JPH0322111A - Travel controlling method for mobile robot - Google Patents

Abstract

PURPOSE:To enable each mobile robot to travel efficiently by detouring and traveling without waiting when a cause to make the mobile robot incapable of traveling is owing to the occurrence of the abnormality of another mobile robot. CONSTITUTION:In the case where another mobile robot in which the abnormality is occurring exists on the traveling route of the mobile robot, said mobile robot is made to detour and travel immediately without waiting untill another mobile robot is repaired. Thus, when each mobile robot 2-1 to 2-10 in a mobile robot system becomes incapable of traveling, it detects its cause, and as the result, it is known that the mobile robot in which the abnormality is occurring blocks up the traveling route. Thus, since it can detour without waiting, the delay of travel can be prevented.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a mobile robot system consisting of a plurality of mobile robots and a control station that controls these mobile robots. The present invention relates to a travel control method for a mobile robot that can search for a detour route and travel in a detour if there is a mobile robot in a pond where an abnormality is occurring.

"Prior Art" In recent years, with the development of FA (factory automation), various mobile robot systems consisting of a plurality of mobile robots and a control station that controls these mobile robots have been developed and put into practical use.

In this mobile robot system, a control station instructs each mobile robot, wirelessly or by wire, to a destination and the work to be performed at that destination.

The mobile robot receives instructions from the control station, looks at the map information, automatically travels to the specified location, performs the specified task at that location, and when the task is completed, moves to the next location on the spot. wait for instructions.

``Problem to be Solved by the Invention'' By the way, in conventional systems of this type, if there is another mobile robot ahead of the travel route, a mobile robot that travels automatically waits until the other mobile robot disappears. was. In this case, if the other mobile robot is operating normally, there is no problem as it will leave the area soon, but if the other mobile robot is stopped due to a malfunction, it will have to wait for a considerable amount of time. It was a problem. In particular, in mobile robot systems introduced to be unmanned, there are usually no humans next to the mobile robot, so it takes a lot of time to repair a malfunctioning mobile robot, and other mobile robots The result was that the smooth operation of the system was hindered.

This invention was made in consideration of these circumstances,
It is an object of the present invention to provide a method for controlling the running of a mobile robot in which the running of a mobile robot is not hindered by other mobile robots that are experiencing an abnormality.

"Means for Solving the Problem" This invention provides a mobile robot system that includes a plurality of mobile robots and a control station that controls these mobile robots, in which each mobile robot indicates the current position of another mobile robot. Position data and message data indicating whether or not an abnormality has occurred are stored, and when the mobile robot becomes unable to run, the mobile robot can view the position data and message data of the other mobile robots. The system detects the cause of the robot being unable to travel, and if it detects that the cause is due to an abnormality in another mobile robot, it searches for a detour route and travels on the searched detour route.

"Operation" According to the present invention, when there is another mobile robot experiencing an abnormality on the travel path of the mobile robot, the mobile robot can be moved without waiting until the other mobile robot is repaired. Since the mobile robot immediately takes a detour, the smooth operation of the mobile robot is not hindered.

Embodiment A mobile robot system to which a travel control method according to an embodiment of the present invention is applied will be described below with reference to the drawings. FIG. 1 is a block diagram showing the overall configuration of the mobile robot system. This diagram. , l is the control station, 2
(2-1 to 2-10) are mobile robots, and the control station l
and each mobile robot 2 are connected wirelessly.

The mobile robot 2 is configured to travel along a magnetic tape attached to the floor of a predetermined travel path.
Further, nodes are set on the travel route at appropriate intervals. Here, the term "node" refers to a driving state change point provided on a travel road, such as a starting point, a stopping point, a branching point, a work point, or the like. FIG. 2 is a diagram showing an example of a running route, and in this diagram, ■, ■, . . . are nodes. A node mark is affixed to the floor of each node, and the mobile robot 2 is provided with a detector for detecting this node mark. Furthermore, nodes are classified into the following three types depending on the location where they are installed.

(1) Map entry node: This is a starting point node when the mobile robot 2 newly enters a travel route, and in FIG. 2, it is ■, ■, ■, ■, @, [stock].

(2) Work m node: A node provided at the work point,
In FIG. 2, they are ■, ■, and O.

(3) Passage node: This is the 7th node that the mobile robot 2 simply passes through, and in FIG. 2, it is all the nodes other than the 7th nodes mentioned above.

Note that nodes other than the above-mentioned transit nodes are also referred to as stations.

FIG. 3 is a block diagram showing the configuration of the control station l, in which 1a is a CPU (central processing unit), lb is a C
A program memory 1c stores programs used in the PUla, and a collision table 1c stores data for preventing collisions between the mobile robots 2. ld is a map memory, and each node shown in FIG.
The XY coordinates of [stock], data indicating the node type, numbers of other nodes connected to the node, distances to each other node connected to the node, etc. are stored. Reference numeral le denotes a data memory for storing data, and this data memory 1e is provided with a reserve table RVT shown in FIG. 4 in advance. This reserve table R
VT is a memory slot R corresponding to each node ~ [stock]
v1 to RV 1 8 (each l byte). 1f
is an operation unit, lg is a communication device, and this communication device 1g receives data supplied from CPtJla from 200 to 3Q.
It transmits data on a Q MHz carrier wave, and also receives data transmitted from the mobile robot 2 on a carrier wave.

Next, the mobile robot 2 will be explained. FIG. 5 is a block diagram showing the configuration of the mobile robot 2. In this diagram, 2a is a CPU, 2b is a program memory storing programs used in the CPU 2a, 2c is a data memory for data storage, and 2d is an operation 2e is a communication device, and 2f is a map memory storing the same data as the map memory ld in the control station l. Further, 2g is a travel control device which receives destination data supplied from the CPU 2a, controls the drive motor while detecting the magnetic tape and node mark on the floor using a magnetic sensor, and causes the mobile robot 2 to travel to the destination node. . 2h is an arm control device which receives a work program number supplied from the CPU 2a, reads the work program of that number from the internal memory when the mobile robot arrives at the work node, and controls the robot arm (not shown) by the read program. ) to perform various tasks.

Next, the operation of the mobile robot system described above will be explained.

First, to place the mobile robot 2 under the control of the control station 1,
Move the mobile robot 2 manually to the map entry node ■, ■,
Move to one of ■, ■, 0, and @, then input the number of that node from the operating section 2d of the mobile robot 2, and switch to automatic mode. When the node number is input, the CPU 2a sends the node number and its own robot number to the control station 1 via the communication device 2e. Control station 1
receives the robot number and node number and writes them into the data memory le. Through the above process, the control station l
detects the number and position of the newly entered mobile robot 2.

Next, for example, when a work to be performed occurs at a work node (station) ■, the control station 1 sends a work point code indicating the work node ■ and a work program to the mobile robot 2 located closest to the work node. Send number. Assume now that the mobile robot 2-1 is stopped at the node (2), and the control station 1 has transmitted the work node code and program number to the mobile robot 2-1.

The CPIJ 2a of the mobile robot 2-1 stores the received work node code and program number in the data memory 2c, and then searches for a travel route to the work node ■. This route search is performed by a conventionally known vertical search method.

Assuming that the route ■→■→■→■→■ is searched by this route search, the CPU 2a then creates the route table ROT shown in FIG. 6 in the data memory 2c, and also creates Send route table ROT to control station l.

As shown in the figure, this route table ROT includes the number "l" of the starting point node ■, and the number r21 of the nodes ■■ and ■ that should be passed sequentially when going to the target work node ■.
, r3J , r4J, work code r65000j indicating that the following data is data related to work, work node number "5", work program number "l2"
, the final posture code r6500 1j indicating that the next data represents the final posture of the robot, the number "5" of the node ■ to be stopped, the number "6" of the node ■ in front, the number "6" of the node ■ behind /1 j 4”, and route table ROT
A final code ``0'' representing the end of ``0'' is written.

The control station 1 writes this route table ROT into the internal data memory le, and then transmits the same table ROT to the other mobile robots 2-2 to 2-to. The other mobile robots 2-2 to 2-to each write the same table ROT into their internal data memory 2C. Next, the mobile robot 2-1 sequentially accumulates the travel distance of the searched route from the starting point node ■ to the destination node ■ based on the inter-node distances stored in the map memory 2f. The first node beyond a predetermined distance L is detected. Now, assume that this node is ■. Next, CP
U2a transmits the numbers of nodes ■ and ■ and route reservation request codes to the control station l, respectively. The CPU 1a of the control station 1 receives this node number and route reservation request code, and checks whether or not these nodes have already been reserved using the reserve table RVT. Then, if the data is not reserved, that is, if the data in the memory slots RV1 to RV3 corresponding to these nodes in the reserve table RVT is "O", the robot number "1" is assigned to each of those memory slots. Write. This means that the route ■→■→■ has been reserved. Next, CPtJ1a of the control station 1 transmits the numbers of the nodes ■ and ■ and the reservation completion code to the mobile robot 2-1. The mobile robot 21 receives these 7 code numbers and the reservation completion code, and first starts traveling toward node (2). The mobile robot 2-1 transmits state data and position data to the control station 1 every time a predetermined period of time elapses while the mobile robot 2-1 is traveling. Here, the status data is data indicating the current status of the mobile robot 2 (running, waiting, working, abnormality occurring, etc.), and the position data is the current position of the mobile robot 2. It is data that shows The control station 1 is
The state data and position data sent from the mobile robot 2-1 and reserved node data indicating the node currently reserved by the mobile robot 2-1 are transferred to other mobile robots 2.
-2 to 2-10.

These mobile robots 2-2 to 2-10 write the received data into internal data memory 2C.

In addition, the control station 1 checks the position data transmitted from the mobile robot 2-■, and the mobile robot 21 checks the position data transmitted from the mobile robot 2-■.
When it is detected that the node has passed through the node ■, the reservation of the node ■ is subsequently canceled. That is, the storage slots RVI and RV2 of the reserve table RVT are cleared.

On the other hand, while the mobile robot 2-1 is moving, the mobile robot 2-1 always
The first node that exceeds the distance L from the current position to the destination node is detected, and if the detected node becomes ■, the number of the node ■ and the route reservation request code are each transmitted to the control station 1. The control station I receives this node number and route reservation request food, and makes a node reservation. When the node reservation is completed, the number of the node (2) and the reservation completion code are transmitted to the mobile robot 2-1.

The mobile robot 2-1 receives these 7 code numbers and the reservation completion code, and travels to node (2).

When the mobile robot 2-1 passes through the 7th node (2), the control station 1 cancels the reservation of the node (3) in the same way as in the case described above. On the other hand, when mobile robot soto 2-1 detects work node ■ as the first node that crosses the distance @L from the current position to the destination maid while traveling from node ■ to ■, the mobile robot soto 2-1 receives the number of work node ■. and a route reservation request code to the control station 1, respectively. The control station 1 receives this node number and route reservation request code and makes a node reservation. When the node reservation is completed, the number of the work node (2) and the reservation completion code are transmitted to the mobile robot 2-1.

The mobile robot soto 2-1 receives these 7 code numbers and the reservation completion code, and travels to the work node (2). When the mobile robot 2-1 passes the node (2), the reservation for the node (2) is canceled at the control station 1 in the same way as in the case described above. Then, when the work node (3) is reached, the arm performs the work from then on. As described above, the mobile robot 2=1 transmits the route table ROT to the control station 1 before starting to travel, and also sequentially transmits status data and position data to the control station 1 while traveling. The control station 1 stores the transmitted route table ROT, status data, and position data in a data memory 1. e, and transmits those tables, data, and reserved node data to all mobile robots 2. Exactly the same process is performed when the other mobile robots 2-2 to 2-1O are running. Therefore, in this mobile robot system, each mobile robot 2 holds the route table, status data, position data, and reserved node data of the pond mobile robot 2 in its internal data memory 2c. Thereby, each mobile robot 2 can constantly detect the travel route, current state, current position, and reserved node of other mobile robots 2.

Next, in the same way as described above, when the mobile robot 2-1 travels according to the route table ROT shown in FIG. 6, a process will be described in which the mobile robot 2-1 cannot proceed forward for some reason.

For example, if the mobile robot 2-1 has not yet been able to make a reservation for node (2) when it reaches node (2), it will temporarily stop at node (2) and perform the next process.

(1) First, the route table ROT of other mobile robots 2-2 to 2-10 stored in the data memory 2C
is scanned to detect the mobile robot Soto 2 which has the node ■ as part of its travel route. Now, let us assume that mobile robots 2-3 and 2-5 fall into this category.

(2) Next, from the reserved node data of the mobile robots 2-3, 2-5 stored in the data memory 2C, the mobile robot 2 that has reserved the node 2 is detected. Suppose now that the mobile robot 2-3 is detected.

(3) Next, from the state data of the mobile robot 2-3 stored in the data memory 2c, the mobile robot 2-
3 is detected, and the next process is performed depending on the state.

(i) When the mobile robot y 2-3 is on standby, the mobile robot 2-1 transmits its own status data as "waiting for expulsion completion" to the control station l. The control station l receives this state data and controls the waiting mobile robot 2-3 based on the route table ROT and position data of each mobile robot 2-2 to 2-lO stored in the internal data memory le. The mobile robot 2-3 finds the mobile robot 2-3 and sends a route transfer instruction and a destination/depart instruction to the mobile robot 2-3. Mobile robot y 2-3, which received this route delivery instruction, similarly to the case described above,
It searches for a route to the designated node, then makes a route reservation, and then travels to that node. When the mobile robot 23 moves, the reservation of the node is canceled.

On the other hand, the mobile robot 2-1 transmits the status data as "waiting for ejection completion" to the control station 1, and then transmits a travel route reservation request to the control station 1 every predetermined period of time. The control station 1 makes a reservation for the mobile robot 2-1 when the mobile robot 23 moves and the node reservation is canceled, and sends a reservation completion message to the mobile robot 21. Mobile robot 2-1
After receiving this reservation, the vehicle will start driving. If a re-route search instruction is sent from the control station 1 while the travel route reservation request is being issued, the route will be searched and the route will be changed.

(11) When the mobile robot 2-3 is running towards that node, the mobile robot 2-1 sends the status data as "waiting to pass" to the control station 1, and thereafter sends a travel route reservation request every certain period of time. It waits for the reservation to be completed while sending it to the control station 1. Note that if an abnormality occurs in the mobile robot 2-3 that is about to pass, a detour route search is performed as described in the next section (iii), and the mobile robot 2-3 changes its route and travels.

(iii) When an abnormality is occurring The mobile robot 2-1 performs a route search again. That is,
The mobile robot 2-1 first sends a route search permission request to the control station 1. The control station 1 receives this request and, if there is no other mobile robot 2 searching for a route, sends route search permission to the mobile robot 2l. The mobile robot 2-1 receives this route search request and searches for a route that bypasses the mobile robot 2-3. Then, when a route is discovered, the CPU 2a of the mobile robot 2-3 updates the route table ROT shown in FIG.
is created in the data memory 2c, and the created route table ROT is transmitted to the control station 1.

As shown in the figure, this route table ROT includes the detour start code r6 5 0 0 3J indicating the start of detour, the number of detour start node ■ "8j1 nodes to be passed sequentially ■,
[Stock] numbers r9J, rlOJ, detour end code "65004" indicating detour end, detour end node number "4"
", the work code "65000" indicating the work instruction, the number "5" of the work node ■, the work program number rloj indicating the work program, the final posture code indicating that the next data represents the final posture of the mobile robot 2. 65001
", the number "5" of the node to be stopped, "5", the number "6" of the forward node "4", the number "4" of the backward node "2", and the final code "0" representing the end of the route table ROT are written.

The control station 1 transmits this route table ROT to the mobile robots 2-2 to 2-10 in the pond. Next, mobile robot 2
-1 transmits a route reservation request to the control station 1 and starts traveling upon completion of the reservation from the control station 1, as in the case described above. Then, the route table ROT shown in FIG.
After traveling along the detour route and reaching the work node (2), the work is executed according to the work procedure indicated by the program number NOJ.

(iv) When a conflict problem is being resolved This conflict problem is being resolved by mobile robot 2 3 or
Waiting for expulsion to be completed, Waiting for work to be completed, Waiting for passage.
, when the device is in a state such as "waiting for normal recovery". In this case, the mobile robot 21 sends status data to the control station l as "waiting for conflict problem resolution", and the mobile robot 2-
Waiting for problem 3 to be resolved.

In this way, each of the mobile robots 2-1 to 2-IO in this mobile robot system detects the cause when it becomes unable to travel, and as a result, the mobile robot that is in the ascending position blocks the travel route. If you know that there is a vehicle, you can turn around without having to wait, which prevents travel delays.

Furthermore, in the above embodiment, the mobile robot detects a magnetic tape on the floor and moves along the tape, but in this invention, the mobile robot moves while detecting the surrounding situation using an ultrasonic sensor. It can also be applied to things that Further, in the above embodiment, the mobile robot has an arm, but the present invention can also be applied to a mobile robot (for transportation, etc.) that simply moves automatically and has an arm.

"Effects of the Invention" As explained above, according to the present invention, if the cause of the inability to move is due to an abnormality occurring in another mobile robot, the robot will take a detour without waiting. This provides the effect that each mobile robot can run efficiently.

[Brief explanation of the drawing]

FIG. 1 is a Bronnock diagram showing the configuration of a mobile robot system according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of a travel path on which each mobile robot travels, and FIG. 3 is a control diagram in FIG. 1. FIG. 4 is a block diagram showing the structure of station 1; FIG. 4 is a block diagram showing the reserve table RVT set in data memory 1e in FIG. 3; FIG. 5 is a block diagram showing the structure of mobile robot 2. Figure 6 shows the route table ROT
Figure 7 shows an example of the structure of the route table R at the time of detour.
It is a figure showing an example of composition of OT. l...Control station, 1a...CPU, lb.
...Program memory, le...Data memory, 2-1 to 2-10...Mobile robot, 2a...CPU, 2b... -Program memory, 2c...Data memory.

Claims (1)

[Scope of Claims] In a mobile robot system consisting of a plurality of mobile robots and a control station that controls these mobile robots, each mobile robot contains position data indicating the current position of other mobile robots and information indicating an abnormality occurrence state. If a mobile robot becomes unable to run, the mobile robot can check the position data and message data of the other mobile robots to determine the cause of the inability to run. A traveling control method for a mobile robot, characterized in that if the abnormality is detected to be caused by an abnormality occurring in another mobile robot, a detour route is searched for, and the mobile robot travels along the searched detour route.