JPH1068640A - Encoder signal output method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable outputting of highly accurate encoder signals by returning a difference between an incremental code accumulated value and an absolute value of an absolute code to an arithmetic section to correct the incremental accumulated value. SOLUTION: Absolute value of an incremental code I obtained from an encoder 1 and an absolute value of an absolute code A are inputted into an arithmetic section 5, the absolute value is compared with an incremental code accumulated value Ia of the incremental code I accumulated by the arithmetic section 5 by a comparator 6 and the resulting difference D is returned to the arithmetic section 5 to always correct the incremental accumulated value Ia by the arithmetic section 5 based on the difference D and a value after correction is constantly outputted as encoder signal 10. Thus, since the difference between the incremental code accumulated value and the absolute value of the absolute code is used to correct the incremental accumulated value, the correction can be completed perfectly even when the correction is interfered by any turbulence thereby always enabling the obtaining of a highly accurate encoder signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an encoder signal output method, and more particularly, to a method of correcting an integrated value of an incremental code with an absolute value of an absolute code.
The present invention relates to a novel improvement for obtaining an absolute encoder which can be used as an incremental encoder and has a rotational position reliability similar to that of an absolute encoder based on an absolute code.

[0002]

2. Description of the Related Art Conventionally, as this kind of encoder signal output method, generally, only when power is turned on,
The incremental code integrated value was corrected by the absolute code.

[0003]

Since the conventional encoder signal output method is configured as described above, there are the following problems. In other words, if a disturbance enters the incremental code for some reason, the integrated value of the incremental code will be disturbed, and this disturbed state will remain until the power is turned off.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. In particular, the present invention can be used as an incremental encoder by correcting an integrated value of an incremental code with an absolute value of an absolute code. It is an object of the present invention to provide an encoder signal output method for obtaining an absolute encoder having the reliability of the rotational position according to the absolute encoder based on the above.

[0005]

SUMMARY OF THE INVENTION An encoder signal output method according to the present invention is an encoder having an incremental code and an absolute code, wherein an encoder has an incremental code and an absolute code. A method of returning to an arithmetic unit and correcting the incremental integrated value with the absolute value in the arithmetic unit.

More specifically, the correction is performed at a speed equal to or lower than a set rotation speed.

More specifically, there is a method using the absolute code of gray binary.

More specifically, there is a method using the absolute code of a pure binary.

More specifically, there is a method using a cyclic random number code as the absolute code.

More specifically, there is provided a method of performing the correction only when the difference is equal to or smaller than a set value or equal to or larger than a set value.

More specifically, the correction is not performed immediately after the power is turned on.

More specifically, the correction is performed at every constant rotation angle.

More specifically, when a zero point signal is generated from the incremental code integrated value, if the incremental code integrated value is within a set value with respect to a predetermined output position or output value of the zero signal, This is a method in which the correction is not performed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an encoder signal output method according to the present invention will be described below with reference to the drawings. In FIG. 1, a reference numeral 1 denotes a well-known optical absolute encoder. A rotary code plate 2 of the absolute encoder 1 has well-known incremental and absolute patterns 2 a formed thereon. When the light 3a passes through the rotary code plate 2 and is input to the photoreceptor 4, an incremental code I, which is a well-known incremental signal, and an absolute code A, which is a well-known absolute signal, are output.

The incremental code I is a CPU
The absolute value of the absolute code A is also input to the arithmetic unit 5 and the comparator 6. The incremental code integrated value Ia output from the arithmetic unit 5 is input to the comparator 6, and the difference D between the incremental code integrated value Ia and the absolute code A compared by the comparator 6 is calculated by the arithmetic unit 5. It has been returned to 5 and entered.

Next, the operation will be described. First, the absolute values of the incremental code I and the absolute code A obtained from the encoder 1 are input to the arithmetic unit 5,
The absolute value and the incremental code integrated value Ia of the incremental code I integrated by the arithmetic unit 5 are compared by the comparator 6, and the obtained difference D is calculated by the arithmetic unit 5.
The arithmetic unit 5 constantly corrects the incremental integrated value Ia based on the difference D, and the corrected value is always output as the encoder signal 10. When correcting the incremental integrated value Ia (feedback control),
A calculation program is set so that the calculation unit 5 corrects the absolute value in accordance with the timing.

In the above-described correction method, the correction operation is performed at or below the set rotation speed of the rotary code plate 2, and the absolute code A may be a well-known gray binary or pure binary. Further, a well-known cyclic random number code can be used. Further, the correction may be performed only when the difference D is equal to or smaller than the set value or equal to or larger than the set value, or the correction may not be performed immediately after the power is turned on. Also,
The above-mentioned correction can be performed at every fixed rotation angle of the rotation code plate 2. Further, when a well-known zero point signal is formed from the incremental code integrated value Ia, the incremental code integrated value Ia is set to the zero point signal. If a predetermined output position (ie, a predetermined rotation angle position) or an output value (a signal having the content of a predetermined pulse or the like) is within a set value, the above-described correction is performed. Can not be.

[0018]

Since the encoder signal output method according to the present invention is configured as described above, the following effects can be obtained. In other words, since the incremental integrated value is corrected by using the difference between the incremental code integrated value and the absolute value of the absolute code, even if there is a disturbance, all corrections are made, and it can be used as if an incremental encoder. It is possible to obtain an absolute encoder having the reliability of the position accuracy according to the absolute encoder based on the above.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an encoder signal output method according to the present invention.

[Explanation of symbols]

 I Incremental code A Absolute code Ia Incremental code integrated value 5 Operation unit

Claims (9)

[Claims] In an encoder having an incremental code (I) and an absolute code (A), an encoder having an incremental code integrated value (Ia) integrated with the incremental code (I) and an absolute value of the absolute code (A) is provided. An encoder signal output method, wherein the difference is returned to a calculation unit (5), and the calculation unit (5) corrects the incremental integrated value (Ia) with the absolute value. 2. The encoder signal output method according to claim 1, wherein the correction is performed at or below a set rotation speed. 3. The encoder signal output method according to claim 1, wherein said absolute code of gray binary is used. 4. The encoder signal output method according to claim 1, wherein the absolute code of the pure binary is used. 5. The method according to claim 1, wherein a cyclic random number code is used as the absolute code. 6. The encoder signal output method according to claim 1, wherein the correction is performed only when the difference is equal to or smaller than a set value or equal to or larger than the set value. 7. The encoder signal output method according to claim 6, wherein the correction is not performed immediately after the power is turned on. 8. The encoder signal output method according to claim 1, wherein the correction is performed at every constant rotation angle. 9. The incremental code integrated value (Ia)
When the zero-point signal is generated from the above, the correction is not performed when the incremental code integrated value (Ia) is within a set value with respect to a predetermined output position or a value to be output of the zero-point signal. An encoder signal output method according to any one of claims 1 to 8.