JPS6334092A - Position sensor for robot - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a robot position detection device, and more particularly to a robot position detection device suitable for detecting the origin position of a robot arm and detecting a runaway position. It is something.

[Conventional technology]

Conventional robots, especially industrial robots equipped with rotary robot arms, are known from, for example,
As described in Japanese Patent No. 96, a robot arm (hereinafter simply referred to as arm) equipped with an origin detection mechanism that can freely set the origin position is known. This origin detection mechanism is
It is a device that changes the position of either or both of the origin detection body and the origin position detection IJ Mitswitch.

[Problem that the invention seeks to solve]

Conventional robot position detection devices share the functions of arm origin position detection and runaway detection, and even if the control microcomputer goes out of control when detecting the origin position, the runaway will not be detected because the device is controlled as the origin position detection. No consideration was given to things that could not be done.

In addition, other detection devices have independent arm origin detection and runaway detection, but limit switches are used to detect runaway, and there is a risk of damage due to shock when the arm collides. In that case, it would be expected that it would not be detected even if it ran out of control, posing a safety problem.

The present invention has been made in order to solve the problems of the prior art described above, and is equipped with an arm origin position detection device and a runaway detection device independently, thereby achieving highly accurate origin position detection and safe runaway prevention. Its purpose is to provide a position detection device for robots that can move freely.

[Means for solving problems]

In order to achieve the above object, the configuration of the robot position detection device according to the present invention is such that the robot is equipped with an origin detection body for detecting the origin position of the robot arm, and a corresponding non-contact sensor for detecting the origin position. , a runaway detection body for detecting runaway of the robot arm and a corresponding non-contact sensor for detecting runaway are provided independently, and the non-contact sensor for detecting the origin position and the non-contact sensor for detecting runaway are provided independently. Each detection circuit is provided independently.

It should be noted that the origin detection body and the runaway detection body are installed so as to be shifted from each other in the direction of the rotation axis of the robot arm.

[Effect]

The origin detector and the runaway detector are attached to a rotating arm, and the corresponding non-contact sensor for detecting the origin position and non-contact sensor for detecting runaway are attached to the fixed side of the arm. Yes, each is detected by an independent detection circuit.

The non-contact sensor for detecting runaway is connected to an emergency stop circuit and can stop the motor when runaway is detected.

These non-contact sensors employ photo sensors, for example, and are highly reliable (and unlike conventional limit switches, there is no risk of damage due to collisions).

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a side view of an industrial robot according to an embodiment of the present invention, and FIGS. 2 and 3 are partially enlarged views of the position detection device section in FIG. ) is a cross-sectional view taken along the arrow A-A of Fig. 2 (bl), Fig. 2 (b) is a side view, and Fig. 3 is a
4 is a block diagram of the control circuit.

In FIG. 1, l is the support of this industrial robot, 1
2 is a first robot arm rotatably attached to the frame 1a (hereinafter simply referred to as arm); 3 is a first arm driving motor; 4 is a frame integral with the support column 1; , 1st
The second arm 5 rotatably attached to the distal end side of the arm 2 is a second arm driving motor.

Means for detecting the origin position and runaway detection in the industrial robot configured as described above will be explained with reference to FIGS. 2 and 3 using the first arm 2 as an example.

In Figure 2.3, 6 is the rotation axis of the first arm, 7
is an origin detection dog related to the origin detection body for detecting the origin position of the first arm 2; this origin detection dog 7 is the origin detection dog 7 of the first arm 2;
It is fixed to arm 2 of. 8 is the origin detection dog 7
This photosensor for detecting the origin position is related to the non-contact sensor for detecting the origin position corresponding to the above, and this photosensor for detecting the origin position 8 is attached to the frame 1a which is on the fixed side with respect to the first arm 2.

Reference numeral 9 denotes a runaway detection dog related to a runaway detection body that detects runaway of the first arm 2 due to runaway of the control microcomputer, etc. This runaway detection dog 9 is attached to the rotation axis of the arm on the arm 2. As shown in FIG. 2 (bl), the origin detection dog 7 is fixed in a vertically shifted position in six directions.1
0 is a runaway detection photosensor related to a runaway detection non-contact sensor corresponding to the runaway detection dog, and this runaway detection photosensor IO is attached to the frame 1a. Reference numeral 11 denotes another runaway detection dog fixed on the first arm 2 at a position symmetrical to the runaway detection dog 9.

The origin position of the first arm 2 is detected as shown in FIG. At the origin shown in FIG.

Further, as shown in FIG. 3, detection of runaway of the first arm 2 due to runaway of the control microcomputer,
When rotates in the direction of the arrow from the broken line to the solid line, the runaway detection dog 11 reaches the runaway detection photosensor 10, and the insertion portion 1
Detected at 0a.

The detection circuit will be explained with reference to FIG.

As shown in FIG. 4, the photosensor 8 for detecting the origin position
is connected to a control microcomputer 12IC, and controls the first arm drive motor 3 based on the Fllll command from this microcomputer 12.

The runaway detection photosensor 10 is connected to an emergency stop circuit 13, and in an emergency, that is, when a runaway is detected, a contact is turned ON via a relay circuit 14, and a driver 15 is actuated to stop the first
The arm drive motor 3 is brought to an emergency stop. That is, even when the microcomputer 12 runs out of control, the runaway detection photosensor IO detects the runaway and brings the motor to an emergency stop.

In this way, in this embodiment, the detection circuit of the photosensor 8 for detecting the home position, the detection circuit of the runaway detection row 7 sensor, and the emergency stop circuit are provided independently, so that the home position can be detected with high accuracy. Position detection and runaway prevention are performed.

In particular, since the sensor uses a non-contact type photo sensor, there is no risk of damage to the limit switch when the arm goes out of control, which is the case with conventional models, making it highly reliable.

Moreover, in this embodiment, since the origin detection dog 7 and the runaway detection dog 9 are disposed vertically and shifted in the direction of the rotation axis 6, the origin position detection photo sensor 8 and the runaway detection photo sensor Even if lO is large, the rotation angle between the two can be made small, which is effective in expanding the robot's operating area.

In the above embodiment, the position detecting device for the first arm 2 has been described, but it goes without saying that the present invention can be similarly applied to the position detecting device for the second arm 4.

〔Effect of the invention〕

As described above, the present invention provides a robot position detection device that is independently equipped with an arm origin position detection device and a runaway detection device, and is capable of accurately detecting the origin position and safely preventing runaway. be able to.

[Brief explanation of the drawing]

FIG. 1 is a top view of an industrial robot according to an embodiment of the present invention, FIGS. 2 and 3 are partially enlarged views of the position detection unit in FIG. 1, and FIG. al is shown in Figure 2 (A of bl)
-A arrow side view, Figure 2(b) is a side view, Figure 3 is the second
Fig. 4 is a block diagram of the control circuit. 1... Strut, 1a... Frame, 2... First arm, 3...・First arm drive motor, 4... Second arm, 6... Rotating shaft, 7... Origin detection dog, 8
...Photo sensor for detecting the origin position, 9.11...
Runaway detection dog, 1O... photosensor for runaway detection, 12... microcomputer, 13... emergency stop circuit. Cow 10 2... End of rod 1 - Figure Z

Claims (1)

[Claims] 1. The robot includes an origin detector for detecting the origin position of the robot arm, a corresponding non-contact sensor for detecting the origin position, and a runaway detector for detecting runaway of the robot arm. , and a corresponding non-contact sensor for detecting runaway are provided independently, and detection circuits for the non-contact sensor for detecting the origin position and the non-contact sensor for detecting runaway are independently provided. A position detection device for a robot. 2. A robot position detection device according to claim 1, in which the origin detection body and the runaway detection body are installed with their positions shifted in the direction of the rotation axis of the robot arm.