JPS61214996A - Sensor device - 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 "Field of Industrial Application" The present invention relates to a sensor device suitable for use in painting robots and the like.

"Prior Art" In recent years, a painting robot as shown in FIG. 7 has been used as a device for automatically painting the inside of, for example, a locker. In this figure, 1 is a robot body, 2 is an arm, and a flexible wrist 3 is attached to the tip of this arm 2.
The coating unit 4 is rotatably and displaceably attached via the . Here, the painting unit 4 is projected downward from the base 5 by a base 5 attached to the flexible wrist 3, a sensor 6 attached to the base 5, a painting spray gun 7, and a rod support part (not shown). It is composed of a supported rod 8. On the other hand, reference numeral IO indicates a door such as a locker, and the door 10 is formed with a rectangular window frame, and this window frame has a groove 10a for fitting a window glass into an outer window frame 10b and an inner window frame. It is formed between the frame 10c and the frame 10c. When painting the inside of the door 10 using the painting unit 4, the robot main body I detects the groove 10a with the sensor 6 while moving the painting unit 4 in the direction of the arrow, and the rod 8 of this groove 10a is detected by the sensor 6. By inserting it and pulling it in the direction of arrow B, the door! Open 0. Next, after pulling out the rod 8 from the groove 10a, the painting unit 4 is closed to the door! 0 and paint the inside with the paint spray gun 7.

Now, in the conventional painting robot described above, a reflective photoelectric sensor shown in FIG. 8 is widely used as the sensor 6. In this figure, the light emitted from the light emitting diode 6a is reflected by the reflective surface +2 (in this case, corresponds to the groove 10a and the window frames 10b and 10C that form it), is received by the phototransistor 6b, and its output is is supplied to the robot control device I3. In this case, the sensor 6 detects the window frame 10b and the groove 10a shown in FIG. 9(C).
.

When the window frame 10c is sequentially passed through, the output is the window frame 10b.
, it becomes a peak at IOc and a valley at W410a, forming a bimodal curve as shown in FIG. Therefore, if you clip this at an appropriate level, you will get two pulses PS+ corresponding to the mountain part, as shown in the same figure (a).
PS2 can be obtained, and thereby the groove 10a can be detected.

For example, when the pulse PS rises, the groove 1
When 0a is detected, the rod 8 is returned a predetermined distance in the direction B in FIG. 7, inserted into the groove 10a, and the door 10 is opened.

"Problems to be solved by the invention" By the way, in the conventional painting robot mentioned above,
Reflective surface because it is painted in various colors! The reflectance of 2 varies. When the paint is black, the reflectance decreases, so the output of the sensor 6 is also curved C2 in Figure 9 (b).
The overall level is lowered, and even the mountain part is at level L.
Since the pulses P S r and P S * are not obtained, it becomes impossible to detect the groove 10a. on the other hand,
When the paint is white, the reflectance increases, and the output of the sensor 6 increases overall as shown by curve C3 in Figure 9 (b), and now even the valley part becomes higher. Only a single pulse is obtained instead of the pulses ps, , pst,
Again, W410a cannot be detected.

Further, the reflectance changes depending on the uneven state of the reflective surface 12, and the groove 10a may not be detected in the same way.

This invention has been made in view of the above-mentioned circumstances, and provides a sensor device that can always accurately detect grooves on a workpiece, regardless of the color of the paint on the workpiece or the unevenness of the surface of the workpiece. The purpose is to

"Means for Solving the Problems" The present invention provides a reflective photoelectric sensor that moves in one direction over a workpiece and outputs a signal corresponding to the outer shape of the workpiece, and a reflective photoelectric sensor that outputs a signal corresponding to the outer shape of the workpiece, and The present invention is characterized by comprising a determining means for extracting the output signal at each time interval, sequentially calculating the amount of change in the output signal, and detecting a predetermined shape portion of the workpiece based on the calculated amount of change.

"Operation" The amount of change in the output signal of the reflective photoelectric sensor at each predetermined time interval is calculated, and the predetermined shape of the workpiece is detected based on the amount of change, so the color of the paint on the workpiece and the unevenness of the surface of the workpiece can be detected. Even if the reflectance changes due to a change in the reflectance, the predetermined shape portion of the workpiece can always be accurately detected.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of essential parts of an embodiment of the present invention, and parts corresponding to those in FIGS. 7 and 8 are given the same reference numerals. In this figure, 20 is an amplifier that amplifies the output signal of the phototransistor 6b of the sensor 6;
21 is an A/D (A/D) that converts the analog detection signal S supplied from the amplifier 20 into digital detection data D;
digital) converter. The detection data D output from this A/D converter 2 is sent to the CPO via the pass line 25.
26 and undergoes the processing described below.

Further, 27 is a ROM that stores programs used in the CPO 26, and 28 is a RAM that is used as a work area and the like.

Next, the operation of this embodiment will be explained with reference to the waveform diagram shown in FIG. 2.3 and the flowcharts shown in FIGS. 4 to 6.

Now, before painting the inside of the locker, the door! 0, a search for the groove 10a is started, and the sensor 6 moves to the window frame to
When passing over the b-groove 10a→window frame 10c in order, the output of the phototransistor 6b of the sensor 6 becomes a bimodal curve as shown in FIG. That is, as the position of the sensor 6 moves in the order of A-+B-+c-D→E,
The output of the phototransistor 6b is the window frame 10b S 1
There are peaks at positions B and D corresponding to 0c, and a valley at position C corresponding to 11Oa. Then, the output signal of the phototransistor 6b is amplified by the amplifier 2o, and the A/
It is converted into digital detection data D by the D converter 21,
The signal is supplied to the CPU 26.

Next, the CPU 26 proceeds with the detection operation of the groove 10a in accordance with the flowchart shown in FIG. First, in step S1 and loop a consisting of steps St and Ss, the sensor 6
It is detected that the sensor 6 has approached the window frame 10b, that is, that the sensor 6 has reached the position A shown in FIG. step s
1 is an initialization routine, as shown in FIG. 5, the variable i=0 and step sp,), and then, at that point, the A/D converter 2! The detection data D supplied from the CPU 11 is temporarily stored in the RAM 28 as detection data D+ (=Do) (step SP). The next step S is ″,
This is a calculation routine for difference data N, and as shown in FIG. 6, variables i1. Step STI to add :l), and step S to temporarily store the detected data D in rZAM28.
T, ), and calculate the difference data N1=DI−D H−+ (step 5-T3). Then, in step S, it is determined whether or not the difference data N is 0. If the difference data N is 0, the loop 121 causes step S to be performed.
If the difference data N1 is not 0, the process goes to the next step S. That is, at the point when the sensor 6 reaches the position A shown in FIG. It is determined that the object has approached, and the process proceeds to the next step S4.

In this step S4, it is determined whether the difference data Nl is positive or not, and if the difference data N: is negative (Nl<0
) performs error processing, returns the sensor 6 to its original position, and starts searching again. On the other hand, if the difference data N is positive (N
l>0), it is considered that the sensor 6 is moving in the direction approaching the window frame 10b, and the process proceeds to the next step S.

Next, step S, and step SiS? and loop Q consisting of N8, sensor 6 is placed above the window frame tab (second
It is detected that the position B) shown in the figure has been reached. Step S
5 is the same initialization routine as step S, and step S6 is the same difference data N1 calculation routine as step S. Then, in step S7, it is determined whether or not the difference data N is positive. If the difference data N1 is positive (N I > 0), the process proceeds to step S8, and returns to step S6 through loop σ. , and the difference data N,
If is 0 or negative (N+≦0), proceed to the next step S. That is, when the sensor 6 reaches position B shown in FIG. 2 and the difference data N1 changes from positive to negative, the sensor 6
is considered to have reached above the window frame 10b. Here, if the variable i becomes larger than a predetermined number in the loop Q, this is determined in step Ss, and it is assumed that the window frame 10b could not be found within the predetermined time, error processing is performed, and the sensor 6 is Return to position and start searching again.

Next, step S, and step S l (1+ S I
1 and loop a consisting of S It, the sensor 6 becomes 1.
It is detected that the position above the loa (position C shown in FIG. 2) has been reached. First, after executing the initialization routine in step S, the differential data N1 calculation routine in step SIG is executed, and in step S It, it is determined whether N1 is negative or not, and the differential data N is calculated.

If is negative (N l < 0), the process proceeds to step Sat, and returns to step 910 through loop a, and if the difference data N1 is 0 or positive (N+≧0), the process proceeds to the next step srs. That is, when the sensor 6 reaches position C shown in FIG. 2 and the difference data N changes from negative to positive, it is considered that the sensor 6 has reached above the groove 10a.

Here, if variable i becomes larger than a predetermined number in loop Q, this is determined in step S1,
It is assumed that 'iRl Oa could not be found within a predetermined time, and error handling is performed.

Next, in step S13, the position information of the painting unit 4 (see FIG. 7) at the time when the detection data D1-1 is read is stored. In other words, the detection data D i-
The time when + is read is regarded as the time when the sensor 6 reaches above the groove 1.0a, and the posture of the robot at that time j is memorized. The reason why the time point at which the detection data D1-1 was read is set here is as follows. As shown in FIG. 3, the detection data Da, Dc, D
If e is obtained sequentially, the detection data Dc is set to the minimum value,
In addition, when the detection data Db, Dd, and Df are obtained sequentially, the detection data Dd is set to the minimum value, and the detection data Db,
When De is obtained sequentially, the detection Db is set to the minimum value. In this way, the point in time when the difference between successive detection data changes from negative to positive (for example, De-Dc>0) or becomes 0 (
For example, if De-Db=0) is detected, the point immediately before that point can be regarded as the minimum value.

Next, step S+4 and step S IS+S
+s and a loop 124 consisting of SL7, it is detected that the sensor 6 has reached above the window frame lOC (position D shown in FIG. 2). First, after executing the initialization routine in step S+4, the differential data N calculation routine in step S+5 is executed, and in step S16, it is determined whether or not the differential data N1 is positive, and the differential data N1 is determined to be positive.
If I is positive, step SL? Then, the process returns to step srs through a loop e4, and if the difference data N1 is O or negative, it is assumed that the sensor 6 has reached above the window frame lOc, and the search ends. On the other hand, if variable i becomes larger than a predetermined number in loop e, this is step Sl? It is determined that the window frame 10c could not be found within a predetermined time, and error handling is performed.

When the groove 10a is detected in the above-described procedure, the coating unit 4 is moved based on the position information stored in step S13, the rod 8 is inserted into the groove 10a, and the door 10 is opened.

Note that the method for detecting the groove 10a is not limited to the above method; for example, the sensor 6 may be moved once above the window frame IOC, and then detected while returning from the window frame 10c to the groove 10a to the window frame 10b. It is possible. In addition, the above-mentioned embodiment I
Here, a case has been described in which a concave portion (groove 10a) of the door 10 is detected, but a convex portion can also be detected in the same manner. Further, in the above-described embodiment, the case where the door 10 of the locker is opened is explained as an example, but the door is not limited to this, and it may be, for example, a door of a car.

"Effects of the Invention" As explained above, according to the present invention, there is provided a reflective photoelectric sensor that moves in one direction over a workpiece and outputs a signal corresponding to the outer shape of the workpiece, and an output of the reflective photoelectric sensor. The present invention includes a determination means for extracting signals at predetermined time intervals, sequentially calculating the amount of change in the output signal, and detecting a predetermined shaped part of the workpiece based on the calculated amount of change. It is possible to obtain the effect that a predetermined shaped portion of a workpiece can always be accurately detected regardless of the unevenness of the surface of the workpiece or the like.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.
2 is a diagram showing the relationship between the position of the sensor 6 and the output of the phototransistor 6b in the same embodiment, FIG. 3 is a diagram for explaining the groove 10a detection method in the same embodiment, and FIG.
6 are flowcharts for explaining the groove detection operation of the same embodiment, FIG. 7 is a side view showing an example of the painting robot, and FIG. 8 is a diagram of the sensor 6 used in the painting robot of FIG. 1. FIGS. 9(a) to 9(c), which are diagrams for explaining an example, show that when the sensor 6 moves over the door 110a, the sensor 6
3 is a diagram showing the relationship between the signal output from the signal generator and the pulses PS, PSt obtained when the signal is cut at level L. FIG. 6...Sensor (reflective photoelectric sensor), 10...
...Door (work), IOa...Groove, 21.
...A/D converter, 26...CPU (judgment means). Figure 1 uOD COe T B1 Figure 7 Figure 8 b

Claims (1)

[Claims] A reflective photoelectric sensor moves in one direction over a workpiece and outputs a signal corresponding to the outer shape of the workpiece, and the output signal of the reflective photoelectric sensor is extracted at predetermined time intervals and the amount of change in the output signal is calculated. A sensor device comprising: determination means for sequentially calculating and detecting a predetermined shape portion of the workpiece based on the calculated amount of change.