JP2000117590A - Mobile robot and production system thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily reconstruct a production line in response to a volume of production while ensuring reliability. SOLUTION: A pallet 10 on which a work 9 is mounted is carried intermittently by a free-flow conveyer 1. A mobile robot 2 which is provided so as to move among a plurality of work stations determines and performs a next work selected by a working strategy table based on whether the work is at a self- process where the robot exists at the time or not, whether a post-process is full of works or not, and whether another robot which moves to a pre - and post-process exists or not. Since the mobile robot 2 is constructed to be an autonomous distribution type, a production line is easily reconstructed by introducing/reducing the mobile robot 2 to/from the production line.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile robot provided to execute a work corresponding to a work position supplied in a state of being stopped at a predetermined work position, and to such a mobile robot. Related to a production system in which a production line is constructed.

[0002]

2. Description of the Related Art Hitherto, a production system using a mobile robot has been proposed, and its features include multi-workability of the mobile robot and a change in production capacity due to increase and decrease of the mobile robot.

[0003]

However, when the number of mobile robots to be used is actually changed in accordance with the production volume, a centralized control device for integrally controlling the operation of these mobile robots is required. When changing the number of control units, it is necessary to redesign the control system taking an enormous amount of time.

In such a centralized control system, it is difficult to respond quickly and appropriately even when a part of the production equipment fails. Also has the vulnerability of stopping.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mobile robot capable of easily reconstructing a production line in accordance with a production amount while ensuring reliability, and a mobile robot. It is to provide a used production system.

[0006]

According to the first aspect of the present invention, the other machine status grasping means provided on the mobile robot grasps the operation situation of another mobile robot located around the own machine. Analyze the operation status of other machines in the production line. In addition, the work status grasping means analyzes the staying state of the work in the production line by grasping the flow state of the work.

[0007] The operation determining means determines the operation of the own machine based on the other machine status grasping means and the work situation grasping means. This makes it possible to determine the operation of the own machine so as to increase the production efficiency based on the operation state of another mobile robot located around and the flow state of the work.

According to the second aspect of the present invention, the transfer means transfers the work to the work position in order. Then, the mobile robot performs a predetermined operation on the workpiece while stopped at the operation position.

Here, the other device status grasping means determines whether there is another mobile robot in the surrounding production process on the production line. Then, the operation determining means determines the allocation of the production process which is in charge of itself in the production line based on the judgment result of the other machine status grasping means. As a result, it is possible to appropriately allocate its own production process based on the cooperative relationship with the robots existing in the surrounding production process, and it is possible to construct a production system with high production efficiency.

According to the third aspect of the present invention, the motion determining means determines whether to move to another process depending on the presence or absence of another mobile robot grasped by the other machine status grasping means. And increase production efficiency.

According to the fourth aspect of the present invention, the work situation grasping means grasps the flow state of the work existing in the surrounding process including its own process in the production line, and the operation determining means grasps the work situation grasped by the work situation grasping means. Since it is determined whether to move to another process according to the flow state of the work, the mobile robot can move efficiently so as to eliminate the stagnation of the work.

According to the fifth aspect of the present invention, since the operation determining means assigns the production process according to the priority of the surrounding processes including the own process in the production line, the mobile robot moves to the process with the higher priority. Thereby, the stagnation of the work can be eliminated from the process having the higher priority.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a vehicle starter production system will be described below with reference to the drawings. FIG. 2 schematically shows the production system. In FIG. 2, the basic elements of the production system are:
The system includes a free flow conveyor 1 as a transport element, a mobile robot 2 as an assembly element, a general-purpose component supply unit 3, a general-purpose assembly unit 4, and a management system 5, and the production system is managed and operated by an operator. .

Next, the above components will be described. Mobile robot 2 ... A robot that is mounted on an unmanned mobile trolley and moves to a predetermined work station by itself, and is an assembly element that automatically performs operations such as assembly, component supply, and inspection. In this embodiment, this is a corresponding general-purpose unit while cooperating with other mobile robots.
Maintain efficient production and adapt to changes in starter production and life. It can also be moved to another production system to function as an assembly element. Further, the general-purpose component supply unit 3 and the general-purpose assembly unit 4 may intermittently work together.

FIG. 3 is a perspective view of the mobile robot 2, and FIG. 4 is a side view of the mobile robot 2. In these FIGS. 3 and 4, the moving carriage 6 has a robot 7
Is installed. The chucking hand 7a of the robot 7 has a CCD camera 8 mounted thereon,
A vision system is configured by image recognition by the D camera 8.

The basic structure of the robot 7 is shown in Table 1 below.
As shown in the figure, 6 axis type, arm stroke is 900
mm, maximum payload is 5 kg, equipped with a vision system as an autonomous function, equipped with a communication function between other mobile robots as a cooperative function, offline teaching as a succession function, and monitoring as a management function There are functions.

[0017]

[Table 1]

Free Flow Conveyor 1 (Continuous / Intermittent Conveyor) The assembly type production system of this embodiment has a unidirectional flow of goods,
The conveyor is a conveyor for controlling the work in one direction of the flow of the object, and normally a pallet 10 (see FIG. 1) on which the work 9 (part to be mounted) is mounted is intermittently suitable for production by the mobile robot 2. Transported. However, in the event of a sudden change in the production plan, the assembly may be performed by a human instead of the machine, so that a continuous conveyor function suitable for humans and an intermittent conveyor function suitable for machines can be compatible (continuous / intermittent conveyor). It has become.

Here, the work station of the free flow conveyor 1 is provided with a work sensor 11 for its own process and a full load sensor 12 for the post-process, along the supply path of the work 9. In this case, the self-process work sensor 1
Reference numeral 1 denotes a sensor for detecting that the work 9 is located in the own process, and a post-process work full load sensor 12 is a sensor for detecting that the work 9 supplied to the post-process has become fully loaded. The detection results of these sensors are transmitted to the mobile robot 2 by an optical communication device (not shown).

On the other hand, the mobile robot 2 is equipped with an optical communication device. The mobile robot 2 obtains the detection information of each sensor transmitted by the optical communication device on the free flow conveyor 1 side, and obtains the information of another adjacent mobile robot 2. It obtains location information.

General-purpose component supply unit 3... A unit / module structure that cooperates with the mobile robot 2 and supplies assembled components, and can be reconfigured. General-purpose assembling unit 4 ... Cooperating with the mobile robot 2,
The unit has a unit / module structure for performing an assembling operation such as press-fitting, which is difficult with the capability of the mobile robot 2, and can be reconfigured. Management system 5: Reconfiguration of the system in response to changes in product production and maintenance of the operating rate of the operating system
Efficient system resource management by supporting improvement activities.

The operator (administrator) plays the role of an operator and an administrator who support indirect operations for efficient operation of the system, such as management work of the above-mentioned various units and work plans accompanying a change in production amount. However, difficult assembling work that is difficult to automate may be directly executed as an operator in some cases.

In this production system, an ID tag (not shown) is embedded in the floor of the work station. An arm program number indicating the operation of the arm at the work station is written in the ID tag, and the mobile robot 2 performs work at the work station by reading the arm program number stored in the ID tag. It has become.

FIG. 1 schematically shows the configuration of the mobile robot 2. In FIG. 1, when the mobile robot 2 arrives at its own process, the mobile robot 2 sends information necessary for operation determination from the free flow conveyor 1 through the non-contact type optical communication device to the detection information of the sensors 11 and 12, A means 2a (corresponding to another equipment status grasping means, work status grasping means) for acquiring other machine information from the mobile robot 2 to operate is operated. Also,
The mobile robot 2 operates the means 2b (corresponding to an operation determining means) for determining the next operation by comparing the acquired information with a work strategy table 2c to be described later for determining the operation. The mobile robot 2 is thus configured to be autonomous and decentralized so that it can self-determine its own motion only by obtaining information on its vicinity.
It is a feature of.

FIG. 5 is a flowchart showing the basic operation of the mobile robot 2. The mobile robot 2 stops at a predetermined work station. The program number of the arm is read from the ID tag. In this case, the arm program number is written in the ID tag in advance. The arm controller executes the specified arm program. After completing the work, move to the next work station.

FIG. 6 shows a production process of the starter produced in the present embodiment, and FIG. 7 is an exploded perspective view of the starter. In these FIGS. 6 and 7, the starter is produced as follows.

(1) Step of press-fitting the housing pin 14 into the main body 13 as a work (2) Step of assembling the clutch 15 (3) Step of assembling the retainer roller 16 (4) Step of assembling the gear 17 (5) Steel ball 18 (6) Step of assembling magnet switch 20 (7) Step of assembling armature 21 (8) Step of assembling yoke 22 (9) Step of assembling end frame 23 (10) Step of inserting through bolt 24 (11) Step of tightening through bolt 24 (12) Step of tightening end frame screw 25 (13) Step of tightening housing bolt 26

As described above, the starter production process is a combination of a press-fitting process, an assembling process, and a tightening process for sequentially assembling parts on the main body 13 as the work 9 mounted on the pallet 10. In this case, the press-fitting step and the tightening step are performed by a general-purpose assembly unit 4 such as a screw tightening machine. In other words, in the press-fitting step and the tightening step, it is difficult to perform the press-fitting control or the tightening control with the current mobile robot 2, so that the press-fitting unit or the tightening unit as the general-purpose assembling unit 4 is used as the assembling element. It is used in the process and the tightening process.

Next, the operation of the present production system will be described with reference to FIG. 8 for three cases: steady state, unsteady state / abnormal state, and handling of manual work. (1) Operation in Steady State The steady assembling work in the production system is described by the steps a (the assembling work by the mobile robot 2 and the general-purpose component supply unit 3) and the steps b (the assembling work by the mobile robot 2 and the general This is shown by the operation of the assembly unit 4).

The pallet 10 on which the work 9 (part to be assembled) is mounted is transported by the free flow conveyor 1 from the previous process to the work station of the own process (process a), and is positioned. Supplies assembled parts from.

The mobile robot 2 is in charge of a plurality of basic processes, and includes a front-back process and a front-back mobile robot 2.
It moves between processes by the function of recognizing the state of the target and autonomously determining the destination. Depending on the process, the mobile robots 2 may overlap each other, and efficient work is performed by cooperation between the mobile robots 2.

When the mobile robot 2 is in charge of the process a, the mobile robot 2 recognizes the position of the assembly component by the vision system, picks up the assembly component, and assembles it on the pallet 10 into the work 9.

The inspection after assembly (such as assembly confirmation) is performed by the mobile robot 2 or the auxiliary jig. The pallet 10 on which the work 9 after assembly is mounted is transported by the free flow conveyor 1 to the next process. The mobile robot 2 performs the next work (part assembly in the process,
Move to the next or previous process) and move on to the next action. When the mobile robot 2 moves to the next process, the hand for the next process is exchanged during the traveling movement in order to improve work efficiency.

In the assembling work in the step b, since the target work cannot be realized by the mobile robot 2, the assembling is performed in cooperation with the general-purpose assembling unit 4. A characteristic operation is that the mobile robot 2 starts the operation by pressing the start switch of the general-purpose assembly unit 4 in the same operation as that performed by a person.

Here, the mobile robot decides the action for moving to the next work station as described above based on the flow state of the work 9 and the moving position state of the other mobile robot 2 as follows. It has become.

FIG. 9 is a data table for determining the action selection, which is stored in the mobile robot 2 in advance.
In FIG. 9, the elements for determining the action selection include “full work for post-process”, “work for own process”,
“Work memory present”, “post-process mobile robot”, and “pre-process mobile robot” are set. In addition, the action selection includes “move to post-process”, “move to previous process”, “standby”,
“Work continuation” is set, and a number is stored corresponding to each action selection.

In this case, when the post-process work full load is “on”, it means that the standby work 9 in the post-process is full, and when the own process work is “on”, the work 9 exists in the current work process. And the working memory is present
“n” indicates that the current work process has been completed, the post-process mobile robot indicates “on”, and a post-process mobile robot exists, and the preceding process mobile robot indicates “on”.
Indicates that there is a mobile robot in the previous process. In the action selection, “move to post-process” indicates that the mobile robot moves to the post-process, “move to pre-process” indicates that it moves to the pre-process, and “standby” indicates Indicates to wait without performing work,
“Continuation of work” indicates that the current work is continued in the own process.

In short, the combination of “on” and “off” in the data table shown in FIG. 9 is a code of behavior for determining the motion pattern of the mobile robot 2, and is summarized in a table in FIG. Is referred to as a work strategy table 2c. In this case, by changing the contents of the work strategy table 2c shown in FIG.
The manner in which the mobile robot 2 cooperates can be freely changed. In other words, by changing the contents of the action selection in the work strategy table 2c, it is possible to arbitrarily set the prior process, the own process, and the post process.

Here, FIG. 10 classifies and shows the conditions for determining the action selection in the work strategy table 2c shown in FIG. 9, and will be described below. (1) If the mobile robot 2 is not located in the post-process when the post-process work 9 is fully loaded, the robot 9 moves to the post-process regardless of other conditions (the storage number is 1). That is, the work 9 cannot be supplied to the post-process even if the work is performed in the own process, and therefore, the work 9 is moved to the post-process in order to eliminate the full loaded state of the post-process work 9.

(2) If the post-process work 9 is full and the post-process mobile robot 2 is present and the preceding process mobile robot 2 is not present, the process moves to the previous process regardless of other conditions (memory number is 2). . In other words, the work 9 cannot be supplied to the subsequent process even if the work is performed in the own process, so that the workpiece 9 moves for the time being to the previous process.

(3) When the post-process work 9 is full and there are the post-process mobile robot 2 and the pre-process mobile robot 2, the process stands by regardless of other conditions (the storage number is 3). In other words, the work 9 cannot be supplied to the subsequent process even if the work is performed in the own process, so that the work 9 stands by at the current position.

(4) When the post-process work 9 is less than the load, if the own process work 9 is present, the work is continued irrespective of other conditions (the storage number is 4). That is, the work 9 is operated in the own process and the work 9 is supplied to the subsequent process.

(5) In the case where the post-process work 9 is less than the above, when there is no own process work 9 and there is work memory, and when there is no post-process mobile robot 2, regardless of the presence or absence of the previous process mobile robot 2. The process moves to the subsequent process (the storage number is 5). That is, since the work 9 is completed and the work 9 is supplied to the subsequent process, the process 9 moves to the subsequent process and performs the work on the work 9.

(6) In the case where the post-process work 9 is less than the present process work 9 and there is no own process work 9, there is work memory, the post-process mobile robot 2 exists, and the pre-process mobile robot 2
If there is no, the process moves to the previous process (the storage number is 6). In other words, although the work 9 is completed and the work 9 is supplied to the post-process, the work 9 is moved to the pre-process for the moment because the post-process mobile robot 2 is present (the storage number is 6).

(7) When there is less work 9 in the post-process and there is no work 9 in the own process, there is work memory, and if there are the post-process mobile robot 2 and the previous process mobile robot, the process waits (memory number is 7). In other words, although the work 9 has been completed and the work 9 has been supplied to the post-process, since the post-process mobile robot 2 and the pre-process mobile robot 2 are present, the work 9 stands by in the self-process.

(8) When there is less work 9 in the post-process and there is no work 9 in the own process, and there is no working memory and no mobile robot 2 in the previous process,
The process moves to the previous process regardless of the presence or absence of (the storage number is 8). That is, since the work 9 is not supplied from the previous process, the process moves to the previous process to eliminate the state.

(9) In the case where the post-process work 9 is less than the present process work 9 and there is no own process work 9, if there is no working memory and the pre-process mobile robot 2 is present, the post-process mobile robot 2
Waits irrespective of the presence or absence (memory number is 9). That is, although the workpiece 9 is not supplied from the previous process, the mobile robot 2 stands by because the preceding process mobile robot 2 is located.

As a result of such an operation, an automated production system using the autonomous distributed mobile robot 2 can be constructed. The mobile robot 2 uses the work strategy table according to the flow state of the work 9 and the position of another machine. Since the mobile robot 2 moves to the determined work station and executes the assembling process of the work 9, the number of mobile robots 2 corresponding to the production amount can be input, and a flexible automated production system can be constructed.

That is, in the production of general automobiles, as shown in FIG. 11, the production amount generally increases gradually from the start of production, and gradually decreases after the minor change. In this case, in the conventional automated production line, since the mobile robot 2 is fixedly incorporated in the production system, it cannot flexibly cope with the production amount of the product.

On the other hand, in the automated production line according to the present embodiment, as shown in FIG. 11, the number of the mobile robots 2 is gradually increased in accordance with the increase in the production amount of the product, and the production amount is decreased. In response, the number of mobile robots 2 can be reduced by gradually reducing the number of mobile robots 2, so that a flexible production system can be constructed. In this case, the operation rate of the mobile robot 2 can be increased by replenishing the mobile robot 2 deviating from the production line to another production line.

When the mobile robot 2 breaks down,
Since it is possible to respond simply by removing the mobile robot 2, the production system can be quickly restored.
Further, when the production amount of the product increases, it is only necessary to put the mobile robot 2 into the current production line, so that it is possible to easily cope with an increase or decrease in the production amount.

(2) Unusual / Abnormal Operation When the production line is stopped during the lunch break, the time from the end of the working hours to the start of the next working time, etc., the specific mobile robot 2 Utilizing the movement function, he works 24 hours a day without any break in various indirect operations (parts arrangement operation, etc.) distributed in the factory. Thereby, the operation rate of the mobile robot 2 can be increased.

When an equipment failure such as an assembly failure occurs, the mobile robot 2 first performs a retry operation, and repairs any repairable failure by itself. If repair is difficult,
By the wireless abnormality notification, the mobile robot 2 notifies the operator of the abnormality and the contents thereof, and the mobile robot 2 returns promptly by the cooperative work between the operator and the mobile robot 2 (the cooperative work between the human and the mobile robot). The human and the mobile robot 2 perform cooperative work under various safety measures (low output unit, safe arm shape, etc.). Self-diagnosis technology has been introduced for stable operation of the mobile robot 2 over the long term.
Analyze their own failure mode and self-aware of the operation status,
Abnormalities can be predicted early and prompt measures can be taken.

(3) Handling of manual assembling work The present system is basically completely automatic, but the assembling work involves difficult work inherent in assembling (such as assembling of a flexible object). Due to factors such as a short product life or a lack of automation technology development, the production system may include manual assembling work. This system is a highly autonomous production system similar to a manual operation line, and is suitable for cooperation between a mobile robot 2 as a component and a person. The operation will be described below.

Basically, (1) the above-mentioned operations in the normal operation are performed by a person in place of a mobile robot. However, to help people work more efficiently,
It is desirable that the work 9 on the free flow conveyor 1 be continuously conveyed at a constant speed without stopping the process. The free-flow conveyor 1 can continuously and intermittently control the movement of the pallet 10 by a continuous / intermittent integration mechanism. In a work process by a person, the pallet 10 is continuously conveyed only in the process. be able to.

At the time when the manual operation is changed to automation,
It is possible to freely switch to a simple intermittent operation. The general-purpose parts supply unit 3 and the general-purpose assembly unit 4
Since safety for workers is ensured, sharing is possible. As described above, this system functions as an extremely flexible automated production system.

According to the present embodiment, the mobile robot 2
Is configured as an autonomous decentralized type that determines the next action selection from the work strategy table 2c based on the flow state of the work 9 and the position conditions of the other machine, so that the mobile robot is fixedly incorporated in the production system. Unlike the conventional one,
The production line can be reconfigured by appropriately increasing or decreasing the number of mobile robots 2 according to the production amount of the product, and it is possible to easily cope with the increase or decrease in the production amount.

In this case, since the mobile robot 2 is configured as a decentralized autonomous type, it is possible to cooperate with the production system only by putting it into the production line or reducing the production line, and to easily provide a highly reliable production system. Can be rebuilt.

The present invention is not limited to the above embodiment, but can be modified or expanded as follows. The present invention can also be applied to a process in which a mobile robot moves to a press-fitting machine, a cutting machine, or the like, and performs a work set or removal. The line form is not a straight line but may be a U-shape, a circle, an ellipse, or the like.

Communication between the mobile robots and between the mobile robot and the equipment can be performed not by an optical communication device but by a wireless device. The flow state of the work includes whether there is a work waiting for the process,
Alternatively, the presence / absence of the work in the previous process may be used, or the work memory may be used in addition to the presence / absence of the mobile robot in the previous / next process. Specifically, the presence / absence of a work in a post-process, the presence / absence of a work in a previous process, the distance to an adjacent mobile robot, information indicating that an adjacent mobile robot is working / waiting, or information indicating that the mobile robot has waited for a certain period of time. It may be used.

Instead of using the work strategy table to determine the action selection, the action selection may be determined based on the conditions shown in FIG. When the mobile robot is on standby, different tasks may be executed according to the satisfaction of different conditions.

The work strategy table of each mobile robot in the same system need not be the same for all the mobile robots.
For example, the first mobile robot and the last mobile robot may change the contents of the action strategy table. Further, the action strategy table of mobile robots having different operation speeds may be changed. As a mobile robot,
A four-axis robot or a configuration having a simple loader mechanism may be used.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an entire configuration according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a production line.

FIG. 3 is a perspective view of a mobile robot.

FIG. 4 is a side view of a mobile robot.

FIG. 5 is a flowchart showing the operation of the mobile robot.

FIG. 6 is a view showing a process of assembling a starter.

FIG. 7 is an exploded perspective view of a starter.

FIG. 8 is a perspective view of a production line showing a moving range of the mobile robot.

FIG. 9 is a diagram showing a work strategy table.

FIG. 10 is a diagram showing the contents of a work strategy table classified and shown;

FIG. 11 is a diagram showing the relationship between the passage of years and the amount of production.

[Explanation of symbols]

1 Free flow conveyor, 2 is a mobile robot, 3 is a general-purpose parts supply unit, 4 is a general-purpose assembly unit, 5 is a management system, 9 is a work, 10 is a pallet, 11 is a work sensor of its own process, and 12 is a work sensor of a post-process. It is.

Continuing from the front page (72) Inventor Tomoyuki Hirota 1-1-1 Showa-cho, Kariya-shi, Aichi Pref. Denso Corporation (72) Inventor Kazuhisa Fukaya 1-1-1, Showa-cho, Kariya-shi Aichi pref. ) Inventor Tsuyoshi Ueyama 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO CORPORATION (72) Inventor Hiroshi Inoue 1-1-1, Showa-cho, Kariya-shi, Aichi F-term inside DENSO Corporation 3C042 RB30 RB32 RB38 RJ11 3F059 AA01 AA03 BA03 BA10 BB05 FC01

Claims (5)

[Claims] 1. A mobile robot provided to perform a predetermined operation on a workpiece supplied in a state where the mobile robot is stopped at a workpiece supply position. Other machine status grasping means for grasping, a work situation grasping means for grasping the flow state of the work, and an operation determining means for deciding an operation of the own machine based on the other machine status grasping means and the work situation grasping means. A mobile robot, comprising: 2. The mobile robot according to claim 1, further comprising: a transfer unit configured to sequentially transfer the work to a work position corresponding to a plurality of production processes forming a production line, wherein the mobile robot is stopped at the work position. Performing a predetermined operation on the work conveyed by the conveying means, the other machine status grasping means determines whether there is another mobile robot in a surrounding production process in the production line, and Means for deciding the assignment of the production process in charge of the production line on the basis of the result of the judgment by the other device status grasping means. 3. The method according to claim 2, wherein the operation determining unit determines whether to move to another process according to the presence or absence of another mobile robot in a surrounding production process grasped by the other machine status grasping unit. Item 2. The production system according to Item 2. 4. The work situation grasping means grasps a flow state of a work existing in a peripheral process including its own process on the production line, and the operation determining means determines a flow of the work grasped by the work state grasping means. 4. The production system according to claim 2, wherein whether to move to another process is determined according to a situation. 5. The method according to claim 2, wherein the operation determining unit determines the allocation of the production process in accordance with the priority of the surrounding processes including the own process in the production line. Production system.