JP2001273032A - Obstacle avoidance system of automated guided vehicle(agv) and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inform a person approaching an AGV that it will stop its operation when the person approaches it nearer. SOLUTION: An area sensor 10 has two detection areas Ew1 and Ew2 which are different in size. When the person enters the larger area Ew2 of the area sensor 10, a buzzer sounds an alarm informing him/her that he/she stands therein, and he/she understands his/her nearer approach to the AGV leads to an operation stop of a robot arm 6. Thus, even when a person carelessly approaches the AGV, the alarm sound makes him/her take care not to nearer approach a guided robot 1 and the operation stop of a robot arm 6 can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system and an apparatus for dealing with obstacles in an unmanned mobile vehicle, and more particularly to providing two obstacle detecting means having detection areas different in width from one another to determine how to deal with the area in which the obstacle is detected. Regarding things that are different.

[0002]

2. Description of the Related Art In recent years, mobile robot systems have been introduced in assembly plants and the like. In this mobile robot system, a traveling path of the mobile robot is provided on the floor of a factory, and a plurality of work stations are provided along the traveling path. Then, the mobile robot is configured to stop in front of each work station and perform assembling work or the like while moving along the traveling path.

As is well known, a mobile robot is configured by mounting a robot arm on an unmanned mobile vehicle body. This mobile robot is provided with, for example, an area sensor (obstacle detection means) including an infrared sensor in order to avoid collision with a person or the like while moving or being operated by the robot arm. Then, when the area sensor detects an obstacle, it is configured to stop the traveling of the unmanned mobile vehicle main body or stop the operation of the robot arm.

[0004]

When a mobile robot stops at a work station and works with a robot arm, a person (operator) sometimes looks at the state of equipment near the mobile robot. is there. However, since humans cannot recognize the detection area of the mobile robot's area sensor, they do not know how close they are to the mobile robot, and even if they take care to maintain the distance from the mobile robot, It may cause a situation where the robot arm stops due to approaching too much.

[0005] As described above, since the detection area of the area sensor cannot be determined even if care is taken so as not to collide with the mobile robot, the movement of the mobile robot is stopped as a result, or the robot arm which is a mounting equipment for the mobile robot is installed. When the operation is stopped, time is wasted correspondingly, and the cycle time of the operation becomes longer, resulting in a problem such as a decrease in productivity.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a system and an apparatus for dealing with obstacles in an unmanned mobile vehicle capable of notifying that the operation will stop when the vehicle approaches further. To be.

[0007]

According to the present invention, there is provided first and second obstacle detecting means having different detection areas, and when the second obstacle detecting means having a large detection area detects an obstacle, When the first obstacle detecting means with a narrow detection area detects an obstacle, the traveling of the unmanned mobile vehicle body is performed to avoid collision with the obstacle. When the equipment is mounted on the equipment, the operation of the equipment is stopped.

According to this configuration, when an obstacle such as a person approaches the unmanned mobile vehicle and enters the detection area of the second obstacle detection means, a notification to that effect is given. For this reason, the person knows that he / she has entered the detection area of the second obstacle detection means, and recognizes that stopping the vehicle further near the unmanned mobile vehicle will cause the operation to stop. Therefore, even if a person approaches the unmanned vehicle inadvertently, the alert is issued, and the person pays more attention so as not to approach the unmanned vehicle further. And stopping the operation of the mounting equipment such as the robot arm can be avoided. Then, if the obstacle further approaches the unmanned mobile vehicle after the notification is made, the traveling and the operation of the mounting equipment are stopped.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a mobile robot system will be described below with reference to the drawings. First, an outline of the mobile robot system of the present embodiment will be described. As shown in FIG. 1, this system is provided with a traveling path 2 of a mobile robot 1 as an unmanned mobile vehicle on a floor of a factory or the like. A plurality of fixed facilities 3 constituting a work station are installed along the traveling path 2, and a work transport conveyor is provided so as to connect the fixed facilities 3, although not shown. The mobile robot 1 stops at each fixed facility 3 while moving on the travel path 2 while being guided by the guide line 4 provided on the travel path 2, and is controlled by a component supply device (not shown) provided in the fixed facility 3. It is configured to automatically execute the work of assembling the supplied parts to the work sent by the conveyor.

As shown in FIGS. 1 and 2, the mobile robot 1 has a robot arm 6 mounted on an unmanned mobile vehicle body 5 as mounting equipment. The unmanned mobile vehicle body 5 includes a traveling mechanism 9 including a plurality of wheels 7 and a traveling and steering motor 8 for driving the wheels 7 at the bottom. Although not shown,
A guide sensor for detecting the guide line 4 and a stop marker sensor for detecting a stop marker provided in front of the fixed facility 3 are provided at the bottom of the unmanned mobile vehicle body 5.

The unmanned mobile vehicle body 5 is provided with two types of area sensors 10 and 11 as obstacle detecting means. These area sensors 10 and 11 are, for example, infrared sensors. One of the area sensors 10 is used for detecting a traveling obstacle, and one area sensor 10 is disposed on each of the front and rear sides of the unmanned vehicle body 5 so that the mobile robot 1 When moving in the forward and backward directions, an obstacle in front of the moving direction is detected. The other area sensor 11 is used for detecting a work failure, and one area sensor 11 is provided on both front and rear sides of the unmanned mobile vehicle body 5.
Each of them is disposed two on each of the left and right sides to cover the entire periphery of the unmanned mobile vehicle body 5. In this case, since the robot arm 6 is mounted on the unmanned mobile vehicle body 5, the area sensor 11 for detecting a work failure is provided obliquely upward so as to emit infrared rays obliquely upward. Thereby, the area sensor 11
Can cover the entire working area of the robot arm 6 around the unmanned mobile vehicle body 5 in the detection area.

Here, the infrared rays emitted from the area sensors 10 and 11 are reflected by obstacles and received by the area sensors 10 and 11. And the area sensor 1
When the infrared rays are received, 0 and 11 output a voltage signal corresponding to the received energy as a detection signal. The infrared rays received by the area sensors 10 and 11 have higher energy as the distance to the obstacle is shorter. Therefore, the distance to the obstacle can be determined from the magnitude of the output voltage of the area sensors 10 and 11.

The voltage signals output from the area sensors 10 and 11 are, as shown in FIG. 3, first and second level detectors 12 and 13 and second level detector 14 respectively.
And 15 are input. First level detector 12, 1
The third and second level detectors 14 and 15 each have a predetermined reference voltage. When the voltage signals input from the area sensors 10 and 11 exceed the reference voltage, the obstacle detection signals Sr1, Sr2, It is configured to output Sw1 and Sw2.

In this case, the reference voltages of the first and second level detectors 12, 13 and 14, 15 are different from each other, and the reference voltages of the second level detectors 14, 15 are different from each other. 13 is set lower than that of FIG. Therefore, the area (detection area) where the second level detectors 12 and 13 output the obstacle detection signal is an area including the detection area of the first level detectors 12 and 13 and an area larger than that. It has become.

FIG. 2 shows an area sensor 10 for detecting a traveling obstacle.
For, the detection area by the first level detection unit 11 is indicated by Er1, and the detection area by the second level detection unit 12 is indicated by Er2. FIGS. 1 and 2 show a first level detection unit 1 for an area sensor 11 for detecting a work failure.
The detection area by E3 is indicated by Ew1, and the detection area by the second level detector 14 is indicated by Ew2. In the following description, Er1 is referred to as a running narrow area detection area, Er2 is referred to as a running wide area detection area, Ew1 is referred to as a working narrow area detection area, and Ew2 is referred to as a working wide area detection area.

The above-described area sensor 10 for detecting a traveling obstacle.
Constitutes first and second obstacle detecting means for detecting a traveling obstacle together with the first and second level detecting sections 12 and 14, and the area sensor 11 for detecting a working obstacle includes first and second obstacle detecting means. The level detectors 13 and 15 constitute first and second obstacle detecting means for detecting a work obstacle.

The obstacle detection signals Sr1, Sw1, Sr2 and Sw2 output from the first level detectors 12 and 13 and the second level detectors 14 and 15 are used as control devices as control means shown in FIG. 16 are given. This control device 16
Is composed mainly of a microcomputer, controls the motor 8 of the traveling mechanism 9 and the robot arm 6 according to a work program, and executes a series of assembling work. Further, a buzzer 17 as a notifying means is connected to the control device 16, and the control device 16 controls the obstacle detection signals Sr 1, Sr 2 from the first and second level detectors 12, 13, 14, 15. The buzzer 17 is sounded, and the operation of the motor 8 of the traveling mechanism 9 and the robot arm 6 are controlled based on the input of the signals Sw1 and Sw2 and the program for dealing with obstacle detection. Therefore, the control device 16 functions as travel control means, robot arm control means, and buzzer control means.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG. Note that the flowchart of FIG. 4 is an interrupt processing program that is executed at regular intervals. When the control device 16 enters the execution of the program of FIG. The validity / invalidation setting is for setting which of the plurality of area sensors 10 and 11 is to be activated according to the situation.

For example, when the mobile robot 1 is running, the area sensor 10 for detecting a traveling obstacle is enabled and the area sensor 11 for detecting a work obstacle is disabled. When operating the robot arm 6 while the mobile robot 1 is traveling, both the area sensors 10 and 11 are enabled. In a situation where the mobile robot 1 is stopped in front of the fixed facility 3 and the robot arm 6 is working, the area sensor 10 for detecting a traveling obstacle is disabled and the area sensor 11 for detecting a working obstacle is enabled. I do. In this case, when all of the area sensors 11 for detecting work faults are enabled, the fixed facility 3 enters the detection area of the area sensor 11 facing the fixed facility 3, and the first level detector 1
3. The second level detector 15 detects the obstacle detection signals SW1 and SW
Since W2 is output, the area sensor facing the fixed facility 3 is disabled, and the other area sensors are enabled.

As described above, since the area sensors to be activated differ depending on the situation, the validity / invalidation setting of the area sensors 10 and 11 is first performed in the first step S1 according to the situation. Here, it is assumed that the mobile robot 1 is stopped in front of the fixed facility 3 and the robot arm 6 is performing work, the area sensor 10 for detecting a traveling obstacle is invalidated, and the area for detecting a working obstacle is disabled. Among the sensors 11,
The two area sensors facing the fixed installation 3 are disabled,
It is assumed that all the remaining area sensors for detecting work trouble are enabled.

After execution of step S1, the control device 16 shifts to step S2, where the working wide area detection area Ew2
It is determined whether or not an obstacle has been detected, that is, whether or not the obstacle detection signal Sw2 has been input from the second level detection unit 15. If the obstacle detection signal Sw2 is not input from the second level detection unit 15, the control device 16 proceeds to step S2.
Is determined to be "NO", the buzzer 17 is kept off in step S3, and the operation returns to the next step S4 with the operation of the robot arm 6 being continued.

Now, a person approaches the mobile robot 1 to see the state of the component supply device and the like of the fixed facility 3, and
It is assumed that the vehicle enters the work wide area detection area Ew2. Then
Since the obstacle detection signal Sw2 is input from the second level detection unit 15, the control device 16 determines "YES" in step S2 and shifts to step S5 when the next program of FIG. 4 is executed. , Where the working narrow area detection area E
It is determined whether or not an obstacle is detected at w1, that is, whether or not the obstacle detection signal Sw1 is input from the first level detection unit 13. If the obstacle detection signal Sw1 is not input from the first level detection unit 13, the control device 16 proceeds to step S
In step S6, the buzzer 17 is turned on to generate an alarm sound, and the process returns to step S4 to maintain the state in which the operation of the robot arm 6 is continued and return.

As described above, when the person is working, the wide-area detection area Ew2
When entering, the buzzer 17 emits an alarm sound, so that the person recognizes that the person has entered the detection area of the area sensor 11 and pays attention not to approach the mobile robot 1 any more. Fixed facilities 3
If the user enters the working narrow area detection area Ew1 at any time while watching the state of the first level detection section 13
Outputs the obstacle detection signal Sw1, the control device 16
Is "YES" in step S5 when the next program of FIG. 1 is executed, and the process proceeds to step S7, where the operation of the robot arm 6 is instantaneously stopped (stop means), and then the process proceeds to step S8. The routine returns with the buzzer 17 kept on and the alarm sound is continuously emitted.

When a person enters the working narrow area detection area Ew1 as described above, the robot arm 6 stops instantaneously, so that collision of the robot arm 6 with a person is avoided. Then, when the person exits from the work-time narrow area detection area Ew1, the control device 16 executes step S when the next program shown in FIG. 1 is executed.
5 is "NO", and the process proceeds to step S6, where the buzzer 15 is kept on and the alarm sound is maintained, and in the next step S4, the operation of the robot arm 6 is restarted and the process returns. . Further, when the person goes out of the work wide area detection area Ew2, the control device 16 turns to "NO" in step S2 when the next program shown in FIG. 1 is executed and shifts to step S3, where the buzzer 17 is turned off. The alarm sound is stopped, and in step S4, the operation of the robot arm 6 is maintained, and the process returns.

As described above, according to the present embodiment, when an obstacle such as a person approaches the mobile robot 1 and enters the working wide area detection area Ew2, the buzzer 17 emits an alarm sound. It is known that the robot has entered the wide-area detection area Ew2 at the time of operation 11 and recognizes that stopping the robot arm 6 will be caused if the robot approaches the mobile robot 1 any further. Therefore, even if a person approaches the mobile robot 1 carelessly, attention is paid so as not to approach the mobile robot 1 any more, and it is possible to prevent the operation of the robot arm 6 from being stopped. .

The countermeasure control at the time of detecting an obstacle as shown in the flowchart of FIG. 4 is similarly executed when the mobile robot 1 is traveling. In this case, the control content is such that when an obstacle is detected in the work wide detection area Er2, the buzzer 16 emits an alarm sound (the traveling speed of the mobile robot 1 may be reduced at the same time), and the work narrows. When an obstacle is detected in the area detection area Er1,
The motor 8 of the traveling mechanism 9 is stopped to stop the mobile robot 1 (the unmanned mobile vehicle body 5).

The present embodiment is not limited to the embodiment described above and shown in the drawings, but can be extended or modified as follows. When an obstacle is detected in the wide area detection areas Er2 and Ew2, a lamp (notifying means) may be turned on instead of the alarm sound by the buzzer 17, or the lamp may be turned on in addition to the alarm sound of the buzzer 17. You may make it light. The unmanned mobile vehicle is not limited to the mobile robot 1, and may be an unmanned transport vehicle (AGV) that mounts and transports parts on the unmanned mobile vehicle main body 5. Is not limited to the robot arm 6. 1st and 2nd in one area sensor
The present invention is not limited to the configuration in which the two level detection units are connected to set two wide and narrow detection areas, but two area sensors having different detection areas in wide and narrow areas may be provided. The area sensor is not limited to an infrared sensor.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a side view of a mobile robot.

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

FIG. 4 is a flowchart showing control contents for coping when an obstacle is detected.

[Explanation of symbols]

In the figure, 1 is a mobile robot (unmanned mobile vehicle), 3 is fixed equipment, 5 is an unmanned mobile vehicle body, 6 is a robot arm (mounted equipment), 10 and 11 are area sensors (first and second obstacle detection) Means, 12 and 13 are first level detection units (first obstacle detection means), 14 and 15 are second level detection units (second obstacle detection means), and 16 is a control device (stop means) ) And 17 are buzzers (notification means).

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Claims (3)

[Claims] A first obstacle detecting means for detecting an obstacle; and a second obstacle detecting means for detecting an obstacle in a wide area including a detection area of the first obstacle detecting means. When the second obstacle detecting means having a large detection area detects an obstacle, the fact is notified, and when the first obstacle detecting means having a small detection area detects an obstacle, an obstacle is detected. In order to avoid a collision, the unmanned mobile vehicle travels, and when the equipment is mounted on the unmanned mobile vehicle, the operation of the equipment is stopped. system. 2. An unmanned mobile vehicle body, first obstacle detecting means for detecting an obstacle, and a second obstacle for detecting an obstacle in a wide area including a detection area of the first obstacle detecting means. Object detecting means, notifying means for notifying when the second obstacle detecting means having a wide detection area detects an obstacle, and the first obstacle detecting means having a narrow detecting area detect an obstacle. An obstacle handling device for an unmanned mobile vehicle, comprising: a stop means for stopping travel of the unmanned mobile vehicle body when detected. 3. A robot arm is mounted on the unmanned mobile vehicle body, and when the second obstacle detecting means having a narrow detection area detects an obstacle, the stopping means stops the operation of the robot arm. The obstacle handling device for an unmanned mobile vehicle according to claim 2, wherein: