JP3204047B2 - Industrial robot safety devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial system for transmitting a sensing signal to an obstacle or the like, stopping the operation of the robot body or the robot arm by recognizing the presence of the obstacle or the like based on the intensity of the reflected wave. The present invention relates to a safety device for a robot.

[0002]

2. Description of the Related Art In recent years, with the advance of production automation, a plurality of self-propelled industrial robots sometimes perform work assembling work by sharing a work station. In this case, usually, each robot is equipped with an optical sensor or the like, detects the intensity of the reflected light to know the existence of another robot, and stops the movement of each robot to prevent collision with each other.

[0003] Japanese Patent Laid-Open No. 5-57669 discloses that
A safety device is shown that allows power supply to the robot arm drive only at the work station and prevents malfunction of the robot arm.

[0004]

By the way, in the above-mentioned conventional safety device using an optical sensor or the like, when a plurality of industrial robots try to enter a work station at the same time, the presence of the other is detected at the same timing. As a result, there is a problem that neither robot enters the work station and gets stuck due to so-called shrinking.

[0005] In addition, in the case of a single industrial robot, if the other party is a moving operator, the industrial robot must be stopped with a sufficient distance to prevent danger. It is desirable to minimize the distance margin for stationary peripheral devices or the like whose installation positions do not change, and to suppress the expansion of the robot working space. The present invention has been made in view of such a problem, and an object of the present invention is to provide a safety device for an industrial robot that does not generate a stuck due to the mutual contact between the industrial robots and does not need to secure an excessive work space. And

[0006]

According to a first feature of the present invention, the surface reflectances of the robot bodies (1) of a plurality of industrial robots (R1, R2) are set to be different from each other. Therefore, if the reflectance of the robot body (1) of the industrial robot (R2) having a high priority is set to be relatively high, the sensing signal emitted from the robot (R1) having a low priority has a high priority. Robot body of high robot (R2) (1)
Is reflected with sufficient intensity to return, and the operation of the robot (R1) stops. During this time, since the return reflection intensity of the sensing signal from the low priority robot (R1) whose reflectance is set relatively low is small, the high priority robot (R
2) Continue work.

[0007] In this way, it is possible to avoid collision between the industrial robots and also to prevent the industrial robots from getting stuck due to the mutual interference .

[0008] The numerals in parentheses of the above means indicate the correspondence with specific means described in the embodiments described later.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. (First Embodiment) FIG. 1 shows a schematic structure of an industrial robot main body. The robot arm is not shown.

In the figure, a caster wheel 52 is provided at the four corners of the lower surface of the robot body 1, and at the center of the lower surface,
A well-known drive wheel 51 that is driven to rotate by the traveling motor 4 and is appropriately turned is provided. A pair of left and right openings 11 and 12 are formed in the upper part of the side surface of the robot body 1, and optical sensors 2A and 2B that emit or receive infrared light as a sensing signal are provided in the robot body 1 facing these openings. ing. In the robot body 1,
A control device 3 with a built-in CPU for controlling the operations of the optical sensors 2A and 2B and the traveling motor 4 is provided.

The side surfaces 1a, 1b of the robot body 1
For a low-priority robot, a normal painted surface having a low infrared light reflectance is used, whereas a high-priority robot has a commercially available reflective tape having a high infrared light reflectance. In FIG. 2, light emitting elements in each of the optical sensors 2A and 2B are connected to a CPU 3 via an I / O circuit 32 of
The operation is started in response to a command signal input from 1 and a certain amount of infrared light is emitted from the openings 11 and 12. Opening 1
The reflected light returning through 1 and 12 is incident on the light receiving element in each of the optical sensors 2A and 2B, and the sensor signal corresponding to the incident light amount is I
It is input to the CPU 31 via the / O circuit 32. One of the optical sensors 2A and 2B emits infrared light forward from the robot body and the other diagonally forward.

The CPU 31 rotates the traveling motor 4 via the motor driving circuit 33 in accordance with a procedure programmed in advance, and moves the robot body 1. Robot body 1
The moving distance from the original position is calculated from the number of rotations of the drive wheel 51, for example. FIG. 3 shows a state in which two industrial robots R1 and R2 having such a structure are simultaneously moving toward the work station S from directions orthogonal to each other. In the figure, the industrial robot R1 has a low priority, and moves from the lower part of the figure toward the upper working station S.

In the normal traveling range, the industrial robot R
The infrared light from the first optical sensor 2A is emitted only to the front as described above, and the L1 region in the figure is moved toward the work station S from the right direction in the orthogonal figure. The area where the reflected light returns when reflected by the side of the robot body 1 of the high industrial robot R2 (hereinafter, referred to as a reflected light area) is shown.

The traveling industrial robot R1 is driven by a driving wheel 51.
Reaches the merging vicinity position X calculated from the number of rotations of the optical sensor 2B, thereafter, from the optical sensor 2B diagonally forward (the reflected light area L
The emission of the infrared light to 2) is started, and in this state, the light beam goes to a target position Y near the work station S (the arrival at the position is also calculated from the rotation speed of the drive wheel 51). Similar control is performed for the industrial robot R2.

During this time, C of each industrial robot R1, R2
FIG. 4 shows a control procedure of the PU 31. In step 101, the rotation of the traveling motor 4 is controlled according to a procedure stored in advance, and the robot body 1 travels. When reaching the target position Y in step 102, the traveling motor 4 stops (step 103). When the position X near the junction is reached in step 104, the operation of the junction optical sensor 2B that emits infrared light obliquely forward is started in addition to the normal optical sensor 2A (step 105).

Next, the operation when the two industrial robots R1 and R2 are simultaneously moving from the vicinity of the confluence to the target position will be described with reference to FIG. Each optical sensor 2
The reflected light areas L1 and L2 of A and 2B are actually shown in FIG.
As shown in (a), the first reflected light intensity is used as a boundary.
Warning regions L11 and L21 and second warning regions L12 and L22
Consists of In the first warning regions L11 and L21, the intensity of the reflected light is relatively small, and if there is reflected light in this region, the industrial robot R1 decelerates to a slow state. In the second warning regions L12 and L22, the reflected light intensity is relatively large, and if there is reflected light in this region, the industrial robot R1 stops traveling.

Although the industrial robot R2 actually has a reflected light region, the reflected light region of the industrial robot R2 is small because the infrared light reflectance of the side surface of the main body 1 of the industrial robot R1 is low. . In the figure, the reflected light region of the industrial robot R2 is omitted for easy understanding. When such industrial robots R1 and R2 move toward the target position, when the industrial robot R2 enters the first warning area L21 (FIG. 5B), the industrial robot R1 starts slowing down. Since the reflected light area of the industrial robot R2 is small, the industrial robot R1 does not enter this area, and the industrial robot R2 continues normal traveling.

When the industrial robots R1 and R2 further approach each other toward the target position, the industrial robot R2 enters the second warning area L22 of the industrial robot R1 (FIG. 5C). Thereby, the industrial robot R1 stops, and only the industrial robot R2 continues traveling to reach the target position Y. Until the industrial robot R2 completes the work at the work station S at the target position Y, the industrial robot R1 maintains the stopped state. After work, industrial robot R2
Returns to the normal route and exits the reflected light area L2, the industrial robot R1 starts traveling to the target position Y again.

FIG. 6 shows a control procedure in the CPU 31 during this time. In the figure, while traveling, sensor signals from the optical sensors 2A and 2B according to the reflected light intensity are received (steps 201 and 202), and when the opponent industrial robot R2 enters the first warning areas L11 and L21, the vehicle slowly moves down. Is started (step 203). When the other industrial robot R2 enters the second warning areas L12 and L22, the traveling is stopped (step 204). Then, when the other industrial robot R2 exits from the reflected light areas L1 and L2, it starts traveling toward the target position again (steps 205 and 20).
6).

The industrial robot R1 counts its own stop time (step 207), and when the stop time exceeds a predetermined value, issues an alarm or the like as an abnormality (steps 208 and 209). Similar control is performed by the industrial robot R2. In this way, by increasing the infrared light reflectance on the side of the main body of the industrial robot with high priority, it is possible to avoid collision of a plurality of industrial robots, and these industrial robots stuck together And efficient operation according to the priority is realized.

Each step in each flow chart of the above embodiment may be realized by a hardware logic configuration as a function executing means. (Second Embodiment) The present invention can be applied to a single industrial robot which is designed to keep the working space of the robot relatively small and to ensure the safety of workers. In other words, if the worker's clothes, etc., have higher infrared light reflectance than the peripheral devices and the priority is raised, the movement of the robot body will stop while maintaining a sufficient safety distance for the worker. Or the operation of the robot arm stops. On the other hand, since the robot main body or the robot arm can sufficiently approach the peripheral device having low infrared light reflectance, it is possible to suppress the expansion of the robot working space while improving the safety of the worker.

(Third Embodiment) In each of the above embodiments, the output of the light emitting element of the optical sensor is fixed and the priority is changed by the infrared light reflectance. , The reflected light area can be changed, and a similar effect can be obtained. (Other Embodiments) The number of industrial robots is not limited to the two described in the above embodiment, and the priority can be changed by changing the infrared light reflectance for each robot in multiple stages. Can be set in multiple stages.

In addition to the optical sensor, other sensing elements using radio waves or the like can be used.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an industrial robot according to a first embodiment of the present invention.

FIG. 2 is a block diagram of an electric circuit of the industrial robot according to the first embodiment of the present invention.

FIG. 3 is a schematic plan view showing the operation of the industrial robot according to the first embodiment of the present invention.

FIG. 4 is a processing flowchart of a CPU according to the first embodiment of the present invention.

FIG. 5 is a schematic plan view showing the operation of the industrial robot according to the first embodiment of the present invention.

FIG. 6 is a processing flowchart of a CPU according to the first embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Robot main body, 2A, 2B ... Optical sensor, 3 ... Control device, 4 ... Traveling motor, 51 ... Drive wheel, 52 ... Caster wheel, R1, R2 ... Industrial robot.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-60-249075 (JP, A) JP-A-63-295190 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B25J 19/06 B25J 19/02

Claims (2)

(57) [Claims] 1. A means (2A, 2B) for emitting a sensing signal toward an obstacle; a means (202) for detecting a reflected return intensity of a sensing signal from an obstacle; At this time, a plurality of industrial robots (R1, R1) having means (204) for stopping the operation of the robot mounted on the robot body (1), respectively.
(2) The safety device for an industrial robot, wherein the surface of each of the robot bodies (1) is set so that the reflectances for the sensing signals are different from each other. 2. A light emitting device that emits infrared light toward an obstacle.
And a light-receiving element that detects the intensity of reflected infrared rays returning from obstacles
When the detected return intensity is greater than or equal to a predetermined value,
Equipped with means to stop operation on the robot body
Equipped with multiple industrial robots and changing the output of each light emitting element
Thus, the sensing sensitivities of the plurality of industrial robots are interchanged.
Industrial robots characterized by different values
Safety equipment.