JPS60195602A - Robot - Google Patents

Abstract

PURPOSE:To relatively easily improve the safety and reliability of a robot not only when teaching operations are made to the robot but also when the robot is operated, by providing a device which specifies and stores the safe operating area of the robot, robot attitude monitoring device, and safety processor. CONSTITUTION:Safe operating areas are taught to a robot main body 20 by actually operating the main body 20 by using a controller 21 and teaching box 24. The main body 20 is composed of plural joints and each joint is driven by a DC servomotor 26. A rotary encoder 27 generates a signal of, for example, 1,000 pulses while the main shaft of the motor 26 makes one turn and the pulse signal is counted at a counter 32. The counted value is read in the controller 21 by a joint angle reading section 33 and the angle position of each joint is detected. A robot position and direction monitoring section 35 compares the position and direction of the front end of the robot main body 20 thus detected and calculated with the safe operating areas stored in a storage section 31 and informs a safety processing section 36 of the result. Therefore, the robot can be operated safely.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a robot that operates safely without interfering with peripheral equipment.

The structure of the conventional example and its problems First, the definitions of words used in the detailed description of the invention of this patent will be clarified.

Allowable operating range: The maximum operating range in which the robot tip can move when each axis of the robot body moves within its respective allowable operating range.

Limited operating range: When the operating range of one or more of the operating axes of the robot body is limited by a means such as a proximity switch or an operating command value, the maximum operating range in which the robot tip can operate. say.

Actual operation area 2 The area in which the tip of the robot operates when the robot actually performs work.

Safe operating area: An area that includes the actual operating area and avoids obstacles, people, etc., and can operate safely.

Generally, the allowable operating range of industrial robots has been set as wide as possible in consideration of the robot's versatility. On the other hand, when performing actual work, under any conditions,
Safety measures are also required to prevent collisions with surrounding equipment and people.

For example, when teaching a work to a playback type industrial robot, a human instructs the robot to move, but if the robot moves unexpectedly due to an error, etc., and collides with peripheral equipment, the worker who is teaching the robot There is a risk of causing harm. Therefore, for safety reasons, it is recommended to limit the range of motion based on the work content in advance.

Furthermore, even while performing playback operations in accordance with the taught work contents, the current situation is that there are cases in which the robot runs away due to strong electromagnetic noise or the like. Therefore, for safety reasons, it is recommended to limit the range of motion of the robot according to the content of the work.

Therefore, in conventional industrial robots, the operating range of each axis is limited by setting a proximity switch, a limit switch, etc. for each axis. There are also examples in which the operating range of each axis is limited by limiting the operating command value of each axis of the controller.

Recently, there are examples where safety is doubled by using both the controller's operation command value and a proximity switch that can be set at any location.

FIG. 1 is a specific example of a Cartesian coordinate system robot with a limited operating area. The orthogonal coordinate system robot 1 is movable in the XYZS axis directions (arrows), and the permissible motion area (not shown) of the robot tip 2 is generally a rectangular parallelepiped. The range of movement of each axis of this robot is limited by means such as each axis movement command value and proximity switch.
e)-(7-a-9-10). This limited operation area is usually a rectangular parallelepiped. However, in the case of actual operation, the area in which the robot can safely operate without interfering with surrounding equipment or humans is more complex and difficult to approximate with a single rectangular parallelepiped.

For example, the hexahedral area where the robot minimizes interference with peripheral equipment is (3-4 to 6-11) - (7-8-9-12).
), the limited motion area of this robot is a rectangular parallelepiped area (3-4-5-e) - (7-s-9-10), a lucky area, and a large unsafe area (11-6-6). -(12-9
-10). Therefore, the above-mentioned limited operation region has the disadvantage that it includes a large amount of unsafe region.

The same applies to various forms of industrial robots.

As an example, consider an articulated robot.

Figures 2 and 3 show the permissible operating range of an articulated robot.
FIG. 2 is a top view and FIG. 3 is a side view of an example. 13 is an articulated robot, 14 is a top view of the allowable motion area, and 15 is a side sectional view of the allowable motion area. As can be seen from both of these figures, a multi-articulated robot generally has a spherical shell-shaped allowable operating range.

The area in which the articulated robot actually operates, which is within the permissible movement area and is regulated by obstacles 16 and 171C shown in FIG. 4, is defined as an actual movement area 18.

If the motion range of each axis is limited so that it can move within this actual motion region 18, each axis of the articulated robot will move in an arc, so as shown in FIG. 5, this limited motion region 19
not only includes most of the obstacles 16 and 17, but also includes a large amount of unsafe areas such as under the mounting surface.

Furthermore, on the other hand, each axis moves in a circular arc, making it difficult to intuitively recognize the movement of the robot tip. Therefore, it takes a lot of effort to limit the movement range of each axis and realize the limited movement area 18. It was a difficult task that required a lot of effort.

Purpose of the Invention In view of the above-mentioned drawbacks, the present invention provides a system that allows easy setting of a safe operation area corresponding to an area in which actual safe operation is possible while avoiding obstacles, etc., as an area rather than a restriction on the operation range of each axis.
In addition, the present invention provides a robot with improved safety during teaching work and playback operations.

Configuration of the Invention The robot of the present invention includes a device for defining a safe operation area;
A robot posture monitoring device that monitors whether the posture of the robot body is within the safe operation area described in 1. Safety processing that performs processing such as giving priority to the robot body when the posture of the robot body is not within the safe operation area. A so-called safe operation area that does not include an unsafe area can be easily defined, and as a result, high safety can be obtained.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 6 shows an example of the equipment configuration of an industrial robot according to an embodiment of the present invention, and FIG. 7 is a diagram explaining their functions. Here, 20 is a robot body, 21 controllers, 22 a keyboard, 23 a CRT, 24 a teaching box, and 25 a controller that can input and output data to the controller 21. Each of the robot main bodies 2o has a motor 26 and a rotary encoder 27.
, a reduction gear 28, and a potentiometer 29 are provided. Inside the controller 21 is a main processing unit (CPU) 3.
0. A storage section 31, a counting section 32 that counts pulses output from the rotary encoder 27, and a potentiometer 29.
An angular position reading section 3 that digitizes and reads the resistance value of
3. Orthogonal transformation calculation unit 34 that calculates the coordinates of the robot tip from the read angular position of each joint, robot position direction monitoring unit 35, safety processing device 36, DC servo driver 37
It consists of

FIG. 8 shows a specific example of the configuration of one joint of the robot body. 38 is a bending joint unit incorporating bearings, reducers, etc., 26 is a DC servo motor that drives the joint unit, 27 is a rotary encoder attached to the DC servo motor 26, 28 is a reducer, 29 is a It is a potentiometer.

FIG. 9, FIG. 10, and FIG. 11 are examples of inputting the safe operation area by teaching. 39 is an example of teaching the safe operation area of a hexahedron, 4o is an example of teaching the safe operation area of a hexahedron, 41.42
43 is a teaching example of a hexahedral safe operation area in which parts of the safe operation area are taught in an overlapping manner, and 43 is a safe operation area in which the taught safe operation area 41 is partially modified using numerical input or the like.

The operation of the industrial robot configured as described above will be explained below.

First, a means for defining and storing the robot's safe operation area will be explained. In this embodiment, the robot main body 20 is actually moved using the controller 21 and the teaching box 24 to teach the safe operation area. For example, as shown in FIG. 9, a safe operation area 39 is taught by specifying the hexahedron area and teaching the 8 vertices of the hexahedron, and the controller 2
1 is stored in the storage unit 31 within the 1. Further, in the case of a hexahedral area as shown in FIG. 10, the safe operation area 40 is taught and stored in the storage unit 31 by specifying the hexahedral area and teaching the six vertices of the pentahedron.

If it is necessary to teach a complex area including recesses, a plurality of hexahedral areas or hexahedral areas may be overlapped. FIG. 11 shows an example in which two hexahedral regions are overlapped. A hexahedral area 41 where each vertex is taught, represented by a black circle, and a hexahedral region 41 where each vertex is taught, represented by an X mark.
The face piece area 42 corresponds to -Toden. The entire two areas can be stored in the storage unit 31 as a safe operation area. Also, if you want to modify a part of the taught area, enter the instruction of the vertex you want to modify and the amount of movement, for example (-〇, 0.0), and you can obtain the area 43 indicated by the 10 mark. can.

In the above example, a method of teaching a safe operation area for the tip of the robot body has been described, but teaching of a safe operation area for the tip of a hand attached to the tip of the robot body can also be defined and stored in the same manner. Furthermore, safe operation areas can be defined and stored in the same manner for other parts of the robot body, for example, the elbow joint, if necessary.

Next, the robot posture monitoring device will be explained.

The robot body 20 is composed of a plurality of joints.
Each joint is driven by a DC servo motor 26, as shown in FIG. The rotary encoder 27 outputs 100
Generates a 0 pulse signal and sends the pulse signal to the counting unit 32
By counting , the angular position of that joint can be found.

Therefore, since the angular position of each joint of the robot body 2o is determined, the position and direction of the tip of the robot body can be determined by calculation.

A potentiometer 29 is partially disposed at the tip of the rotary encoder 27 via a reducer 28, and indicates a resistance value according to the angular position of the joint unit 38, which is read into the controller 21 by the angular position reading section 33. Then, the joint angle position is detected. Each detected joint angle is converted into the position and direction of the tip of the robot body by the orthogonal transformation calculation unit 34.

The robot position/direction monitoring unit 36 compares the detected and calculated position/direction of the robot body tip with the safe operation area stored in the storage unit 31 and determines whether the robot tip is within the safe operation area. The safety processing section 36 outputs the results to the safety processing section 36.

In the above example, we monitored whether the position of the tip of the robot body was within the safe operation area, but it is also possible to monitor the position of the tip of the hand attached to the tip of the robot body in the same way. The position of the elbow joint, for example, can also be monitored. .

For each location being monitored, if any one is not within the safe operation area, the safety processing device 3
Processing such as sending a signal to 6 to make the robot body inoperable is required.

In this embodiment, the robot posture monitoring device includes a reducer 2a potentiometer 29, an angular position reading section 33, an orthogonal transformation calculation section 34, and a robot position direction monitoring section 36.

In addition, the devices that define and store the safe operation area include the robot body 20, controller 21, keyboard 22, and CRT.
23, a teaching box 24, a computer 26, and a storage section 31.

Finally, the safety processing device will be explained.

When the robot is in operation, the safety processing device 36 in the controller 21 immediately cuts off the power to the DC servo driver 37 and stops the DC servo motor if the robot tip or other required monitoring location is not within the respective safe operation area. It has the function of holding the position and posture of the robot by activating a holding brake (not shown) built into the DC servo motor, as well as outputting an error message and sounding a warning buzzer (not shown).

If the robot is being taught, the robot should be stopped in a servo-locked state when the tip of the robot or other areas that need to be monitored are at the boundaries of their respective safe operation areas, a warning will be given to the teaching worker, and the teaching worker will be able to stop the robot. By returning the tip to the safe operating area, continued teaching is possible.

As described above, in this embodiment, by providing a means for defining and storing a safe operation area, a robot posture monitoring device, and a safety processing device, the following great practical effects can be achieved.

1. The safe operation area can be easily input and stored in the controller by teaching or numerical input, or input from another computer, and there is no unsafe operation area.

2. Since the safe operation area can be set as a set of one or more hexahedrons or pentahedrons, even complex areas can be input easily.

3. The input safe operating area can be easily modified.

4. Potentiometers are used to detect the angular position of each joint of the robot body, making it highly safe and reliable.

5. While the robot is operating, it constantly monitors whether the tip of the robot is within the safe operation area. If it is not within the area, it immediately stops and maintains its position, making it extremely safe. .

6. During teaching, the robot's operation is stopped in a servo-locked state at the boundary of the safe operation area and a warning is issued to the teaching operator, so accidents due to operational errors during teaching can be prevented.

7. The safe operation area can be defined in various places such as the tip of the robot, the hand part, the elbow part, etc. as necessary, so it can cope with various situations and has extremely high safety.

Effects of the Invention As described above, the robot of the present invention is provided with a means for defining and storing a safe operation area, a robot posture monitoring device, and a safety processing device, so that it can be operated relatively easily both during teaching and during robot operation. Both can be made into safe and reliable industrial robots, which have great practical effects.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the limited movement area of a conventional Cartesian coordinate system robot, Fig. 2 is a top view showing the permissible movement area of an articulated robot, Fig. 3 is a side view of the same, and Fig. 4 is an explanatory diagram showing the limited movement area of a conventional Cartesian robot. FIG. 6 is a diagram showing a restricted actual operation area including the actual operation area in FIG. 4. FIG. 6 is a perspective view showing the equipment configuration of an industrial robot in an embodiment of the present invention. Fig. 7 is a configuration diagram explaining its functions, Fig. 8 is a sectional view showing the specific structure of one joint of the robot body in an embodiment of the present invention, Figs. FIG. 11 is an explanatory diagram showing a safe operation area based on teaching. 20...Rohono) main body, 21--controller, 22--keyboard, 23--
CRT, 24...Teaching box, 26
... Computer, 26 ... DC servo motor, 27 ... Rotary encoder, 2
8...Reducer, 29...Potentiometer, 30...Main processing unit, 31...
...Storage section, 32...Counting section, 33...
・Angle position reading section, 34...Orthogonal transformation calculation section,
36...Position/direction monitoring unit, 36...Safety processing device, 37...DC servo driver, 38
...Joint unit, 39.4o.41.42.
43...Safe operation area. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 4 Figure 3 15 Figure 4 7 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 f; 11 Figure 4?

Claims (1)

[Claims] (1) Teach the safe operation area in which a multi-degree-of-freedom robot can safely operate without colliding with peripheral devices within the robot's operation range as position information of a monitoring target point that can be set at any position a device for specifying and storing
A robot posture monitoring device that monitors and determines whether the robot's monitored point is within the safe operation area, and a robot that makes the robot body inoperable if the robot's monitored point is not within the corresponding safe operation area. A robot equipped with a safety processing device that performs such processing.