JPH0775372A - Method for outputting encoder signal - Google Patents

Abstract

PURPOSE:To make high-precision control with precise data by comparing prestored precise data with rough data obtained at this time upon power-on in particular. CONSTITUTION:A-phase and B-phase incremental signals 2 are counted to obtain precise data A, and the precise data A is stored upon power-off and compared with rough data B upon power-on to initialize by using the precise data A when within a constant range of errors, thereby obtaining high-precision axial data from motor rise.

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 in particular, when the power is turned off and then on again,
The present invention relates to a new improvement for comparing the rough data from the code plate with the absolute fine data stored in advance, outputting the absolute fine data within a certain error range, and performing highly accurate control.

[0002]

2. Description of the Related Art Conventionally, as an encoder signal output method of this kind used in the past, in order to increase the resolution of an absolute encoder signal, tracks for the number of bits are formed on a code plate to achieve high precision. I was getting an encoder signal.

[0003]

Since the conventional encoder signal output method is configured as described above, there are the following problems. That is, forming tracks corresponding to the number of bits on the code plate becomes extremely expensive, and the receiving circuit on the control device side also has a complicated configuration. Also, in this way, the A-phase and B-phase incremental signals are counted,
In the encoder configured to convert to absolute data, when the power source was turned on, there was only a reproducibility of the shaft position of about 3 bits (motor pole data for the U, V, and W phases, that is, rough data) of the code plate.

The present invention has been made to solve the above problems, and particularly, when the power is turned on again after the power is turned off, the rough data from the code plate and the absolute fine data stored in advance are stored. In comparison, an object of the present invention is to provide an encoder signal output method that outputs this absolute precision data within a certain error range and performs highly accurate control.

[0005]

An encoder signal output method according to the present invention is an encoder signal output method in which an encoder signal is output from an encoder provided on a rotating shaft of a motor having U, V and W phase coils. , A phase and B phase incremental signals obtained from the code plate of the encoder are counted to output absolute precision data, and the absolute precision data is stored when the power is turned off. When the power is turned on again, the absolute precision data is stored. In this method, the rough data and the absolute precise data are compared with each other, and if they are within a certain error range, the absolute precise data is used for initialization.

More specifically, when the rough data and the absolute fine data are out of a certain error range, the motor is started by the rough data to set the preload signal to the H level, and the Z from the code plate is set. In this method, the preload signal is set to the L level by the phase strobe signal to obtain the absolute precise data.

[0007]

In the encoder signal output method according to the present invention, the A-phase and B-phase incremental signals are counted and converted into absolute fine data, and the time (5 seconds to 10 seconds) during which the motor rotates due to inertia when the power is turned off is counted. The precise absolute absolute data at that time is stored, and the rough data from the code plate and the absolute precise data are compared at the next power-on. If the comparison result is within a certain error range (within ± | LSB), this absolute precision data can be output to obtain axis data that is an encoder signal. If the comparison result is out of the certain error range, the motor is started up with this rough data to set the preload signal to the H level, and the Z phase strobe signal from the code plate sets the preload signal to the L level. Axis data based on absolute precision data can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of an encoder signal output method according to the present invention will be described in detail below with reference to the drawings. In FIG. 1, reference numeral 1 denotes A-phase / B obtained from a code plate (not shown) of an encoder 2A provided on a rotary shaft of a motor (not shown) having U-, V-, and W-phase coils.
This is a counter to which the phase incremental signal 2 is input, and the absolute precision data A obtained by counting with this counter 1 is latched and stored by the latch unit 3, and this latch unit 3 is backed up by the battery 4.

After the power is turned off, the encoder 2A operates the encoder 2A by the timer time operation circuit 4 after the power is turned off until the motor rotates due to inertia and stops, and latches the absolute precision data A. The absolute precision data A from the latch unit 3 is input to the comparison unit 5 and output as the data output 10.

The encoder 2A, the latch unit 3 and the comparing unit 5 have a timing signal 11a from a timing unit 11.
Is input to obtain the timing of each operation. The absolute rough data of 3 bits or more is formed on the code plate (not shown) for switching the U, V and W phase coils of the motor. B (that is, U, V, W
The magnetic pole data) is input to the comparison unit 5 and the selector 12, and any one of the above data A or B as the counter load value from the selector 12 is input to the encoder 2A.

Next, the operation will be described. In a normal state, the A phase / B phase incremental signal 2 is counted by the counter 1, and the absolute precise data A obtained from this counter 1 is initialized via the latch unit 3 and output as a data output 10 which is an encoder signal. It

Next, in the state after the power is turned off, the timer time operation circuit 4 is activated after the power is turned off, and the encoder 2A is operated during the time (5 to 10 seconds) during which the motor rotates by inertia after the power is turned off. Then, the absolute precision data A obtained during that time is latched and stored in the latch unit 3.

Next, when the power is turned on again, the absolute coarse data B and the absolute fine data A are compared by the comparison unit 5, and if they are within a certain error range (within ± | LSB), this absolute fine data is obtained. A is selected by the selector 12, returns to the counter 1, and is output as the data output 10.

If the comparison result is out of the above-mentioned error range, as shown in FIG. 2, after initializing the rough data B, the position of the center c between a and b, that is, the Z-phase strobe. After passing the signal 30, the preload signal 31 from the load control unit (not shown) changes from H level to L level, and after that, the coarse data B is re-initialized and output, and then the absolute precision data A is used as an encoder signal. The axis data 32 is obtained.

[0015]

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, when the power is turned on again after the power is turned off, the axis data can be obtained using the precise data, so high-precision control can be performed from the initial startup of the motor, greatly contributing to downsizing and cost reduction. can do.

[Brief description of drawings]

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

FIG. 2 is a waveform diagram.

[Explanation of symbols]

 2A Encoder 2 A phase / B phase incremental signal A Absolute precision data B Rough data 30 Z phase strobe signal 31 Preload signal

Claims (2)

[Claims] 1. An encoder signal output method for outputting an encoder signal from an encoder (2A) provided on a rotary shaft of a motor having U-, V-, and W-phase coils,
The absolute precision data (A) is output by counting the A-phase / B-phase incremental signals (2) obtained from the code plate of the encoder (2A), and the absolute precision data (A) is stored when the power is turned off. When the power is turned on again, the rough data (B) from the code plate is compared with the absolute precision data (A), and if the error is within a certain error range, initialization is performed using the absolute precision data (A). An encoder signal output method characterized by the above. 2. When the rough data (B) and the absolute fine data (A) are out of a certain error range, the motor is started by the rough data (B) and the preload signal (31) is set to H level. The encoder signal output method according to claim 1, wherein the level is set, and the preload signal (31) is set to the L level by the Z-phase strobe signal (30) from the code plate to obtain the absolute precision data (A). .