JP2003150248A - Control circuit for encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the original position of machinery and equipment correspond to the original signal of an encoder by an electrical setting work. SOLUTION: A control circuit 2 of an encoder main body 1 is constituted of an up-down counter 21, a shift quantity storage setting circuit 22, and a shift signal generation circuit 23. A shift signal to be generated when the original signal of the encoder main body 1 is shifted only by a prescribed angle of rotation value from the generation point of time is used as a new original signal so that it is not necessary to execute any mechanical adjustment work for making the original position of the machinery and equipment correspond to the original signal of the encoder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control circuit for an encoder which is connected to an output shaft of an electric motor used as a drive source for mechanical equipment and serves as a speed / position sensor for the mechanical equipment and the electric motor.

[0002]

2. Description of the Related Art For example, in an incremental encoder, which is connected to an output shaft of an electric motor used as a drive source for mechanical equipment and serves as a speed / position sensor for the mechanical equipment and the electric motor, one pulse is generated for each rotation of the encoder. The origin signal is used for associating with the origin position of the mechanical equipment, for correcting the measured value of the incremental pulse, that is, for correcting the cumulative error of the coordinate position of the mechanical equipment, and the like.

In particular, in order to match the rotational position of the output shaft of the electric motor when the origin signal of the encoder is generated with the original position of the mechanical equipment, when the electric motor is incorporated into the mechanical equipment, the electric Mechanical adjustment work was performed on the rotational position of the output shaft.

[0004]

As described above, a skillful technique and a long working time are required for the mechanical adjustment work when the electric motor is incorporated in the mechanical equipment.

An object of the present invention is to provide an encoder control circuit that solves the above problems.

[0006]

According to the first aspect of the present invention, there is provided a control circuit for an encoder, which is connected to an output shaft of an electric motor used as a drive source for mechanical equipment, and which serves as a speed / position sensor for the mechanical equipment and the electric motor. The encoder body is provided with a signal processing function of generating a shift signal issued when the electric motor rotates by a predetermined rotation angle from the time when the origin signal is issued, and using the shift signal as a new origin signal. Is characterized by.

A second invention is characterized in that, in the encoder control circuit of the first invention, the encoder main body is provided with the signal processing function.

Further, a third invention is characterized in that, in the control circuit of the encoder of the first invention, the signal processing function is provided in a control device of the electric motor.

According to the encoder control circuit of the present invention, the origin signal and the origin position of the mechanical equipment can be associated with each other by an electrical setting operation.

[0010]

1 is a block diagram of an encoder control circuit showing an embodiment of the present invention, in which 1 is an incremental encoder main body connected to an output shaft of an electric motor (not shown), and 2 is an encoder. It is a control circuit of the main body 1.

The control circuit 2 measures the two-phase incremental pulse output from the encoder body 1 with the rotation of the electric motor while increasing or decreasing the current counter value based on a predetermined phase relationship. The operation of reading the current counter value of the up / down counter 21 and storing the value based on this counter value as the shift amount at the timing of generation of the down counter 21 and the origin signal that generates one pulse per revolution of the encoder body 1 A shift amount memory setting circuit 22 for presetting the shift amount in the down counter 21 and a counter value of the up / down counter 21 are monitored, and a "carry signal" or "borrow signal" as this counter value is issued. A shift signal generation circuit 23 that outputs a pulsed shift signal when It is configured.

Since the control circuit 2 has a simple circuit structure which can be formed by a well-known technique, the control circuit 2 is a new encoder main body integrated with the encoder main body 1 or is desired for the electric motor. By incorporating it in a control device that supplies drive power, it can be used as a speed / position sensor for this mechanical equipment and electric motor.

The operation of setting the shift amount in the control circuit 2 will be described below.

First, mechanical equipment is set to the origin position, and the electric motor, the control device, the encoder body 1, the control circuit 2 are set.
Power is turned on to the entire mechanical equipment including the above. It is assumed that the counter value of the up / down counter 21 is cleared to “zero” only during this setting work when the power is turned on.

Next, in order to move the coordinate position of the mechanical equipment in a direction permitting it at a very low speed, a small amount of driving power is started to be supplied from the control device of the electric motor to the electric motor.
The electric motor begins to rotate slowly in the desired direction. Along with the rotation of the electric motor, the 2-phase incremental pulse output from the encoder body 1 is increased / decreased by the up / down counter 2.
1 measures.

The shift amount memory setting circuit 22 reads the current counter value of the up / down counter 21 when the up / down counter 21 is measuring the two-phase incremental pulse and the origin signal is output from the encoder body 1. A value based on this counter value is stored as a shift amount in a non-volatile memory or the like.

That is, as described above, by using the non-volatile memory, the above-mentioned operation may be performed once when the entire machine is powered on for the first time.

After the above-described work of setting the shift amount, the operation of presetting the shift amount stored in the non-volatile memory in the up-down counter 21 is stored at the timing of generation of the origin signal of the encoder body 1 each time. The shift signal generation circuit 23 monitors the counter value of the up / down counter 21 after presetting, and when the "carry signal" or "borrow signal" as this counter value is issued, one-shot By outputting a pulse-shaped shift signal and using this shift signal as a new origin signal, the association with the origin position of the mechanical equipment is completed by a simple electrical setting operation.

In the above description of the embodiment, the incremental type encoder has been described as an example, but in the case of the absolute type encoder, after the power is turned on, the encoder immediately after the power is turned on without rotating the motor. Since the absolute value of the main body is in proportion to the shift amount, the setting operation of the shift amount is completed by reading the absolute value.

[0020]

According to the present invention, when the output shaft of the electric motor is incorporated into the mechanical equipment, it suffices to simply install the output shaft without paying attention to the rotational position of the output shaft. Can be associated with a simple electrical setting operation.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a control circuit of an encoder showing an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Encoder main body, 2 ... Control circuit, 21 ... Up-down counter, 22 ... Shift amount memory setting circuit, 23 ... Shift signal generation circuit.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 5H269 BB07 EE03 FF01 FF03 JJ02                       JJ06                 5H303 AA01 AA04 BB01 BB06 CC01                       DD01 EE03 EE10 FF10 GG06                       GG11 HH05 HH07 LL03 LL09

Claims (3)

[Claims] 1. A control circuit of an encoder, which is connected to an output shaft of an electric motor used as a drive source of mechanical equipment and serves as a speed / position sensor of the mechanical equipment and the electric motor, at a time when an origin signal is issued from the encoder body. An encoder control circuit having a signal processing function of generating a shift signal generated when the electric motor rotates by a predetermined rotation angle and using the shift signal as a new origin signal. 2. The encoder control circuit according to claim 1, wherein the encoder body is provided with the signal processing function. 3. The encoder control circuit according to claim 1, wherein the signal processing function is provided in a controller of the electric motor.