JP2012053838A - Unmanned carrier and traveling control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an unmanned carrier for avoiding an obstacle and a traveling control method.SOLUTION: An avoidance distance is preliminarily set on path data, and when an obstacle 1701 is detected ahead a direction of traveling, an unmanned carrier horizontally travels only by the avoidance distance, and then travels forward. Also, the avoidance distance may be set in each section in the path data as well as the direction of avoidance. Furthermore, when the obstacle 1701 is not detected in measurement data obtained during traveling on an avoidance path, the unmanned carrier travels forward only by vehicle length + a prescribed distance, and then returns to an original path 1702.

Description

  The present invention relates to a technique for an automatic guided vehicle and a travel control method.

  In order to save labor and improve the accuracy of transportation in factory production lines and warehouses, automatic guided vehicles (AGV: Automatic) that automatically run on the target travel route and load and unload cargo Guided Vehicle) has been introduced. Various types of obstacle avoidance methods for such automatic guided vehicles have been developed and applied.

Patent Document 1 discloses an unmanned transport platform that emits laser light in an oblique direction and receives a reflected laser beam from a reflector provided on a rail, and determines that an unmanned transport vehicle has an obstacle and stops itself. An anti-collision device is disclosed.
In Patent Document 2, when light such as laser light is emitted and the reflected light reflected by the reflector installed in the ground station cannot be received, between the ground station and the automatic guided vehicle, A safety device for an automated guided vehicle traveling system that determines that an obstacle is present and stops the automated guided vehicle is disclosed.
Further, in Patent Document 3, a distance measurement sensor for measuring the distance from the preceding automatic guided vehicle is disposed on the front wheel of the automatic guided vehicle, and when the inter-vehicle distance with the preceding automatic guided vehicle is equal to or less than a certain distance, A collision prevention device for an automatic guided vehicle that decelerates or stops itself is disclosed.

JP-A-6-259133 Japanese Patent Laid-Open No. 8-161047 JP 2000-20126 A

  However, the techniques described in Patent Documents 1 to 3 are to decelerate or stop when an obstacle is detected forward.

  The present invention has been made in view of such a background, and an object of the present invention is to provide an automatic guided vehicle and a travel control method for avoiding an obstacle.

In order to solve the above-mentioned problem, the present invention is characterized in that an avoidance distance is set in advance on route data, and when an obstacle is detected forward in the traveling direction, the vehicle travels forward after traversing the avoidance distance. To do.
Other solutions are described as appropriate in the embodiments.

  ADVANTAGE OF THE INVENTION According to this invention, the automatic guided vehicle and traveling control method which avoid an obstacle can be provided.

It is a figure which shows the structural example of the unmanned conveyance system which concerns on this embodiment. It is a block diagram which shows the structural example of the controller in the automatic guided vehicle which concerns on this embodiment. It is a flowchart which shows the procedure of a map data creation process. It is a figure which shows the collection method of measurement data. It is a figure which shows the example of map data. It is a flowchart which shows the procedure of a route data creation process. It is a figure which shows the example of a path | route. It is a figure which shows the example of route data. It is a figure which shows the example of the corresponding | compatible information of the path | route and coordinate which concerns on this embodiment. It is a sequence diagram which shows the procedure of the process at the time of driving | running | working of the automatic guided vehicle which concerns on this embodiment. It is a flowchart which shows the procedure of the traveling control process which concerns on this embodiment. It is a figure explaining the determination method of the steering angle and actual moving distance in case a path | route is a straight line. It is a figure explaining the determination method of the steering angle and actual moving distance in case a path | route is a curve. It is a figure which shows an outline | summary in the avoidance control process which concerns on this embodiment. It is a figure for demonstrating the flow of the obstacle avoidance control process which concerns on this embodiment (the 1). It is a figure which shows the example of the various ranges in this embodiment. It is a figure for demonstrating the flow of the obstacle avoidance control process which concerns on this embodiment (the 2). It is a flowchart which shows the flow of the avoidance control process which concerns on this embodiment (the 1). It is a flowchart which shows the flow of the avoidance control process which concerns on this embodiment (the 2). It is a figure which shows the stop determination method which concerns on this embodiment. It is the figure which showed the stop state of the automatic guided vehicle at the time of using the stop determination with respect to this embodiment.

  Next, modes for carrying out the present invention (referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate. In addition, the same code | symbol is attached | subjected to the same component in each figure, and description is abbreviate | omitted.

(System configuration)
FIG. 1 is a diagram illustrating a configuration example of an unmanned conveyance system according to the present embodiment.
The automatic transport system 9 includes an automatic guided vehicle 1, a host computer (external device) 2, and an operation management computer (external device) 3. Furthermore, an upper host may be installed on the host computer 2 (not shown).
The automatic guided vehicle 1 moves in the traveling area according to the route data 133 (FIG. 2), and loads or unloads it.
The host computer 2 is connected to the operation management computer 3 via a network 5 such as a LAN (Local Area Network), and the measurement data 131 (FIG. 2) sent from the automatic guided vehicle 1 as with the operation management computer 3. The map data 132 (FIG. 2) is created from the above, and the route data 133 is created by the user.
As with the host computer 2, the operation management computer 3 creates map data 132 from the measurement data 131 (FIG. 2) and the like sent from the automatic guided vehicle 1, or performs unmanned conveyance by a wireless LAN via the wireless master station 4. It has a function of sending an instruction to the vehicle 1 and receiving a status report from the automatic guided vehicle 1.

The automatic guided vehicle 1 includes a controller 10, a laser distance sensor 20, a programmable controller 30, steering wheels 40, traveling wheels 50, a touch panel display 60, and a wireless slave station 70.
The controller 10 is a device that controls the operation of the automatic guided vehicle 1. Details of the controller 10 will be described later with reference to FIG.
The laser distance sensor 20 is a sensor that can measure the distance to an object, and is a sensor that emits a laser, a millimeter wave, or the like, detects the reflected light (reflected wave), and measures the distance to an obstacle. . Since the laser distance sensor 20 scans laser waves and millimeter waves greatly to the left and right, the laser distance sensor 20 is attached to a position where the automatic guided vehicle 1 can measure 180 degrees or more. That is, the laser distance sensor 20 can rotate in a range of 180 degrees or more, and can emit a laser at every predetermined angle.
The programmable controller 30 is a device that controls the steered wheels 40 controlled using the steering angle as a parameter and the traveling wheels 50 controlled using the speed as a parameter.
The touch panel display 60 is an information input / output device for performing various settings and maintenance of the automatic guided vehicle 1.
The wireless slave station 70 is a device that receives a communication message transmitted from the wireless master station 4 and passes it to the controller 10.

(Controller configuration)
Next, referring to FIG. 1, the configuration of the controller will be described along FIG.
FIG. 2 is a block diagram illustrating a configuration example of a controller in the automatic guided vehicle according to the present embodiment.
The controller 10 includes a program memory 110 such as a ROM (Read Only Memory), a data memory 130 such as a RAM (Random Access Memory), and a CPU (Central Processing Unit) (not shown).
The data memory 130 stores measurement data 131, map data 132, and route data 133.
The measurement data 131 is data related to the distance to the obstacle measured by the laser distance sensor 20.
The map data 132 is map information created and transmitted by the host computer 2, the operation management computer 3, or a map data creation personal computer (not shown) using the recognition processing result based on the measurement data 131. It is the map information of the travel area which the conveyance vehicle 1 drive | works. The map data 132 will be described later.
The route data 133 is route information on which the automated guided vehicle 1 scheduled to travel on the map data 132 is scheduled. Note that the route data 133 is created by editing software with reference to the map data 132 being executed by the user on the host computer 2 or the like, similar to the creation of the map data 132. The route data 133 is stored in the data memory 130 by being sent to the automatic guided vehicle 1 from the host computer 2, the operation management computer 3, or a map data creation personal computer (not shown). The route data 133 includes speed information of the automatic guided vehicle 1 at each location. The route data 133 will be described later.

  Each program for controlling the automatic guided vehicle 1 is stored in the program memory 110, and the processing unit 111 that processes information is realized by executing these programs by the CPU. The processing unit 111 includes a coordinate conversion unit 112, a data acquisition unit 113, a measurement data acquisition unit 114, a matching unit 115, a position estimation unit 116, a travel route determination unit 117, a travel control unit 118, a stop control unit 119, and an avoidance control unit 120. Is included.

The coordinate conversion unit 112 has a function of converting the destination address included in the work instruction acquired from the host computer 2 into coordinates defined in the map data 132 (that is, set in the travel area). Here, the address is a predetermined place in the traveling area where the automatic guided vehicle 1 travels.
The data acquisition unit 113 has a function of acquiring various data such as route data 133 and map data 132 from the data memory 130.
The measurement data acquisition unit 114 has a function of acquiring the measurement data 131 collected by the laser distance sensor 20 during manual operation by the remote controller or during travel control of the automatic guided vehicle 1.
The matching unit 115 has a function of matching the measurement data 131 sent from the laser distance sensor 20 and the map data 132 during the travel control of the automatic guided vehicle 1.
The position estimation unit 116 has a function of estimating the current position of the automatic guided vehicle 1 based on the matching result by the matching unit 115.

The travel route determination unit 117 has a function of determining the next destination position on the route based on the speed information of the automated guided vehicle 1 included in the route data 133 and the current position estimated by the position estimation unit 116. Have Further, it has a function of calculating the steering angle from the deviation from the route of the automatic guided vehicle 1.
The travel control unit 118 has a function of instructing the programmable controller 30 about the speed information included in the route data 133 and the steering angle calculated by the travel route determination unit 117.
The stop control unit 119 has a function of determining whether or not the automatic guided vehicle 1 has reached the destination address and stopping the automatic guided vehicle 1 if reached.
The avoidance control unit 120 has a function of controlling the vehicle so as to avoid the obstacle when the obstacle is detected forward while the automatic guided vehicle 1 is traveling.

  In order to run the automatic guided vehicle 1, it is necessary to create the map data 132 and the route data 133 and store it in the automatic guided vehicle 1 before the automatic guided vehicle 1 is put online (automatic operation). Further, it is necessary to associate the destination address with the coordinates of the route data 133. Hereinafter, a procedure for creating the map data 132 and the route data 133 will be described with reference to FIGS. 3 to 9 with reference to FIGS. 1 and 2.

<Map data creation process>
FIG. 3 is a flowchart showing the procedure of map data creation processing, and FIG. 4 is a diagram showing a measurement data collection method.
First, the user manually operates the automatic guided vehicle 1 at a low speed while visually checking the surroundings with a manual controller or a remote controller (remote controller). At this time, the laser distance sensor 20 collects the measurement data 131 (S101).
At this time, as shown in FIG. 4, the laser distance sensor 20 rotates a laser emitting unit (not shown) by 180 degrees (or 180 degrees or more) by 0.5 degrees, for example, and emits the laser light 411 at a cycle of 30 ms. Fire. This means that every time the automatic guided vehicle 1 advances from about 1 cm to about 10 cm, the measurement for 180 degrees is performed. The laser distance sensor 20 receives the reflected light of the emitted laser beam 411 and calculates (measures) the distance to the obstacle 421 based on the time from when the laser beam 411 is emitted until it is received. The measurement data acquisition unit 114 stores data relating to the calculated distance to the obstacle in the data memory 130 as measurement data 131. The measurement data 131 is collected at regular intervals. Reference numerals 401 to 403 denote sections, and avoidance information (such as avoidance distance and avoidance direction) is set for each of these sections.

After collecting all the measurement data 131 in the area, the measurement data 131 is output to the host computer 2, the operation management computer 3, or a map data creation personal computer (not shown) via an external interface (not shown).
Then, the user creates map data 132 based on the output measurement data 131 by operating the map creation software running on the host computer 2, the operation management computer 3, or a map data creation personal computer (not shown). (S102 in FIG. 3). Specifically, the map data 132 is created by superimposing the collected measurement data 131.
The created map data 132 is sent to the automated guided vehicle 1 via an external interface (not shown) and stored in the data memory 130.
Note that the once created map data 132 is not updated unless the processes of steps S101 to S102 are performed again.

(Map data example)
FIG. 5 is a diagram illustrating an example of map data.
As shown in FIG. 5, a wall 501 and an obstacle 502 in the travel area are recorded as data in the map data 132.

<Route data creation process>
Next, a route data creation process for creating route data indicating a route on which the automated guided vehicle 1 should travel will be described with reference to FIGS.
FIG. 6 is a flowchart showing a procedure of route data creation processing.
First, the user sets route position information by designating a route on the map data 132 by using route creation software executed on the host computer 2, the operation management computer 3 or a map data creation personal computer (not shown). (S201). The route creation software has a function that allows a user to easily create a route on a map by referring to the map data displayed by the route creation software and tracing the map screen with a pointing device such as a mouse. . The route position information created in this way is data represented by a sequence of coordinates defined in the map data 132. Further, when setting the route position information, the user sets the address and the correspondence information between the address and the coordinates in the route data 133 by setting the address.

Next, the user sets speed information for designating a speed when the automatic guided vehicle 1 travels unattended on a route created by the route creation software (S202). For example, referring to FIG. 4, in the first section 403, the second speed (1.2 [km / h]), and in the next curve section 402, the first speed (0.6 [km / h]). In the section 401 that has passed through the curve, the vehicle is set on the route so as to travel at the third speed (2.4 [km / h]).
The speed can be set in several steps in the order of creep speed (slow forward speed), 1st speed, 2nd speed, and the like. For example, the maximum speed may be set to 9 km / hr (150 m / min) and divided into 10 parts. However, the creep speed is determined to be slower than the first speed (for example, 0.3 km / hr).

  Then, the user uses route creation software executed by the host computer 2, the operation management computer 3 or a map data creation personal computer (not shown), and avoidance information such as avoidance distance and avoidance direction for each section in the route data 132. Is set (S203). Although specific examples will be described later, the avoidance information is set as (avoidance direction, avoidance distance), for example. For example, (traveling direction right, 5 m).

(Route data example)
Next, an example of the route data 133 will be described with reference to FIGS.
FIG. 7 is a diagram illustrating an example of a route.
FIG. 7 shows an example of a route in the factory which is a traveling area of the automatic guided vehicle 1, and “A” to “H” indicate “A address” to “H address”.
Further, “address A”, “address C”, “address E”, and “address G” in FIG. 7 indicate locations where “wholesale work” is performed. In addition, “B address”, “D address”, “F address”, and “H address” in FIG. 7 indicate locations where “loading work” is performed.
The address designation is a legacy part inherited from a conventional system in which an automatic guided vehicle travels on a white line.

FIG. 8 is a diagram illustrating an example of route data.
In FIG. 8, “B”, “C”, “E”, and “G” correspond to “B”, “C”, “E”, and “G” in FIG.
FIG. 8A shows a route in which the load is loaded at “B address” and is wholesaled at “C address” (B → C).
Similarly, FIG. 8B shows a route for loading at “B address” and wholesale at “E address” (B → E), and in FIG. 8C, loading at “B address”. And the route to be wholesaled by “G address” is indicated (B → G).
In this way, the route data 133 can be specified as product location → wholesale location or wholesale location → product location.

In the example of FIG. 7, the settable route data 133 is, for example, as follows.
(1) Wholesale → Product A → B, A → D, A → F, A → H
C → B, C → D, C → F, C → H
E → B, E → D, E → F, E → H
G → B, G → D, G → F, G → H

(2) Product → Wholesale B → A, B → C, B → E, B → G
D → A, D → C, D → E, D → G
F → A, F → C, F → E, F → G
H → A, H → C, H → E, H → G

The map data 132 and the route data 133 are created by the host computer 2, the operation management computer 3 or a map data creation personal computer (not shown) based on the measurement data 131 collected by one automatic guided vehicle 1. Applies to all automated guided vehicles 1
The creation of the map data 132 and the route data 133 can also be performed for each of all automatic guided vehicles 1 that are put online. This is because, when the individual difference between the laser distance sensor 20 and the traveling system (steering wheel 40, traveling wheel 50) is large, the map data 132 collected by one automatic guided vehicle 1 is applied to all automatic guided vehicles 1. This is because it is considered more effective to apply them individually.

FIG. 9 is a diagram illustrating an example of correspondence information between a route and coordinates according to the present embodiment.
As shown in FIG. 9, in the route data 133, the route is managed by coordinates. Specifically, the route data 133 is expressed as a list of coordinates. The route data 133 also stores data in which addresses 1101 to 1103 are associated with coordinates. Addresses 1101 to 1103 correspond to the addresses “A” to “H” in FIGS. 7 and 8.

<Control processing during travel>
Next, a process when the automatic guided vehicle 1 travels unmanned along FIGS. 10 and 11 will be described with reference to FIGS. 1 and 2.
FIG. 10 is a sequence diagram showing a processing procedure when the automatic guided vehicle according to the present embodiment travels.
When entering online, the user first brings the automated guided vehicle 1 to a certain address, and inputs the current address via the touch panel display 60, for example.
As a result, the automatic guided vehicle 1 sends information indicating that it has been placed online to the host computer 2 (S301). Here, online entry also serves as an inquiry for the next work.
The host computer 2 that has received the cum / next work inquiry from the automated guided vehicle 1 through the operation management computer 3 transmits a work instruction to the automated guided vehicle 1 (S302). This work instruction stores a destination address and information related to the work contents performed at the destination address (product work is performed in the example of step S302).
The automatic guided vehicle 1 that has received the work instruction via the operation management computer 3 performs the travel control described later in FIG. 11 (S303), and sends the current state (address passage information, work completion information, etc.) to the operation management computer 3. Report (S304).
The automatic guided vehicle 1 repeats the processes of steps S303 and S304 until it reaches the destination address.

Then, after traveling control (S305), when the vehicle arrives at the destination address and completes the work (here, the loading work), the automatic guided vehicle 1 transmits a status report indicating that the loading work is completed to the operation management computer 3 ( S306).
The operation management computer 3 that has received the status report indicating that the loading operation has been completed transmits a similar status report to the host computer 2.
Next, the host computer 2 transmits a work instruction for wholesale work as the next work to the automatic guided vehicle 1 via the operation management computer 3 (S307). In this work instruction, information regarding the destination address and work content (wholesale work in the example of step S307) is stored.
The automatic guided vehicle 1 that has received the work instruction via the operation management computer 3 performs travel control described later in FIG. 11 (S308), and the current state (address passage information, work completion information, etc.) is transferred to the operation management computer 3. Report (S309).
The automatic guided vehicle 1 repeats the processes in steps S308 and S309 until it reaches the destination address.

Then, after traveling control (S310), when the vehicle arrives at the destination address and completes the work (here, the wholesale work), the automatic guided vehicle 1 manages the status report (the wholesale work completion report) that the wholesale work is completed. It transmits to the computer 3 (S311). This also serves as an inquiry for the next work.
The operation management computer 3 that has received the status report indicating that the wholesale operation has been completed transmits a similar status report to the host computer 2.

The host computer 2 that has received the wholesale work completion report via the operation management computer 3 transmits the next work instruction to the automatic guided vehicle 1 (S312).
Here, it is assumed that movement (no loading work and wholesale work) is instructed as the work content.
The automatic guided vehicle 1 that has received the work instruction via the operation management computer 3 performs the travel control described later in FIG. 11 (S313), and sends the current state (address passage information, work completion information, etc.) to the operation management computer 3. Report (S314).
The automatic guided vehicle 1 repeats the processes of steps S313 and S314 until it reaches the destination address.

Then, after the travel control (S315), when the vehicle arrives at the destination address, the automatic guided vehicle 1 transmits a status report (moving work completion report) indicating that the vehicle has arrived at the destination address to the operation management computer 3 (S316). This also serves as an inquiry for the next work.
The operation management computer 3 that has received the status report indicating that the moving work has been completed transmits a similar status report to the host computer 2.
The host computer 2 that has received the movement work completion report via the operation management computer 3 confirms the next work (S317).

In FIG. 10, the host computer 2 that has received the completion report of the loading operation in step S306 immediately sends an instruction for the wholesale operation, which is the next operation, to the automatic guided vehicle 1. An instruction for the next work may be transmitted to the automatic guided vehicle 1 after receiving the next work inquiry. The same applies to wholesale work and moving work.
In addition, when the destination address is not reached in FIG. 10, the automatic guided vehicle 1 may not perform the status report.

  Further, when an abnormality occurs in the automatic guided vehicle 1, the automatic guided vehicle 1 autonomously enters the current position by inputting the current address to the automatic guided vehicle 1 via, for example, the touch panel display 60 in the same manner as when online. May be obtained.

<Running control process>
FIG. 11 is a flowchart showing the procedure of the travel control process according to the present embodiment. Note that the processing in FIG. 11 corresponds to the details of the processing in steps S303, S305, S308, S310, S313, and S315 in FIG.
First, the automatic guided vehicle 1 receives a work instruction via the operation management computer 3 (S401).
Next, the coordinate conversion unit 112 of the automatic guided vehicle 1 converts the destination address included in the work instruction into coordinates according to the correspondence information between the addresses and coordinates stored in the route data 133 (S402).
When the data acquisition unit 113 of the automatic guided vehicle 1 selects the route data 133 from the current address to the destination address from the route data 133 stored in the data memory 130, the data acquisition unit 113 acquires the corresponding route data 133 (S403). ).

Subsequently, the laser distance sensor 20 performs the laser distance measurement described in FIG. 4, and the measurement data acquisition unit 114 performs the laser distance sensor measurement for position determination to acquire the result of the laser distance measurement (S404).
Then, the matching unit 115 performs matching between the map data 132 stored in the data memory 130 and the measurement data 131 acquired in step S404 (S405).
Next, the avoidance control unit 120 performs an avoidance control process (S406). The avoidance control process will be described later.
And the position estimation part 116 estimates the present position (X, Y) of the present automatic guided vehicle 1 based on the matching result of step S405 (S407). Since the processing in step S405 and step S407 is a technique described in Japanese Patent No. 4375320 and the like, a detailed description thereof will be omitted. However, in outline, a place that matches the shape of the measurement data 131 is searched on the map data 132, The current position of the automatic guided vehicle 1 is estimated from the search result. The estimated current position is obtained in the form of coordinates.

Next, the travel route determination unit 117 determines the travel distance d and the actual travel distance da based on the speed information v set in the route data 133 (S408). Calculation of the actual movement distance da will be described later with reference to FIGS.
In step S <b> 408, when the automated guided vehicle 1 is off the route, the travel route determination unit 117 uses the speed information set in the portion of the route closest to the automated guided vehicle 1. In this embodiment, a perpendicular is extended from the reference point of the automatic guided vehicle 1 to the route, and speed information set at a point where the perpendicular and the route intersect is used. In the present embodiment, the reference point of the automatic guided vehicle 1 is the center of the front surface of the automatic guided vehicle 1.
The moving distance is determined such that the moving distance increases as the speed set in the route data 133 increases. For example, the speed and the moving distance may be directly proportional, or the speed and the moving distance may be a quadratic function or a higher-order function.

Here, the relationship between the speed and the moving distance d is illustrated. As described below, a sufficient length is taken so as to reach the moving destination that is the end point of the moving distance d by the time of the next distance sensor measurement.
First speed: 5.0 mm / 30 ms (0.6 km / h), moving distance d: 100 mm
2nd speed: 10.0 mm / 30 ms (1.2 km / h), moving distance d: 200 mm
3rd speed: 20.0 mm / 30 ms (2.4 km / h), moving distance d: 300 mm
4th speed: 26.7 mm / 30 ms (3.2 km / h), moving distance d: 400 mm
Here, the distance every 30 ms is an example when the measurement interval of the laser distance sensor 20 is 30 ms, and the numerical value varies depending on the measurement interval.

  After step S408, the travel route determination unit 117 determines the target destination coordinates on the route based on the movement distance d obtained in step S408 and the current position coordinates (X, Y). The destination position is determined (S409).

Next, the travel route determination unit 117 determines the steering angle θ based on the current coordinates (X, Y) and the destination coordinates determined in step S409 (S410). The process of step S410 will be described later with reference to FIGS.
Further, the travel route determination unit 117 determines the speed by acquiring again the speed v set on the route from the route data 133 based on the current coordinates (X, Y) (S411).

  At this stage, since the steering angle θ and the speed v for moving the automatic guided vehicle 1 are determined, the travel control unit 118 sends these parameters to the programmable controller 30 to thereby move the end point of the moving distance d. Aiming at the destination, the automatic guided vehicle 1 is moved (S412). Actually, the next measurement by the laser distance sensor 20 is performed at a timing earlier than the movement time corresponding to the movement distance d.

At the time of the next laser distance sensor measurement (after 30 msec), the stop control unit 119 determines whether or not the automatic guided vehicle 1 has reached the destination address (coordinates corresponding to the destination address) (S413). The process of step S413 will be described later with reference to FIGS.
If the result of step S413 is that the automatic guided vehicle 1 has not reached the destination address (S413 → No), the controller 10 returns the process to step S404.
As a result of step S413, when the automatic guided vehicle 1 has reached the destination address (S413 → Yes), the controller 10 ends the traveling control process.

  When the automatic guided vehicle 1 reaches the destination address, the controller can store the current coordinate information as it is in the data memory 130 and can be used in the next operation.

<Determination of steering angle and actual travel distance>
Next, a method for determining the steering angle and the actual movement distance will be described with reference to FIGS. 12 and 13 with reference to FIGS. 1 and 2. This is the process performed in steps S408 and S410 in FIG.
FIG. 12 is a diagram for explaining a method for determining the steering angle and the actual movement distance when the route is a straight line as indicated by a thick solid line.
In the present embodiment, the reference point 1201 of the automatic guided vehicle 1 is set at the front center of the automatic guided vehicle 1. When the travel distance d is determined based on the speed, the travel route determination unit 117 moves from the reference leg 1201 of the automatic guided vehicle 1 to the route from the perpendicular foot 1203 on the route (a list of coordinates indicated by the route data 132). A point corresponding to the movement distance d is obtained along with the movement destination coordinates 1202. Then, the travel route determination unit 117 sets the angle of the steered wheels 40 as the steering angle θ so that the automatic guided vehicle 1 can be moved (directed) in the direction of the movement destination coordinates 1202.
At this time, the relationship between the actual moving distance da and the moving distance d is da = d / cos θ.

FIG. 13 is a diagram illustrating a method for determining the steering angle and the actual movement distance when the route is a curve as indicated by a thick solid line.
Even when the route is a curve, the travel route determination unit 117 has a perpendicular foot 1301 on the route from the reference point 1201 of the automatic guided vehicle 1 (the shortest distance on the route from the reference point 1201 of the automatic guided vehicle 1). A point) is calculated, and the destination coordinate 1302 on the route is determined by calculating the length of the curve from the point 1301 as the moving distance d. In such a method, the amount of calculation is large, but when the curvature of the route is large, it is possible to obtain the accurate destination coordinates 1302 on the route.
The relationship between the actual moving distance da and the moving distance d is da = d / cos θ.

According to the method described in FIGS. 12 and 13, the steering angle and speed can be determined so that the next movement destination coordinates are on the route even if the current coordinates are not on the route.
As described above, according to the present embodiment, as the speed increases, the moving distance is increased and the target destination coordinates on the route are set farther according to the traveling speed of the automatic guided vehicle 1. The vehicle 1 can be controlled to perform stable running with less blur.

<Avoidance control>
FIG. 14 is a diagram showing an overview of the avoidance control process according to the present embodiment.
In this embodiment, as shown in FIG. 14A, when the automatic guided vehicle 1 traveling on the route 1702 detects an obstacle 1701 forward, the obstacle 1701 is bypassed as shown in FIG. 14B. To avoid obstacles.

(Avoidance control process flow)
Next, the flow of the obstacle avoidance control process according to the present embodiment will be described with reference to FIGS.
First, when the automatic guided vehicle 1 is traveling on the route 1702, the avoidance control unit 120 detects an obstacle 1701 forward (FIG. 15A). The detection of the obstacle 1701 is determined by whether or not an object is detected in front of the own vehicle in the measurement data 131 acquired from the laser distance sensor 20.
As shown in FIG. 16, a caution / deceleration range (first distance) 1903, a stop range (second distance) 1902, and an emergency stop range 1901 are set according to the distance between the automatic guided vehicle 1 and the obstacle. The range of the distance from the obstacle is estimated by the avoidance control unit 120 based on the current traveling speed, the matching result with the map data 132, and the like.

Here, each range will be described. When an obstacle exists in the caution / deceleration range 1903, the avoidance control unit 120 causes the automatic guided vehicle 1 to travel at a low speed (for example, 1st speed travel).
If an obstacle exists in the stop range 1902, the avoidance control unit 120 performs an avoidance control process that bypasses the obstacle 1701 after stopping for a certain period of time. It should be noted that the stop for a certain period of time is that the obstacle is expected to move during the stop.
The emergency stop range 1901 is a range used when an obstacle is suddenly placed in front of the automatic guided vehicle 1, and the processing performed by the avoidance control unit 120 is the same as the stop range 1902.

If the obstacle 1701 detected in FIG. 15A is within the caution / deceleration range 1903 (FIG. 16), the avoidance control unit 120 causes the automatic guided vehicle 1 to travel at a low speed (for example, travel at the first speed).
When the obstacle 1701 is not removed and the distance between the automatic guided vehicle 1 and the obstacle 1701 enters the stop range 1902 (FIG. 16), the avoidance control unit 120 stops the automatic guided vehicle 1 for a certain period of time (FIG. 15 (b)).
If the obstacle 1701 is not removed even after stopping for a certain time, the automatic guided vehicle 1 moves the automatic guided vehicle 1 by a predetermined distance xa (FIG. 15C). The traverse distance xa is set for each section in the route data 133 as described above. For example, a certain section A is set to 3 m leftward, and the next section B is set to 2 m rightward. Set 3m leftward and 2m rightward in one section, give priority to the leftward direction, and if the distance measured by the laser distance sensor 20 is 3m or more in the leftward direction, move rightward You may set as follows.

  After traversing, the automatic guided vehicle 1 travels at a low speed forward while acquiring measurement data 131 by the laser distance sensor 20 (FIG. 15D). That is, it proceeds in parallel with the path 1702.

The avoidance control unit 120 proceeds forward while always determining whether or not an obstacle is detected in the measurement data 131, and when the obstacle is no longer detected in the measurement data 131, the leading of the automatic guided vehicle 1 is It is determined that the object overlaps the rear edge of the obstacle 1701 (FIG. 17A).
The avoidance control unit 120, when the obstacle 1701 is no longer detected in the measurement data 131 and travels at a low speed forward by the vehicle length + α, causes the automatic guided vehicle 1 to traverse again (FIG. 17B), and the route 1702 The automatic guided vehicle 1 is returned to the top, and normal running is started (FIG. 17C).

(Details of avoidance control processing)
Next, details of the avoidance control process will be described with reference to FIGS. 18 and 19 with reference to FIGS.
18 and 19 are flowcharts showing a flow of avoidance control processing according to the present embodiment. Conventional automatic guided vehicles stop when they detect an obstacle in front of the route, and perform an abnormal stop to stop while notifying the obstacle if the obstacle is not removed within a certain time (Fig. 18 corresponds to the processing of steps S511 to S513).
On the other hand, the automatic guided vehicle 1 according to the present embodiment reduces such an abnormal stop by performing the following avoidance process.
The avoidance control unit 120 determines whether an obstacle is detected in front of the route (S501 in FIG. 18). As described above, this determination is performed by the avoidance control unit 120 determining whether or not there is an object in front of the path during the distance measurement by the laser distance sensor 20.
As a result of step S501, when an obstacle is not detected ahead of the route (S501 → No), the avoidance control unit 120 advances the processing to step S407 in FIG.
As a result of step S501, when an obstacle is detected ahead of the route (S501 → Yes: FIG. 15A), the avoidance control unit 120 determines whether or not the distance to the obstacle is within the caution / deceleration range. Determination is made (S502).
As a result of step S502, when the distance to the obstacle is not within the caution / deceleration range (S502 → No), the processing unit 111 performs normal traveling (S503), and then returns the process to step S502. The processing in step S503 is the same as the processing in steps S404, 405, and 407 to 412 in FIG.

As a result of step S502, when the distance to the obstacle is within the attention / deceleration range (S502 → Yes), the avoidance control unit 120 causes the automatic guided vehicle 1 to travel at a low speed (1st speed travel) (S504). At this time, the avoidance control unit 120 may display a warning on the touch panel display 60 and also cause the host computer 2 or the like to display a warning. Further, the avoidance control unit 120 may output a warning sound from a sound generator (not shown).
Thereafter, the avoidance control unit 120 determines whether or not the distance to the obstacle is within the stop range (S505).
When the distance to the obstacle is not within the stop range as a result of step S505 (S505 → No), the avoidance control unit 120 returns the process to step S504.

If the distance to the obstacle is within the stop range as a result of step S505 (S505 → Yes), the avoidance control unit 120 temporarily stops the automatic guided vehicle 1 (S506: FIG. 15B).
During the temporary stop, the avoidance control unit 120 determines whether or not the obstacle has been removed at a constant cycle (S507). Whether or not the obstacle has been removed is determined based on the measurement data 131 acquired from the laser distance sensor 20.
If the obstacle has been removed as a result of step S507 (S507 → Yes), the processing unit 100 returns the process to step S404 of FIG.

If the obstacle has not been removed as a result of step S507 (S507 → No), the avoidance control unit 120 determines whether an obstacle has been detected on the avoidance path (S508). Here, the measurement data 131 obtained by the laser distance sensor 20 is acquired at the position where it is currently stopped, and the avoidance control is performed to determine whether or not an obstacle is detected on the avoidance path within a range that can be acquired and recognized by the measurement data 131. The unit 120 determines. The avoidance route is a route along which the automatic guided vehicle 1 travels after traversing.
As a result of step S508, when an obstacle is detected on the avoidance route (S508 → Yes), the avoidance control unit 120 returns the process to step S506 while continuing the temporary stop.

  As a result of step S508, when no obstacle is detected on the avoidance route (S508 → No), the avoidance control unit 120 avoids the avoidance distance set in the section where the automatic guided vehicle 1 currently exists from the route data 133. Then, avoidance information such as an avoidance direction is acquired (S509), the steered wheel is controlled, and the automatic guided vehicle 1 is traversed by the avoidance distance in the acquired avoidance direction to avoid obstacles (S510: FIG. 15 (c) )).

Then, the avoidance control unit 120 causes the automatic guided vehicle 1 to travel at a low speed (for example, first speed travel) on the avoidance route while performing distance measurement by the laser distance sensor 20 (S514: FIG. 15D).
Then, the avoidance control unit 120 determines whether an obstacle has been detected ahead while traveling at a low speed on the avoidance route (S515).
As a result of step S515, when an obstacle is detected ahead of the route (S515 → Yes), the avoidance control unit 120 stops the automatic guided vehicle 1 (S511). Thereafter, the automatic guided vehicle 1 remains stopped until the operator removes the obstacle on the avoidance route and the route and presses the rerun button on the touch panel display 60.
When the operator removes an obstacle on the route (reference numeral 1702 in FIG. 15) and presses the rerun button on the touch panel display 60 (S512), the avoidance control unit 120 routes the automatic guided vehicle 1 along the route (reference numeral 1702 in FIG. 15). ) (S513), the processing unit 100 returns the process to step S404 in FIG. 11 to perform normal traveling control.

  In step S515, when an obstacle is detected in front of the route (S515 → Yes), the avoidance control unit 120 performs the same processing as steps S502 to S505, and then pauses in the same manner as in step S506. It waits until the obstacle is removed (until no obstacle is detected by the laser distance sensor 20), and when the removal of the obstacle is detected (when the obstacle is no longer detected), the original route (reference numeral 1702 in FIG. 14). The automatic guided vehicle 1 may be returned to the route indicated by), and the process may be returned to step S404 in FIG.

If no obstacle is detected ahead of the route as a result of step S515 (S515 → No), the avoidance control unit 120 determines whether the current position exceeds the avoidance section of the route data 133, thereby It is determined whether or not an object exists across different avoidance sections (S516 in FIG. 19). The avoidance section is a section in which the avoidance distance and the avoidance direction are defined as applicable in the route data 133. The avoidance sections may coincide with the sections indicated by reference numerals 401 to 403 in FIG. 3 or may be set individually.
As a result of step S516, when the obstacle exists across different avoidance sections (S516 → Yes), the avoidance control unit 120 stops the automatic guided vehicle 1 (S511 in FIG. 18). Thereafter, the automatic guided vehicle 1 remains stopped until the operator removes the obstacle on the avoidance route and the route and presses the rerun button on the touch panel display 60 (S512 and S513 in FIG. 18).

As a result of step S516, when the different avoidance sections do not exist (S516 → No), the avoidance control unit 120 has an obstacle within the range (ranging range) measured by the laser distance sensor 20. By determining whether or not the obstacle has passed, it is determined whether or not the obstacle has been passed (S517). As shown in FIG. 17 (a), the automatic guided vehicle 1 is over the obstacle unless the laser distance sensor rotates in the direction of 180 ° and the emitted laser detects the obstacle. This is because it can be determined.
As a result of step S517, when the obstacle is not passed (S517 → No), the processing unit 111 returns the process to step S514 of FIG.
As a result of step S517, when the vehicle is passing an obstacle (S517 → Yes: FIG. 17A), the avoidance control unit 120 travels a predetermined distance (vehicle length + α) on the avoidance route (S518: FIG. 17B). )) Thereafter, the automatic guided vehicle 1 is caused to traverse and the automatic guided vehicle 1 is returned to the route (S519: FIG. 17C). Thereafter, the processing unit 100 returns the process to step S404 in FIG. 11, and the automatic guided vehicle 1 performs normal traveling control for traveling on the route 1702 (FIG. 17).

<Stop judgment>
Next, the stop determination method will be described along FIGS. 20 and 21 with reference to FIGS. 1 and 2. This is a process performed in the process of step S413 in FIG.

  As illustrated in FIG. 20, the stop control unit 119 is configured such that when the automatic guided vehicle 1 is off the route, that is, the traveling direction of the automatic guided vehicle 1 is the movement destination coordinates 1202 and the movement destination coordinates 1302 in FIGS. 12 and 13. The target stop line 1502 is determined so as to pass through the center point 1501 of the automatic guided vehicle 1 and to be perpendicular to the direction of the steered wheels 40 (traveling direction). This target stop line 1502 forms an angle θ (steering angle) with the crossing line 1503. Reference numeral 1601 is a coordinate corresponding to the destination address.

FIG. 21 is a diagram illustrating a stopped state of the automatic guided vehicle 1 when the stop determination for the present embodiment is used.
As shown in FIG. 21, when the target stop line 1502 described in FIG. 20 is on the coordinates 1601 corresponding to the target address or exceeds the coordinates corresponding to the target address, the stop determination unit performs unmanned conveyance. It is determined that the car 1 has reached the destination address (S413 → Yes in FIG. 11). Since the automatic guided vehicle 1 is controlled so as to travel on the route, the coordinates 1601 and the center point 1501 corresponding to the destination address finally use the target stop line 1502 for determination of stop. When the steering angle θ is not 0 degree, that is, even when the automatic guided vehicle 1 is deviated from the route, the deviation between the center point 1501 of the automatic guided vehicle 1 and the coordinates 1601 corresponding to the destination address at the time of stop is reduced. Can be stopped.

  Moreover, in this embodiment, although the address is converted into a coordinate, it is not restricted to this, You may perform driving control of the automatic guided vehicle 1 only by coordinate information.

(Summary)
According to this embodiment, since the target address is managed by coordinates, it is possible to specify the address that has been performed by hardware-like running control such as an electric wire or a reflective tape, while using an electric wire or a reflective tape. It is possible to make the automatic guided vehicle 1 self-propelled. In addition, even when an obstacle exists on the route, the obstacle can be avoided autonomously. Thereby, it can reduce that the situation which delays work arises.
Further, by calculating the steering angle θ and controlling the steering wheel 40 with the steering angle θ, it is possible to return to the route even if the automatic guided vehicle 1 is off the route.
Further, by calculating and applying the target stop line 1502, it is possible to reduce the deviation when the destination address is reached.

1 Automated guided vehicle 1
2 host computer 3 operation management computer 4 wireless master station 5 network 9 unmanned conveyance system 10 controller 20 laser distance sensor 30 programmable controller 40 steering wheel 50 traveling wheel 70 wireless slave station 110 program memory 111 processing unit 112 coordinate conversion unit 113 data acquisition unit 114 Measurement data acquisition unit 115 Matching unit 116 Position estimation unit 117 Travel route determination unit 118 Travel control unit 119 Stop control unit 120 Avoidance control unit 130 Data memory 131 Measurement data 132 Map data 133 Route data 1902 Stop range (second distance)
1903 Caution / Deceleration distance range (first distance)
d Travel distance da Actual travel distance

Here, the relationship between the speed and the moving distance d is illustrated. As described below, a sufficient length is taken so as not to reach the moving destination that is the end point of the moving distance d by the time of the next distance sensor measurement.
First speed: 5.0 mm / 30 ms (0.6 km / h), moving distance d: 100 mm
2nd speed: 10.0 mm / 30 ms (1.2 km / h), moving distance d: 200 mm
3rd speed: 20.0 mm / 30 ms (2.4 km / h), moving distance d: 300 mm
4th speed: 26.7 mm / 30 ms (3.2 km / h), moving distance d: 400 mm
Here, the distance every 30 ms is an example when the measurement interval of the laser distance sensor 20 is 30 ms, and the numerical value varies depending on the measurement interval.

Claims (6)

Measure the surrounding environment with a sensor that can measure the distance to the object, match the map data with the measurement data obtained by the measurement, find the current position, and based on the obtained current position , An automatic guided vehicle traveling along preset route data,
An avoidance control unit configured to perform an avoidance control process in which an avoidance distance is set in advance on the route data and an obstacle is detected forward in the traveling direction and then travels forward after traversing the avoidance distance. An automated guided vehicle. The avoidance control unit includes:
After detecting the obstacle, if the distance to the obstacle is within the first distance, travel at a reduced speed,
The automatic guided vehicle according to claim 1, wherein the avoidance control process is performed when a distance from the obstacle is within a second distance shorter than the first distance. The avoidance control unit includes:
The suspension control process is performed when the obstacle is detected after the stop when the distance to the obstacle is within the second distance, and the obstacle is detected after the stop. The automated guided vehicle described in 1. The avoidance control unit includes:
After the traversing, while traveling forward, in the measurement data, when the obstacle is not detected,
The automatic guided vehicle according to claim 1, wherein the automatic guided vehicle is returned to the original route after traveling for a length of the automatic guided vehicle plus a predetermined distance. The avoidance distance is set for each section of the route data,
The avoidance control unit includes:
2. The automatic guided vehicle according to claim 1, wherein the automatic guided vehicle is stopped when it is detected that an obstacle exists across different sections while traveling forward after the traversing. Measure the surrounding environment with a sensor that can measure the distance to the object, match the map data with the measurement data obtained by the measurement, find the current position, and based on the obtained current position , A travel control method by an automated guided vehicle that travels along preset route data,
The automatic guided vehicle is
On the route data, an avoidance distance is set in advance, and when an obstacle is detected forward in the traveling direction, an avoidance control process of traveling forward after traversing the avoidance distance is performed. .

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