JPS60190810A - Pulse encoder - Google Patents

Abstract

PURPOSE:To make it possible to monitor the number of rotation accurately, by providing an optical detecting device, which detects the rotary angle within one rotation, so as to face against a code plate, and counting the number of rotations by another counter based on a signal voltage that is generated in correspondence with the rotation of a rotary body in addition to the optical detecting device. CONSTITUTION:An encoder is constituted of a first detedtor 4, a second detector 5, a counter circuit 6, an amplifier 8 and an output circuit 9. An output signal from the first detector 4 is amplified by the amplifier 8, and a signal corresponding to the rotary angle within one rotation of a rotary body is obtained. The number of rotations of the rotary body is counted by the counter circuit 6 based on the output signal from the second detector 5. Said signals from the amplifier 8 and the counter circuit 6 are inputted to the output circuit 9 in parallel. From its output side, the number of rotations and the rotary angle within one rotation of the rotary body are read out together. By the relatively simple constitution such as this, a common code plate can be utilized in the simultaneous detection of the number of rotations and the rotary angle within one rotation of the rotary body.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a pulse encoder for detecting rotation of a rotating body.

The pulse encoder according to the present invention is a so-called full-stroke absolute pulse encoder that can count the total number of revolutions of a rotating body and also detect the rotation angle within one revolution, that is, even when the rotary body has rotated more than one revolution. It is a pulse encoder that can detect the entire stroke including the rotation speed and rotation angle, and can detect the entire angle as a final absolute angle value, not just an incremental value.For example, it can be used to detect and control the position of a robot's arm. It is used for

PRIOR ART Conventionally, as a detection device for this tumor, a speed reduction device is interposed between the input shaft and the output shaft of a motor (for example,

For example, the output shaft rotates once while the motor rotates 1000 times), there is a device that detects the rotation speed of the motor and the rotation angle within one rotation by providing a resolver on the output shaft, but in such a device, It requires a multi-stage reduction gear, a resolver, a phase detection circuit, etc., making the configuration relatively complex, large and expensive, and there are also problems in that mechanical friction occurs.

There is also a device that detects the rotation angle within one rotation, which consists of a code plate that rotates together with the rotating body and an optical detection device that opposes it. OBJECTS OF THE INVENTION In view of the above-mentioned problems, the main object of the present invention is to provide a first optical system that faces a code plate and detects a rotation angle within one rotation. In addition to the optical detection device, a second optical detection device is added, and based on the signal voltage generated in the second detection device according to the rotation of the rotating body, a counter circuit consisting of a CMO8 integrated circuit detects the rotation. Based on the concept of counting the number of rotations of a rotating body, a common code plate can be used to jointly detect the number of rotations of a rotating body and the rotation angle within one rotation with a relatively simple and inexpensive configuration. It's about doing.

Another object of the present invention is to operate the CMO8 integrated circuit by performing a sampling operation using a sampling pulse generated in the sampling signal generation circuit of the CMO8 integrated circuit and all of the generators constituting the second detection device. The aim is to reduce the consumption of batteries as a power source.

Furthermore, another object of the present invention is to enable proper monitoring of the rotation speed even when the NC power is not turned on.
Another object of the present invention is to obtain a rotation detection device that can simultaneously detect rotation angles within one rotation by turning on an external power source such as an NC power source.

41 of the invention. - According to the present invention, there is provided a code plate which rotates together with the rotating body, and which has a light transmission area in an angular range of 180' along its circumference. A gray code consisting of a plurality of Qi tunnels including a first channel provided and a second channel provided with a light transmission area in an angular range of 180 degrees and shifted by 90'' from the light transmission area of the first channel. : A fixed slit plate provided with a first slit group corresponding to each channel of the code plate and a second slit group corresponding to the first and second channels of the code plate facing the code plate: the fixed slit [consisting of a first if element and a first receiving t element group provided opposite to the first slit group of the plate] A first detection device for detecting a rotation angle within the rotation; A second detection device comprising a second light emitting element and a second light receiving element group provided opposite to the second slit group; pulse logic processing of the electrical output signal from the second light receiving element group; A counter circuit consisting of a CMOS integrated circuit (CMOS integrated circuit) that counts up and down the number of revolutions of a rotating body according to its rotational direction, which has a sampling signal generation circuit that performs sampling operation on the second optical element: A pulse encoder is provided, which includes a battery for supplying power to the integrated circuit and a battery for supplying power to the integrated circuit.

Example The present invention will be described in detail below based on the drawings.

FIG. 1 shows an example of a code plate in a pulse encoder according to an embodiment of the present invention. A second channel in which a light transmitting area 12 is provided in an angular range of 180° and shifted by 90° from the light transmitting area of the first channel.
channel, a third channel having a light transmitting area 13 in an angular range of 90° shifted by 45 degrees from the light transmitting area of the second channel;
channel, and a light transmitting area of the third channel;
A fourth channel is provided with a light transmission area 14 in an angular range of 45° offset by 2.5°, thereby forming a so-called gray code. Here, the Gray code refers to the multiple channels that make up the entire system (the one shown is H4-1-1).
channel) and 扛 go to one Nayanel VC and change from a transparent area to a former shielding area or vice versa.
At an angular position of 1Z, the code is such that such a strange IL will not occur in other channels (that is, such a strange fhi will not occur in two or more channels at the same time). 7L is a well-known model. Therefore, the number of channels for forming the gray code can be set as appropriate whether the code board shown has four channels or not.

Fig. 2 shows an example of the pulse encoder as an example of /) both legs &2. Cord (Each channel V of anti-1 is provided so as to correspond to it/(31 slit group 2 consisting of 4 Suriri I-7Jh)
1, and the first channel η of the coated plate 1 at a predetermined angle from the first slit gauge 21.
I will respond to Kuyanonel. A second slit l'B consisting of 142 slits 1 provided in l:'')
l! -22 was formed. 1st slit right here +i
The same number of 21 constitutes the Gray code -j-y, and the number of channels V is set to correspond to O. Fig. 3 shows the light emitting elements 41', This shows an example of a printed board 3 having 51k, in which the code plates 1V are mounted facing each other as shown in FIG. The gold that has passed through the transparent area further passes through each of the slit basins a of the first slit group 21 of the fixed slit plate 2, and then passes through the slits provided oppositely to each of the slits and passes through the slits of the respective channels. The light enters the first light receiving element group 42 which optically reads the code. - The second slit group 2 of the fixed slit plate 2, which was originally transmitted through the light transmission area of the first and second channels of the code plate 1 from the light emitting element 51 of the power tube 2;
A second channel is transmitted through each slit 2l-' of 2, and is then provided oppositely to each slit 7'L, and passes through the slit to optically read the code of the first and second channels. The light is incident on the second light receiving element group 52. Note that, for example, an LED is used as the light emitting element, and in the drawing, the first light emitting element 41 and the second light emitting element J (-element 51 and L2
Although one element for each element is shown, the number of these elements can be set as appropriate depending on the size of the opposing slits [11. They are provided so as to face each of the slits described above.

FIG. 4 is a diagram showing a configuration in which the structures of FIGS. 1, 2, and 3 are assembled, in which a code plate that rotates together with the rotating body is used to detect the rotation of the rotating body in a quaternary manner. 1 and the fixed slit plate 2 are made of purple and printed temporary 31. having light emitting elements 41 and 5'l on both of them, respectively. 1=-Equipped with a light receiving element group 42 and 52.

FIG. 5 is a diagram showing a schematic configuration of a pulse encoder as an embodiment of the present invention, and shows one specific circuit for a second detection device 5 to be described later.

In the figure, reference numeral 4 denotes a first optical detection device that projects within one rotation of the rotary body, and includes a code plate 1, a fixed slit plate 2, and a (1':4
The first light emitting element 4J and the first light emitting element are placed on both sides of the two.
A sub-meter 42 is provided, which transfers the code temporary rotation (C) from the light-emitting element 41 to the original overpass area of each channel of the coated plate 1 and its corresponding (fij constant slit). Appropriately pass through each slit of the first slit of Saka 2
421, 422
The light was received at 423°424, and it was changed to No. 4. sumi = 1-do Depending on the temporary rotation, the code ('? of ν?
-5-)-J'1' of the channel, when the transmission area 1 faces each slit, the light is received by the corresponding light receiving element, while the light blocking area of each channel is
L-When facing the slit, the corresponding receiver L element does not receive light, so for example, Fig. 3 iC7J
-<-j When four rows of channels are formed on the coated plate 1, the light-receiving elements l of εW 1 ] From 1°42 to 4-bit binary scale; it is possible to obtain a +9i constant number, and by this, the rotation angle gi within one rotation can be expressed as 1si constant according to the number of channels. 1
It can be read at 7 degrees. Note that the first utterance [
, element-41 is activated by six predetermined external sources such as an NC power source.

Next, in the present invention, the code plate 1 and the fixed slit plate 2 are sandwiched, and a second optical detection device is installed separately from the first optical detection device 4.
An optical detection device 5 is provided.

That is, a second light emitting element 51 and a second light receiving element group 52 are provided on both sides of the code plate 1 and fixed slit plate 2, respectively. Here, the second light emitting element 51 is a counter circuit 6 made of a CMO8 integrated circuit as described later.
The sampling operation is performed by a sampling pulse SLP generated in a sampling signal generation circuit included in the sampling signal generation circuit, and in the illustrated embodiment, in addition to the base of all transistors 530, the sampling pulse
The sampling operation of LED 51'i connected to the collector circuit of is activated. In this way, the second light emitting element, the LED
51e The sampling operation is performed by the sampling pulse generated from the sampling signal generation circuit in order to reduce the consumption of the battery 7, which is the power source of the CMO8 integrated circuit.

The second light receiving element group 52 includes two light receiving elements 521 and 522.
One of the light-receiving elements 521 faces the second slit group 22 provided in the fixed slit plate 2 that corresponds to the first channel of the code plate 1, and the other light-receiving element 521 faces The element 522 is the second slit group 2
2, it faces the one corresponding to the second channel of the code plate l.

Now, while the light transmitting area formed in the first channel in accordance with the rotation of the code plate faces the corresponding slit, the light emitted from the light emitting element 51 which is made to emit light in a sampling manner as described above is emitted. The light is originally received by a light-receiving element, for example, a photodiode 521, and the electric signal generated thereby is applied to the pace of the transistor 55,
Since the transistor 55 is turned on, the potential at the connection point between the resistor 54 and the collector of the transistor 55, ie, the point A, decreases by 'yo-4. Therefore, during the period when the light transmitting area formed in the first channel of the code plate faces the corresponding slit, the light receiving element 52 receives light from the light emitting element 51 which is sampling tc Q jf. During this period, a signal voltage consisting of the train of sampling pulses is generated at the core connection point, ie, point A. Since the Yuan Liaoba area of the first channel is formed in an angular range of 180° along the circumference of the code plate, the signal voltage is equal to half the period of one rotation of the rotating body. Similarly, during the period when the transparent area formed in the second channel of the code plate faces the corresponding slit, In other words, during the period when the 9 element Kaiko 522 is receiving light from the light emitting element 51 which is emitting light in a sampling manner,
The connection point between the resistor 56 and the collector of the transistor 57, that is, point B (C) generates a signal voltage tone consisting of a train of sampling pulses as described above. Since it is provided in an angular range of 1) (0 degrees), the signal voltage is shifted by 90' from the signal voltage generated at the point A. Note that Vcc is Indicates the applied DC voltage.

6 is a counter circuit consisting of a CMO8 integrated circuit,
A signal voltage generated at the point A and point B according to the rotation of the rotating body, that is, a signal voltage consisting of a sampling pulse train whose phase is shifted by 90° from each other and each half a rotation of the rotating body is inputted. , process these with pulse logic,
One pulse is generated for each revolution of the rotating body, and this pulse is used to count up and down depending on the rotational speed of the rotating body and the direction of rotation, thereby calculating the rotational speed of the rotating body. do.

The output of the counter circuit 6 and the output of the first detection device 4 for detecting the entire rotation angle of the rotating body, that is, the signal from the first light receiving element group 42, are input to the output circuit 9 in parallel. , on its output side, a signal sound corresponding to the rotational speed of the rotating body and the rotation angle within one rotation is emitted to read the current position to, for example, a control device of a robot.

Note that 8 is a signal amplified by the signal from the first light receiving element group 42. :J derac C1 [)σ first light emitting element 4
1. As a power source for the amplifier 8 and the output circuit 9, the N'C power source (
FIG. 6 is a circuit diagram showing a specific example of the counter circuit 6 in the device shown in FIG. /
D. Clock signal input terminal CLK.

an up/down counter having an enable terminal ENfr;
61, 62, 63 are flip-flops, 64°65
is Nantes Gate, 66i′i Noah Gate, 671°67
2.673.674.675.676.677 is an inverter. 69 is an oscillator, and the output of the oscillator is a differential circuit tN3681, an inverter 675°676,
J=? . (R flip-flop 61°62.63 and clock signal input terminal CL of up/down counter
Supply to T4.

The Noritsubu flops 61 and 63 have the form of a Schitch circuit, and input 1% of the signal voltage generated at the point A and BA through a predetermined inverter (LV) every half rotation of the rotating body. A high voltage level and a low voltage level are pulsed repeatedly (that is, one cycle per rotation of the rotating body). By inputting an appropriate combination of the outputs of the flip-flops 61 and 62 to the flip-flops 64 and 65 (which delay the output waveform of the Noritsu flop 61 by one clock), At the falling or rising edge of a pulse that repeats 1 and 0 every 4 U of half a rotation of the rotating body that is output by flip-frog (both occur once for each rotation of the rotating body)
Enable all detection (for example, detect as a falling pulse)
At the same time, the output of the flip-flop 63 at that time is also input. In this way, the outputs of the Nandt gates 64 and 65 at a predetermined time are set to 1 when one output is 0, and the outputs are reversed depending on the direction of rotation of the output sound rotating body.

The output of the Nant gates 64 and 65 enables the up/down counter 60 through 66 NOR gates! j child EN
Since the K input is input, the counter 60 receives the counter '?' once every rotation, no matter which direction the rotating body rotates. 3:
k) Set to J production state. On the other hand, only the output of the tint game 1-64 is input to the up/down terminal U/1) of the counter 60, so for example, when the rotating body rotates in the right direction VC0, the up/down terminal U/1) When rotating counterclockwise, a downward or subtractive process is performed. This ↓9 indicates in which direction the rotating body has finally rotated.

FIG. 7 shows an example of the tangential relationship between the first detection length 4, the second detection device 5, the counter circuit 6, the amplifier 8, and the output circuit 9 in the device V shown in FIG. In the figure, the first detection length [output signal from i74 2 intensifier 1] is amplified by the unit 8, and the rotation angle range within one rotation of the rotating body is
A signal corresponding to the number of rotations of the rotary body counted by the counter circuit 6 based on the pressure signal of the second detection device 5'7) and the like is input manually to the output circuit 9 in parallel. 1) 4-force side〃) The number of rotations of the rotating body and the rotation angle within one rotation are both read.

FIG. 8 shows how each channel of the Gray code formed on the code plate changes with respect to the first and second YS element groups as the code plate rotates. cltc2+C3 and C4
How do the codes of each channel, that is, the first to fourth channels, change for each light receiving element in the first light receiving element group? Cr + CS indicates how the codes of the first and second channels change for each light receiving element of the second light receiving element group, and in each time chart, for example, a high level indicates the light of each channel. It is assumed that the low level corresponds to the light-blocking area of each channel, and the low level corresponds to the light-blocking area of each channel.

As shown in this time chart, at point P where flZ changes from c'1 high level to low level, cl.

No changes occurred in C2, C3 and C4.

That is, in the present invention, the P point is the point at which the above-mentioned change in c' occurs and at the same time (rcC') is at a high level, and the up-down counter 60 mentioned above performs up-down counting under these conditions. In other words, since this is the timing for adding or subtracting the rotational speed of the rotating body depending on its rotational direction, at this timing, the above-mentioned C1 to Cak
The signal for detecting the rotation angle within one revolution is not changed in any way.

In other words, C, -C in the range S shown in FIG.
The reference point, that is, the range of σ, for detecting the rotation angle within one rotation shall be set by the code specified in 4. Preferably, this allows addition or subtraction of the number of rotations at a stable position where the indication of the rotation angle within one rotation does not change, that is, at a stable position where the rotation angle within one rotation shows 0°.

And the above ↓ conditions? The position of the second slit group on the fixed slit plate may be shifted from the position of the first slit group so as to meet the above requirements.

Effects of the Invention According to the present invention, a common code plate can be used for jointly detecting the rotational speed of a rotating body and the rotational angle within one rotation with a relatively simple and inexpensive configuration.

In addition, according to the present invention, since the light emitting elements constituting the entire second detection device used for detecting the rotational speed are sampled and operated by the battery as the power source of the CMO8 integrated circuit, battery consumption is reduced. can be reduced to extend its lifespan.

Further, according to the present invention, even when the NC power is not turned on, the rotation speed can be properly monitored and held in the counter, and the rotation angle within one rotation can be determined at the same time as the NC power is turned on. can be detected at the same time, so
Full stroke absolute type rotation detection device 7
Is it advantageous? Obtainable.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a code plate in a pulse encoder as an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a fixed slit plate in a pulse encoder as an embodiment of the present invention. FIG. 3 is a diagram showing an example of a printed board in a Norse encoder as an embodiment of the present invention, and FIG. 4 is a diagram showing a configuration in which the structures of FIGS. 1, 2, and 3 are assembled. , FIG. 5 is a diagram showing a schematic configuration of a Norms encoder as an embodiment of the present invention, FIG. 6 is a circuit diagram showing a specific example of a counter circuit in the device shown in FIG. 5, and FIG. , Fig. 5 is a diagram showing an example of the connection relationship of the first detection device, second detection device, counter circuit, amplifier, and output circuit in the device; Fig. 8 shows the gray code formed on the code plate. , is a time chart showing the state that changes according to the rotation of the code plate. (Explanation of symbols) 1... Code board, 2... Fixed slit plate, 3... Printed board, 4... First detection device, 41 ...First light emitting element, 42...
...First light receiving element group, 5...Second detection device, 51...Second light emitting element 5, 52...
... Second light receiving element group, 6 ... Counter circuit, 7 ... Battery, 8 ... Multiplier 11], 9
...Output circuit. Patent Applicant FANUC Co., Ltd. Patent Application Agent Patent Attorney V Te Akira Ki Kazuyuki Nishidate Patent Attorney Ken Hiraiwa Patent Attorney Akira Yamaguchi Patent Attorney Masaya Nishiyama Figure 1 Figure 2 21 2/ Figure 3 Figure 4

Claims (1)

[Claims] 1. A first channel that is a code plate that rotates with the rotary body and has the entire original transmission area in an angular range of 180 degrees along its circumference, and a light transmission area of the first channel that is shifted by 90 degrees and 180 degrees. 8” with a former western pass area in the angle range of
Gray code consisting of multiple channels including 2 channels? A fixed slit plate that faces the code plate and includes a first slit group corresponding to each channel of the code plate and a second slit group corresponding to the first and second channels of the code plate: the fixed slit plate; 1st slit of slit plate]・The first emitting element and the first emitting element provided opposite to the group.
A first detection device that detects rotation angles within one rotation is comprised of a group of light-receiving elements and a second light-emitting element and a second group of light-receiving elements are provided opposite to the second slit group of the fixed slit plate. a second detection device consisting of; an electrical output signal from the second light receiving element group; A counter circuit consisting of a CMC)S integrated circuit that performs pulse logic processing and counts up and down the rotational speed of a rotating body according to its rotational direction, and has a sampling signal generation circuit that operates the second light emitting element for sampling; and A pulse encoder comprising: a battery that supplies power to the integrated circuit.