JP2771893B2 - Simulation method of travel management in unmanned transport system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an unmanned transport system, and more particularly, to data transfer between a management machine and a plurality of unmanned transport vehicles by means of communication means such as wireless and ground signal lines. The present invention relates to a method for simulating travel management of an automatic guided vehicle in a system for performing travel control of the automatic guided vehicle.

[Prior Art] In this type of unmanned transport system, a method of controlling the traveling of the unmanned transport vehicles so that they do not collide with each other has been conventionally known. There was such a problem.

Therefore, the present applicant has proposed that the traveling
If there is an avoidance area in which two AGVs can pass each other, the avoidance instruction is issued when the two AGVs travel in the same direction and one can follow the other. Has proposed a method in which an unnecessary stop operation can be suppressed as much as possible to prevent a collision by giving a follow-up instruction and a stop instruction to one of the automatic guided vehicles in other cases. -74950).

[Problems to be Solved by the Invention] By the way, when actually installing an unmanned transport system that performs such travel control, how many unmanned transport vehicles are prepared on a similar travel route and how the travel speed is changed If
It is extremely difficult to judge whether the required cargo handling can be carried out efficiently and economically in the shortest time without collision of the automatic guided vehicle, which requires complicated calculations, However, when trying to evaluate the efficiency of driving management by changing various conditions, there were many factors that required actually operating the system or relying on experience and intuition.

The present invention solves the above-mentioned problems, and can simulate the control method of the above proposed contents using a computer or the like, and has the same evaluation as actually installing the system and moving the automatic guided vehicle. It is an object of the present invention to provide a simulation method capable of easily obtaining a value.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method for managing the traveling of a plurality of automatic guided vehicles in which a single management device can exchange data by means of communication means such as wireless and ground signal lines. In the automatic transfer system, a traveling route is divided into a plurality of zones, each zone is numbered, and the traveling route is stored with a list of zone numbers and zone lengths, and at least two arbitrary traveling routes. Between at least two traveling on that travel route
By storing an area (common area) in which two automatic guided vehicles may collide with each other in a zone number sequence, and by driving one of the two automatic guided vehicles on an avoidance path provided in advance. Data in which an area (avoidance area) in which two radio guided vehicles can pass each other is stored in a zone number sequence;
Each zone has data storing a range of distance (monitoring distance) for monitoring the front side of the automatic guided vehicle in the traveling direction from the zone, and the zone number of the current position is searched from the detected travel distance of each automatic guided vehicle. At the same time, based on the zone of the current position of any two automatic guided vehicles, whether or not the same common area exists within the range of the monitoring distance on the front side in the traveling direction is searched. In the case where there is an avoidance area in the common area and two unmanned guided vehicles can pass each other, an avoidance instruction to perform the two unattended guided vehicles in the unmanned guided vehicle is issued in the common area. If the traveling directions of the two automatic guided vehicles are the same, and it is possible for one to follow the other and travel,
A follow-up instruction to follow one of the guided vehicles after the other, and in other cases, a process of transmitting a stop instruction to one of the guided vehicles, on the computer for all combinations of the guided vehicles. A method of simulating the traveling management, wherein the stored data further includes data for setting the traveling speed of the automatic guided vehicle, the content of the cargo handling process, the time required for the cargo handling process for each zone, and collision prevention. And data for the traveling speed set for each zone or an instruction for collision prevention are given at a predetermined time interval predetermined for each cycle of the simulation process. If it is, multiply the travel speed data corresponding to the instruction to obtain a value corresponding to the travel distance detection value of the automatic guided vehicle, and calculate the value of the current position of the automatic guided vehicle from that value. In addition to searching for the zone number, the time required for the automatic guided vehicle between any zones or the amount of load between any zones can be calculated based on the integrated value of the time interval and the time data required for cargo handling for each zone. Calculate the time required for transportation, record it as a cycle time evaluation value, and further arbitrarily change the above various setting data to set the layout of the traveling route, the number of automatic guided vehicles, the traveling speed of the automatic guided vehicles, the loading location The cycle time evaluation value when various conditions such as an unloading place are changed is recorded.

Also, in the above method, the layout of the traveling route,
The present position of the load and each automatic guided vehicle, the traveling time, and the time required for transporting the load may be displayed on a display, and the display may be sequentially changed by changing the step time. .

[Operation] According to this method, the detection value of the traveling distance of the automatic guided vehicle is obtained for each cycle of the simulation processing, the current position zone number of the automatic guided vehicle is searched from the value, and the unmanned guided vehicle between arbitrary zones is obtained. The travel time of the transport vehicle or the time required for transporting an arbitrary amount of load between arbitrary zones is obtained, recorded as a cycle time evaluation value, and further, by changing the various setting data described above, the layout of the travel route is obtained. The cycle time evaluation value when various conditions such as the number of the automatic guided vehicles, the traveling speed of the automatic guided vehicles, the loading location, the unloading location, etc. are changed is recorded.

In addition, the process of changing the movement of each automatic guided vehicle and the cycle time evaluation value within an arbitrary time by changing the interval time can be sequentially displayed on the display.

Embodiment First, an example of an unmanned transfer system to which the simulation method of the present invention is applied will be described with reference to the drawings.

FIG. 1 shows a conceptual configuration of the unmanned transport system. The system includes one management machine 1 and a plurality of automatic guided vehicles 2a, 2b,
2c is a device for performing traveling management by exchanging data with each other by a communication means such as a radio signal and a ground signal line.

FIG. 2 shows an example of a traveling route used in the method of the present invention. In this example, the first route travels from point a to point a ', the second route travels from point b to point b', and the third route travels from point c to point c '. Each traveling route is divided into a plurality of virtual zones of a predetermined length. Each zone is given a number, and “traveling route data” in which the traveling route is described in a sequence of the zone number and the zone length is stored on the management machine and the automatic guided vehicle.

In addition, in addition to the above data, an avoidance route that allows the two AGVs to pass each other by allowing one of the two AGVs to travel on a preset avoidance path is stored as a zone number sequence. Stored “evasion route data”. Each of the above-mentioned route data has various data corresponding to each zone number as shown in the example of FIG. 3 described later. In addition, it is assumed that each of the automatic guided vehicles 2a, 2b, and 2c runs the first, second, and third routes exclusively.

An area (common area) where two automatic guided vehicles traveling along the traveling route may collide between any two traveling routes is stored in the management machine 1 in a zone number sequence. The "common area data" and an area (avoidance area) in which one of the two AGVs can pass each other by traveling on a preset avoidance path, so that the two AGVs can pass each other in a zone number sequence. "Avoidance area data" stored
And “monitoring distance data” that stores a range of distance (monitoring distance) for monitoring the front side of the automatic guided vehicle in the traveling direction from each zone for each zone.

FIGS. 3A to 3D show examples of “travel route data”, “avoidance route data”, “common area data”, and “avoidance area data”, respectively. The “travel route data” includes a zone number Z, a zone length lz, a monitoring distance C (corresponding to “monitoring distance data”), a traveling speed v _z , and data W of cargo handling work. "Bypass route data" includes zone number Z, the zone length lz, monitoring the distance C, the traveling velocity v _z, the data Z ^p of the stop zone. The monitoring distance C is a distance for monitoring a common area on the traveling direction side of the automatic guided vehicle, and is determined as a distance that can be reliably stopped from the zone according to the traveling speed.

The following Table 1 shows the traveling speed v _L to be traveled by the automatic guided vehicle corresponding to the distance L ′ (see FIG. 4) between the position of the automatic guided vehicle and the avoidance area, the preceding vehicle, and the common area during the collision prevention processing. Shows the data. When there is a preceding vehicle, it refers to a case where two unmanned guided vehicles travel in the same area in the same direction and one follows the other.

Table 2 below shows data on the time required for cargo handling. This time is measured in advance and stored.

FIGS. 4 (a), 4 (b), and 4 (c) show how the automatic guided vehicle 2i and each of the avoidance area, the preceding vehicle, and the common area can be prevented from colliding with the automatic guided vehicle 2j. Are shown. The data of the minimum inter-zone distance L is transmitted from the management machine 1 to each automatic guided vehicle at the time of collision prevention processing as described later.

FIG. 5 to FIG. 8 are flowcharts showing the operation of the management device 1, which will be described below.

In FIG. 5, the management machine 1 receives a zone number from each automatic guided vehicle (step a), searches a zone number of a current position from traveling route data (step b), and combines the automatic guided vehicles with each other. Then, it is determined whether or not the condition for instructing any of avoiding, following, and stopping is satisfied (step c). Then, corresponding avoidance, follow-up, and stop processes are performed (steps d, e, and f), and then the minimum inter-zone distance L is transmitted (step g).

The avoidance process is performed as shown in the flowchart of FIG.
Calculate the distance lk between the zone and the avoidance area (step d
1), on the condition that the vehicle is within the monitoring distance from the avoidance area, the vehicle transmits an avoidance road traveling instruction to the vehicle traveling on the avoidance road (step d2), and Then, the inter-zone distance lk of the avoidance area is set as the minimum inter-zone distance L of the carrier (step d3).

The follow-up process is performed as shown in the flowchart of FIG.
The distance lc between the zone and the preceding vehicle is calculated (step e1), and the zone where the preceding vehicle exists is approached within the monitoring distance. If it is smaller than the zone distance L, a new L = lc
Is set (step e2).

The stop processing is performed as shown in the flowchart of FIG.
Calculate the distance lc between the zone and the common area (step f
1), ls is the minimum inter-zone distance L of the carrier at that time
If it is smaller, L = ls is newly set (step
f2).

FIG. 9 is a flowchart showing the operation on the automatic guided vehicle side, which will be described below.

The automatic guided vehicle calculates the traveling distance l2 from the traveling start point (step a '). The current position zone is determined from the traveling distance l2 and the traveling route data shown in FIG. 3A (step b '), and the zone number is transmitted to the management machine 1 (step c'). Each time the current zone position is updated, the travel distance at the time of entering the zone is stored as l1 '= l2 (step d'). Thereafter, it is checked whether or not the avoidance road traveling instruction or the minimum inter-zone distance L has been received from the management device 1 (step e '). When the avoidance road traveling instruction has been received, the stored avoidance road traveling speed command value is set. The vehicle travels (steps f 'and g') and stops on the avoidance road (step h ').

Whenever the minimum inter-zone distance L is received, the travel distance at the time of entering the zone targeted for the minimum inter-zone distance L is stored as l1 = l1 '(step S1). i '). Then, the distance L 'between the automatic guided vehicle, the avoidance area, the zone where the preceding vehicle exists, and the common area is obtained from l2, l1, L (steps j', k '), and the automatic guided vehicle is smoothly moved according to this value. determining a traveling speed command value v _L as can be stopped (step l ').

When the minimum inter-zone distance L has not been received, the traveling speed command value becomes a normal set value (step m ').

The above is the description of the transport system in which the simulation method of the present invention is implemented. Next, the processing content of the simulation method will be described.

In this process, the position of the automatic guided vehicle (hereinafter, referred to as a vehicle body) is sequentially searched at a predetermined interval Δt.

First, the travel distance l2 of the vehicle body (see FIG. 4) is calculated from [Delta] L2 = v _z or v _L × Δt l2 = ΣΔl2.

Next, the current position zone of the vehicle body is searched by comparing with the integrated value of the zone length lz passing through l2. When the current position zone is updated, the traveling distance at that time is stored as l1 = l2, and if there is a cargo handling operation in the zone before the update (w ≠ 0), the time tw required for the cargo handling operation is calculated. Subtract the step time Δt for each calculation cycle (tw = tw−Δt),
Until = 0, the above-mentioned travel distance calculation is not performed assuming that the vehicle body has stopped for cargo handling work.

The above-described collision prevention processing is determined from the current position zone of each vehicle body. If collision prevention processing is necessary, the distance L between the common area, the preceding vehicle, the avoidance area and the vehicle body zone is determined, and the actual distance L 'is further determined. L ′ = L− (l2−11), and the traveling speed for preventing collision corresponding to L ′
v Select _L from the data in Table 1 stored above. At this time, the smaller value of v _z and v _L is used in the above processing.

The above calculation of the traveling distance and the search of the current position zone are performed based on the traveling route data. However, when the vehicle body is instructed to travel on the avoidance road, it corresponds to the avoidance area data to be targeted shown in FIG. 3 (d). This is performed based on the avoidance route data shown in FIG. Then, when it reaches the zone of the stop zone Z ^p equal number, as being stopped until avoid running instruction is canceled, the above processing is not performed. If the last zone of the avoidance route data is reached after the avoidance travel instruction is canceled, the process returns to the process based on the travel route data of the same zone number.

The elapsed time is integrated (t = ΣΔt) to obtain the elapsed time.

Based on the results of each of the above processes, the position of the vehicle body on the traveling route, the traveling speed, the contents of cargo handling work, the details of the collision prevention processing, and the elapsed time are displayed on the display. By repeating this, the display can be sequentially performed with the passage of time.

The above simulation processing can be executed by a computer program, and the required time under each condition can be calculated by variously changing various setting data. That is, by arbitrarily changing various setting data,
It is possible to record and display cycle time evaluation values when various conditions such as the layout of the traveling route, the number of automatic guided vehicles, the traveling speed of the automatic guided vehicles, loading locations, and unloading locations are changed.

The schematic procedure of the cycle time calculation according to the processing contents is shown in the flowcharts of FIGS. 10 (a) and 10 (b).
The outline of the cycle time calculation will be described below with reference to FIG.

First, it is checked whether or not there is a cargo handling operation in the zone where each vehicle body is currently located (step S1). If there is, the cargo handling operation is completed until the loading operation is completed, that is, until tw = 0 (until YES in S2). Is subtracted from the time tw required for each calculation cycle (S3), and the current position zone is determined (S3).
7). If there is no cargo handling work in the current position zone, it is checked whether the vehicle is traveling on an avoidance road (S4). If the vehicle is not traveling on an avoidance road, a traveling distance integrated value l2 is calculated (S6), and the process proceeds to S7. If the vehicle is traveling on the avoidance road in S4, it is checked whether or not the vehicle is in the stop zone (S5). If the vehicle is not in the stop zone, the process proceeds to S6.
Proceed to S7 without processing S6.

Next, it is checked whether or not the zone has been updated (S8).
(S11), and further calculates the distance L 'to the avoidance area, the preceding vehicle, and the common area (S12), and calculates the traveling speed v from L'.
_L is determined (S13). Next, the step time is calculated as t = t + Δ
The elapsed time is obtained by integrating with t (S14) and displayed on the display (S15). In S8, if the zone is updated, it is checked whether all vehicles have been driven (S9). If NO, the mileage is set to l1 =
Stored as l2 (S10), and proceed to S11. If YES, the operation ends.

FIG. 11 shows an example of a display screen. In this example, the current position zone, the traveling speed, the cargo handling state, the collision prevention processing state, and the moving state of the load for each vehicle body at an arbitrary elapsed time are displayed. This display can be updated sequentially as the real time elapses. Therefore, the total time required to end the cargo handling operation can be displayed.

[Effects of the Invention] As described above, according to the simulation method of the present invention, unnecessary stoppages are minimized by using instructions for avoiding, following, and stopping for prevention of collision of the automatic guided vehicle, and efficient traveling management is achieved. While performing, determine the time required for the automatic guided vehicle to travel between any zones or the time required to transport an arbitrary amount of load between any zones, record it as a cycle time evaluation value, and furthermore, lay out the travel route, It is possible to record the cycle time evaluation value when various conditions such as the number of carriers, the traveling speed of the automatic guided vehicle, the loading location, the unloading location, and the like are changed. Therefore, the travel management can be simulated without actually constructing and operating the unmanned transport system, and the economic effect is extremely large.

In addition, the layout of the traveling route, the load, the current position of each automatic guided vehicle, the traveling time, and the time required for transporting the load are sequentially displayed on the display screen, and by changing the step time, each time can be changed within an arbitrary time. The movement of the automatic guided vehicle and the process of changing the cycle time evaluation value can be visually observed by simulation, and useful information for performing a rational design of the automatic guided vehicle system can be obtained.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an example of an unmanned transport system to which the method of the present invention is applied, FIG. 2 is a plan view showing an example of a traveling route of an unmanned transport vehicle in the system, and FIG.
(B), (c) and (d) are diagrams showing examples of preset data used in the method of the present invention, and FIGS. 4 (a) and (b)
(C) is a plan view showing a state in which the automatic guided vehicle is receiving the minimum inter-zone distance L, and FIGS. 5, 6, 7, and 8 show processing on the management machine side in the system. 9 is a flowchart showing processing on the automatic guided vehicle side, FIGS. 10 (a) and 10 (b) are flowcharts of cycle time calculation processing in the method of the present invention, and FIG. 11 shows an example of a display screen. FIG. 1 ... management machine, 2a, 2b, 2c, 2i, 2j ... unmanned carrier.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G05D 1/02

Claims (2)

(57) [Claims] An unmanned transport system in which a single management device manages the traveling of a plurality of unmanned guided vehicles capable of exchanging data by means of a communication means such as a radio signal and a ground signal line, wherein a traveling route is divided into a plurality of zones. Data obtained by dividing the zones, numbering each zone, and storing the traveling route in the order of the zone number and the zone length, and at least two unmanned conveyances traveling on the traveling route between at least two arbitrary traveling routes Area where vehicles may collide (common area)
Is stored in a zone number sequence, and one of the two automatic guided vehicles travels on a preset avoidance path, thereby
Area where the two radio guided vehicles can pass each other (avoidance area) in the form of a zone number sequence, and the range of monitoring distance (monitoring distance) from each zone to the front of the unmanned guided vehicle in the traveling direction With the stored data, the zone number of the current position is searched from the detected distance value of each AGV, and the monitoring distance on the front side in the traveling direction based on the zone of the current position of any two AGVs Is searched for the same common area within the range, and if it exists, there is an avoidance area in the common area to prevent collision, and two AGVs can pass each other. In such a case, an avoidance instruction for passing the unmanned guided vehicle by two vehicles is issued, and the traveling directions of the two unmanned guided vehicles are the same in the common area, and one follows the other and travels behind. Do If it is possible, a process of transmitting a follow-up instruction to follow one of the guided vehicles behind the other, and in other cases, a process of transmitting a stop instruction to one of the guided vehicles, A method of simulating travel management by performing a combination of automatic guided vehicles on a computer, wherein the stored data further includes, for each zone, a traveling speed of the automatic guided vehicle, a cargo handling process, and a time required for the cargo handling process. And the traveling speed data corresponding to the instruction for preventing collision are added, and the traveling speed data set for each zone or the traveling speed data set for each zone at a predetermined time interval predetermined for each cycle of the simulation process. When an instruction for collision prevention is given, a value corresponding to the travel distance detection value of the automatic guided vehicle is calculated by multiplying the travel speed data corresponding to the instruction, and the value is used. In addition to searching for the zone number of the current location of the automatic guided vehicle, the time required for the automatic guided vehicle to travel between any zones or any zone can be calculated based on the integrated value of the time interval and the time data required for cargo handling processing for each zone. Calculate the time required to transport an arbitrary amount of load between them, record it as a cycle time evaluation value, and further arbitrarily change the above various setting data to set the layout of the traveling route, the number of automatic guided vehicles, A method for simulating travel management in an unmanned transport system, wherein cycle time evaluation values when various conditions such as a traveling speed of a car, a loading place, and an unloading place are changed are recorded. 2. The method according to claim 1, wherein the layout of the traveling route, the load, the current position of each AGV, the traveling time,
A method for simulating travel management in an unmanned transport system, wherein a time required for transporting a load is displayed on a display, and the display can be changed sequentially by changing a time interval.