JP2579112Y2 - Multi-turn absolute encoder - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-turn absolute encoder, and more particularly to a clear operation (origin setting) of a multi-turn absolute encoder.

[0002]

2. Description of the Related Art A conventional multi-rotation absolute encoder is used as a position detector of an AC servomotor for driving an industrial robot. The output shaft of the AC servomotor is provided with a speed reducer. To make the movable range of the industrial robot an absolute value, the rotational speed of the encoder is stored and the main power supply
The number of rotations must be counted even at the time of FF, and the absolute position within one rotation must be detected when the main power supply is turned on.

As disclosed in Japanese Patent Application Laid-Open No. 3-287014, the absolute position of multiple rotations is detected by a magnetic encoder of one pulse per rotation and a counter for counting one pulse per rotation. Is configured to be detected by an optical absolute encoder.
The magnetic encoder for one pulse per rotation and the counter for counting one pulse per rotation are backed up by a battery so that they can operate even when the main power is off.

When the multi-rotation absolute encoder is mounted on an industrial robot or the like, it is necessary to perform origin matching for matching the mechanical origin of the industrial robot with the origin of the multi-rotation absolute encoder. Origin adjustment is performed by setting the robot arm at the position of the mechanical origin of the industrial robot and connecting the clear input terminal of the multi-rotation absolute encoder to the main power supply for several seconds. The reason why the clear input is performed for several seconds is to prevent the noise from being erroneously executed as a clear operation start signal when the noise is mixed into the clear input terminal.

[0005]

As described above, in the multi-turn absolute encoder, the clear input needs to be performed for a predetermined time (several seconds). However, in the conventional multi-rotation absolute encoder, if the clear input terminal is connected to the main power supply for several seconds, the operator cannot reliably recognize whether or not the clear operation has been performed. Conventionally, in order to reliably recognize whether or not a clear operation has been performed, a worker himself / herself counts a predetermined time required for input of a clear signal, or performs a clear input terminal for a predetermined time or more. And the main power supply. As described above, if the predetermined time was counted by itself, it was not possible to accurately count the number of hours due to rushing work, and it was not possible to reliably perform the clearing operation, or When connected, there is a disadvantage that the clear signal is input for much longer than a predetermined time, thereby significantly increasing the working time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and has means for confirming the end of a clear input time required for a clear operation. An object of the present invention is to provide an absolute encoder.

[0007]

In order to solve the above-mentioned problems, in the present invention, detection of position information within one rotation of a rotating shaft is performed.
Having a first pattern of use, the position detecting hands for outputting within one revolution position information of the rotating shaft by reading the first pattern
A step and a second pattern for detecting the number of revolutions of the rotating shaft, and detecting the second pattern to detect multi-rotation information of the rotating shaft.
Chestnut a rotation information detection means for obtaining a distribution, from the one rotation in the position information and the multi-rotation information, a signal processing means for calculating the multi-rotation position information of the rotary shaft, the rotational information detecting means
A multi-rotation absolute encoder including a clear signal input unit for inputting an input signal , wherein a clear input signal is input to the rotation information detecting unit for a predetermined time.
Can, multi-rotation absolute encoder, characterized in that it comprises a stop means for stopping the output of the multi-rotation position information from the signal processing means, and a confirmation means for notifying whether the multi-rotation position information is stopped I will provide a.

According to a preferred aspect of the present invention, the confirmation means includes a light-emitting light source that responds to a stop of the output of the multi-rotational position information . Furthermore, in a preferred embodiment of the present invention,
According to this, after the clear operation is performed, the rotation information detection is performed.
Outputting means outputs predetermined information.

[0009]

According to the present invention, a stop means for stopping the multi-rotation absolute position information output from the signal processing means when a clear input signal is inputted to the rotation information detection means for a predetermined time; Confirmation means for notifying whether or not the motor stopped has been provided. By stopping the multi-rotation absolute position information, the end of the input time of the clear input signal required for the clear operation can be confirmed, and the clear operation can be quickly and reliably performed. It can be carried out.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic block diagram showing a configuration of a multi-turn absolute encoder according to an embodiment of the present invention. The multi-rotation absolute encoder shown in FIG. 1 detects an absolute position of the rotation shaft 7 within one rotation and a multi-rotation amount of the rotation shaft 7. On the rotating shaft 7, a first code plate 1 for detecting an absolute position within one rotation and a second code plate 2 for detecting an amount of multiple rotations are integrally supported.

The first code plate 1 is made of a transparent glass plate, and is formed by forming a circular absolute pattern indicating an absolute position within one rotation by a chrome pattern.
The second code plate 2 is formed with a magnetization pattern that outputs a signal of one pulse per rotation to the magnet. The first detection unit 3 as an absolute position detection unit is positioned at a position facing the absolute pattern formed on the first code plate 1, and receives light from a light emitting unit (not shown) to receive one from the absolute pattern. A bit signal corresponding to an absolute position in the rotation is detected and output.

Further, the magnetization pattern formed on the second code plate 2 is detected by rotation information detecting means comprising a second detecting section 4 and a second signal processing section 6. That is, the second detection unit 4 is positioned at a position facing the magnetization pattern formed on the second code plate 2. Second
Is composed of two or more magnetoresistive elements, detects a leakage magnetic field from the second code plate 2, and outputs an incremental signal (two-phase rectangular wave) of one pulse per rotation. The output of the second detector 4 is connected to the input of the second signal processor 6. The second signal processing unit 6 counts rotation information detected by the second detection unit 4 and holds status data (voltage detection data of a backup power supply, overflow data of rotation information count, and the like).

The second detecting section 4 further comprises a magnetoresistive element.
Counter that counts incremental signals output from the
And the backup power source indicates at least one of a capacitor inside the encoder or an external battery. The voltage detection data is data for confirming whether or not the storage of the count value of the rotation information and the counting operation have been performed at a predetermined voltage (circuit operating voltage of the second signal processing unit 6) or higher (a predetermined voltage or higher). (Data for confirming whether or not the count value is the rotation information obtained in step (1)).

The rotation information detecting means (second detecting unit 4 and second signal processing unit 6) within the backup range 10 indicated by the broken line in FIG. 1 is used even when the main power supply (for example, 5V) is turned off by the backup power supply. It is configured to be able to operate at all times. On the other hand, the first detection unit 3
Is connected to an input of a first signal processing unit 5 as signal processing means. The first signal processing unit 5 includes: an absolute position within one rotation detected by the first detection unit 3; a multi-rotation count value and status data input from the rotation information detection means via a signal line 6-1. , The serial data 20 of the absolute position information (multi-turn absolute data) including the multi-turn amount is output via the serial output terminal 8. The first signal processing unit 5 is also connected to the clear input terminal 9.

FIG. 4 is a diagram showing a configuration of the serial output terminal 8 of FIG. In FIG. 4, serial data 20 output from a first signal processing unit 5 is input to a line driver 11 and transmitted to an external controller such as a robot via two output lines 11-1 and 11 # 2. An LED 13 as a communication monitor and a current limiting resistor 12 are connected in series between the two output lines 11-1 and 11 # 2, and the output line 11-1 is at a high level and the output line 11-2 is at a low level. The LED 13 is turned on when the level is high, that is, when the input to the line driver 11 is high.

The serial data 20 output from the line driver 11 includes a 3-bit start bit, 18-bit data, 3-bit CRC (cyclic redundancy check) bit, and 1-bit stop bit. The 18-bit data, CRC bits, and stop bits are Manchester-encoded and transmitted at regular intervals (42 μs). FIG. 5 shows an example of Manchester-encoded serial data. While the serial data 20 is being output, the line driver 1
The 1 output line 11-1 is intermittently at a high level. Therefore, the LED 13 blinks and appears to a human as if it were continuously lit.

The multi-rotation absolute encoder according to the embodiment of the present invention having the above configuration performs a clear operation as follows. The clearing operation for aligning the origin of the robot or the like (origin search) clears the counting amount of the rotation information, the voltage detection data of the backup power supply, and the overflow data of the counting amount of the rotation information in the second signal processing unit 6. That is.

The clear operation is started by connecting the clear input terminal 9 to 5 V of the main power supply for a certain period of time (for example, 3 seconds) when the main power supply is turned on. That is, by connecting the clear input terminal 9 to the main power supply, a clear input signal is input to the rotation information detecting means. The connection method between the main power supply and the clear input terminal 9 may be such that the wiring of the main power supply and the clear input terminal 9 are directly connected, or a switch function is provided between the main power supply wiring and the clear input terminal 9. It may be provided by switching the switch. In FIG. 2, a indicates the time when the connection of the clear input terminal 9 is started, and c indicates the time when the connection of the clear input terminal 9 is terminated (cut off). Even if the clear input signal is input, serial data (for example, 1425) indicating the number of rotations at the start of input of the clear input signal is continuously output for the first three seconds, that is, during the period from a to b. That is, the first signal processing unit 5 stops outputting the serial data at the time point (b) after 3 seconds from the input start time (a) of the clear input signal. In other words, the clear operation can be started at the time (b) when three seconds have elapsed from the start of the input of the clear input signal.

When the output of the serial data is stopped, the output line 11-1 of the line driver 11 goes low and the output line 1
Since the signal 1-2 is at the high level, the LED 13 is turned off. After visually confirming that the LED 13 is turned off,
The clear input terminal 9 can be cut off from the main power supply to stop the input of the clear input signal (c). The clear operation is started simultaneously with the stop of the input of the clear input signal (c).
Of the rotation information in the signal processing unit 6, the voltage detection data of the backup power supply, and the overflow data of the rotation information count amount.

If the output of the serial data is stopped during the transmission of the serial data and the transmission is terminated in the middle, an error occurs due to a CRC check. Therefore, the clear operation is accepted until the transmission is completed, but the clear operation is not started. Need to be As described above, the clear operation is started at the time (c) at which the input of the clear input signal is stopped.

When the clear operation is completed and the output of the serial data is resumed (d), the serial data representing the number of rotations becomes 0 as shown in FIG. On the other hand, as shown in FIG. 3, when the clear input signal is input for less than the predetermined time of 3 seconds due to noise or the like, the serial data (1425) indicating the number of rotations is stopped. , The serial data (1425) is always output.

In this embodiment, when performing the clear operation, the main power supply is connected to the clear input terminal, and after a predetermined time has elapsed, the output of the serial data is stopped. Then, using the output stop of the serial data, for example, L
By turning off the ED, the operator is notified that the connection between the clear input terminal and the main power supply may be cut off. The multi-rotation absolute encoder starts a clear operation when the operator disconnects the clear input terminal from the main power supply, and restarts serial data output when the clear operation ends. Thus, the multi-rotation absolute encoder of the present embodiment includes means for allowing the operator to confirm the end of the input time for the clear input signal required for the clear operation, and can perform the clear operation quickly and reliably.

[0023]

As described above, according to the present invention, the end of the input time of the clear input signal necessary for the clearing operation can be confirmed by stopping the multi-rotational position information. The clear operation can be performed reliably.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration of a multi-turn absolute encoder according to an embodiment of the present invention.

FIG. 2 is a timing chart of a clear input.

FIG. 3 is a timing chart of an erroneous clear input.

FIG. 4 is a diagram showing a configuration of a serial output terminal 8 of FIG.

FIG. 5 is a diagram illustrating an example of serial data.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st code board 2 2nd code board 3 1st detector 4 2nd detector 5 1st signal processing part 6 2nd signal processing part 7 Rotation axis 8 Serial output terminal 9 Clear input terminal 11 Line driver 12 Resistance 13 LED

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yuji Yamazaki 471 Nagaodaicho, Sakae-ku, Yokohama-shi, Kanagawa Pref. Nikon Co., Ltd. Yokohama Works (56) References JP-A-287014 (JP, A) JP-A-63-91724 (JP, A) JP-A-53-6081 (JP, A) JP-B-59-3043 (JP, B2) (58) Fields investigated (Int. . ^6, DB name) G01D 5/245 G01D 5/249

Claims (3)

(57) [Scope of request for utility model registration] 1. A first method for detecting position information within one rotation of a rotation shaft.
A position detecting unit having a pattern, reading the first pattern and outputting position information within one rotation of the rotating shaft; and a second pattern for detecting a rotation speed of the rotating shaft. Rotation information detecting means for detecting and obtaining multi-rotation information of the rotation axis; signal processing means for calculating multi-rotation position information of the rotation axis from the position information within one rotation and the multi-rotation information ; A clear input signal is input to the information detection means.
And A signal input means, in the multi-rotation absolute encoder wherein the clear input signal is a predetermined time the rotational information detecting means
When input, the multi-rotational position from the signal processing means
Multi-rotation absolute encoder, characterized in that it comprises a stop means for stopping the output of the location information, and a confirmation means for notifying whether the multi-rotation position information is stopped. 2. The multi-rotation absolute encoder according to claim 1, wherein the confirmation unit includes a light-emitting light source that responds to a stop of the output of the multi-rotation position information . 3. The signal processing device according to claim 2, wherein the rotation information detecting means includes a signal processing unit.
The multi-rotational position information from the means is cleared after stopping
After the completion of the above clearing, predetermined information is output.
The multi-rotation absolute according to claim 1, wherein the force is applied.
Lute encoder.