JPS5997895A - Detector for position of work of robot - Google Patents

Abstract

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

Description

[Detailed description of the invention] The present invention relates to a work position detector for a robot.

In assembly robots that are being put into practical use these days, an important issue is how to quickly and skillfully perform fastening operations, parts insertion operations, etc. repeatedly without failure.

For example, in the case of fastening work, an automatic screw tightening machine that automatically supplies screws can be gripped by a mechanical hand attached to the tip of a robot's movable part, or it can be attached directly to the tip of a robot's movable part and the automatic screw tightening machine automatically supplies screws. It is conceivable to accurately position the tip of the screw driver over the screw hole of the workpiece, and then lower the automatic screw driver vertically to perform the screw tightening work.

However, in order to perform this work effortlessly and quickly, it is necessary to improve the repeatability of the robot, but also to improve the screw hole position of the workpiece supplied to the robot's work position and the robot's positioning position (target position). must always match, otherwise there is a high probability that the screw tightening operation will fail.

Therefore, when teaching the robot as a countermeasure to the above problem, the robot is moved by remote control using a teaching box, for example, so that the tip of the automatic screw tightening machine that the robot can access is positioned over the screw hole position of the workpiece. It is necessary to collect position data for positioning.

However, it is very difficult to carry out the above-mentioned teaching with unparalleled accuracy, and even if it is possible, it not only requires a high degree of skill, but also has the disadvantage that it is very time-consuming.

Therefore, the present applicant first provided a working position detecting means capable of detecting the working position of the screw hole, etc. of the workpiece as described above at the working end of the robot, and this working position detecting means includes the above-mentioned working position. A robot teaching device (Japanese Patent Application No. 57-91462) that automatically scans a predetermined area and stores the current position of the robot when the working position detecting means detects the working position of the robot. The proposed method allows teaching to be performed relatively easily, accurately, and quickly.

Therefore, an object of the present invention is to provide a robot work position detector suitable for such a robot teaching device.

Therefore, the robot work position detector according to the present invention has a main body that can be attached to the tip of the movable part of the robot.
A movable detecting body is provided, the detecting body is always urged in a direction away from the main body by an elastic body, and a working position detecting section for detecting the working position of the robot is provided at the tip of the detecting body, Further, either the main body or the detecting body is provided with a retreat detecting means for detecting that the detecting body has retreated by a predetermined distance with respect to the main body.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the state of teaching of a horizontal articulated robot to which the present invention is applied.

In the figure, a horizontal articulated robot 1, also called 5CARA type, has a column 3 fixed upright on a base 2, and an elevating section 4 that moves up and down in the direction of arrow Z with respect to the column 3. , a first arm 5 that rotates in the direction of arrow θ1 on the x-y plane with respect to this elevating part 4, and a first arm 5 that rotates in the direction of arrow θ2 on the x-y plane with respect to this 3-first arm 5. The shaft is constituted by a second arm 6 that rotates, and a wrist portion 8 that is attached to an end plate 6a of the second arm 6 and that has a base 7a of a working position detector 7, which will be described later, rotatably attached via a bearing. There is.

The lifting section 4 is driven in the direction of arrow Z by the motor M1 attached to the column 3 via the speed reducer GBI and the rotation-linear motion conversion mechanism in the column 3. 4 is driven in the direction of arrow θ1 via a speed reducer GB2.

Further, the second arm 6 is driven in the direction of arrow θ2 by a motor M3 attached to the first arm 5 via a speed reducer GB3.

Note that PG1 to PG3 are pulse generators attached to the output shafts of the respective motors M1 to M3, and are connected to the elevating section 4 and the first. The movement positions of the second arms 5 and 6 are detected.

Moreover, the elevating part 4 and the first. A toothed booby IJPU1゜4-PU2 rotatably attached to the connecting shaft of the second arms 5 and 6, and a toothed pulley PU fixed to one of the bases 7a.
Toothed bells) VTt and VT2 are installed between the first and third bells, respectively. The second arms 5 and 6 are respectively indicated by the arrow θ1. Even when turning in the θ2 direction, the posture of the work position detector 7 remains constant.

Although it is not necessary to keep the posture of the working position detector 7 constant in the direction of the rotational force □, if a mechanical hand or the like is attached to the wrist portion 8, the above-mentioned mechanism is required.

Then, on the front side of this horizontal articulated robot 1, an automobile instrument panel 10, in which a glove box lid 12 is temporarily installed in a glove box 11, is transported from the direction of arrow Y and stopped at the position shown in the figure for a predetermined period of time. , a work conveyor 9 is installed to convey the work downstream.

The instrument panel 10 is clamped on the conveyor 9, and the glove box lid 12 is provided with holes 12a into which tapping screws are inserted, as shown in an enlarged view in FIG.

Each hole 12a of this glove box lid 12
The glove box 1 shown in FIG.
A light emitter 14 in which a light emitting diode 13 is embedded is fitted into each hole 11a on the first side during teaching.

In FIG. 3, the light emitter 14 is provided with an aperture 14a that narrows down the light emitted from the light emitting diode 13, and the aperture 14a is located at the center of the holes 11a and 12a.

Next, referring to FIGS. 4(a) and 4(b), the working position detector 7
An example will be explained.

In FIGS. 4(a) and 4(b), a toothed boo is fixed to the lower end of the base 7a! The outer cylinder 7b is attached to the J PU3 using the mounting hole 7d of the flange 7c provided at one end of the outer cylinder 7b.
It is fixed by T.

The outer cylinder 7b and the base 7a constitute the main body of the working position detector 7.

Inside the outer cylinder 7b, there are two directions: the direction of arrow M, which is the direction in which the inner cylinder 7e as a detection object advances outward from the outer cylinder 7b, and the outer cylinder 7.
It is inserted so as to be slidable in the direction of arrow N, which is the direction of retreating toward the inside of the outer cylinder 7b, that is, in the axial direction of the outer cylinder 7b,
The inner cylinder 7e is advanced to the illustrated position in the direction away from the outer cylinder 7b by the biasing force of a coil spring 7f, which is an elastic body.

Further, the light receiving end face 15a of the optical fiber 15 serving as a working position detection unit is attached to the tip of the inner cylinder 7e in an exposed manner. A hood 7h having an aperture lower 2 for improving detection accuracy by narrowing down the light input to the end face portion 15a is fixed with screws 71.

A known proximity switch 16 as a backward detection means is attached to the frame portion 7j inside the outer cylinder 7b, and this proximity switch 16 moves the inner cylinder 7e to the outer cylinder 7b by a predetermined distance indicated by the arrow N. When the dog 71, which is attached to the large diameter portion 7k at one end of the inner cylinder 7e, approaches the inner cylinder 7e, it is turned on.

In addition, in the same figure, 7m is a retaining ring for preventing the inner cylinder 7b from being pulled out, 7n is a screw for fixing to the dog 7 and for preventing rotation of the inner cylinder 7b, and one side of the inner cylinder 7b is It is loosely fitted into a long hole 7p bored in the hole 7p.

After the optical fiber 15 once exits from the inner tube 7e, it is guided to a detection circuit provided within the upper end of the base 7a, and the lead wire 16a of the proximity switch 16 once exits from the outer tube 7b. Thereafter, it is guided to a control device, which will be described later, through each movable part of the robot.

The detection circuit is configured as shown in FIG. 5, for example.

That is, in this detection circuit, the phototransistor PT receives the light transmitted through the optical fiber 15, and causes a current corresponding to the intensity of the light to flow through the resistor R.

Then, the voltage Vx generated across this resistor R is received by, for example, a CMO8 Schmitt trigger inverter (2), and depending on whether the voltage Vx is larger or smaller than the human power threshold level VTH, the output e becomes ゝゝL // or ゝゝゝSet the circuit constants so that it becomes H〃.

For example, the light input through the optical fiber 15 is
The output e is set to "L" when the light is emitted by the light emitting diode 13 shown in the figure, and is set to "H" at other times.

In this way, when the output e of the Schmitt trigger inverter ■ is "L", the output transistor Tr is off, so the output PH becomes "H", and when the output e is "H", the output transistor Tr is turned off. The Tr is turned on and the output PH becomes "L".

Note that the output PH of the detection circuit shown in FIG. 5 is also transmitted to a control device to be described later.

Based on the above premise, the position data of the hole 12a of the glove box slit 12 in the instrument panel 10 on the workpiece conveyor 9 shown in FIG. 1 is obtained using a teaching device which will be described later. .

After the teaching is completed, an automatic screw tightener is attached to the wrist 8 to drive and control the robot 1 based on the position data obtained through the teaching, thereby performing the work of fastening the glove box lid 12.

FIG. 6 is a control block diagram of the horizontal articulated robot 1 of FIG. 1 including a robot teaching device.

Note that the deviation counter 21 . Drive section 22. Speed detection section 23. The position counter 24 is a digital DC servo system of the motor M1 that drives the lifting section 4 in FIG. The digital DC servo systems of the second arms 5 and 6 are configured in exactly the same way, so
Illustrations are omitted.

First, the basics for driving and controlling the robot will be explained.

In the same figure, the movement data calculation unit 17 has a first
- The pre-teach data area 19a and the plane scanning data area 1 of the memory 19 are read by the third reading circuits 32 to 34.
The following arithmetic processing is performed in accordance with the data read out from the vertical scanning data area 9b and the vertical scanning data area 19C.

(b) When the pre-teach data area 19a is accessed, the pre-teach data area 19a has, for example,
Position data representing the vicinity of each hole 12a of the glove box lid 12 in the robot space coordinate system of the robot 1 shown in FIG. When the position data is sequentially read out by the first reading circuit 32, the read position data and the elevating section 4 and the first... Based on the current position data of each part of the second arms 5 and 6, the amount of movement of the lifting section 4 and the movement angle of the first and second arms 5 and 6 are calculated, and the calculation results are sent to the pulse distributor 20.
Output to.

Note that each of the above position data corresponds to the tip of the work position detector 7 in FIG. 1 (corresponds to the tip of the automatic screw tightening machine when the automatic screw tightening machine is attached to the wrist part 8 of the robot 10).
shows the target position.

In addition, in this pre-teach data area 19a, there is actually a hole 12 to be worked on first from the origin position of the robot 1.
a″!, a movement trajectory between each hole 12a, and a large number of relay position data 11- for determining the movement trajectory from the last hole 12a to the origin position, etc. are also stored. However, a description of the processing of each relay position data will be omitted below.

Furthermore, each of the above position data may be created by actually moving the robot using a teaching box instead of using a CAD system.

However, in that case, it is not necessary to create final accurate position data, so rough teaching is sufficient.

(b) When the plane scanning data area 19b is accessed The plane scanning data area 19b contains, for example, two types of positions for calculating position data indicating the starting point and ending point necessary for the linear interpolation executed by the pulse distributor 20. Vector data is stored, and these position vector data are stored in the second
When read by the reading circuit 33, based on those position vector data and the above-mentioned current position data,
The above-mentioned starting point position data and ending point position data are calculated cyclically, and the calculation results are sequentially distributed as pulses = 1.
2- Output to device 20.

This matter will be discussed in more detail later.

(c) When the vertical scanning data area 19C is accessed The vertical scanning data area 19C stores position data for vertically lowering the tip of the working position detector 7 in FIG. 1 by a predetermined amount toward the hole 12a. and this position data is the third
When the position data is read out by the readout circuit 34, the elevating portion 4 is
, and sends the calculation result to the pulse distributor 20.
Output to.

When the interpolation mode signal SM is not input, the pulse distributor 20 forms a pulse signal representing the amount of movement (angle) of each part in the number of pulses based on the data sent from the movement data calculation section 17. Then, each pulse signal is output to the deviation counter 21 of each digital DC servo system.

Further, when the interpolation mode signal SM is input, the tip of the work position detector 7 moves straight between the two positions based on the start point position data and the end point position data sent from the movement data calculation unit 17. linearly interpolated pulses are formed, and the interpolated pulses are connected to the first . Motor M2 that drives the second arms 5 and 6. Output to the deviation counter of the digital DC servo system for M3.

Note that when a disable signal DA, which will be described later, is input, this pulse distributor 20 outputs this disable signal D.
The pulse output is controlled so that the current position of the tip of the working position detector 7 at the time when A is input does not change even if there is a time lag, and the output is stopped.

In the digital DC servo system, the rotation of the motor M1 is controlled via the D/A converter and servo amplifier in the drive unit 22 according to the count output of the deviation counter 21, and its speed and position (rotation) are controlled. The outline of the amount control is as follows.

That is, when the motor M1 should be rotated in the forward direction, the pulse signal from the pulse distributor 20 is sent to the up-count terminal U of the deviation counter 21, and the pulse signal fed back from the pulse generator PG1 operated by the motor M1 is sent to the up-count terminal U of the deviation counter 21. The signals are input to the down count terminals of the counter 21 via switching circuits (not shown), respectively.

In this way, from the time the motor M+ starts rotating until a certain period of time has elapsed, the motor M+ rotates at a speed determined by the period of the pulse signal and the output characteristics of the pulse generator PG1.
The count value of the deviation counter 21 increases, and after the predetermined period of time has elapsed, the count value of the deviation counter 21 is kept constant.

Then, when the pulse signal input to the up-count terminal U of the deviation counter 21 disappears, the count value is decremented by the pulse signal from the pulse generator PG+.

Using the count value of the deviation counter 21 that changes in this way as a speed reference value, this speed reference value and the actual speed value from the speed detection section 23 (obtained by F/V conversion of the pulse signal from the pulse generator PCI) The drive section 22 performs speed feedback control so that the two match.

15- In this way, the deviation counter 21 starts counting the pulse signals of the pulse distributor 20, so that the motor M
1 begins to rotate, and the count value of the deviation counter 21 increases, remains constant, decreases, and becomes zero, causing the motor M1 to rotate by the number of rotations corresponding to the number of pulses and then stop, thereby changing the position (rotation amount). ) control is carried out,
When the amount of rotation of motor M1 is above or below a predetermined value, the following correction is performed.

That is, if an incremental type pulse generator PGl is used, the rotational direction of the motor M1 can be detected by distinguishing the phase of its output pulse signal.

Therefore, the above-mentioned switching circuit is provided with this discrimination function.
When the motor M1 rotates in the normal direction, the pulse signal from the pulse generator PGr is inputted to the down-count terminal of the deviation counter 21 as described above, and when the motor M1 rotates in the reverse direction, the pulse signal is inputted to the up-count terminal U.

By doing this, the count value of the deviation counter 21 will not become zero when the amount of rotation does not reach the predetermined value, so the count value will be zero by rotating the motor M1 further in the positive direction. If the amount of rotation exceeds a predetermined value, the count value of the deviation counter 21 is a negative value, so the motor M1 is rotated in the opposite direction, and the pulse generator is rotated in accordance with the rotation. The negative count value is incremented in the positive direction by the pulse signal output from the PCI, so that the count value becomes zero.

Thereby, the motor Ml is eventually activated by the pulse distributor 2
It rotates by the number of rotations corresponding to the number of pulses of the pulse signal from 0 and then stops.

In addition, the current position register 25 receives information from the three position counters 24 that count the apparent amount of rotation (forward rotation amount - reverse rotation amount) from the starting point of each motor M+ -Ma that is drive-controlled as described above. The current position data indicating how far each part of the robot 1 has moved from the origin position is always held.

Each of these position counters 24 also detects the phase of the pulse signal from each pulse generator PG1 to PGa, and outputs the pulse signal during forward rotation of the motors M1 to M3 to the up-count terminal, and the pulse signal during reverse rotation to the up-count terminal. A switching circuit is connected to the input side, respectively, to input the respective down count terminals.

In the manner described above, the tip of the work position detector 7 attached to the wrist portion 8 of the robot 1 shown in FIG. 1 can be moved according to the command value.

Next, the teaching operation will be explained. In FIG. 6, the detection circuit 26 has a circuit configuration as shown in FIG.
The output PH becomes ``H'' only when the light-receiving end surface 15a of the optical fiber 15 at the tip of the working position detector 7 in FIG. 4(b) captures .

When the teaching mode signal TM shown in FIG. 7 is input, the control section 31 executes various tasks described below.

Next, when the robot start command ST shown in FIG. 7(B) is input, the enable signal EN1 is switched to the first
The first read circuit 32 is activated, whereby the position data representing the first target position, for example, the position d1 shown in FIG. The position data is output to the movement data calculation section 17.

After receiving the position data, the movement data calculation unit 17
As shown in FIG. 7), movement data for each part of the robot 1 is calculated based on the falling timing of the enable signal ENI, and the calculation results are output to the pulse distributor 20.

On the other hand, when the robot start command ST is input, the control unit 3
1, the clear signal CL shown in FIG. 7 Q1.1 is sent to three flip-flop circuits (FF) 27 and 28.

29. Output to reset terminal R of 30, FF27-3
Since it is initialized to 0, the disable signal 19-DA, which is the Q output of the FF 30, is not input to the pulse distributor 20 at the time when the calculation result is input to the pulse distributor 20, and the disable signal 19-DA is not input to the pulse distributor 20, and the interpolation Mode signal SM is also not input.

Therefore, the pulse distributor 20
After receiving the calculation result from , a pulse signal corresponding to the calculation result is distributed and output to each deviation counter 21 of each digital DC servo system at the timing shown in FIG. 7(e).

As a result, positioning control is performed according to the input pulse signal by the action of the digital DC servo system described above, so that the tip of the work position detector 7 attached to the wrist 8 of the robot 1 is as shown in FIG. It is positioned at the position d1 shown.

In the above explanation, the robot 1 is suddenly moved from the origin to the first target position, but as mentioned above, in reality, the robot 1 is moved from the origin to the first target position, but in reality, the robot 1 is moved from the origin to the first target position, but in reality, the robot 1 is moved from the origin to the first target position. , the movement trajectory of the robot 1 is limited.

Next, when the pulse distributor 20 finishes distributing the pulse signal and outputs the distribution end signal PE shown in FIG. , thereby opening the AND gate GI.

In fact, when this pulse distribution end signal PE is input to the control section 31, the control section 31 outputs the interpolation mode signal SM to the pulse distributor 20 at the timing shown in FIG. ) The enable signal EN is activated at the timing shown in
2 to the second readout circuit 33, and the second readout circuit 3
Activate 3.

Thereby, horizontal scan data area 19 of memory 19
The following two types of position vector data are read from b, and these position vector data are output to the movement data calculation unit 17.

That is, these position vector data are position vectors indicating the length of one side D1 and the direction of the robot coordinate system shown in FIG. 9 in the area S that may include the hole 12a of the glove box lid 12 shown in FIG. This data indicates X (the base point coordinates of the vector are arbitrary), and a position vector (2) indicating the length of the side D2 obtained by dividing the other side and the direction in the robot coordinate system (the base point coordinates of the vector are arbitrary).

After receiving the above two position vector data, the movement data calculation unit 17 calculates the position vector data and the current position register 25 based on the falling timing of the enable signal EN2 as shown in FIG. The following calculations are performed using the current position data of each part, and the calculation results are transferred to the pulse distributor 20.

That is, first, the current position of the tip of the work position detector 7 (corresponding to position d+ in FIGS. 8 and 9) is calculated based on the current position data of each part of the robot 1 taken in from the current position register 25. do.

Next, the current position d1 of the tip of this working position detector 7
The position d2 in FIGS. 8 and 9 is calculated by using as the base point coordinates of the above-mentioned position vector A.

Then, these positions d+ and +Jz are transferred to the pulse distributor 20 as the starting point and ending point position data of the first linear interpolation.

Since the pulse distributor 20 is in the interpolation mode operation state by the interpolation mode signal SM mentioned above,
The movement data calculation unit 17 transfers the linear interpolation pulses to the motor M2 which drives the first and second arms 5 and 6 at the timing shown in FIG. 7 (E).
．． Output to the deviation counter of the digital DC servo system for M3.

As a result, the tip of the working position detector 7 moves straight from the position d1 to the position d2 in FIG. 8 due to the action of the digital DC servo system described above.

On the other hand, the movement data calculation unit 17 calculates the above-mentioned position d1. dz
After calculating and completing the data transfer, immediately move to position d.
2 as the base coordinates of the position vector B (see Figure 9),
The position d3 in FIGS. 8 and 9 is calculated.

Then, position d2. d3 is transferred to the pulse distributor 20 as the next starting point and ending point position data.

Following the first interpolation process, the pulse distributor 20 performs an interpolation process 23- based on the next start point and end point position data.

Thereby, the tip of the working position detector 7 comes to horizontally scan an area S including the hole 12a shown in FIG.

It is assumed that the movement data calculation unit 17 uses the position vector -X when calculating the positions d+, ds, . . . shown in FIGS. 8 and 9.

Next, when the tip of the work position detector 7 reaches a position facing the hole 12a as shown in FIG. An output PH of "H" is output.

Since this "H" output PH sets the FF 28 via the AND gate Gl opened by the Q output of the FF 27, the plane position detection signal HK (7th
(see figure (IJ)) occurs.

When this plane position detection signal HK is generated, the OR gate G
Since FF'30 is sent via FF'2, its Q output, disable m DA (see FIG. (including clearing of), and the data in the movement data calculation unit 17 is also cleared.

Therefore, the tip of the work position detector 7 stops at a position facing the hole 12a.

On the other hand, when the plane position detection signal I (K is generated), the control section 31 outputs a clear signal CL at the timing shown in FIG. "Close" and release the stoppage of the pulse distributor 20.

Then, the control unit 31 outputs the enable signal ENa to the third readout circuit 34 to activate the third readout circuit 34 at the timing shown in FIG. Position data for vertically sifting the tip of the work position detector 7 by a predetermined amount toward the hole 12a is read from the data area 19C, and the position data is output to the movement data calculation unit 17.

After receiving the position data, the movement data calculation unit 17
As shown in FIG. 7), the movement data of the lifting section 4 of the robot 1 is calculated based on the falling timing of the enable signal EN3, and the calculation result is output to the pulse distributor 20.

After receiving the calculation result from the movement data calculation section 17, the pulse distributor 20 activates the deviation counter 2 of the digital DC servo system for the lifting section 4 at the timing shown in FIG. 7(A).
1, a pulse signal according to the calculation result is distributed and output.

As a result, the tip of the working position detector 7 descends toward the hole 12a (vertical scanning) due to the action of the digital DC servo system described above.

The hood 7h at the tip of the inner cylinder 7e of the working position detector 7 (see FIGS. 4(a) and 4(b)) comes into contact with the hole 12a, and the inner cylinder 7e
When it retreats a predetermined amount into the outer cylinder 7b and the proximity switch 16 is turned on, the FF2'9 is set and the vertical position detection signal VK (see the seventh diagram), which is its Q output, is generated.

When this vertical position detection signal VK is generated,
Since FF30 is set via G2, a disable signal DA (see FIG. 7 (N)), which is its Q output, is generated, thereby stopping the operation of the pulse distributor 20 and disabling the work position detector. 7 also stops.

When the vertical position detection signal VK is generated, the control section 31 outputs a clear signal CL at the timing shown in FIG. Release.

1, the control unit 31 at the timing shown in FIG.
The enable signal EN4 is output to the arithmetic/write circuit 35 to activate the arithmetic/write circuit 35.

The calculation/writing circuit 35 calculates the current position of the tip 7-h of the retracted inner cylinder 7e in the 1 work position detector 7 based on the current position data of each part of the robot 1 stored in the current position register 25. The data, that is, the position data of the hole 12a in the robot coordinate system is calculated I7, and the calculation result is written in the teaching data storage area 19d of the memo January 9.

Then, the control unit 31 monitors the memory 19 and stores the first hole 12a in the teach data storage area 19d.
After confirming that the position data has been written, the screen shown in Figure 7 (
The enable signal ENI shown in c) is transmitted to the first readout circuit 32.
and repeat the above operation.

After the teaching for all the holes 12a is completed, the system waits until a command to start the fastening work is input.

Note that the position data of each hole 12a obtained as described above is data indicating the target position of the tip of the automatic screw driver when the automatic screw driver is attached to the wrist portion 8 of the robot 10, and is necessary for the fastening work. Data for performing the lowering operation of the automatic screw tightening machine is stored in another area of the memory 19.

Further, during playback, position data in the teach data storage area 19d is read out via a readout circuit (not shown).

Next, modifications of the above embodiment will be listed.

@) In the above embodiment, an example was described in which the light receiver (light receiving end surface portion 15a) was attached to the work position detector 7 side, and the light emitter was attached to the hole 12a. It is also possible to adopt a reflection method in which a reflector 3γ having a reflector plate 36 as shown in FIG. 10 is fitted into the hole 11a of the glove box 11.

Note that if there is a certain degree of difference in brightness between the glove box lid 12 and the hole 12a, the position of the hole 12a can be detected without providing a light emitter on the hole 12a side.

(B) As a method of scanning the area S shown in FIGS. 8 and 9, in addition to the above-mentioned example, an example as shown in FIG. 11 (1) (B) can be considered.

(c) As shown in FIG. 4(b), if the hood 7h having the aperture lower 2 is attached to the tip of the inner cylinder 7e, the aperture lower 2 may be blocked by dust, etc. As shown, the light receiving end face 15a of the optical fiber 15
The open end of the air hose 38 is housed in the hood 7h as shown in the figure, with a slight gap provided between the air hose 38 and the throttle lower 2.
It is a good idea to clean the inside.

2) In the above embodiment, an example was described in which the proximity switch 16 was provided on the outer cylinder 7b side, but it is of course possible to provide it on the inner cylinder 7e side, and it can also be provided in the outer cylinder 7b as in the above embodiment. The relationship between the two may be reversed without inserting the inner cylinder 7e.

Note that an IJ9 limit switch may be provided in place of the proximity switch 16, and this limit switch may be struck directly by the dog 71, but in this case, the inner cylinder 7
Since there is no more room for displacement in e, there is a risk that the switch will be damaged if the robot 1 does not stop at the same time as the switch is turned on.

(e) In the above embodiment, the hole in the glove box lid of an automobile instrument panel was targeted, but other parts of the instrument panel (meters, etc.) or other workpieces may be targeted. For example, when teaching the position of a welding point on a car body, for example, a luminescent paint may be applied to the welding point position, and the position where the luminescent paint is applied may be detected.

Note that if there is nothing on the target work that obstructs the plane scanning of the work position detector 7, it becomes possible to take a larger scanning area, which further simplifies pre-teaching.

(f) In the above embodiment, an example was described in which the present invention was applied to a three-axis horizontal articulated robot, but the present invention is not limited to this, and can be similarly applied to a robot with any axis configuration.

As described above, if a robot is taught using the robot work position detector according to the present invention, teaching can be performed relatively easily, accurately, and quickly.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the teaching state of a horizontal articulated robot to which the present invention is applied, FIG. 2 is an enlarged partial view of the glove box lid shown in FIG. 1, and FIG. A5 sectional view on line G1, Figure 4 (A)
((2) is an enlarged side view and a partially exploded 31-plane view showing an example of the working position detector shown in FIG. 1, respectively. FIG. 5 is a circuit diagram showing an example of the detection circuit, and FIG. 1 is a control block diagram of the horizontal articulated robot shown in FIG. 1 including the robot's teaching device; FIGS. 10 is a perspective view of a reflector, FIGS. 11(A) and 11(B) are views showing other examples of plane scanning, and FIG. The figure is a partial sectional view showing another embodiment of the work position detector. 1...Horizontal articulated robot 7...Work position detector 7b...Outer cylinder (main body) 7e
... Inner cylinder (sensing object) 7f ... Coil spring (elastic body) 9 ... Parts conveyor 10 ... Instrument panel 12 ... Glove box lid 32- 12a ... Hole 14 ... - Light emitter 15... Optical fiber 15, a... Light receiving end surface section (work position detection section) 16
... Proximity switch (backward detection means) 17 ... Movement data calculation section 19 ... Memory 20 ... Pulse distributor 21 ... Deviation counter 22 ... Drive section 23 ...
・Speed detection unit 24...Position counter 25...Current position register 26...Detection circuit 27.28, 29.30...Flip flow circuit 3
1...Control unit 32-34...First to third readout circuit 35...Arithmetic/write circuit Ml-Ma...Motor PGI-PGa...Pulse generator No. (A) Special 1978-97895 (11) 7d 7d Fig. 8 Fig. 10 Fig. 11 (-r) (O) No. 9
Figure 5 2 584 Figure 12 Procedural Amendment Form) April 4, 1980 Kazuo Wakasugi, Director General of the Patent Office ■, Indication of Case Patent Application No. 57-207640 2, Title of Invention: Detection of Working Position of Robot Device 3. Relationship with the case of the person making the amendment Patent applicant: 2 Takaracho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture (399) Nissan Motor Co., Ltd. 4: Agent: 1-20-5 Higashiikebukuro, Toshima-ku, Tokyo March 1982 9th (Shipping date: March 29th of the same year) 6.
In column 7 of the brief explanation of the drawings of the specification subject to amendment, in line 6 of page 33 of the specification of contents of the amendment, “Fig. Corrected as 585-

Claims (1)

[Claims] 1. There is a main body (
7b), a detection body (7e) displaceable in the axial direction of the main body (7b), and an elastic body (7e) that always urges the detection body (7e) in a direction away from the main body (7b). 7f
), a working position detection unit (15a) provided at the tip of the detection body (7e) to detect the working position of the robot, and a work position detection unit (15a) provided on either the main body (7b) or the detection body (7e). and the detection object (7e) is connected to the main body (7b).
1. A work position detector for a robot, characterized in that it comprises a backward detection means (16) for detecting that the robot has retreated by a predetermined distance.