JP3152107B2 - Control method of multi robot system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-robot system in which, for example, a large number of robot cameras are movably mounted on a rail of a museum or a ceiling of a museum, and images from each camera are distributed to a large number of clients. In particular, the present invention relates to a control method for causing a plurality of robots to travel along a common rail in arbitrary directions and speeds.

[0002]

2. Description of the Related Art With the development of multimedia technology based on high-definition television such as high-definition television, optical fiber communication, and high-efficiency data compression, the following application systems have been proposed. It is a system that allows you to freely visit and watch, for example, museums and museum exhibits while staying at home with a high-definition television.

[0003] This system can be realized by the following means. A rail with a robot camera runs around the ceiling of the museum. The robot camera mounted on the rail travels freely in the hall when a viewer at home operates the controller, and the direction and zooming of the camera are remotely controlled by the controller. A video signal photographed by the camera is transmitted to a television receiver viewed by the operator of the controller. This configuration itself is a robot camera system widely used in television stations and the like.
Spreading this to the individual level by multimedia technology, people with physical disabilities and people in remote areas are at home, watching the TV while operating the controller, as if walking around the museum and watching We are planning a system that allows you to enjoy images that look like you are.

In the case of such an application, as described in the above example, a museum is equipped with a large number of robot cameras, and a large number of people at various places remotely control the robot cameras via communication lines. A premise is a multiple system in which the images of the cameras controlled by the respective users are received by a familiar television via a communication line. This is a schematic example of a multi-robot system to which the present invention is applied. In the following, a person who remotely controls a robot is called a remote operator or simply an operator, and a receiver device of information (camera image in the above example) collected by the robot. Is called a client. The controller and the client operated by the operator correspond as described above.

[0005]

In the above-described multi-robot system, it is necessary to prevent a large number of robots individually controlled by a large number of operators from competing on a trajectory (rail). In other words, robots having different running directions and speeds collide on the track, which makes it inconvenient to be unable to perform the work specified by each.

Therefore, a plurality of trajectories are arranged side by side, the position, traveling direction and speed of each robot are centrally controlled, and the traveling route of a certain robot is appropriately selected in relation to the traveling state of other surrounding robots. A system is conceivable in which the robot travels as instructed while avoiding collision between robots. However, in this case, there are many problems as follows.

First, the track equipment is complicated and expensive, for example, by providing a plurality of tracks in parallel to provide a point for switching the travel route, and running errors and failures are apt to occur at points and the like. If the number of robots is overwhelmingly large relative to the number of parallel orbits, measures such as stopping some of the robots are necessary to avoid collisions, and the robots will move according to the operator's command. Not many opportunities occur.

Further, as a control system for centrally managing the position, traveling direction and speed of each robot and selecting a traveling route of each robot, the control system is more sophisticated than the centralized train management system operated by JR and the like. (Due to the fact that many robots in this system do not know how they move, unlike trains whose operation is controlled by a schedule), the implementation of which requires a great deal of labor and time in software development. Also, a great deal of cost is required for hardware of a sensor system for knowing the position, running direction, and speed of each robot in detail.
In addition, even if software for a certain museum's robot camera system is developed, it cannot be applied to other systems having different orbital layouts.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a multi-robot system in which a large number of individually controlled robots travel, share a common trajectory, and use a simple control system. An object of the present invention is to provide a control method that avoids collision of robots and does not substantially interrupt command work of each robot.

[0010]

A control method for a multi-robot system according to the present invention is characterized by having the following constituent elements (1) to (4).

A plurality of robots equipped with sensors for collecting information run along a common trajectory.

Each robot operates according to time-series command information individually given from the central control unit, and the traveling direction and traveling speed on the track are individually controlled.

The collection information collected by each robot is distributed to designated clients. There is approach detection means for detecting that two robots have approached each other on the trajectory and the distance between them has become less than or equal to a predetermined value.

A first robot operating in accordance with the command information A and collecting information to be distributed to the client a, and a second robot operating in accordance with the command information B and collecting information to be distributed to the client b. A command information switching process for providing command information A to the second robot and simultaneously providing command information B to the first robot when the approach to the robot is detected by the approach detection means; The collection information switching process for changing the collection information for the client b and changing the collection information by the second robot for the client a at the same time is performed.

In the above control method, each robot and the approach detecting means are connected to the central control section via a data transmission line, and the central control section responds to a detection signal of the approach detecting means so that the central control section transmits the command information. A method of executing the switching process and the collection information switching process can be adopted.

In the above-mentioned control method, each robot is provided with a connector which is coupled to each other so that signals can be transmitted and received when two robots come into contact with each other on the trajectory. Data necessary for the switching process can be exchanged between the contacted robots via the connector. In this case, contact 2
By exchanging required data between the two robots via the connector, the command information switching process and the collection information switching process can be executed by the two robots.

In the above control method, when the approach detecting means detects the approach of the two robots, the relative speeds of the two robots are gradually reduced in preference to the command information given to the two robots. It is desirable to adopt a method in which the braking control to be performed is executed by one or both of the two robots and the two robots are brought into contact at a very low speed.

[0018]

The first robot is slowly moving forward on the trajectory according to the command information A (information collected by this first robot is distributed to the client a), and the second robot is moving on the same trajectory according to the command information B. Is moving forward at a high speed and approaching from behind the first robot (information collected by the second robot is distributed to the client b). Then, when the second robot moving forward at a high speed approaches the first robot moving ahead at a low speed to a close distance, the approach detecting means detects that, and the command information switching process and the collection information switching process are executed. . As a result, the first robot that has caught ahead and operates according to the command information B to move forward at a high speed, and the second robot that has caught up operates according to the command information A to move forward at a low speed. At the same time, the collection information of the first robot is distributed to the client b, and the collection information of the second robot is distributed to the client a. In other words, the roles of the first robot and the second robot are switched, and 2
From the viewpoint of both clients operating the two robots, the two robots run on separate orbits arranged side by side at an arbitrary speed, and the high-speed robot overtakes the preceding low-speed robot. It will be the same as

The first robot stopped on the orbit and the second robot
When the first approaching robot and the second approaching robot are likely to collide with each other, the roles of both robots are switched in the same manner as described above, and the robot viewed from the client side Will continue.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rough inside view of a museum to which the multi-robot system of the present invention is applied is shown in FIG. 1, and an overall outline of the system configuration is shown in FIG. As shown in Fig. 1, one rail 1 is placed on the ceiling of the museum along the ornamental course.
, And a plurality of robot cameras Rn (n = 1, 2,... I) are attached so as to hang on the rail 1. Each robot camera Rn is individually controlled to
Follow along.

As shown in FIG. 2, each robot camera Rn
Is equipped with a high-definition television camera 3 via a head 2 that is servo-controlled. The television camera 3 shoots an exhibit such as a painting or a sculpture, transmits the video signal to each client via the central control unit 4, and projects the image on a television receiver 5 installed on the client side for viewing. A robot camera controller 6 is attached to the television receiver 5 of each client.

FIG. 4 shows the system configuration of each robot camera Rn. As shown in FIGS. 4 and 2, proximity sensors 7 corresponding to the above-described approach detection means are provided on the front and back surfaces of the main body of the robot camera Rn. It uses a proximity sensor such as an electromagnetic or photoelectric type. When the two robot cameras approach a certain distance or less, the detection signals of the proximity sensors 7 of both robot cameras are turned on. A robot-to-robot connector 8 is also provided on the front and back of the main body of the robot camera Rn. The connectors 8 are connected to each other when two robot cameras come into contact with each other, and can transmit signals to each other via both connectors 8. When the connectors 8 are connected to each other, the robot control unit 9 of the two robot cameras obtains a specific logic signal from a specific connector pin, and the signal is used as a contact detection signal between the robot cameras. Is done.

As shown in FIG. 4, each robot camera Rn
A drive unit 10 for moving the robot forward or backward along the rail 1 at an appropriate speed, an azimuth drive unit 11 for changing the azimuth of the TV camera 3, a depression drive unit 12 for changing the depression angle of the TV camera 3, And a zoom drive unit 13 for changing the focal length of the taking lens of the television camera 3.
These drive units 10 to 13 are servo-controlled by the robot control unit 9.

The robot controller 9 is connected to a data transmission path connected to the central controller 4 via a transmission controller 14, and the video signal output system of the television camera 3 is connected to the central controller 4 via a transmission controller 15. It is connected to the data transmission path.
The data transmission path connecting each robot camera Rn and the central control unit 4 may be a wired method using the rail 1 or a wireless method using laser or infrared light.

Each client and the central control unit 4
The connection is made via a public digital line such as ISDN or a dedicated digital line using optical fiber communication or satellite communication. From the controller 6 operated by the client-side operator, the traveling drive unit 1 in the robot camera Rn is provided.
0, command information for servo-controlling the azimuth angle drive unit 11, depression angle drive unit 12, and zoom drive unit 13 is generated, transmitted to the central control unit 4 via the data transmission path, and transmitted from the central control unit 4. The information is transmitted to one predetermined robot camera. This command information is transmitted from the transmission control unit 14 to the robot control unit 9, and each of the driving units 10 to 1 according to the command information.
3 is servo-controlled. In the opposite data flow, a video signal from the television camera 3 is transmitted from the transmission control unit 15 to the central control unit 4, and further distributed from the central control unit 4 to a television receiver 5 of a predetermined client.

In the controller 6, the traveling drive unit 1
In relation to 0, there are a forward button, a reverse button, and a stop button, and there are a speed-up button and a deceleration button. The azimuth drive unit 11, the elevation drive unit 12, and the zoom drive unit 13 have a (+) button and a (-) button, respectively. The input signals of these buttons of the controller 6 are transmitted to the robot control unit 9, and the robot control unit 9 generates servo control signals of the driving units 10 to 13 from the signals and gives them to each unit. This controls forward / backward / stop / acceleration / deceleration of the robot traveling, and controls increment and decrement of the azimuth, elevation, and zoom displacement of the camera.

In performing such servo control, each drive unit 1 is stored in the servo information memory 16 of the robot control unit 9.
The information of the latest control amount given to 0 to 13 is stored while being updated. When the two robot cameras come into contact with each other, information on the latest control amount stored in the memory 16 is exchanged via the connector 8 as described below.

Next, two robot cameras R1 and R2
5 will be described in sequence with reference to the flowcharts of FIGS. 5 and 6.

First, it is assumed that the robot camera R1 is used by the client a and the robot camera R2 is used by the client b. That is, the robot camera R1 is servo-controlled according to the command information A generated from the controller 6 of the client a, and the camera R
The video signal from 1 is displayed on the television receiver 5 of the client a. On the other hand, according to the command information B generated from the controller 6 of the client b, the robot camera R
2 is servo-controlled, and the video signal from the camera R2 is displayed on the television receiver 5 of the client b.

Assume, for example, that the robot camera R1 is moving forward at a high speed and gradually approaching the robot camera R2 moving forward at a low speed. The robot controller 9 of each robot camera Rn performs the monitoring control shown in the flowchart of FIG. 5, and the central controller 4 performs the monitoring control shown in the flowchart of FIG.

When the two robot cameras R1 and R2 approach each other below a predetermined interval, the outputs of the respective proximity sensors 7 are turned on. In response to this signal, both robot control units 9
Knows that another robot camera is approaching forward or backward, and notifies the central control unit 4 of that (step 500 → 501). The central control unit 4 receives the approach notification from both robot control units 9 and prepares for the command information switching process and the video signal switching process between the robot cameras R1 and R2 while contacting the robot cameras R1 and R2. Wait for the notification (step 600 → 601 → 602).

After issuing the approach notification, the robot controllers 9 perform braking control in step 502 in order to avoid a violent collision between the robot cameras R1 and R2. This braking control is performed by forcibly reducing the forward speed of the robot camera R1 on the side approaching at high speed among the robot cameras R1 and R2.
The signal from the connector 8 is checked while performing the braking control, and the robot camera waits until the robot cameras R1 and R2 come into contact with each other (step 503).

Further, both robot control units 9 include a connector 8
When the contact detection signal is obtained from the control information, the central control unit 4 is notified of the fact (step 504), and the latest control amount information stored in each servo information memory 16 via the coupled connector 8 is notified. Are exchanged with each other (step 505). Now two robot cameras R1 and R
In 2, the parameters indicating the current operation state of each of the drive units 10 to 13 are exchanged.

In response to the contact notification, the central control unit 4 executes command information switching processing and video signal switching processing for the robot cameras R1 and R2 and the clients a and b (steps 603 → 604). . That is,
Command information A generated from the controller 6 of the client a is supplied to the robot camera R2,
2 is servo-controlled according to the command information A, and the camera R
The video signal from 2 is displayed on the television receiver 5 of the client a. At the same time, the command information B generated from the controller 6 of the client b is supplied to the robot camera R1, and the robot camera R1 is servo-controlled according to the command information B, and the video signal from the camera R1 is projected on the television receiver 5 of the client b. It is.

As described above, the roles of the robot cameras R1 and R2 are switched, so that the robot camera R1 is used by the client b and the robot camera R2 is used by the client a. In addition, the continuity of the operation due to the switching of roles is almost maintained, and the confusion of the transient operation is very slight.

[0036]

According to the present invention, in a multi-robot system in which a large number of individually controlled robots travel on the same trajectory, two robots operating according to different control commands are likely to collide on the trajectory. When the command information switching process and the collection information switching process are executed, the roles of the two robots are switched, and when viewed from the client side that has given command information to each robot and received the robot collection information, Each of the two robots continues to operate as instructed, and can continuously transmit the collection information requested by the client to the client.

Therefore, as compared with a system in which a plurality of tracks are arranged side by side on the same route to switch points in order to avoid collision between robots, the track equipment and its control system are much simpler and less expensive, and the operation of the track equipment is much simpler. The reliability is also high. In addition, since the system performs the command information switching process and the sampling information switching process in response to the detection signal of the approach detection means, there is no need for a complicated and sophisticated control function such as a centralized train management system. Hardware and software are simple and inexpensive. Moreover, with such a simple control system, it is possible to appropriately avoid collision of a robot that is individually controlled and does not know how to move.

If the command information switching process and the collection information switching process are performed by the central control unit, the configuration of hardware and software on each robot side is simplified. If the connector is provided and part or all of the command information switching process and the collection information switching process are performed on each robot side, the configuration of the central control unit is simplified, and the transient state at the time of switching is reduced. Can be controlled well. Of course, by appropriately braking the two robots so that they come into contact at a very low speed, mechanical damage due to the collision can be almost completely prevented.

[Brief description of the drawings]

FIG. 1 is a rough internal view of a museum to which the multi-robot system of the present invention is applied.

FIG. 2 is a schematic external view of the robot camera in the embodiment.

FIG. 3 is a block diagram showing a schematic configuration of the entire system of the embodiment.

FIG. 4 is a block diagram showing a schematic configuration of the robot camera in the embodiment.

FIG. 5 is a flowchart showing an operation of a main part of the robot control unit in the embodiment.

FIG. 6 is a flowchart showing an operation of a main part of a central control unit in the embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rail (track) 2 head 3 television camera 4 central control unit 5 television receiver 6 controller 7 proximity sensor (approach detection means) 8 connector 9 robot control unit 10 traveling drive unit 11 azimuth drive unit 12 depression drive unit 13 zoom Drive unit 14 Transmission control unit 15 Transmission control unit 16 Servo information memory

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 5/222-5/257 H04N 7/18

Claims (5)

(57) [Claims] 1. A method for controlling a multi-robot system, comprising: A plurality of robots equipped with sensors for collecting information travel along a common trajectory. Each robot operates according to time-series command information individually given from the central control unit, and the traveling direction and traveling speed on the track are individually controlled. The collection information collected by each robot is distributed to designated clients. There is approach detection means for detecting that two robots have approached each other on the trajectory and the distance between them has become less than or equal to a predetermined value. A first robot operating according to the command information A and collecting information to be distributed to the client a, and a second robot operating according to the command information B and collecting information to be distributed to the client b. When the approach is detected by the approach detection means, the command information A is given to the second robot, and at the same time, the command information B is given to the first robot. A collection information switching process for changing the collection information by the second robot to the client a at the same time as changing the collection information for the client b is performed. 2. The robot according to claim 1, wherein each of the robots and the approach detecting means are connected to the central control unit by a data transmission line, and the central control unit responds to a detection signal of the approach detecting means by the central control unit. A method for controlling a multi-robot system, comprising: executing an information switching process and the collection information switching process. 3. The robot according to claim 1, wherein each of the robots is provided with a connector which is capable of transmitting and receiving signals when two robots come into contact with each other on the trajectory. A control method for a multi-robot system, wherein data necessary for the switching process is exchanged between the contacted robots via the connector. 4. The command information switching process and the collection information switching process according to claim 3, wherein required data is exchanged between the two contacted robots via the connector. A method for controlling a multi-robot system, wherein the method is executed on the side. 5. The robot according to claim 1, wherein when the approach detecting means detects the approach of the two robots, the relative information of the two robots is given priority over the command information given to the two robots. A control method for a multi-robot system, wherein braking control for gradually decreasing the speed is performed by one or both of the two robots, and the two robots are brought into contact at a very low speed.