 111, in the vicinity of the zone boundary, there is a plurality of pieces of position information including those that have entered the zone and those that have not entered the zone, and means for determining that the zone has entered the zone It is because it becomes necessary.

  In the present embodiment, a circle having a predetermined radius in plan view is assumed on the basis of position information (coordinates), and it is determined that the time when the active tag 111 has entered the zone is when all the circles enter the zone. This will be described with reference to FIG. FIG. 3 is an explanatory view showing determination criteria of the entry determination means.

  In FIG. 3, t 1, t 2, t 3, t 4 and t 5 indicate positions of the active tag 111 at equally spaced times T 1, T 2, T 3, T 4 and T 5. The active tags 111 move linearly at a constant speed, and t1, t2, t3, t4, and t5 are also arranged at equal intervals in a straight line.

  d1, d2, d3, d4 and d5 represent position information (coordinates) at times T1, T2, T3, T4 and T5. Although the true positions of the active tag 111 are t1, t2, t3, t4, and t5, since there is an error in the position information (coordinates), as shown in FIG. In the present embodiment, the maximum error is ra.

  In this embodiment, a circle whose radius in plan view is the same as the maximum error is assumed on the basis of position information (coordinates), and it is determined that the time when the active tag 111 enters the zone when all the virtual circles enter the zone. doing. For example, although d3 is a position information (coordinates), the zone is entered, but the virtual circle of d3 is not all included in the zone. Therefore, it is not determined that the zone has been entered. The position information (coordinates) does not enter the zone in the first place in d4 and naturally the virtual circle does not all enter the zone, so it is not determined that the zone has been entered. In d5, it is determined that all of the virtual circles have entered the zone, that is, the active tag 111 has entered the zone at time T5.

  In the present embodiment, once entering a certain zone, it is determined that the user has entered the zone until entering another zone. Further, in the present embodiment, the management device 123 is configured to store time data (T5 in the present case) when it is determined that the active tag 111 has entered the zone.

  In the present embodiment, the radius of the virtual circle is the same as the maximum error ra. However, the present invention is not limited to this and may be set arbitrarily. Moreover, although it was set as an imaginary circle, it is not necessary to make it circular shape. If the direction (posture) of the automatic guided vehicle can be grasped by the attitude detection unit (not shown) and / or the magnetic tape sensor 112b etc., for example, as shown in FIG. It is good to set it as the long circle which added distance L from the center of active tag 111 to the end of unmanned carrier vehicle 11 to ra in the front, and back in the back. In this way, it is the same as determining that the entire vehicle body of the automatic guided vehicle 11 has entered the zone, which is visually easy to understand. Further, as shown in FIG. 5, assuming that the position information (coordinates) and the center of the active tag 111 coincide with each other, the contour line obtained by enlarging the plan view outline line of the unmanned conveyance vehicle 11 by ra only is set as a virtual shape. Good.

  In this embodiment, such a determination criterion is used, but it may be determined that the active tag 111 has entered the zone when the position information generated immediately before has entered the predetermined number of zones continuously. It may be determined that the active tag 111 has entered the zone when the central point of the plurality of pieces of position information generated immediately before has entered the zone. There are various judgment criteria.

  Further, in the present embodiment, only when the active tag 111 enters the zone is determined, similarly, exit determination means may be provided to determine that the active tag 111 has exited the zone.

  The management device 123 has a function as command generation means, and when it is determined that the active tag 111 has entered the zone, determines whether there is a risk of collision with another unmanned transport vehicle, and there is a risk of collision. If there is, the unmanned transfer vehicle 11 is stopped. If there is no risk of collision, the command to the AGV 11 is generated as necessary in light of the purpose of setting the zone there.

  The second communication unit 124 transmits and receives wireless communication with the first communication unit 114 of the automatic guided vehicle 11 under the control of the management device 123.

  Further, the management device 123 generates a travel route, and stores detailed information on the travel route and detailed information on each intersection.

  In the present embodiment, the above-described configuration is adopted as a method of calculating the position coordinates of the active tag 111. However, of course, the present invention is not limited to such a configuration. For example, if the receiving device 121 has a function capable of measuring the direction and distance of the active tag 111, position coordinates of the active tag 111 are calculated based on the measurement result of the single receiving device 121. It may be Also, if the receiving device 121 has a function capable of measuring only the distance to the active tag 111, signals from at least three receiving devices are received, and the position of the active tag 111 is calculated. May be In addition, methods other than these may be used.

  Further, in the present embodiment, the receiving device 121 transmits, to the management device 123, information on the time when the signal from the active tag 111 is received, in addition to the information on the straight line described above. The management device 123 is configured to record the information of this time in the position information.

Next, a method of using the AGV control system 1 in a factory will be described.
As described above, as shown in FIG. 1, at the factory, a receiving area and an article storage rack are arranged, and a departure point SP near the receiving area, an arrival point AP near the article storage area, a departure point and an arrival point A connecting road is provided. Further, a magnetic tape M as a guiding means for guiding the automatic guided vehicle 11 is laid on a traveling path represented by a solid line in the drawing. The magnetic tape M is not laid on the other travel paths. The traveling path on which the magnetic tape M is laid is one way. The AGV control system 1 transports the goods from the departure point SP to the arrival point AP.

(Zone setting)
First, as preparation in advance, a zone is set in the management apparatus 123 and stored in the management apparatus 123. In the present embodiment, zones are set as follows. Although this work itself is performed by the worker, the traveling control device 12 supports the work.

(1) Zone length The purpose of zones is collision prevention. If two active tags 111 enter one zone, there is a possibility of a collision, so in the present embodiment, when the AGV 11 travels in the traveling route, when the active tag 111 enters a zone, When there is an active tag 111 of another unmanned transfer vehicle 11 in the zone one ahead, the management device 123 immediately stops the unmanned transfer vehicle 11.

  Here, the length of the zone becomes important. This will be described with reference to FIG. FIG. 6 is an explanatory view for showing the length of the necessary zone. Although two unmanned conveyance vehicles and each active tag are attached with a different code for convenience of explanation, these two are same specification. Further, FIG. 6 is for explaining the length of the necessary zone, and is not a part of this embodiment.

  In the entry determination means of the present embodiment, assuming that the radius is the circle of the position measurement maximum error centering on the position information (coordinates), the time when the active tag 111 enters the zone when all the virtual circles enter the zone It is judged. Therefore, as in the case of the unmanned transfer vehicle 11a shown in FIG. 6, when the center of the active tag 111a actually enters the zone Za even slightly, it may be determined that the active tag 111a has entered the zone Za. That is, even when the unmanned transfer vehicle 11a traveling in the front is stopped in a state as shown in FIG. 6 due to a failure or the like, it may be determined that the active tag 111a has entered the zone Za.

  On the other hand, it is determined that the active tag 111b has finally entered the zone Zb when 2ra advances after the center of the active tag 111b actually enters the zone Zb as in the unmanned transfer vehicle 11b shown in FIG. There is also the possibility. This means that the AGV 11b traveling behind may not be determined that the active tag 111b has entered the zone Zb until the state shown in FIG. Also, in practice, there is a free running distance due to a time lag of the position measurement cycle (100 ms in the present embodiment). Then, the length of the necessary zone is the length of the unmanned conveyance vehicle 11a, the diameter of the imaginary circle (twice the maximum position measurement error ra in this embodiment), the free running distance due to the time lag of the position measurement cycle (this In the embodiment, the distance by which the AGV 11b travels for 100 ms), the braking distance B at the set speed, and the distance C at the time of stopping for safety are added. Strictly speaking, the free running distance in the time required for processing by the reception device 121, the position information generation means 122, and the management device 123 also has to be added, but since it is an extremely short distance, it is ignored in this embodiment. .

  Needless to say, the free running distance and the braking distance increase as the speed increases. Also in the present embodiment, as shown in FIG. 1, the length of the zone having a large setting speed (for example, zone Z3) is longer than that of the zone having a small setting speed (for example, zone Z1).

  In the present embodiment, when the active tag 111 enters a certain zone, if there is another active tag 111 in the next zone, the unmanned transfer vehicle 11 is immediately halted. In this way, the zone length is set in this way, but if this rule is not adopted, there is no need to set the zone length in this way, and it is suitable for the adopted rule The length of the zone can be set.

(2) Shape of Zone In this embodiment, since it is desired to unify the collision prevention rule also at the intersection, the zone has a complicated shape at the intersection as in the zone Z4 shown in FIG. This is to prevent the vehicle body portion from remaining even if there is no active tag 111 of another unmanned transfer vehicle 11 in the intersection.

(3) Zone location
In this embodiment, when it is desired to stop the automatic guided vehicle 11 in a predetermined zone, the management device 123 sends an instruction to stop the automatic guided vehicle 11 when it is determined that the active tag 111 has entered the zone. Of course, although there is a braking distance, it still does not stop so that the unmanned transfer vehicle 11 completely fits in that zone. Therefore, the position of the zone is set in consideration of the position where the AGV actually stops.

(4) Form of Zone The form of the zone of the arrival point AP will be described with reference to FIGS. 7 and 8. FIG. 7 is an explanatory view showing the form of a zone not adopted at the arrival point. FIG. 8 is an explanatory view showing the form of the zone at the arrival point.
As shown in FIG. 1, in the present embodiment, the unmanned transfer vehicle 11 leaves the magnetic tape M while moving upward in the figure and moves in the right or left direction immediately before the arrival point AP. Here, assuming that the zone is set as shown in FIG. 7, if the active tag 111 moves as shown by an arrow, the active tag 111 proceeds without being determined to be entered into the zone Zc or the zone Zd, and the unmanned person goes unmanned There is a possibility that the transport vehicle 11 may collide with the article storage rack.
For this reason, as shown in FIG. 8, the position of the zone Zc is shifted so as to form the zone Ze, and a large zone Zf is set outside the zone Ze. That is, a dual zone in which the zone Ze is provided in the zone Zf is set.

  When it is determined that the active tag 111 has entered either the zone Ze or the zone Zf, the usage of these two zones sends a command to stop the unmanned transport vehicle 11 and determines that the zone Zf has entered only. Is to notify the operator of the abnormality. As a specific zone of this embodiment, the zone Z6 corresponds to the zone Ze, and the zone Z7 corresponds to the zone Zf.

(5) Purpose of zone For the purpose of zone, in addition to grasping the position of the automatic guided vehicle 11, in addition to preventing a collision, when the active tag 111 enters the predetermined zone, the automatic guided vehicle 11 is stopped or decelerated There is an acceleration, etc. In consideration of these, the position, shape, form and the like of the zone are set.

(6) Setting of stop zone
Although not provided in the present embodiment, a zone may be provided which causes an emergency stop when entering this zone.

(When unloading)
When a part enters the unloading site, the operator loads the part into the unmanned transfer vehicle 11 and sends data of the part and identification information of the active tag 111 mounted on the unmanned transfer vehicle 11 to the management device 123. The management device 123 determines a zone of an arrival point and creates and stores a travel route. To create a traveling route is the same as arranging all the passing zones from the departure point to the arrival point. In addition, at this time, the management device 123 creates a command (including not to send in particular) to be sent to the unmanned transfer vehicle 11 when the active tag 111 of the unmanned transfer vehicle 11 enters for all the passing zones. I remember.
Although this method is used in the present embodiment, a worker may specify an arrival point, and a worker may also specify a travel route. The arrival point does not have to be the front of the article storage rack for storing the relevant part, and may be a position that does not hinder the operator from unloading the unmanned carrier 11 and moving it to the article storage rack. At this time, the management device 123 also creates a traveling route at the time of return with the arrival point as the departure point. The point of arrival on return is usually the point of departure for unloading.

As an example, a command until the unmanned transfer vehicle 11c moves to the zone Z6 which is an arrival point is shown. The description of the zones which do not particularly transmit the command will be omitted.
(1) Departure time (zone Z1)
It is guided by the magnetic tape M and goes straight at low speed.
(2) At the time of entering zone Z2, decelerate to a slow speed, and stop at the point where the magnetic tape M is bent at a right angle left. Follow the magnetic tape M and rotate 90 ° to the left. Take off, accelerate to high speed and go straight.
(3) When entering zone Z3 Decel to low speed.
(4) At the time of entering zone Z4, decelerate to a slow speed, and stop at the point (the center of the intersection) where the magnetic tape M is in the shape of a ditch. Follow the magnetic tape M and rotate 90 ° to the left. Start and go straight at low speed. (5) When entering zone Z5 Stop. The orientation of the vehicle body remains unchanged, and parallel movement is made to the left using the posture detection unit (advances and goes straight on).
(6) Stop when entering zone Z6.

(During driving)
The traveling control means 12 constantly monitors which zone the active tag 111 moving toward the arrival point has entered. Then, when the active tag 111 enters a new zone, the management device 123 confirms whether the command to be sent to the AGV 11 is stop. If it is the stop command, the stop command is sent to the unmanned transfer vehicle 11 via the second communication unit. If it is not a stop command, the process proceeds to the next step (processing). (Step 1)

Next, it is checked whether the other active tag 111 has entered the zone immediately ahead on the traveling route of the zone into which the active tag 111 has entered. When the other active tag 111 has entered, a stop command is sent to the AGV 11 via the second communication unit. If the other active tag 111 has not entered the zone one ahead, the process proceeds to the next step (processing).
However, if one zone ahead is an intersection where the other can also enter, not only when the other active tag 111 is entering, but also when the other active tag 111 does not receive a stop command, the intersection is already Also when it is going to enter the zone of (2), a stop command is sent to the AGV 11 via the second communication unit. (Step 2)

  Next, the management device 123 confirms whether there is a command to be sent to the automatic guided vehicle 11 (for example, deceleration). If there is a command to be sent, the command is sent to the AGV 11 via the second communication unit. If there is no command to send, nothing is done. (Step 3)

  The command generation means generates a command after determining that the active tag 111 has entered the zone, which means that the command is selected through the processing from step 1 to step 3.

  In the present embodiment, for example, when entering zone Z2, “decelerate to be slow, and stop at the point where the magnetic tape M bends at right angle left. According to the magnetic tape M, rotate 90 ° to the left. Command to accelerate at a high speed and go straight ahead at a time, but first decelerate to slow down and stop at the point where the magnetic tape M is bent at a right angle left. When it stops, it sends a signal that it has stopped. After the command from the unmanned transfer vehicle 11 is awaited, the magnetic tape M is rotated 90 ° to the left according to the next magnetic tape M. Take off, accelerate to high speed and go straight. The command may be sent.

At the time of start-up, it is not the time when the active tag 111 has entered a new zone, but the management device 123 performs the same processing as when the active tag 111 has entered a new zone. However, the process of step 1 is not performed.
That is, when the operator is ready and presses the departure button (not shown), the drive control means 113 notifies the traveling control device 12 that the departure button (not shown) is pressed via the first communication unit. The management device 123 carries out the processing from step 2 to step 3, and normally is guided to the magnetic tape M and goes straight at low speed (unless another active tag 111 has entered the zone ahead) The command is generated and sent to the automatic guided vehicle via the second communication unit. As a result, the unmanned transfer vehicle 11 departs.

  The unmanned transfer vehicle 11 advances with the drive control means 113 controlling the drive means based on the travel command from the management device 123.

(arrival)
In the present embodiment, when the number of unmanned conveyance vehicles 11 stopped at the arrival location AP becomes equal to or more than a predetermined number, the operator is notified by a not-shown rotary weir. The worker who saw it unloads the part and stores it in the article storage rack. Of course, each time you arrive at the destination AP, you may unload it, but in consideration of efficiency. In the present embodiment, the notification means is a rotary whistle, but of course the notification means is not limited to this.

After unloading the parts, the operator presses a departure button (not shown) of the AGV 11.
The drive control means 113 notifies the travel control device 12 that the departure button (not shown) has been pressed via the first communication unit. The management device 123 performs the processing from step 2 to step 3 as at the time of start. However, one zone ahead is treated as an intersection that can be approached from the other.
For example, in the case of the unmanned conveyance vehicle 11d, when the departure button is pressed, the other active tag 111 does not enter the zone Z5 which is one zone ahead, and the other active tag 111 does not try to enter either In this case, the orientation of the vehicle body remains unchanged, and a command for parallel movement to the left (slow and go straight) is generated using the posture detection unit, and sent to the AGV via the second communication unit. As a result, the unmanned transfer vehicle 11 departs.

  Then, when the active tag 111 enters the zone Z5, the processing from step 1 to step 3 is performed, and if the other active tag 111 has not entered the zone Z7 which is one zone ahead, Move in parallel (advance and go straight on) and stop when the magnetic tape M is at the center of the eight magnetic tape sensors 112b. 2 Send to the automated guided vehicle via the communication unit. The following is omitted.

(Modification of the embodiment)
As a modification of the embodiment, the magnetic tape M may not be laid or may be laid slightly.
In this case, the zone of the AGV control system 1 is set as it is, and the following zone is superimposed on the place where the magnetic tape M was laid.

(1) Straight portion As shown in FIG. 9, seven elongated zones are set in parallel with the traveling path. The central zone Z14 is set to the position where the magnetic tape M is laid. The content of the command of the management device 123 in the case where the unmanned transfer vehicle 11 travels from the top to the bottom in the drawing will be described.
The active tag 111 is started from the state of entering the zone Z14. When the active tag 111 enters the zone Z13, the unmanned transfer vehicle 11 is slightly rotated left while traveling (the traveling direction is changed to the left at a predetermined angle). In a car, it is an image that turns the steering wheel a little to the left and immediately returns straight. If the vehicle travels for a predetermined time and the active tag 111 has entered the zone Z13, the unmanned transfer vehicle 11 is slightly rotated left while traveling again. When the active tag 111 enters the zone Z14, the unmanned transfer vehicle 11 is slightly rotated while traveling.
When the active tag 111 enters the zone Z12, the unmanned transfer vehicle 11 is rotated to the left more than before while traveling. If the active tag 111 subsequently enters zone Z13, nothing is done. Then, when the active tag 111 enters the zone Z14, the unmanned transfer vehicle 11 is slightly rotated while traveling. Alternatively, based on the speed of the AGV 11 and the time that the active tag 111 has stayed in the zone Z13, the angle to be rotated to the right is calculated and rotated to the right.
When the active tag 111 enters the zone Z11, it is determined that the control is impossible, and the unmanned transfer vehicle 11 is stopped.
The same applies to the case where the active tag 111 deviates from the zone Z14 to the zone Z15.

(2) Intersection Portion As shown in FIG. 10, the zones Z11 to Z17 which are longitudinally elongated and the zones Z21 to Z27 which are elongated horizontally are set to overlap.

  The content described above relates to an embodiment of the present invention to the last, and does not mean that the present invention is limited to the above content. For example, in the above embodiment, it has been described that the position information generation means 122 is present alone, but the management device 123 may be implemented with the function of the position information generation means 122 or the position information generation in the reception device 121. The function of the means 122 may be implemented. In the latter case, information on the detected relative position of the UWB tag with respect to the reception device 121 may be transmitted to the management device 123 via a network such as a LAN.

1 AGV control system 11 unmanned conveyance vehicle 12 travel control device 111 active tag 113 drive control means 114 first communication unit 121 reception device 122 position information generation means 123 management device 124 second communication unit

Claims (1)

An AGV control system comprising: an unmanned carrier and a travel control device for controlling the traveling of the unmanned carrier,
The unmanned transport vehicle is
An active tag that wirelessly transmits a pulse signal for positioning including unique identification information;
Driving means for automatically traveling itself,
First communication means for communicating with the travel control device;
Drive control means for controlling the drive means based on a command from the travel control device;
The travel control device
Zone setting means capable of setting zones of any size and any shape in any places;
A first storage unit that stores the zone set by the zone setting unit;
A receiving device for receiving the pulse signal wirelessly transmitted from the active tag;
Position information generating means for periodically measuring the position of the active tag based on the pulse signal received by the receiving device, and generating position information thereof;
Entry determination means for determining that the active tag has entered the zone when the location information generated by the location information generation means satisfies a predetermined condition for the zone stored in the first storage unit; ,
Command generation means for generating a command to the AGV based on the determination of the entry determination means;
Second communication means for communicating with the unmanned transport vehicle;
AGV control system with.

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