JP2720526B2 - Travel control method for mobile robot - Google Patents

Description

The present invention relates to a traveling control method for each mobile robot in a mobile robot system including a plurality of mobile robots and a control station that controls these mobile robots. .

"Conventional technology" In recent years, with the development of PA (factory automation), various systems of this kind have been developed and put into practical use. In this mobile robot system, the control station instructs each mobile robot to a destination and an operation to be performed at the destination by radio or wire. The mobile robot, which has received an instruction from the control station, automatically travels to and arrives at the instructed place, performs the instructed work at that place, and waits for the next instruction at that place when the work is completed.

[Problems to be Solved by the Invention] In the mobile robot system described above, a part of the traveling path may not be used due to system maintenance or a change in the layout of a factory. In such a case, it is very difficult to change the route map of the ROM provided in each mobile robot or to change the logic of the portion that controls the blocking. It was difficult to change freely.

The present invention has been made in view of such circumstances, and has as its object to provide a traveling control method for a mobile robot that can easily prohibit traveling on some traveling paths.

[Means for Solving the Problems] The present invention comprises a plurality of mobile robots that travel along a guideline that constitutes a route, and a control station that controls these mobile robots, and each mobile robot has an internal map memory. In a mobile robot system that searches for a route to a destination by using a robot and automatically travels along the searched route, the control station determines whether a node (a branch point, a work point, or the like) in the guideline to be prohibited from passing is used. When instructed by the user, send data indicating between the nodes to each mobile robot, each mobile robot receives the data, writes in the internal memory the passage prohibition between nodes in the guidelines indicated by the data, An avoidance table that stores data indicating between the prohibited nodes and data for avoiding collision with another mobile robot. The shortest route from the departure point to the destination in the map stored in the map memory is searched based on the shortest route.

According to the present invention, according to the present invention, the control station sends data indicating between nodes in the guideline to be prohibited to each mobile robot to each mobile robot, and each mobile robot receives the data, and stores in the memory the prohibition of traffic between nodes in the guideline. Write.
With such processing, it is possible to extremely easily prohibit traffic between specific nodes.

Hereinafter, a mobile robot system to which a traveling control method according to an embodiment of the present invention is applied will be described with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of the mobile robot system. In this figure, 1 is a control station, 2
Reference numerals -1 to 2-10 denote mobile robots, and the control station 1 and each of the mobile robots 2-1 to 2-10 are wirelessly connected. The mobile robot 2 travels along a magnetic tape attached to a floor of a predetermined traveling path, and nodes are set on the traveling path at appropriate intervals. FIG. 2 is a diagram showing an example of a traveling path, in which... Are nodes. Each node has a node mark attached to the floor, and the mobile robot 2 is provided with a detector for detecting the node mark. There are the following three types of nodes.

(1) Map entry node: This is a node serving as a starting point when the mobile robot 2 newly enters the travel path. In FIG.

(2) Work node: a work node where work points S1, S2, and S3 are provided. In FIG. When the mobile robot performs work, it stops at this work node, then proceeds to the work point S1 (or S2 or S3) and stops to perform work.

(3) Passing nodes: nodes that the mobile robot merely passes through, and in FIG. 2 are all nodes other than the above nodes.

FIG. 3 is a block diagram showing the configuration of the control station 1. In this figure, reference numeral 1a denotes a CPU (central processing unit), 1b denotes a program memory storing programs used in the CPU 1a, and 1c denotes a collision between robots. 4 is a collision table in which data for prevention is stored. 1d is a map memory which stores a network table shown in FIG. 4 and a scene table shown in FIG. 5, respectively. in this case,
The network table is a table in which information on each of the nodes is stored. As shown in the drawing, the network table includes data blocks NB, NB,... Corresponding to the respective nodes. (X-
Y) Coordinates, data indicating node type, numbers of other nodes connected to the node (connection node numbers 0 to
3), scene No. 0 to scene No. 3 (described later) and the like are stored.

Further, the scene table is a table in which information on the travel route between the nodes is stored. As shown in FIG. 5, data blocks SB and SB corresponding to each of the nodes are provided.
……. And each data block SB
Each stores a start point node number, an end point node number, a straight line distance between nodes, a measured distance between nodes, and the like, and data (bottom line) indicating whether or not traffic is prohibited. The data indicating whether or not traffic is prohibited is 1-bit data, and "1" is written when traffic is prohibited between nodes, and "0" is written when traffic is not prohibited between nodes. The scene No. 0 to scene No. 3 in the above-described network table (FIG. 4) relate to each traveling route between the node and each node written in the column of connection node numbers 0 to 3. This is the number of the data block SB (FIG. 5) in which data is stored.

Next, in FIG. 3, reference numeral 1e denotes a data memory for storing data, 1f denotes an operation unit, and 1g denotes a communication device.
Transmits the data supplied from the CPU 1a on a carrier wave of 200 to 300 MHz, and receives data transmitted on the carrier wave from the mobile robots 2-1 to 2-10.

Next, the mobile robot 2 will be described. FIG. 6 is a block diagram showing the configuration of the mobile robot 2. In this figure, 2a is a CPU, 2b is a program memory storing programs used in the CPU 2a, 2c is a data memory for storing data, and 2d is an operation. Reference numeral 2e denotes a communication device, and 2f denotes a map memory in which the same network table and scene table as the map memory 1d in the control station 1 are stored. A traveling control device 2g receives destination data supplied from the CPU 2a, controls a driving motor while detecting a magnetic tape and a node mark on the floor surface by a magnetic sensor, and causes the mobile robot to travel to a target node. Reference numeral 2h denotes an arm control device, which receives a work program number supplied from the CPU 2a, reads a work program of that number from an internal memory when the mobile robot arrives at a work node, and reads the work program of the robot arm (not shown in the figure) by the read program. ) To perform various operations.

In the mobile robot system having the above configuration, the control station 1 wirelessly instructs each mobile robot 2 of a target node and a task to be performed at the node. The mobile robot 2 receiving the instruction searches for a travel route to the target node using the network table and the scene table in the map memory 2f, and then automatically travels to the target node along the searched route, and at that node, The operation specified by the control station 1 is performed.

Next, the above-described route search will be described in detail. Now, the mobile station 2 at the node shown in FIG.
Is instructed to go to the node. In this case, the CPU 2a of the mobile robot 2 first accesses the data block NB corresponding to the node of the network table in the map memory 2f, and the number “1” of the other node connected to the node via the travel path. , "3", "6"
(See FIG. 2). Next, in the scene table,
Check the traffic prohibition data of the data block DB corresponding to each of the nodes-,-,-. And
If no traffic is prohibited between any of the nodes, next, the nodes,...,.
Is calculated as a straight line distance between each of the nodes. Further, for example, when the passage between the nodes is prohibited, the nodes are excluded and the straight-line distances between the other nodes and the nodes are calculated. Next, a node having the shortest distance calculated in the above processing is detected. Then, for example, if the detected node is, the route of → is determined first by the above processing.

Next, in the same manner as described above, the node numbers "2" and "4" of the nodes connected to the nodes are detected from the network table. If you weren't closed,
The straight-line distance between the node and the target node is calculated. Next, a node having the minimum calculation result is detected. Now, assuming that a node is detected, the route indicated by → is determined. Hereinafter, the same processing is repeated, whereby
A route to the destination node is searched.

Next, a case in which traveling of a part of the traveling path is prohibited will be described. In this case, the clerk inputs the node number using the operation unit 1f of the control station 1, and then operates the function key for instructing the prohibition of driving. For example, when traveling is prohibited between nodes, the node numbers "2" and "6" are sequentially input, and then the function keys are operated. When these operations are performed, the CPU 1a detects this, and transmits the node numbers “2” and “6” and data indicating the passage prohibition to each mobile robot 2. Each mobile robot 2 receives these data, and writes "1" in a traffic-prohibited area in the data block DB corresponding to between the nodes of the scene table in the map memory 2f. As a result, thereafter, between nodes is excluded from the route of the route search.

The present invention is applicable not only to a mobile robot traveling along the floor while detecting the magnetic tape on the floor, but also to a mobile robot traveling while detecting the surrounding situation by an ultrasonic sensor. can do. In the above embodiment, the mobile robot has an arm. However, the present invention can be applied to a mobile robot that does not have an arm and simply travels automatically (for transportation or the like).

Further, in the above embodiment, the traffic prohibition information is stored in the map memory, but may be stored in the data memory.

[Effects of the Invention] As described above, according to the present invention, the control station sends data indicating between nodes in the guideline to be prohibited from traffic to each mobile robot, and each mobile robot receives the data, and Since the traffic prohibition between the nodes in the guide line is written in the memory, the traffic prohibition between the specific nodes can be extremely easily performed on the user side.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a mobile robot system according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of a traveling path on which each mobile robot travels, and FIG. 3 is a control station 1 in FIG. 4 and 5 are diagrams showing a network table and a scene table respectively stored in a map memory, and FIG. 6 is a block diagram showing a configuration of the mobile robot 2. As shown in FIG. 1 ... Control station, 1a ... CPU, 1b ... Program memory, 1
d: Map memory, 2-1 to 2-10: Mobile robot, 2
a: CPU, 2b: Program memory, 2f: Map memory.

Claims (1)

(57) [Claims] 1. A mobile robot comprising: a plurality of mobile robots that travel along a guideline that constitutes a route; and a control station that controls the mobile robots. In the mobile robot system which automatically travels along the searched route, the control station moves data indicating the nodes between the nodes in the guideline which should be prohibited from passing when the user instructs between the nodes. Each mobile robot receives the data, writes the data in the internal memory, and writes the prohibition between nodes in the guidelines indicated by the data, and collides with the data indicating the prohibited nodes and other mobile robots Based on the avoidance table in which the data for avoiding the obstacle is stored. Travel control method for a mobile robot, characterized by searching for a shortest route from the starting point to the destination in the inner.