阅读说明：本技术 编码器及编码器的控制方法 (Encoder and control method of encoder ) 是由 西野祥平 近藤洋平 于 2020-09-16 设计创作，主要内容包括：一种编码器(10),包括：相信号生成部(12),其根据测量对象的移动,生成相位彼此相差90度的正弦波的第一模拟信号及第二模拟信号并输出；利萨如角计算部(14),其根据第一模拟信号及第二模拟信号求得利萨如角；以及振幅调整部(26),其仅调整从相信号生成部(12)输出的第一模拟信号的振幅并输出至利萨如角计算部(14)。(An encoder (10) comprising: a phase signal generation unit (12) that generates and outputs a first analog signal and a second analog signal of sine waves having phases that differ by 90 degrees from each other, in accordance with the movement of the measurement object; a lissajous angle calculation unit (14) that calculates a lissajous angle from the first analog signal and the second analog signal; and an amplitude adjustment unit (26) that adjusts only the amplitude of the first analog signal output from the phase signal generation unit (12) and outputs the adjusted amplitude to the lissajous angle calculation unit (14).)

1. An encoder, comprising:

a phase signal generating unit that generates and outputs a first analog signal and a second analog signal of sine waves having phases different by 90 degrees from each other, in accordance with movement of a measurement object;

a lissajous angle calculation unit that calculates a lissajous angle from the first analog signal and the second analog signal; and

and an amplitude adjusting unit that adjusts only the amplitude of the first analog signal output from the phase signal generating unit and outputs the adjusted amplitude to the lissajous angle calculating unit.

2. The encoder of claim 1,

the amplitude adjustment unit automatically adjusts and outputs the amplitude of the first analog signal to be equal to the amplitude of the second analog signal.

3. A method of controlling an encoder, comprising:

a phase signal generation step of generating and outputting a first analog signal and a second analog signal of sine waves having phases different by 90 degrees from each other, in accordance with the movement of the measurement object;

a lissajous angle calculation step of calculating a lissajous angle from the first analog signal and the second analog signal; and

an amplitude adjusting step of adjusting only the amplitude of the first analog signal output from the phase signal generating step and outputting the adjusted amplitude to the lissajous angle calculating step.

4. The control method of an encoder according to claim 3,

the amplitude adjustment step automatically adjusts and outputs the amplitude of the first analog signal and the amplitude of the second analog signal to be equal to each other.

5. The control method of an encoder according to claim 3 or 4, further comprising:

a step of detecting the amplitude of said first analog signal, an

Detecting the amplitude of the second analog signal.

Technical Field

The invention relates to an encoder for seeking lissajous angle and a control method of the encoder.

Background

From sinusoidal signals acquired from the sensors and having phases different by 90 degrees from each other, the encoder calculates and outputs the moving distance and the like of the measurement object. However, since an error is added to each of the sinusoidal signals acquired from the sensors and having phases different from each other by 90 degrees, in order to obtain an accurate lissajous angle by making the amplitudes of the two signals uniform, the errors of the signals having phases different from each other by 90 degrees are corrected, as shown in japanese patent laid-open publication No. 2011-075404.

Disclosure of Invention

However, when the errors of both signals having phases different by 90 degrees are corrected as in japanese patent application laid-open No. 2011-075404, there is a problem that the circuit scale and the number of man-hours increase.

An object of the present invention is to provide an encoder and a method of controlling the encoder, which can obtain an accurate lissajous angle with a simple configuration.

In a first aspect of the present invention, an encoder includes: a phase signal generating unit that generates and outputs a first analog signal and a second analog signal of sine waves having phases different by 90 degrees from each other, in accordance with movement of a measurement object; a lissajous angle calculation unit that calculates a lissajous angle from the first analog signal and the second analog signal; and an amplitude adjusting unit that adjusts only the amplitude of the first analog signal output from the phase signal generating unit and outputs the adjusted amplitude to the lissajous angle calculating unit.

In a second aspect of the present invention, a method for controlling an encoder includes: a phase signal generation step of generating and outputting a first analog signal and a second analog signal of sine waves having phases different by 90 degrees from each other, in accordance with the movement of the measurement object; a lissajous angle calculation step of calculating a lissajous angle from the first analog signal and the second analog signal; and an amplitude adjusting step of adjusting only the amplitude of the first analog signal output from the phase signal generating step and outputting the adjusted amplitude to the lissajous angle calculating step.

The present invention can obtain an accurate lissajous angle with a simple configuration.

The above objects, features and advantages can be easily understood from the following description of the embodiments with reference to the accompanying drawings.

Drawings

Fig. 1 is a configuration diagram of an encoder according to an embodiment.

Fig. 2 is a diagram showing a lissajou waveform.

Fig. 3 is a diagram showing an a-phase signal and a B-phase signal.

Fig. 4 is a flowchart illustrating a control method of an encoder according to an embodiment.

Fig. 5 is a configuration diagram of an encoder in modification 1.

Detailed Description

The encoder and the method for controlling the encoder according to the present invention will be described in detail below with reference to the accompanying drawings, taking preferred embodiments as examples.

[ embodiment ]

Fig. 1 is a configuration diagram of an encoder 10 according to an embodiment.

The encoder 10 includes a phase signal generating section 12 and a lissajous angle calculating section 14.

The phase signal generating unit 12 has a sensor for detecting movement of a measurement object (not shown) such as a motor, and generates an analog signal based on a position (for example, a rotational position) of the measurement object. The phase signal generating unit 12 generates an a-phase signal of the first analog signal and a B-phase signal of the second analog signal of the sine wave having phases different by 90 degrees from each other in accordance with the movement of the measurement object. The phase signal generating unit 12 outputs an a-phase signal from the output terminal 12a and outputs a B-phase signal from the output terminal 12B.

The lissajous angle calculation unit 14 has an input terminal 14a for receiving an a-phase signal and an input terminal 14B for receiving a B-phase signal. The lissajous angle calculating section 14 finds the lissajous angle from the received a-phase signal and B-phase signal. The lissajous angle calculation unit 14 outputs a signal indicating the position of the measurement target based on the lissajous angle obtained from the a-phase signal and the B-phase signal.

Fig. 2 is a diagram showing a lissajou waveform 20. The horizontal axis of fig. 2 represents the value of the a-phase signal, and the vertical axis represents the value of the B-phase signal. An angle formed by a straight line connecting points on the lissajous waveform 20 (broken line) from the origin of coordinates in fig. 2 and the positive direction of the horizontal axis is the lissajous angle θ. When the amplitudes of the a-phase signal and the B-phase signal are equal, the lissajous waveform becomes a circle like the lissajous waveform 20, and an accurate lissajous angle θ can be obtained. However, the lissajous waveform obtained when some error is added to the signal and the amplitudes of the a-phase signal and the B-phase signal are different from each other becomes an ellipse like the lissajous waveform 20 ', and the lissajous angle θ' obtained by this has an error. Here, an example is shown in which the lissajous waveform 20' is a case where the amplitude of the a-phase signal is smaller than that of the B-phase signal.

Fig. 3 is a diagram showing the a-phase signal 22 and the B-phase signal 24. The vertical axis represents signal values and the horizontal axis represents time. The solid line a-phase signal 22 and the solid line B-phase signal 24 correspond to the lissajou waveform 20' of fig. 2, and the amplitude of the solid line a-phase signal 22 becomes smaller than the amplitude of the solid line B-phase signal 24. Thus, the lissajous waveform 20' of fig. 2 is an ellipse having a minor axis direction in the direction of the transverse axis and a major axis direction in the direction of the longitudinal axis. Here, in fig. 3, when the solid-line a-phase signal 22 is adjusted to have the same amplitude as the B-phase signal 24, the signal becomes the broken-line a-phase signal 22. The lissajous waveform 20 of fig. 2 can be obtained from the a-phase signal 22 and the B-phase signal 24 of the broken lines.

As described above, in order to correct the error of the lissajous angle caused by the addition of the error to the a-phase signal 22 and the B-phase signal 24, the encoder 10 is provided with the amplitude adjustment unit 26 between the output terminal 12a of the phase signal generation unit 12 and the input terminal 14a of the lissajous angle calculation unit 14. The amplitude adjustment unit 26 adjusts only the amplitude of the input a-phase signal 22a (22), and outputs the adjusted a-phase signal 22b (22) to the lissajous angle calculation unit 14. Specifically, the amplitude adjustment unit 26 is constituted by a variable resistor or the like, and can adjust the amplitude of the a-phase signal 22b by changing the resistance value by an operation of the operator.

Further, an amplitude detection device 28 is provided outside the encoder 10. The amplitude detection device 28 detects the amplitude of the phase a signal 22B output from the amplitude adjustment unit 26 and the amplitude of the phase B signal 24 output from the output terminal 12B of the phase signal generation unit 12. The amplitude detection device 28 has a display unit (not shown), and displays the amplitude value of the a-phase signal 22B and the amplitude value of the B-phase signal 24 to the operator. The operator operates the amplitude adjustment unit 26 while observing the display on the display unit of the amplitude detection device 28, and can adjust the amplitude of the a-phase signal 22B to be equal to the amplitude of the B-phase signal 24. Although the amplitude detection device 28 is provided outside the encoder 10 in fig. 1, the amplitude detection device 28 may be provided inside the encoder 10. In this case, the amplitude detection device 28 may not have a display unit, and a display unit may be provided outside the encoder 10.

As described above, by adjusting the a-phase signal 22 of the solid line of fig. 3 to the a-phase signal 22 of the broken line, the shape of the lissajous waveform is adjusted to a circular shape like the lissajous waveform 20. This makes it possible to obtain an accurate lissajous angle θ, and the lissajous angle calculation unit 14 can accurately output a signal indicating the position of the measurement target.

Conventionally, hardware such as a circuit for correcting two-phase signals is required in order to obtain an accurate lissajous angle from analog signals whose phases are different from each other by 90 degrees. However, the encoder 10 according to the embodiment can obtain an accurate lissajous angle by hardware that adjusts the amplitude of only one phase of the analog signal. Therefore, according to the encoder 10 of the embodiment, an accurate lissajous angle can be obtained with a simple configuration as compared with the conventional one.

Fig. 4 is a flowchart illustrating a control method of the encoder 10 in the embodiment.

First, the phase signal generating unit 12 generates and outputs the a-phase signal 22 and the B-phase signal 24 of sine waves having phases different by 90 degrees from each other, in accordance with the movement of the measurement object (step S1).

Next, the amplitude detection device 28 detects the amplitude of the a-phase signal 22b output from the amplitude adjustment unit 26 (step S2).

Further, the amplitude detection device 28 detects the amplitude of the B-phase signal 24 output from the output terminal 12B of the phase signal generation unit 12 (step S3).

Then, the operator operates the amplitude adjustment unit 26 while observing the display on the display unit of the amplitude detection device 28, to adjust only the amplitude of the a-phase signal 22B so as to be equal to the amplitude of the B-phase signal 24 (step S4).

Then, in step S4, the lissajous angle calculation unit 14 obtains the lissajous angle θ based on the a-phase signal 22B and the B-phase signal 24 adjusted and outputted by the amplitude adjustment unit 26 (step S5).

In the above-described embodiment, the case where the amplitude adjustment unit 26 is provided so that the amplitude of the a-phase signal 22 can be adjusted has been described. However, the amplitude adjusting unit 26 may be provided between the output terminal 12B of the phase signal generating unit 12 and the input terminal 14B of the lissajous angle calculating unit 14, and may adjust only the amplitude of the B-phase signal 24.

[ modified examples ]

The above embodiment may be modified as follows.

(modification 1)

Fig. 5 is a block diagram of the encoder 10 according to modification 1. In the above embodiment, the adjustment of adjusting the amplitude of the a-phase signal 22B to be equal to the amplitude of the B-phase signal 24 is performed by the operation of the operator. The encoder 10 of modification 1 performs this adjustment by automatic adjustment. Therefore, in fig. 5, a control device 32 is added to the outside of the encoder 10 in fig. 1.

The amplitude of the a-phase signal 22B and the amplitude of the B-phase signal 24 detected by the amplitude detection device 28 are input to the control device 32. The control device 32 has a driver (not shown) and mechanically controls a variable resistor of the amplitude adjustment unit 26 and the like to automatically adjust the amplitude of the a-phase signal 22 so that the amplitude of the a-phase signal 22B becomes equal to the amplitude of the B-phase signal 24. That is, in the flowchart of the control method of the encoder 10 in the modification, the execution subject of step S4 in fig. 4 is changed to the control device 32 by the operator, but the other steps are the same as those in the above embodiment. This automatically adjusts the amplitude of the a-phase signal 22B to be equal to the amplitude of the B-phase signal 24. As a result, the number of man hours of the operator can be saved.

In fig. 5, the amplitude detection device 28 and the control device 32 are provided outside the encoder 10, but both the amplitude detection device 28 and the control device 32 may be provided inside the encoder 10.

[ invention obtained from the embodiment ]

The invention that can be grasped from the above-described embodiments and modifications is described below.

(first invention)

Encoder (10), comprising: a phase signal generation unit (12) that generates and outputs a first analog signal and a second analog signal of sine waves having phases that differ by 90 degrees from each other, in accordance with the movement of the measurement object; a lissajous angle calculation unit (14) that calculates a lissajous angle from the first analog signal and the second analog signal; and an amplitude adjustment unit (26) that adjusts only the amplitude of the first analog signal output from the phase signal generation unit (12) and outputs the adjusted amplitude to the lissajous angle calculation unit (14).

Thus, an accurate lissajous angle can be obtained with a simple configuration as compared with the conventional one.

The amplitude adjustment unit (26) may automatically adjust and output the amplitude of the first analog signal to be equal to the amplitude of the second analog signal. This can save the number of man hours for the operator.

(second invention)

A method of controlling an encoder, comprising: a phase signal generation step of generating and outputting a first analog signal and a second analog signal of sine waves having phases different by 90 degrees from each other, in accordance with the movement of the measurement object; a lissajous angle calculation step of calculating a lissajous angle from the first analog signal and the second analog signal; and an amplitude adjusting step of adjusting only the amplitude of the first analog signal output from the phase signal generating step and outputting the adjusted amplitude to the lissajous angle calculating step.

Thus, an accurate lissajous angle can be obtained with a simple configuration as compared with the conventional one.

The amplitude adjustment step may automatically adjust the amplitude of the first analog signal to be equal to the amplitude of the second analog signal, and output the adjusted amplitude. This can save the number of man hours for the operator.

The control method of the encoder (10) further includes a step of detecting the amplitude of the first analog signal and a step of detecting the amplitude of the second analog signal.