JPH09300252A - Travel robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently perform a work with a robot arm, with a safety function attained against an obstruction. SOLUTION: Non-contact truck obstruction detection sensors 25 are fitted to the front and the back of a transfer truck 12 with a robot arm 13 mounted thereon. Also, the detection ranges A1 of the truck sensors 25 are set approximately in parallel with the surface of a travel route. Also, non-contact arm obstruction detection sensors 26 are arranged on the peripheral part of the transfer truck 12. In this case, the arm sensors 26 are mounted, so as to be directed slantwise upward, and the detection ranges A2 of the arm sensors 26 are set up, so as to cover the height of the operation zone of the arm 13. The obstruction detection distance of the truck sensors 25 in a travel direction is set at a value larger than the obstruction detection distance of the arm sensors 26 in the same direction. Furthermore, a control device, upon receipt of an obstruction detection signal from the truck sensors 25, stops the transfer truck 12. Also, the control device stops the arm 13, upon receipt of an obstruction detection signal from the arm sensors 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile robot in which a robot arm for carrying out various operations is mounted on an unmanned carrier truck which moves between a plurality of facilities.

[0002]

A mobile robot having a robot arm mounted on an automated guided vehicle has recently been adopted in, for example, an assembly line of parts for automobiles. In this type of mobile robot, for example, the actual Kaihei 6-332 is used.
As shown in Japanese Patent Publication No. 10, it is considered to provide a safety function for stopping the operation of a human or other mobile robot or the like when it is approaching in the vicinity.

Specifically, as partially shown in FIG.
In this type of assembly line, a plurality of equipments 2, 3 and 4 (only three are shown) are provided along a traveling path 1, and a plurality of mobile robots 5 and 6 (only two are shown) are provided on the traveling path. 1
It is adapted to move (self-propelling) in the direction of arrow a.
Each of the mobile robots 5 and 6 receives a work, for example, in the equipment 2, moves to the next equipment 3 while inspecting the work, performs the work of assembling the work that has been inspected in the equipment 3, and further installs the adjacent equipment. At step 4, work such as receiving another work is performed.

Each of the mobile robots 5 and 6 is provided with a robot arm 8 on an unmanned transportation vehicle 7, and photoelectric sensors 9 (for detecting obstacles in front, rear, left and right of the unmanned transportation vehicle 7). Only the front photoelectric sensor 9 is provided. In this case, each photoelectric sensor 9 is attached so as to be oriented parallel (horizontal) to the transport path 1. When an obstacle such as a worker is detected within the detection range A of the photoelectric sensor 9, the safety function is realized by stopping the operations of the automatic guided vehicle 7 and the robot arm 8.

In the conventional robot, as shown in FIG. 7, for example, when the front mobile robot 5 is stopped at the equipment 4, the rear mobile robot 6 is stopped between the equipment 2 and the equipment 3. Then, after the previous mobile robot 5 moves toward the next equipment, the subsequent mobile robot 6 moves to the equipment 3. However, the mobile robot 6 later is equipped with the equipment 2 and the equipment 3.
Although the robot arm 8 can safely perform its work during the waiting time between the robot arm 8 and the robot arm 8, the work of the robot arm 8 is stopped, and the work is stagnated and the robot arm 8 is operated. There was a problem that the rate decreased.

Further, as shown in FIG. 8, there is a case where the mobile robots 5 and 6 face each other along a traveling path 1 having two lanes as shown by arrows b and c. It is conceivable that one mobile robot 5 moves to the equipment 3 while the other mobile robot 6 stops at the equipment 2 and is working by the robot arm 8.

At this time, if the width of the traveling path 1 is relatively narrow,
Both mobile robots 5 and 6 will intrude into each other within the detection range A of the photoelectric sensor 9 for detecting an obstacle on the side of the unmanned transport vehicle 7. Therefore, the work of the robot arm 8 of the mobile robot 5 that was previously stopped at the equipment 2 part is stopped halfway, and at the same time, the work of the robot arm 8 of the other mobile robot 6 is also stopped. However, there is also a problem that both of them cannot move without stopping.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a mobile robot capable of efficiently performing work by a robot arm while realizing a safety function for obstacles.

[0009]

A mobile robot according to the present invention comprises an obstacle detection sensor for a trolley for detecting an obstacle in the traveling direction of an automated guided vehicle, and an obstacle for an arm for detecting an obstacle around a robot arm. The object detecting sensor is separately provided, and the safety ensuring operation is independently performed for the unmanned carrier vehicle and the robot arm based on the detection signals of the respective obstacle detecting sensors (claim 1). invention).

According to this, by performing the safety ensuring operation, it is possible to prevent the accident of contact between the unmanned transporting vehicle and the robot arm, and to perform the work safely. Then, the obstacle detection range of the trolley obstacle detection sensor and the obstacle detection range of the arm obstacle detection sensor can be set separately, and for example, the obstacle detection range of the trolley obstacle detection sensor can be set as an obstacle. Even if there is an object, when the arm obstacle detection sensor does not detect the obstacle, the work of the robot arm can be continued. As a result, the work by the robot arm can be efficiently performed while realizing the safety function for the obstacle.

In this case, it is effective to set the obstacle detection distance in the traveling direction of the truck obstacle detection sensor to be longer than the obstacle detection distance in the same direction of the arm obstacle detection sensor (claim 2). Invention). Thereby, even if there is an obstacle such as another unmanned carrier in the forward direction of the unmanned carrier, the unmanned carrier is stopped before the obstacle enters the detection range of the arm obstacle detection sensor. As a result, the work can be continued without executing the safety ensuring operation of the robot arm.

Furthermore, by mounting the obstacle detection sensor for the arm so as to be directed upward,
The detection range can be set up to the height of the operation area of the robot arm (the invention of claim 3). According to this, it is possible to set the detection range in a substantial operation area of the robot arm, and it is possible to ensure safety associated with the operation of the robot arm. Moreover, in the lower part of the operation area of the robot arm, the detection range in the horizontal direction need not be widened so much, and for example, it does not hinder the passing of other unmanned carrier vehicles or the like.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention (corresponding to claims 1, 2 and 3) will be described below with reference to FIGS. 1 to 3 schematically show a configuration of a mobile robot 11 according to the present embodiment, and the mobile robot 11 is configured to include a robot arm 13 on an unmanned transfer cart 12.

As is well known, the unmanned carrier vehicle 12 (hereinafter abbreviated as "carrier vehicle 12") has a substantially rectangular box shape as a whole, and the main body 12 has an upper surface as a working table (mounting table).
A wheel 12b (see FIG. 2) is provided at the bottom of a. The wheel 12b is not shown,
It is adapted to be driven by a drive motor and a steering motor using a battery as a power source, and these constitute the traveling unit 14 shown in FIG.

Then, as shown in FIG.
4 is controlled by the traveling controller 15. In this case, the automated guided vehicle 12 moves in the forward and backward directions. Although not shown in the figure, a guide tape or guide wire for guiding a route is provided on the floor of the traveling road, which will be described later. A sensor is provided.

On the other hand, the robot arm 13 (hereinafter abbreviated as "arm 13") is composed of, for example, an articulated arm, and is provided with a hand 16 for gripping a work (not shown) and performing a predetermined work at a tip portion thereof. Has been done. The arm 13 (and the hand 16) is controlled by the arm controller 17 shown in FIG.
Thus, the arm 13 is adapted to execute work such as work assembly, machining, and inspection.

The mobile robot 11 according to the present embodiment is
For example, it is used in an assembly line for automobile parts, and a plurality of units work simultaneously in the assembly line. This assembly line is provided with a plurality of facilities along the traveling path on which the mobile robot 11 travels, and FIGS. 5 and 6 respectively show a part of the assembly line.

Here, in the vicinity of the traveling road 18 shown in FIG. 5, along the traveling road 18 are three facilities 1 in order from the left side in the drawing.
9, 20, and 21 are provided. The plurality of mobile robots 11 move, for example, in the equipment 19 while moving in the direction of arrow a.
Receives the work, moves to the next equipment 20 while inspecting the work, assembles the work that has been inspected in the equipment 20, and receives another work in the adjacent equipment 21. . Further, the traveling road 22 shown in FIG. 6 has, so to speak, two lanes,
As shown by arrows b and c, the mobile robot 11 moves to face each other and stops at the facilities 23 and 24 respectively in each lane to perform a predetermined work.

At the front and rear of the main body 12a of the transport carriage 12, there are provided obstacle detection sensors 25 for the carriage for detecting obstacles in the traveling direction (forward and backward directions) of the transport carriage 12, respectively. Two on each side. These trolley obstacle detection sensors 25 (hereinafter referred to as "trolley sensor 2
5 ”) is composed of a non-contact type object detection sensor, for example, an ultrasonic sensor, and an obstacle (such as a person or a carriage 12 of another mobile robot 11) in a set detection range A1 (only the front is shown). It is designed to detect It should be noted that the detection range A1 of the trolley sensor 25 is defined by the traveling paths 18, 2
It is set to be almost parallel (horizontal) to the road surface of No. 2.

The main body 12a of the carrier 12 has
An arm obstacle detection sensor 26 for detecting obstacles around the arm 13 is provided. This arm obstacle detection sensor 26 (hereinafter referred to as “arm sensor 2
6 ”) is also composed of, for example, a non-contact type ultrasonic sensor, and is located at the center of the front and rear portions of the main body 12a, one at each, and at the front and rear of the left and right sidewalls, respectively. Two
A total of 6 pieces are provided.

These arm sensors 26 detect obstacles (people and the arm 13 of the other mobile robot 11) within the set detection range A2. At this time, in this embodiment, FIG. As shown in FIG.
The obstacle detection distance in the traveling direction of 5 (direction of arrow a in FIG. 1) is set longer than the obstacle detection distance in the same direction (horizontal horizontal direction) of the arm sensor 26.
Further, in the present embodiment, as shown in FIG. 2, these arm sensors 26 are attached at an angle of θ so that they are directed obliquely upward, and the detection range A2 thereof is the operating area of the arm 13. It is set to the height.

On the other hand, as shown in FIG. 3, the main body 12a of the carrier 12 has a control device 27 for controlling each mechanism.
Is provided. The control device 27 includes a microcomputer and the like, and has an arithmetic processing unit 27a and an input / output port unit 27b.
And the like. The control device 27 gives a control signal to the traveling controller 15 and the arm controller 17 in accordance with a preset work program to execute an assembly work. The controller 27 is adapted to receive signals from the carriage sensor 25 and the arm sensor 26, and individually control ON / OFF of the carriage sensor 25 and the arm sensor 26. Or detection range A
1 and A2 are adjusted.

At this time, as will be described later in the description of the operation, the control device 27, by its software configuration, when the obstacle detection signal is input from the vehicle sensor 25, the operation of ensuring the safety of the transport vehicle 12 is performed. In this case, it will be stopped. When an obstacle detection signal is input from the arm sensor 26, the arm 1
In this case, the safety ensuring operation No. 3 is executed. Therefore, the control device 27 functions as the carriage control means and the robot control means according to the present invention. The carriage sensor 25 and the arm sensor 2
In No. 6, only necessary items are turned on according to the work program.

Next, the operation of the above structure will be described with reference to FIGS. When the power of the mobile robot 11 is turned on and the work program is activated, the cart sensor 25 and the arm sensor 26 are turned on by the instructions in the program. The flowchart of FIG.
Control device 2 when the power of the vehicle sensor 25 is turned on
Control procedure (a) executed by the control unit 7 and the arm sensor 2
6 shows a control procedure (b) executed by the control device 27 when the power source of No. 6 is turned on.

Here, as shown in FIG. 4A, when the power supply of the vehicle sensor 25 is turned on, the detection signal of the vehicle sensor 25 is constantly monitored, and the vehicle sensor 25 is an obstacle. Is not detected (N in step S1
o) and only when the arm sensor 26 does not detect an obstacle (No in step S2), the carriage 1
2 can be moved (traveled), and the carriage 12 is started (step S3).

On the other hand, when a person or another carrier truck 12 exists within the detection range A1 of the carriage sensor 25, the carriage sensor 25 detects the obstacle and outputs a detection signal (step S1). Yes). Then, the carrier 12 is temporarily stopped (step S4). At this time, even when the arm sensor 26 is turned on and an obstacle is detected (Yes in step S2), the carrier 1
2 is to be suspended (step S
4). As a result, when an obstacle is present within a predetermined distance in the traveling direction of the transport vehicle 12, the transport vehicle 12 is stopped, and when the obstacle is no longer present, the transport vehicle 12 is moved.

On the other hand, as shown in FIG. 4B, when the arm sensor 26 is powered on, the detection signal of the arm sensor 26 is constantly monitored, and the arm sensor 26 detects an obstacle. When not detected (step S
Only when No) in 10), the arm 13 is operated (step S11), and when an obstacle is detected within the detection range A2 of the arm sensor 26 (Yes in step S10),
The arm 13 is temporarily stopped (step S1).
2).

In this way, the carrier 12 and the arm 1
3 is controlled, the mobile robot 11 moves from the equipment 19 toward the equipment 20 while the previous mobile robot 11 is stopped at the equipment 21 and is performing work, as shown in FIG. 5, for example. When the vehicle is present, the previous mobile robot 11 (transportation vehicle 12) enters the detection range A1 of the vehicle sensor 25 in the middle thereof. For this reason, the transport carriage 12 of the mobile robot 11 after that is stopped, and contact or the like is prevented in advance.

At this time, the previous mobile robot 11
However, even if it is within the detection range A1, the arm sensor 2
6 will be stopped where it does not enter the detection range A2 of 6 and the arm 13
The work (inspection work) is continuously executed. When the front mobile robot 11 moves from the equipment 21 and goes out of the detection range A1 of the carriage sensor 25, the transport carriage 12 of the rear mobile robot 11 moves to reach the equipment 20. In this case, since the work can be performed by the arm 13 even when the carriage 12 is temporarily stopped, it is possible to perform the work efficiently without loss of time.

Further, for example, as shown in FIG. 6, when two mobile robots 11 face-to-face on a traveling path 22 having a relatively narrow width, one of the mobile robots 11 has a facility 23.
It is conceivable that the other mobile robot 11 moves to the equipment 24 while stopping at a part and performing work by the arm 13. However, at this time, since the detection range A2 of the arm sensor 26 is set obliquely upward, both mobile robots 11 do not intrude into each other within the detection range A2 of the arm sensor 26. The mobile robots 11 can perform their respective work.

By the way, for example, as shown in FIG. 6, in each mobile robot 11, when the mobile robot 11 is stopped at the equipment 23, 24, that side (the right side surface portion in the traveling direction).
The arm sensor 26 is turned off.
As a result, the arm 13 can be extended to the equipment 23, 24 side to perform work. Here, if there is a mistake in the work program, there is a risk that the arm 13 may perform an erroneous operation such as moving to the side opposite to the equipment.

However, in this embodiment, the detection range A2 of the arm sensor 26 is set up to the height of the operation area around the arm 13, so that the arm 13 detects the detection range A2 due to an erroneous operation. When the arm 13 enters, the operation of the arm 13 itself is stopped, so to speak, it also functions as a safety screen.

As described above, according to the present embodiment, by performing the safety ensuring operation based on the detection signals of the carriage sensor 25 and the arm sensor 26, it is possible to realize the safety function against obstacles. Since the transport carriage 12 and the arm 13 are independently controlled based on the carriage sensor 25 and the arm sensor 26 provided separately, the unmanned transport carriage 7 is detected by the obstacle detection of the photoelectric sensor 9. Unlike the conventional one in which both the robot arm 8 and the robot arm 8 are stopped, even when the cart sensor 25 detects an obstacle, the work by the arm 13 is continuously executed unless the arm sensor 26 detects the obstacle. Therefore, the excellent practical effect that the work by the arm 13 can be efficiently performed can be obtained.

In the above embodiment, the transport carriage 12 and the arm 13 are stopped as a safety ensuring operation.
As a safety ensuring operation, decelerating the carriage 12 or
An operation such as moving the arm 13 to a predetermined retracted position is also conceivable. Further, the non-contact type object detection sensor is not limited to the ultrasonic sensor, and a sensor using light such as an infrared sensor can be adopted. In addition, when an obstacle is detected, a visual or audible alarm may be given, and the present invention can be appropriately modified and implemented without departing from the scope of the invention.

[Brief description of drawings]

FIG. 1 is a plan view schematically showing the configuration of a mobile robot together with a detection range, showing an embodiment of the present invention.

FIG. 2 is a side view schematically showing the configuration of a mobile robot together with a detection range.

FIG. 3 is a block diagram schematically showing an electrical configuration.

FIG. 4 is a flowchart showing a control procedure when the cart sensor is on (a) and the arm sensor is on (b).

FIG. 5 is a plan view schematically showing a part of an assembly line.

FIG. 6 is a plan view schematically showing another part of the assembly line.

FIG. 7 is a diagram corresponding to FIG. 5, showing a conventional example.

FIG. 8 is a diagram corresponding to FIG. 6;

[Explanation of symbols]

In the drawing, 11 is a mobile robot, 12 is an automated guided vehicle, and 1
3 is a robot arm, 18 and 22 are running paths, and 19 and 2
0, 21, 23, 24 are equipments, 25 is an obstacle detection sensor for a trolley, 26 is an obstacle detection sensor for an arm, 27 is a control device (transportation trolley control means, robot control means), A1,
A2 indicates a detection range.

Claims (3)

[Claims] 1. A robot arm mounted on an automatic guided vehicle, wherein work is carried out by the robot arm while moving between a plurality of facilities, wherein the automatic guided vehicle is provided with a robot arm. A non-contact type obstacle detection sensor for a truck that detects an obstacle, and a conveyance carriage control unit that executes a safety ensuring operation of the unmanned conveyance carriage based on an obstacle detection signal of the obstacle detection sensor for a carriage, and A non-contact type obstacle detection sensor for an arm, which is provided on an automated guided vehicle and detects an obstacle around the robot arm, and a safety ensuring operation for the robot arm based on a detection signal from the obstacle detection sensor for the arm A mobile robot comprising: 2. The obstacle detection distance in the traveling direction of the trolley obstacle detection sensor is set to be longer than the obstacle detection distance in the same direction of the arm obstacle detection sensor. 1. The mobile robot according to 1. 3. The obstacle detection sensor for the arm is mounted so as to be inclined so as to be directed upward, so that the detection range is set up to the height of the operation area of the robot arm. 2. The mobile robot described in 2.