JPH07276272A - Origin indexing device - Google Patents

Abstract

PURPOSE:To perform indexing operation of an origin without being influenced from the operation speed set in the other program by providing a speed setting means apart from a usual operation command, in the case of origin indexing even if there is an operation command. CONSTITUTION:In a six-shaft type articulated robot, when origin indexing of a first arm is performed against a rotator (holding part) containing a shoulder part 12a, the first arm 1 is moved in the minus direction (A-direction) by a first target distance by means of a robot control device 50. In the midst of the movement, it is judged whether an ON signal indicating contact of the extreme end of a probe 32 with the inner wall 21a of a reference hole 21 is detected from a relay 33 or not, so as to control to stop the first arm 1, and the stop position is read by an encoder 52 and stored in RAM 53. Next the first arm 1 is moved in the reverse direction until the extreme end of the probe 32 abuts to the inner wall 21b of the reference hole 21, and the stop position at that time is read and stored, and the origin of the first arm is computed from the stored two stop positions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot origin indexing device using a plug gauge.

[0002]

2. Description of the Related Art A commonly used articulated robot needs to store reference coordinates, and it is necessary to index each arm to a mechanical origin prior to this storage. As this origin indexing device, there is a device as disclosed in Japanese Patent Laid-Open No. 04-275888. This is provided with a first reference hole and a second reference hole in each of the movable portion and the holding portion of the robot, and a rod-shaped body fitted in the first reference hole, and a second reference hole attached in the rod-shaped body. A plug gauge consisting of a probe inserted into the reference hole is used. By fitting such a plug gauge into the first reference hole of the holding part and moving the movable part of the robot, the conduction signal when the probe contacts the movable part is detected and the position of the origin is calculated. It is a thing.

[0003]

Such an automatic origin indexing device has an effect that the plug gauge can be easily inserted as compared with a non-electric type device in which the plug gauge is simply inserted, but the cost is high. Become. In addition, in the case of a 6-axis robot, there are 6 locations that need origin indexing. Therefore, six plug gauges were needed. Therefore, there is a problem that the cost is further increased and the work takes time.

On the other hand, the program for performing the origin index is stored in advance in the ROM, and the origin index is automatically executed by pressing a switch provided in the operating box. However, the operation command of the program for performing the origin index is internally processed in the same manner as the operation command of the user program created by the operator. Therefore, the same speed determination routine is used when executing these operation commands. However, the operating speed at this time is changed by the operator setting the command speed on the user program. Therefore, when the operator presses the button on the operating box to perform the home position indexing, the operation speed at the time of home position indexing changes depending on the command speed set in the previously executed operation program and is constant. There are cases where it is not. However, even in such a case, since a safety process for reducing the operation speed is performed with respect to a command from the operating box, the plug gauge may be damaged although it is not a great risk. Also, the fluctuation of the operating speed is the second with the plug gauge.
This causes variation in the timing of contact with the reference hole and the generation of the conduction signal, resulting in deterioration of the accuracy of the origin index. Especially, when the stop position is stored as the position where the conduction signal is generated after stopping the movable part to prevent the plug gauge from being damaged, the difference in the operating speed appears as the difference in the stop position. It is likely to cause deterioration of output accuracy.

The present invention has been made in order to solve the above problems, and an object thereof is to provide an origin indexing device in which the moving speed of a movable part is appropriate at a low cost.

[0006]

The present invention has been made to solve the above-mentioned problems, and the means described in claim 1 includes at least one movable part driven by a driving device. The plurality of movable parts of the robot provided and the first and second reference holes respectively formed in the holding part that holds the movable parts so as to be movable relative to each other When the tubular body portion of the plug gauge including the probe mounted in the tubular body portion is inserted into the first reference hole and the movable portion is moved relative to the holding portion, the probe is moved to the second In the origin indexing device for indexing the plurality of movable parts to the mechanical origin by detecting the contact with the reference hole, it is determined whether or not the origin index is executed by being activated in response to the operation command. means When the determination means determines that the origin index is to be executed, the first operation speed determination means determines the operation speed of the movable portion at the time of origin indexing, and the origin determination must be executed by the determination means. When it is determined, it is determined by the second operating speed determining means for determining the operating speed of the movable part based on the set speed preset on the program, and the first and second operating speed determining means. An operation command executing means for moving the movable body according to the operation command according to an operation speed.

The means described in claim 2 is provided in the movable part of the robot having a plurality of movable parts driven by a driving device, and a holding part for holding the movable parts so as to be relatively movable. The first and second reference holes provided are overlapped with each other, and the tubular body portion of the plug gauge including the tubular tubular portion and the probe mounted in the tubular portion is inserted into the first reference hole. Then, when the movable part is moved relative to the holding part, the probe moves to the second
In the origin indexing device for indexing the movable part to the mechanical origin by detecting the contact with the reference hole of
At least two of the plurality of first reference holes of the robot have the same diameter, and a mark indicating the depth of each of the first reference holes of the same diameter is provided on the cylindrical portion of the plug gauge, A retaining member is provided at a portion of the cylindrical body portion that is inserted into the first reference hole having the same diameter.

[0008]

According to the first aspect of the present invention, the determination means determines whether or not the operation command to be executed is for origin determination in correspondence with the operation command. Then, when it is determined that it is for origin indexing, the first operation speed determining means determines the dedicated speed for origin indexing as the operation speed. Further, when it is determined that the operation command is not for origin determination but an operation command by a normal program, the second operation speed determination means determines the operation speed based on the set speed preset on the program. . When the operation speed is thus determined, the operation command executing means moves the movable body according to the operation command in accordance with the operation speed.

According to a second aspect of the present invention, at least two of the plurality of first reference holes of the robot have the same diameter, so that the plug gauge can be made common, and The difference in the depth of the reference holes makes it possible to adjust the insertion amount of the plug gauge by providing the marks indicating the respective depths. In order to prevent the amount of insertion into the first reference hole from becoming smaller than the entire length of the plug gauge, and to prevent the plug gauge from coming off easily, the portion to be inserted into the first reference hole is provided with a retainer. By providing the member, it is possible to prevent the plug gauge from falling off when indexing the origin.

[0010]

Embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the robot provided with the origin indexing device of this embodiment is a 6-axis articulated robot, and includes a base 11 mainly placed on the floor and the base 1.
1, a rotator 12 rotatably attached about a vertical axis, a first arm 1 rotatably supported on the rotator 12 about a horizontal axis 100, and a first arm 1 at its tip about a horizontal axis. The second arm 2 is supported so as to be capable. The above structure constitutes the 1, 2 and 3 axes.
The second arm 2 is provided with rotating parts that form the four, five, and six axes, although it will not be described in detail because it has the same structure as a general robot.

Since the robot described above has six axes, it has six origin indexing positions. In this embodiment, the origin indexing of the first arm 1 with respect to the rotator 12 will be described. FIG. 3 is a sectional view taken along line CC of FIG. A servo motor 122 that rotates the rotator 12 is installed in the rotator 12. The rotator 12 has a bifurcated shape with shoulders 12a and 12b. The first arm 1 is supported by the shoulder portions 12a and 12b.
Both ends are supported by b. Of these, the support portion 1a is supported by the shoulder portion 12a via the rotating shaft 15, and the support portion 1b is
It is supported by the shoulder portion 12b via a rotary shaft 16. The rotary shaft 15 and the rotary shaft 16 rotate coaxially around the axis 100. The rotating shaft 15 has a gear 17 for transmitting the driving force of a servo motor for driving the first arm (not shown),
It is fixed to the support portion 1a. The rotary shaft 16 is a second not shown
Gear 1 for transmitting driving force of arm driving servo motor
8 and 19, the support portion 1b is rotatably supported.

As shown in FIGS. 2 and 3, the first arm 1
A first reference hole 20 for indexing the origin of the first arm 1 with respect to the rotator 12 is formed in the supporting portion 1a of the above. Further, the shoulder portion 12a of the rotator 12 has a second reference hole 21 corresponding to the first reference hole 20 when the origin is indexed.
Has been drilled. Next, the plug gauge of this embodiment will be described with reference to FIG. In FIG. 4, (a) is 1, 2, 3
A plug gauge 30 used for a shaft, (b) is
It is a plug gauge 60 used for 4, 5 and 6 axes.

In FIG. 4 (a), a plug gauge 30 includes a cylindrical body portion 31 and a cylindrical body portion 3 which are cylindrical members made of metal.
Made of thin rod-shaped metal (electric conductor) with the end attached inside 1.
The probe 32 of FIG. The cylindrical body portion 31 and the probe 32 are made of a silicone rubber adhesive layer (insulator) 40.
And the cylindrical body portion 31 and the probe 32 are in an insulating relationship. Thus, the cylindrical body portion 31
Wear of the plug gauge can be reduced by making the plug metallic. Also, the silicone rubber adhesive layer 4
The reason for providing 0 is not only to insulate the cylindrical portion 31 and the probe 32 from each other, but also the probe 32 to the second reference hole 2
It absorbs the impact when it contacts the inner wall of
The probe 3 is caused by a positioning error of the arm 1 (movable part).
2 has the effect of reducing the bending stress.

An O-ring 35 is attached near the tip of the outer periphery of the cylindrical body portion 31 so as to act as a retainer when the plug gauge 30 is inserted into the first reference hole 20. Marking grooves 36a, 36b, 36c are sequentially formed on the outer periphery of the cylindrical body portion 31. This is a measure of the depth when the plug gauge 30 is inserted into the reference holes of the 1, 2, and 3 axes of the robot. That is, the reference holes of the 1, 2 and 3 axes have the same diameter but different depths. Therefore, in order to use the plug gauge 30 in common, the mark groove 36a indicates the depth of the biaxial, the mark groove 36b indicates the uniaxial, and the mark groove 36c indicates the triaxial depth of the reference hole. Also,
The diameter of the cylindrical body portion 31 is within the first reference hole 20.
Are set so that they can be fitted accurately.

Further, as shown in FIG. 5, the probe 32 is
The tip is adapted to protrude from the cylindrical body portion 31. In this plug gauge 30, the probe 32 has the second reference hole 21.
It plays the role of a continuity sensor that detects the contact with the inner wall of the. That is, the probe 32 and the shoulder 12a of the rotator 12 are connected via the relay 33 and the power source 34,
The conduction signal from the relay 33 is sent to the robot controller 50.
Is being communicated to. Robot controller 50
Includes a CPU 52 connected to the relay 33 via the interface 51, a ROM 54 storing a robot position control program and an origin indexing program, a RAM 53 storing robot teaching data and the like, and each drive axis of the robot. Servo CPU 5 that controls the servo motor to drive
It consists of 5.

An operating box 56 is connected to the CPU 52 via the interface 51 to perform robot teaching work and origin indexing work. The servo motor 58 that rotationally drives the first arm 1 is a servo CPU 55.
This absolute rotation angle is controlled by the encoder 57.
Is detected by this and this value is fed back to the servo CPU 55. This encoder 5
Although 7 uses an absolute encoder, it is also possible to use an incremental encoder.

The probe 32 and the relay 33 described above are also provided.
The cord 42 for connecting to is attached via a connection terminal 41 (for example, a pin jack). This is 1,
Plug gauge 30 used for 2, 3 axes, 4, 5,
This is because the plug gauge 60 used for 6 axes can be easily replaced. Since the plug gauge 60 used for the 4, 5 and 6 axes shown in FIG. 4B has substantially the same configuration as the plug gauge 30, corresponding members have the same names and only different points will be described. . The diameter of the cylindrical body portion 61 of the plug gauge 60 is 1, 2,
Since the diameter of the triaxial reference hole 20 is different from the diameter of the 4, 5, 6-axis reference hole 20, the diameter is smaller than the diameter of the cylindrical body portion 31. Further, the mark groove 6 formed behind the O-ring 65
6a corresponds to the depth of the 4-axis reference mark groove and 66b corresponds to the depth of the 6-axis reference hole. A step portion 66c is formed behind the cylindrical body portion 61, and the step portion 66c corresponds to the depth of the 5-axis reference hole. Although the description is omitted because it has the same configuration as the plug gauge 30, 62 is a probe,
Is a silicon rubber adhesive layer that insulates the cylindrical portion 61 and the probe 62 from each other.

As described above, by making the plug gauge 30 common to a plurality of shafts, the amount of insertion into the first reference hole 20 is shortened with respect to the entire length of the plug gauge, and the plug gauge during automatic operation is reduced. There is a possibility that 30 may easily fall out. However, since the O-ring 35 functions as a retaining member, it is possible to prevent the plug gauge from falling off during indexing. Further, the retaining member is not limited to the O-ring 35, and a band-shaped rubber member may be used, or a plurality of grooves may be provided at the tip portion of the plug gauge 30.

Further, in the above-described embodiment, the mark grooves 36a, 36 are used as a guide for the depth of the first reference hole 20.
Although b, 36c, 66a, 66b and the stepped portion 66c are used, they may be used as a mark by simply drawing a line. Next, the operation of the origin indexing device of this embodiment will be described. In addition, here, a case will be described in which the origin of two axes is determined by the plug gauge 30. In indexing the origin of the first arm 1 with respect to the rotator 12, the operator moves the first arm 1 by the JOG operation using the operating box 56 to move the first reference hole 20 and the rotator 12 on the first arm 1 side. The second reference holes 21 on the side are substantially aligned with each other. Then, the operator inserts the plug gauge 30 from the first reference hole 20 toward the second reference hole 21. At this time, marking grooves 36a, 36b, 36c are formed in the cylindrical body portion 31, and the one corresponding to the two axes is the marking groove 36a. Therefore, the cylindrical body portion 31 is fitted into the first reference hole 20 to the depth of the mark groove 36a. At this time, the second reference hole 2
Only the tip end of the probe 32 protruding from the cylindrical body portion 31 is inserted into 1. Here, the protruding probe 32
Since the tip end of is extremely smaller than the diameter of the second reference hole 21, the accuracy of the above-mentioned alignment of the first reference hole 20 and the second reference hole 21 by the operator is not so required.

When the above work is completed, the operator instructs the robot controller 50 to start the origin indexing work from the origin indexing switch on the operating box 56. At this time, the operator uses the switch on the operating box 56 to index the origin (two axes in this case).
Is also specified. As a result, the CPU 52 causes the ROM
The following processing is performed based on the origin indexing program stored in 54.

In step 200, the first arm 1 is moved in the negative direction (direction A) by a preset first target distance. During this movement, it is judged in step 202 whether or not the conduction signal indicating that the tip of the probe 32 has come into contact with the inner wall 21a of the second reference hole 21 is detected from the relay 33. If the signal from the relay 33 is detected in step 202 and the tip of the probe 32 comes into contact with the inner wall 21a of the second reference hole 21 (YES),
Go to step 204. Further, if the conduction signal from the relay 33 is not detected even after moving by the first target distance (NO), it is considered that the plug gauge 30 is abnormal or the like, so the routine proceeds to step 220, and an error is issued to the operating box 56. Display and exit.

In step 204, the continuity signal is relay 3
The first arm 1 is stopped at the position detected from 3. In step 206, the position where the first arm 1 is stopped in step 204 is read by the encoder 57, and this position is stored in the RAM 53 as J1. Step two
In 08, the first arm 1 is moved in the plus direction (B direction) by the second target distance in the opposite direction to step 200.
During this movement, the tip of the probe 32 moves to the second reference hole 2
The inner wall 21b of the side opposite to the above-mentioned step 202 of 1
In step 210, it is determined whether or not the conduction signal indicating that the contact has been detected is detected from the relay 33. Step 21
At 0, the signal from the relay 33 is detected, and the probe 3
If the tip of No. 2 contacts the inner wall 21b of the second reference hole 21 (YES), the process proceeds to step 212. Further, if the conduction signal from the relay 33 is not detected even after moving by the second target distance (NO), there is a possibility that the plug gauge 30 is abnormal or the like, so the process proceeds to step 220 and an error is displayed in the operating box 56. And finish.

In step 212, the continuity signal is relay 3
The first arm 1 is stopped at the position detected from 3. In step 214, the position where the first arm 1 is stopped in step 212 is read by the encoder 57, and this position is stored in the RAM 53 as J2. Step two
In step 16, the origin JT of the first arm 1 is calculated from the positions J1 and J2 stored in step 206 and step 212 by the following equation and stored.

JT = (J1 + J2) / 2 At step 218, the first arm 1 is positioned at the position JT stored at step 216, and the origin indexing operation is completed. The first target distance and the second target distance described above are set to be larger than the distance at which the conduction signal is actually generated based on the diameter of the second reference hole 21.

In the above-described origin indexing process,
Step 200, Step 208 and Step 218
When executing the operation command, the operation speed determination program described below is executed. This operation speed determination program is an operation command (M
It is also activated when executing an OVE instruction or the like).

In step 300, it is determined whether or not the operation command currently executed is an operation command for origin determination. That is, if the command is a normal execution command instead of an operation command for indexing the origin (NO), steps 302 to 310.
The conventional speed determination shown in is performed. Further, if the operation command is to perform origin indexing, that is, if the origin indexing switch on the operating box 56 is pressed and the flag indicating origin indexing is set (YES),
Go to step 314.

First, the conventional speed determination shown in steps 302 to 310 will be described. Step 302
Then, the operation speed which is the reference of all the operations is determined. This is determined by the product of MAX speed and override value. The MAX speed is a value determined from the capability of the servo motor that the robot has on each axis, and the override value is the ratio that determines the maximum speed at which the robot actually operates and is shown as a ratio to the MAX speed. The operator can change the operating box 56 appropriately.

In step 304, it is judged whether the currently executed execution instruction is not the automatic execution state based on the program but the execution of the individual operation instruction using the operating box 56. In this case, there are cases where the JOG operation is performed by the operating box 56, and cases where the operation command in the user program is individually designated and executed. If it is not the execution of individual operation commands using the operating box 56 but the automatic execution state based on the user program (NO), step 306 is skipped and the process proceeds to step 308. Further, in the case of executing an individual operation command using the operating box 56, (Y
ES), and proceeds to step 306.

In step 306, the speed for individual operations using operating box 56 is determined.
When the operating box 56 is used, it is usually time to check the operation locus, so it is necessary to set the speed lower than that when the user program is automatically executed. Therefore, the operating speed is newly determined by adding the OB speed to the operating speed determined in step 302. The OB speed is expressed as a ratio to the operation speed determined in step 302, and can be changed by the operator from the operating box 56.

At step 308, it is determined whether the currently executed execution instruction is an operation instruction based on the user program. Here, operating box 56
If the operation command is not based on the user program (NO), step 3
Skip 10 and end the speed determination process (step 3).
12). If the operation command is based on the user program (YES), the process proceeds to step 310.

In step 310, the operation speed during program execution is determined by multiplying the operation speed determined in step 302 or step 306 by the command speed set in the user program. This command speed is expressed as a ratio to the operation speed determined in step 302 and is set in the user program.

On the other hand, in step 314, the speed setting for origin indexing is performed separately from the operation speed determination described above. This is determined by the product of MAX speed and parameter value. What is MAX speed? Step 30
The same robot as 2 is a value determined from the ability of the servo motor in each axis, and the parameter value is shown as a ratio to the MAX speed, so that the operator can change it appropriately from the operating box 56. Has become.

As described above, in the origin indexing work, the speed is set separately from the operation command of the program in step 310. Therefore, the movement speed of the robot at the time of origin index is not influenced by the operation speed of the program executed immediately before. In this embodiment, the movable part is the first arm 1 and the holding part is the rotator 12. The holding portion does not necessarily have to be fixed, and may be another positionable movable portion that supports the movable portion (first arm 1) like the rotator 12 of this embodiment. That is, as long as it can be positioned through the other movable portion, it can be positioned on the fixed portion as a result.

In this embodiment, the first arm 1 which is a movable part.
The first reference hole 20 is formed in the rotator 12 and the second reference hole 21 is formed in the rotator 12 which is the holding portion, and the plug gauge 30 is inserted from the movable portion side. On the contrary, the second reference hole may be formed in the movable portion, the first reference hole may be formed in the holding portion, and the plug gauge may be inserted from the holding portion side.

[0035]

As described above, according to the robot origin indexing apparatus of the present invention, the means described in claim 1 is different from the normal operation command in the case of origin command even if it is an operation command. By providing the speed setting means, it is possible to perform the origin indexing work without being affected by the operation speed set by another program. Therefore, since the moving speed of the movable portion is always appropriate, the safety of the origin indexing device can be improved. In addition, since it is possible to prevent variations in the timing of generation of the conduction signal and the stop position of the movable part due to the difference in operation speed, the accuracy of origin determination is improved.

According to the second aspect of the present invention, at least two of the plurality of first reference holes of the robot have the same diameter, so that the plug gauge can be made common. At this time, with respect to the difference in depth of the first reference hole, the amount of inserting the plug gauge can be adjusted by providing a mark indicating each depth. In such a case, since the amount of insertion into a certain first reference hole is shorter than the entire length of the plug gauge, it may be easier to pull out during automatic operation. The plug gauge can be prevented from slipping off when the origin is indexed by providing a retaining member in the portion to be removed. Therefore, the origin can be automatically indexed with the plug gauge inserted in the first reference hole. Further, by making the plug gauge common, it is not necessary to replace the plug gauge for each drive axis of the robot, so that the work of indexing the origin can be performed efficiently and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a side view of a robot of this embodiment.

FIG. 2 is a rear view of the robot of this embodiment.

FIG. 3 is a sectional view taken along line CC of FIG.

FIG. 4 is a diagram showing a plug gauge of the origin indexing device of the present embodiment.

FIG. 5 is a diagram showing an electrical configuration of an origin indexing device of the present embodiment.

FIG. 6 is a flow chart for explaining the operation of this embodiment.

FIG. 7 is a flow chart for explaining the operation of the present embodiment.

[Explanation of symbols]

 1 1st arm (movable part) 12 Rotator (holding part) 20 1st reference hole 21 2nd reference hole 30 Plug gauge 31 Cylindrical body part 32 Probe 33 Relay 35 O-ring 36 Mark groove 57 Encoder 58 Servo motor

Front Page Continuation (72) Inventor, Hiromasa, 1-1, Asahi-cho, Kariya city, Aichi prefecture, Toyota Koki Co., Ltd. (72) Inventor, Kenichi, Fukuoka, 1-1, Asahi-cho, Kariya city, Aichi prefecture Toyota Koki Co., Ltd.

Claims (2)

[Claims] 1. A first and second movable member of a robot having at least one movable member driven by a driving device, and first and second holes respectively formed in a holding member that holds the movable member in a relatively movable manner. The plug hole is overlapped with the reference hole, and the tubular body portion of the plug gauge including the tubular tubular portion and the probe mounted in the tubular body portion is inserted into the first reference hole, and the movable portion is held by the holding portion. In the origin indexing device for indexing the movable part to the mechanical origin by detecting that the probe comes into contact with the second reference hole when moved relative to the origin, Judgment means for judging whether or not to execute indexing, and a first operation speed determination for deciding an operation speed of the movable part at the time of origin indexing when it is judged by this judgment means to execute origin indexing. Determining means, and second operation speed determining means for determining the operation speed of the movable part based on a preset speed set on a program when the determining means determines not to execute the origin indexing; An origin indexing device comprising: an operation command executing means for moving the movable body according to the operation command in accordance with the operation speeds determined by the first and second operation speed determining means. 2. A first and a first hole respectively provided in the plurality of movable parts of a robot having a plurality of movable parts driven by a drive device, and a holding part which holds these movable parts in a relatively movable manner. The two reference holes are superposed on each other, and the tubular body portion of the plug gauge including the tubular tubular body portion and the probe mounted in the tubular body portion is inserted into the first reference hole, and the movable portion is inserted into In the origin indexing device for indexing the plurality of movable parts to the mechanical origin by detecting that the probe comes into contact with the second reference hole when the probe is moved relative to the holding part, a plurality of robots included in the robot are provided. At least two of the first reference holes of the plug gauge have the same diameter, and a mark indicating the depth of each of the first reference holes of the same diameter is provided on the cylindrical portion of the plug gauge. The same diameter first 1. An origin indexing device, characterized in that a retaining member is provided in a portion to be inserted into the reference hole 1.