JPH0436808A - Industrial robot - Google Patents

Abstract

PURPOSE:To easily discriminate the positioning defect of an industrial robot by comparing the counted number of pulses with the set number of pulses and then outputting an abnormality signal if no coincidence is obtained between both numbers of pulses. CONSTITUTION:A 1st detection means 4 outputs a 1st detection signal to a counter means 6 when a mobile object 2 passes through the point of the means 4. When the object 2 reaches the position of a 2nd detection means 5 through an arm 1, the means 5 outputs a 2nd detection signal to the means 6. The means 6 counts the number of pulses which are outputted to a pulse motor 3 from a drive means 8 while the 2nd detection signal is inputted after the 1st detection signal. Then a comparison means 7 compares the number of pulses counted by the means 6 with the set number of pulses. Thus an abnormality signal is outputted only when no coincidence is obtained between both numbers of pulses. As a result, the positioning defect of a robot is decided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an industrial robot, and particularly to a linearly driven industrial robot.

[Prior Art] Conventionally, there has been an industrial robot I, in which a moving body that performs work such as transporting objects is movably attached to an arm that is a guide rail, and this moving body is linearly driven by a pulse motor.
There is.

The moving body and the drive shaft of the pulse motor are connected by a belt drive system, and when the pulse motor rotates, the belt is driven, thereby moving the moving body. This industrial robot controlled the movements necessary for work by numerically controlling the pulse motor that drives the moving body.

[Problems to be Solved by the Invention] In the above-mentioned industrial robot, the teeth of the belt that connects the pulse motor and the moving body are worn out due to long-term use.
There was a problem in that back-crash occurred and the positioning accuracy of the moving body deteriorated.

There is also the problem that positioning errors occur due to tax adjustment when the pulse motor is driven.

[Object of the Invention] In view of the above-mentioned problems, the present invention provides an industrial robot that can quickly detect when a positioning problem occurs due to back crash or step-out of the pulse motor.

[Means for Solving the Problem] As shown in the block diagram of FIG. 1, the industrial robot according to claim 1 of the present invention has a movable body (1) that performs work, etc., and a movable body (1) that moves in a straight line. The arm (2) is a guide rail for moving the body (1), and the pulse motor (1) drives the moving body (1).
3), a driving means (8) that outputs pulses to the pulse motor (3) to drive the pulse motor (3), and an arm (2).
), which detects passage of the moving object (1) with a small error and outputs a first detection signal; and an arm spaced apart from the first detection means (4) by a predetermined distance. (2)
a second detection means (5) that is provided in A counting means (6) for counting the number of pulses outputted from the driving means (8) to the pulse motor (3) during that period compares the number of pulses counted by the counting means (6) with the set number of pulses, and The comparison means (7) outputs an abnormal signal when the number of pulses differs from the set number of pulses.

As shown in the block diagram of FIG. 2, the industrial robot of claim 2 includes a moving body (1) for performing work,
) is a guide rail for linear movement of arm (2
), a pulse motor (3) that drives the moving body (1), a drive means (8) that outputs pulses to the pulse motor (3) to drive the pulse motor (3), and an arm (2). a first detection means (4) provided to detect passage of the moving object (1) with a small error and output a first detection signal;
a second detection means (5) that is provided on the arm (2) at a predetermined distance from the detection means (4) and that detects passage of the moving body (1) with a small error and outputs a second detection signal; A measuring means (9) for measuring the travel time from when the first detection signal is input until when the second detection signal is input;
) compares the measured travel time with the set time and outputs an abnormal signal if the travel time and the set time differ.

The industrial robot according to claim 3 is the industrial robot according to claim 1 or claim 2, in which either the first detection means 4 or the second detection means 5 is provided at the origin of the arm 1. .

[Function] In the industrial robot according to claim 1 of the present invention, the moving body 1 moves the arm 2 linearly by the pulse motor 3 controlled by the driving means 8. When the mobile object 1 passes the point of the first detection means 4, the first detection means 4 outputs a first detection signal to the counting means 6. Furthermore, moving body 1 or arm 2
When it reaches the position of the second detection means 5, this second detection means 5 is moved.
The detection means 5 outputs a second detection signal to the counting means 6. The counting means 6 counts the number of pulses output from the drive means 8 to the pulse motor 3 from the time when the first detection signal is input until the second detection signal is input.

Then, the comparing means 7 compares the number of pulses counted by the counting means 6 and the set number of pulses, and outputs an abnormal signal only when the number of pulses counted by the counting means differs from the set number of pulses.

As a result, when the moving body Y is not moving between the first detection means 4 and the second detection means 5 at the set number of pulses, that is, when the positioning is defective, an abnormality signal is output.

In particular, since the first detection means 4 and the second detection means 5 detect the position of the moving object 1 with a small error, it is possible to detect an error in the distance of the moving object 1 with one pulse, and therefore, even with a single pulse, an error can be detected. If there is, it can be determined that the positioning is defective.

In the industrial robot I according to claim 2, the mobile body 1 is the first
The measuring means 9 measures the travel time from the detecting means 4 to the second detecting means 5, and the comparing means 7 compares the measured travel time with a preset time, and if the two are different. Outputs an abnormal signal only when

As a result, an abnormality signal is output only when the time taken for the movable body I to reach the second detection means 5 from the first detection means 4 is other than the set time, that is, when the positioning is defective.

In the industrial robot according to claim 3, since the first detection means 4 or the second detection means 5 is provided at the origin position of the arm 2, it also serves as the detection means for setting the origin of the moving body 1. be able to.

[Example] Hereinafter, one embodiment of the present invention will be described based on the drawings.

Reference numeral 10 is a Peru Drive type robot of this embodiment, as shown in FIG.

No. n 12 is a frame consisting of a rectangular parallelepiped arm portion 14 and a storage portion 16.

Reference numeral 18 denotes a guide rail provided in the longitudinal direction of the upper surface of the arm portion 14.

Reference numeral 20 is a slider that slides on the guide rail 18. This slider 2 is a moving body as defined in the claims, and is used as a robot I by attaching members necessary for work to the slider 20 that moves in a linear direction. A pair of movable pulleys 22, 24 are provided at the bottom of the slider 20 along the guide rail 18.

Reference numeral 2B denotes a drive pulley, which is provided inside the arm portion 18 on the storage portion 16 side. The drive pulley 2G has irregularities along its circumferential surface, forming a gear.

Reference number 28 is a driven pulley and is provided inside the arm portion 18 at a position opposite to the drive pulley 26. The peripheral surface of this driven pulley 28 is also provided with irregularities.

? No. 1 30 is a stepping motor that drives the drive pulley 26, and is provided inside the storage section 16.

Reference numeral 32 denotes a south-facing belt, the length of which is approximately twice the length required to drive the slider 20. One end 32a of this belt 32 is removably fixed to one end of the arm portion 14 by a pin 36 via a suppressing piece 34. As shown in FIG. 3, this belt 32 is connected to the movable pulley 22 of the slider 20, the driven pulley 28,
The driving pulley 2G and the movable pulley 24 are hung in this order and are removably fixed to the storage section 16 side of the arm section 4 via a pressing piece 38 with a bolt 40. The belt 32 as a whole has an Ω-shaped loop.

Reference numeral 42 denotes a first uri-set switch provided at a portion of the guide rail 18 through which the slider 20 passes. This first
When the slider 20 passes, the reset switch 40 switches to the first
It outputs a detection signal.

Reference numeral 44 denotes a second reset switch provided on the guide rail 18 at a predetermined distance from the first reset switch 42. This second reset switch 44 also outputs a second detection signal when the slider 20 passes therethrough.

Next, the control structure of this robot 10 will be explained using the block diagram shown in FIG.

Reference numeral 4G is a driver circuit that outputs pulses to the stepping motor 30 to drive it.

Reference numeral 48 denotes a microcomputer (hereinafter referred to as microcomputer), which is internally equipped with an I10 port CPU and memory. A driver circuit 46, a first reset switch 42, and a second reset switch 44 are connected to the microcomputer 48.

Reference numeral 50 denotes an operation box for operating the microcomputer 48. A liquid crystal section 52 provided on the front side determines the operation status, and keys 54 are used to perform the operation.

Reference numeral 56 denotes an external controller, and the microcomputer 48 can also be operated from this external controller 56.

Reference numeral 58 denotes an alarm device, which is configured to sound a buzzer when an abnormal signal is output from the microcomputer 48.

The detection accuracy of the first reset switch 42 and the second reset switch 44 is set to be smaller than the distance that the slider 20 moves with one pulse (for example, Q, 1
．． (within ml). As a result, if there is an error in the ] pulse, it can be determined that the positioning is defective.

In the robot 10 having the above configuration, the functions of the first reset switch 42 and the second reset switch 44 when the slider 2° is moving will be explained with a focus on the microcomputer 48 (see the flowchart in FIG. 6).

In the following explanation, the set time refers to the normal time it takes for the slider 2o to move from the position of the first reset switch 42 to the second reset switch 44, and this set time is the time taken by the microcomputer 48. Enter in advance. Also, the waiting time is the time when the slider 20 first moves.
This shows the normal time it takes for the slider 2o to reach the position of the first reset switch 42. This waiting time is also input into the microcomputer 48 in advance. The moving time is the time from when the first detection signal is input until the second detection signal is input, that is, the time it takes for the slider 20 to move from the first reset switch 42 to the second reset switch 44 position. It shows. At this time, fljl is measured by multiplying the number of pulses output from the driver circuit 46 to the stepping motor 30 between the input of the first detection signal and the input of the second detection signal by the frequency of the pulse. This is the calculated value.

In step 1, the slider 20 passes the position of the first reset switch 42, and the first detection signal is output to the microcomputer 4B.
Determine whether you have entered the .

If the information has been entered, proceed to step 2; if not, proceed to step 4.

In step 2, if the slider 20 passes the position of the second reset switch 44 and the second detection signal is input to the microcomputer 48, the process proceeds to step 3; if not, the process proceeds to step 6.

In step 3, if the time from the input of the first detection signal to the input of the second detection signal, that is, the travel time, is the same as the set time, the process returns to step 1, and if the time exceeds the set time, If it is shorter, proceed to step 7.

In step 4, if the waiting time has not elapsed,
Return to step 1, and if the waiting time has elapsed, proceed to step 5.

In step 5, the microcomputer 48 outputs an abnormal signal and the alarm device 58 does not sound the buzzer.

In step 6, if the set time has not elapsed, return to step 2; if the set time has elapsed, step 7
Proceed to.

In step 7, the microcomputer 48 outputs an abnormal signal and the alarm device 58 does not sound the buzzer.

As a result of the above, the stepping motor 30 may be out of step and the belt 3
If a positioning failure occurs due to the back crash in step 2, the travel time and set time will no longer match, and the alarm device 32 will sound a buzzer. Therefore, the administrator of this robot 10 can easily determine the positioning failure.

Furthermore, since it is possible to install the first reset switch 42 and the second reset switch 44 at any position on the arm section 14, these two switches 42 and 44 are located at a position on the arm section 14 where the slider 20 always passes during work. By attaching it to the camera, it is possible to constantly monitor for positioning errors.

Note that the alarm device 58 is not limited to a buzzer, and may have other structures such as a blinking light, automatic stopping of the slider 20, etc.

- In the embodiment described above, the set time and the moving time were compared, but instead of this, the number of pulses output between the first reset button 42 and the second reset switch 42 and the number of pulses set in advance are compared. Defective positioning can also be determined by comparing the number of pulses.

Furthermore, if either the first reset switch 42 or the second reset switch 44 is attached to the origin position of the arm 14, limited positioning can be performed at the same time.

According to the "Effects of the Invention", in the robot of claim 1, if a positioning failure occurs due to a pulse motor adjustment or a back crash, the counted pulse number and the set pulse number will differ, and an abnormal signal will be output. Ru. This makes it easy to determine whether the robot is positioned incorrectly.

Also in the robot of the second aspect, if a positioning failure occurs, the set time and the movement time are different and an abnormality signal is output, so that the positioning failure can be easily determined.

Furthermore, in the double-duty robot according to claim 1 or claim 2, if the first detection means and the second detection means are provided at a position of the arm through which a moving object always passes during work, positioning errors can be constantly monitored. be able to.

In the industrial robot according to the third aspect, since either the first detection means or the second detection means is provided at the origin, the origin can also be positioned.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an industrial robot according to claim 1 of the present invention, FIG. 2 is a block diagram of a robot according to claim 2, and FIG. 3 shows an embodiment of the present invention. FIG. 4 is a block diagram of the robot, FIG. 5 is a perspective view of the robot, and FIG. 6 is a microcomputer flowchart 1 for detecting poor positioning.・It is. [Explanation of symbols] 10...Robot 12...Frame 14...Arm portion 20...Slider 30...Stepping motor 32... ... Belt 42 ... First reset switch 44 ...
・Second reset switch 46...Driver circuit 48...Microcomputer 58...Alarm device

Claims (1)

[Claims] 1. A moving body (1) that performs work, etc., an arm (2) that is a guide rail for linear movement of the moving body (1), and a pulse motor that drives the moving body (1). (3), a drive means (8) that outputs pulses to the pulse motor (3) to drive the pulse motor (3), and a drive means (8) provided on the arm (2) to detect the passing of the moving object (1) with a small error. a first detection means (4) that outputs a first detection signal using an arm;
2), which detects passage of the moving object (1) with a small error and outputs a second detection signal; and a second detection signal is input after the first detection signal is input. The counting means (6) counts the number of pulses output from the driving means (8) to the pulse motor (3) during the period, and compares the number of pulses counted by the counting means (6) with the set number of pulses. and comparing means (7) for outputting an abnormal signal when the number of pulses differs from the set number of pulses. 2. A moving body (1) that performs work, etc., an arm (2) that is a guide rail for moving the moving body (1) in a straight line, and a pulse motor (3) and a pulse motor that drive the moving body (1). (3) to drive the pulse motor (3) by outputting pulses to the arm (2); A first detecting means (4) for outputting an output, and an arm (
2), which detects passage of the moving object (1) with a small error and outputs a second detection signal; and a second detection signal is input after the first detection signal is input. The measuring means (9) measures the traveling time of the mobile object (1) until An industrial robot comprising: comparison means (7) that outputs an abnormal signal when the robot is in use. 3. The industrial robot according to claim 1 or 2, characterized in that either the first detection means (4) or the second detection means (5) is provided at the origin of the arm (1). .