TWI703311B - A double-feedback rotary encoder eccentricity correction apparatus - Google Patents

Abstract

A double-feedback rotary encoder eccentricity correction apparatus comprises a servo driver, a first rotary encoder and a second rotary encoder. The servo driver transforms a servo speed order to a current control order in order to control spinning of an axis of a rotor. A transmission apparatus is activated by the axis of the rotor, and a main machine axis is activated by the transmission apparatus. The first rotary encoder is connected to the motor. The first rotary encoder is capable of producing a first speed feedback of rotary encoder by measuring spin rate of the axis of the rotor and then delivering the first speed feedback of rotary encoder to the servo driver. The second rotary encoder is connected to the main machine axis. The second rotary encoder is capable of producing a second speed feedback of rotary encoder by measuring spin rate of the main machine axis and then delivering the second speed feedback of rotary encoder to the servo driver.

Description

Double feedback rotary encoder eccentricity correction device

The present invention relates to a device for eccentricity correction of a rotary encoder, and more particularly to a device for double feedback eccentricity correction through two or more rotary encoders.

In mechanical spindle applications, such as machine tool lathe spindles or robot mechanical spindles, due to the need for accurate positioning of the spindle, the existing technology will install an encoder on the spindle side to avoid the mechanical error of the belt transmission structure and reduce the positioning accuracy. However, If the encoder on the spindle side is installed with eccentricity, it will cause the spindle to be positioned incorrectly. Therefore, most suppliers usually use strict installation specifications to limit the physical eccentricity caused by the on-site installation or use traditional correction modules. However, these methods will not only increase multi-channel verification procedures, allow the installation of machine tool lathe spindles or The mechanical spindle of the robot takes a lot of time, which greatly reduces the user friendliness of the product, and also increases the time and money required to correct the eccentricity error.

Therefore, the present invention provides a device for rapid eccentricity correction of a mechanical spindle in response to the above-mentioned deficiency in the prior art.

The previous technical paragraphs are only used to help understand the content of the present invention. Therefore, the content disclosed in the previous technical paragraphs may include some that do not constitute what is known to those with ordinary knowledge in the technical field. Of learned technology. The content disclosed in the previous technical paragraph does not represent the content or the problem to be solved by one or more embodiments of the present invention, and has been known or recognized by those with ordinary knowledge in the technical field before the application of the present invention.

Based on the shortcomings of the prior art, the object of the present invention is to provide a double feedback rotary encoder eccentricity correction device, which can save the time of installing the mechanical spindle.

Another object of the present invention is to provide a double feedback rotary encoder eccentricity correction device, which can make the motor have better running quality.

In order to achieve part or all of the above objectives or other objectives, the present invention provides a double feedback rotary encoder eccentricity correction device, including a servo driver, a first rotary encoder and a second rotary encoder. The servo driver will The servo speed command is converted into a current control command to control the rotation of the motor shaft. When the motor shaft rotates, the transmission mechanism is driven, and the mechanical spindle is driven through the transmission mechanism; the first rotary encoder is electrically connected to the motor and measured The speed feedback of the first rotary encoder is generated after measuring the rotation speed of the rotating shaft of the motor, and the speed feedback of the first rotary encoder is transmitted to the servo drive; the second rotary encoder is electrically connected to the mechanical spindle, and the mechanical The rotation speed of the rotating shaft of the main shaft generates a second rotary encoder speed feedback, and transmits the second rotary encoder speed feedback to the servo driver.

In one embodiment, the servo driver includes a subtractor, and the servo driver receives the speed feedback of the first rotary encoder and the speed feedback of the second rotary encoder, and returns the speed of the first rotary encoder and the second rotary encoder through the subtractor. The encoder speed feedback subtraction produces the speed feedback error, and the error model of the speed feedback error is a sine wave.

In one embodiment, the servo driver calculates the position eccentricity error according to the speed feedback error, and uses the position eccentricity error as a correction table to perform eccentricity self-correction.

In one embodiment, the servo drive further includes an integrator, and the integrator generates a corresponding position eccentricity error according to the integration of the speed feedback error.

In an embodiment, the servo driver further includes a lock-in amplifier, and the lock-in amplifier calculates the amplitude and phase of the position eccentricity error according to the position eccentricity error.

In an embodiment, the amplitude and phase may be sine wave values.

In one embodiment, the servo driver further includes a position eccentricity error data storage device, and the servo driver stores the position eccentricity error in the position eccentricity error data storage device to form a correction table.

In one embodiment, the correction table includes the amplitude and phase of the position eccentricity error.

In an embodiment, the servo driver may be an integrated drive and control device.

In an embodiment, the first rotary encoder and the second rotary encoder may be magnetic, optical or electromagnetic induced rotary encoders, and the second rotary encoder includes a sensed part and a sensing part, and the sensed part is located at The mechanical spindle is electrically connected to the sensing part.

In an embodiment, the transmission mechanism may be a belt set, a reducer, a gear or a coupling.

Based on the above, the embodiments of the present invention have at least one of the following advantages or effects. In the embodiment of the present invention, without installing additional position sensors or external precision measurement equipment and other calibration equipment, the speed feedback is received by the double feedback rotary encoder eccentricity correction device and the calculation is performed Later, it can predict the eccentricity error and generate feedback compensation based on the eccentricity error. This feedback compensation will allow the servo drive to generate the next control command without eccentricity error, and use this to fix the accuracy error, which can improve instantly The precision performance when the motor is running gives the motor a better running quality.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

1: Double feedback rotary encoder eccentricity correction device

10: Servo drive

101: Subtractor

102: Integrator

103: Lock-in amplifier

104: Position eccentricity error data storage device

1041: Calibration table

11: Motor

111: The axis of rotation of the motor

12: The first rotary encoder

13: Transmission mechanism

14: Mechanical spindle

15: The second rotary encoder

151: Sensor

152: sensed part

A-ECCD _ERROR : Amplitude of position eccentricity error

ECCD _ERROR : Position eccentricity error

P-ECCD _ERROR : Phase of position eccentricity error

I _CMD : Current control command

V _CMD : Servo speed command

V _ERROR : Speed recovery error

V _IBD1 : The first rotary encoder speed feedback

V _IBD2 : Second rotary encoder speed feedback

FIG. 1 is a diagram showing the eccentricity correction device of a double feedback rotary encoder provided by the present invention according to the technology disclosed in the present invention; and FIG. 2 is an embodiment according to FIG. 1 showing the double feedback rotary encoder provided by the present invention Schematic diagram of the servo driver of the eccentric correction device.

In order to enable your reviewer to have a better understanding and approval of the structural purpose and effect of the present invention, the detailed description is given below with the drawings. The technical means and effects used to achieve the purpose of the invention will be described below with reference to the drawings, and the examples listed in the following drawings are only an aid to help your reviewers understand, but the technical means of this case are not limited to the enumerated Schema. In addition, the directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only directions for referring to the attached drawings. Therefore, the directional terms used are used to illustrate but not to limit the present invention.

Please refer to Figure 1. Figure 1 is a double feedback rotary encoder eccentricity correction device proposed by an embodiment of the present invention, suitable for installation on existing processing machines, the double feedback rotary encoder eccentricity correction device 1 includes a servo drive 10. Motor 11, first rotary encoder 12, transmission mechanism 13, mechanical spindle 14, and second rotary encoder 15, servo drive 10, motor 11, first rotary encoder 12, transmission mechanism 13, mechanical spindle 14, and the first The two rotary encoders 15 are electrically connected to each other, and the way of electrical connection For example, it may be a wired or wireless connection. It is worth noting that the double feedback rotary encoder eccentricity correction device 1 in this embodiment may include more than two rotary encoders. Here, two rotary encoders are taken as an example, but it is not limited thereto.

Please continue to refer to Figure 1. The servo driver 10 in the double feedback rotary encoder eccentricity correction device 1 can command V _CMD according to the servo speed, and convert the servo speed command V _CMD into a current control command I _CMD to control the rotating shaft of the motor 11 The center 111 rotates, the motor 11 drives the transmission mechanism 13 through the rotating shaft 111, and drives the mechanical spindle 14 to rotate through the transmission mechanism 13. The servo speed command V _{CMD is} for example issued by an external controller, which is a conventional Control elements such as computers, chipsets, etc., are not limited by the present invention. The servo driver 10 can be an integrated drive and control device, but is not limited to this. The servo driver 10 can generate a servo speed command V _CMD according to a rotation speed preset by the user. In addition, the mechanical main shaft 14 may be a belt set of a lathe, a reducer of a robot, a gear or a coupling of other applications, etc. depending on the application field, and the present invention is not limited thereto.

The first rotary encoder 12 is electrically connected to the motor 11. The first rotary encoder 12 measures the rotation speed of the rotating shaft 111 of the motor 11 to generate the first rotary encoder speed feedback V _IBD1 , and connects the first rotary encoder The speed feedback V _{IBD1 is} transmitted to the servo driver 10, the second rotary encoder 15 is electrically connected to the mechanical spindle 14, and the second rotary encoder 15 measures the rotation axis of the mechanical spindle 14 (not shown in Figure 1). The second rotary encoder speed feedback V _IBD2 , and the second rotary encoder speed feedback V _{IBD2 is} transmitted to the servo driver 10. In this embodiment, the first rotary encoder 12 and the second rotary encoder 15 may be magnetic, optical or electromagnetic induced rotary encoders, etc., and the second rotary encoder 15 further includes a sensed part 152 and a sensing part 151 The sensed part 152 is located on the mechanical main shaft 14 and is electrically connected to the sensing part 151, which is not limited by the present invention.

In addition, the servo driver 10 receives the first rotary encoder speed feedback V _IBD1 and the second rotary encoder speed feedback V _IBD2 , and according to the first rotary encoder speed feedback V _IBD1 and the second rotary encoder speed feedback V _The subtraction of _IBD2 produces a speed feedback error V _error , where the error model of the speed feedback error V _error is a sine wave, such as a sine wave. The servo drive 10 calculates the position eccentricity error ECCD _error according to the speed feedback error V _error , and uses the position eccentricity error ECCD _error as a correction table for the servo drive 10 to perform the second rotary encoder 15 to the rotation axis of the mechanical spindle 14 according to the correction table. Perform eccentricity correction to adjust the eccentricity error of the mechanical spindle 14 and store the correction table in the servo driver 10, or store the correction table in the second rotary encoder 15 for the second rotary encoder 15 to self-calibrate. As a result, compared with the existing single encoder configuration, the double feedback rotary encoder eccentricity correction device of the present invention can effectively solve the positioning error and backlash caused by the transmission mechanism, thereby improving the installation of the double feedback rotary encoder of the present invention. The positioning accuracy and smoothness of the processing machine of the encoder eccentricity correction device can also determine whether the transmission mechanism is damaged by detecting the position eccentricity error, so as to improve the processing efficiency.

Please refer to FIG. 2. FIG. 2 is a system architecture diagram of the servo driver 10 in the double feedback rotary encoder eccentricity correction device 1 according to the embodiment of FIG. The servo driver 10 further includes a subtractor 101, an integrator 102, a lock-in amplifier 103, and a position eccentricity error data storage device 104. The subtractor 101, integrator 102, a lock-in amplifier 103, and a position eccentricity error data storage device 104 are electrically connected to each other They are all calculated in a linear manner. In this embodiment, the component sequence of the integrator 102 and the lock-in amplifier 103 can also be reversed, which is not limited in the present invention. After the servo driver 10 receives the first rotary encoder speed feedback V _IBD1 and the second rotary encoder speed feedback V _IBD2 , the first rotary encoder speed feedback V _IBD1 and the second rotary encoder speed feedback from the subtractor 101 V _IBD2 is subtracted to generate a speed feedback error V _error and sent to the integrator 102. The integrator 102 performs an integration operation according to the velocity feedback error V _error to generate a corresponding position eccentricity error ECCD _error , and transmits it to the lock-in amplifier 103. The lock-in amplifier 103 calculates the position of the eccentric position of the eccentric ECCD _error error error ECCD _error of the amplitude and the phase A-ECCDerror P-ECCDerror, wherein the amplitude and the phase A-ECCDerror P-ECCDerror sine wave value, for example, may be a sine value sine Or the cosine value. Eccentricity error position data storage device 104 may store the position of the eccentric _error between the amplitude values and the phase A-ECCDerror P-ECCDerror ECCD error, and the position of the eccentric _error between the amplitude values and the phase A-ECCDerror P-ECCDerror made into the error correction table ECCD 1041 is stored in the position eccentricity error data storage device 104 for the second rotary encoder 15 to perform eccentricity self-calibration.

In the present invention, only the signals of the first rotary encoder speed feedback V _IBD1 and the second rotary encoder speed feedback V _IBD2 are subtracted to obtain the speed feedback error V _error , and for the speed feedback error V _error After the signal is integrated to phase lock, the amplitude and phase values of the position eccentricity error ECCD _error can be obtained. An example of the correction table 1041 is shown in Table 1, and the correction table 1041 is stored in the eccentricity error data storage device 104 of the servo drive 10 , For the servo driver 10 to perform eccentricity error correction according to the correction table 1041.

The above are only preferred embodiments of the present invention, and are not intended to limit the scope of rights of the present invention. At the same time, the above description should be understood and implemented by those skilled in the relevant technical fields, because other things do not deviate from the spirit of the present invention. All equivalent changes or modifications completed should be included in the scope of the patent application.

1: Double feedback rotary encoder eccentricity correction device

10: Servo drive

11: Motor

111: The axis of rotation of the motor

12: The first rotary encoder

13: Transmission mechanism

14: Mechanical spindle

15: The second rotary encoder

151: Sensor

152: sensed part

V _IBD1 : The first rotary encoder speed feedback

V _IBD2 : Second rotary encoder speed feedback

Claims (8)

A double feedback rotary encoder eccentricity correction device, comprising: a servo driver, including a subtractor and an integrator, the servo driver converts the servo speed command into a current control command according to a servo speed command to control a motor When the rotation axis rotates, the rotation axis of the motor drives a transmission mechanism, and drives a mechanical spindle to rotate through the transmission mechanism; a first rotary encoder is electrically connected to the motor, and the first rotary encoder is After measuring the rotation speed of the rotating shaft of the motor, a first rotary encoder speed feedback is generated, and the first rotary encoder speed feedback is transmitted to the servo drive; and a second rotary encoder, and the mechanical spindle Electrically connected, the second rotary encoder measures the rotational speed of the rotating shaft of the mechanical spindle to generate a second rotary encoder speed feedback, and transmits the second rotary encoder speed feedback to the servo driver; The servo driver receives the speed feedback of the first rotary encoder and the speed feedback of the second rotary encoder, and returns the speed of the first rotary encoder and the speed of the second rotary encoder through the subtractor The subtraction produces a speed feedback error. The error model of the speed feedback error is a sine wave. The servo drive calculates a position eccentricity error according to the speed feedback error, and uses the position eccentricity error as a correction table for eccentricity Self-correction, and the integrator generates the corresponding position eccentricity error according to the speed feedback error integration. For example, the double feedback rotary encoder eccentricity correction device in the scope of the patent application, wherein the servo driver further includes a lock-in amplifier, and the lock-in amplifier calculates an amplitude and a phase of the position eccentricity error according to the position eccentricity error . For example, the double feedback rotary encoder eccentricity correction device of the second item of the scope of patent application, wherein the amplitude and the phase can be sine wave values. For example, the double feedback rotary encoder eccentricity correction device in the scope of patent application, wherein the servo driver further includes a position eccentricity error data storage device, and the servo driver stores the position eccentricity error in the position eccentricity error data storage device Form a correction table. For example, the double feedback rotary encoder eccentricity correction device of item 4 of the scope of patent application, wherein the correction table includes the amplitude and the phase of the position eccentricity error. For example, the double feedback rotary encoder eccentricity correction device of the first item in the scope of patent application, wherein the servo driver can be an integrated drive and control device. For example, the double feedback rotary encoder eccentricity correction device of the first item in the scope of patent application, wherein the first rotary encoder and the second rotary encoder can be magnetic, optical or electromagnetic induced rotary encoders, and the second rotary encoder The device includes a sensed element and a sensing element, and the sensed element is located on the mechanical spindle and electrically connected to the sensing element. For example, the double feedback rotary encoder eccentricity correction device of the first item of the scope of patent application, wherein the transmission mechanism can be a belt group, a reducer, a gear or a coupling.

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