CN219551549U

CN219551549U - Optical encoder and servo system

Info

Publication number: CN219551549U
Application number: CN202223465871.XU
Authority: CN
Inventors: 张开新; 周凯
Original assignee: Suzhou Huichuan Control Technology Co Ltd
Current assignee: Suzhou Huichuan Control Technology Co Ltd
Priority date: 2022-12-21
Filing date: 2022-12-21
Publication date: 2023-08-18
Anticipated expiration: 2032-12-21

Abstract

The utility model discloses an optical encoder and a servo system, and belongs to the technical field of position detection. The optical encoder comprises an optical sensing chip, an analog-to-digital conversion module and a single-turn analysis module, wherein: the optical sensing chip is used for converting the received optical signals into main code channel sine and cosine analog signals, vernier code channel sine and cosine analog signals and segment code channel sine and cosine analog signals; the analog-to-digital conversion module is used for converting the main code channel sine and cosine analog signals, the cursor code channel sine and cosine analog signals and the segment code channel sine and cosine analog signals into main code channel sine and cosine digital signals, cursor code channel sine and cosine digital signals and segment code channel sine and cosine digital signals; the single-circle analysis module is used for processing the main code channel sine and cosine digital signals, the cursor code channel sine and cosine digital signals and the segment code channel sine and cosine digital signals in parallel based on the vernier principle by utilizing the hardware logic controller, and analyzing to obtain single-circle absolute position information. The utility model aims to reduce the delay time of the output position of the encoder and improve the response speed of a servo system.

Description

Optical encoder and servo system

Technical Field

The present utility model relates to the field of position detection technologies, and in particular, to an optical encoder and a servo system.

Background

The servo motor is widely applied to automatic production, laser cutting, robots and other high-precision and high-speed automatic control systems. The servo encoder is used as one of the most important components of the servo motor and is responsible for feeding back the rotated position information of the motor, and the performance of the servo encoder directly determines the precision and the response speed of the servo system.

At present, most of the mainstream servo encoders in the market are communication encoders, including magnetic encoders and optical encoders, the two encoder main control chips adopt MCU to perform position analysis, but the logic of MCU serial processing causes longer position feedback delay of the communication encoder, thereby causing lower response speed of the servo system.

Disclosure of Invention

The utility model mainly aims to provide an optical encoder and a servo system, which aim to reduce the delay time of the output position of the encoder and improve the response speed of the servo system.

In order to achieve the above objective, the present utility model provides an optical encoder, which includes an optical sensing chip, an analog-to-digital conversion module and a single-turn analysis module, wherein a first output end of the optical sensing chip is connected to a first input end of the analog-to-digital conversion module, and an output end of the analog-to-digital conversion module is electrically connected to the first input end of the single-turn analysis module, wherein:

the optical sensing chip is used for converting the received optical signals into main code channel sine and cosine analog signals, cursor code channel sine and cosine analog signals and segment code channel sine and cosine analog signals;

the analog-to-digital conversion module is used for converting the main code channel sine and cosine analog signals, the cursor code channel sine and cosine analog signals and the segment code channel sine and cosine analog signals into main code channel sine and cosine digital signals, cursor code channel sine and cosine digital signals and segment code channel sine and cosine digital signals;

the single-circle analysis module is used for processing the main code channel sine and cosine digital signals, the cursor code channel sine and cosine digital signals and the segment code channel sine and cosine digital signals in parallel based on a vernier principle by utilizing a hardware logic controller, and analyzing to obtain single-circle absolute position information.

Optionally, the device further comprises a TMR chip, wherein a first output end of the TMR chip is electrically connected with a third input end of the single-turn analysis module, and the first input end of the TMR chip is electrically connected with the third input end of the single-turn analysis module, wherein:

the TMR chip is used for generating a measurement signal when the optical encoder rotates for one circle and transmitting the measurement signal to the single-circle analysis module;

the single-turn analysis module is further used for counting the rotation number of the optical encoder based on the received measurement signal when the optical encoder is in a normal power supply state.

Optionally, the TMR chip further comprises a multi-turn parsing module and an exclusive-or gate circuit, wherein the first output end of the TMR chip is electrically connected with the first input end of the multi-turn parsing module, the second output end of the TMR chip is electrically connected with the input end of the exclusive-or gate circuit, and the output end of the exclusive-or gate circuit is electrically connected with the second input end of the multi-turn parsing module, wherein:

the TMR chip is also used for generating a measurement signal when the optical encoder rotates for one circle and transmitting the measurement signal to the exclusive OR gate circuit;

the TMR chip is also used for generating a measurement number signal when the optical encoder rotates for one circle and transmitting the measurement number signal to the multi-circle analysis module;

the exclusive-OR gate circuit is used for generating an excitation signal based on the measurement signal and outputting the excitation signal for waking up the multi-turn analysis module;

the multi-turn analysis module is used for counting the number of rotations of the optical encoder based on the received measurement signal after being awakened when the optical encoder is in a normal power supply state or a power failure state.

Optionally, the device further comprises a voltage monitoring module, an input end of the voltage monitoring module is connected with a power supply input end of the multi-ring analysis module, an output end of the voltage monitoring module is electrically connected with a second input end of the multi-ring analysis module, and an output end of the multi-ring analysis module is connected to a fourth input end of the single-ring analysis module, wherein:

the voltage monitoring module is used for outputting a pulse signal to the multi-turn analysis module when the voltage of the power supply input end of the multi-turn analysis module is monitored to be greater than or equal to a first preset threshold value, and the pulse signal is used for waking up the multi-turn analysis module;

and the multi-turn analysis module is used for sending the rotation turns of the optical encoder obtained by current counting to the single-turn analysis module after receiving the pulse signals.

Optionally, the output end of the multi-turn parsing module is connected with the fourth input end of the single-turn parsing module through an SPI interface.

Optionally, the first output end of the analog-to-digital conversion module is connected with the first input end of the single-turn analysis module through an SPI interface.

Optionally, the hardware logic controller includes: FPGA, CPLD or ASIC.

Optionally, the optical sensor further comprises a comparator and an amplifier, wherein the input end of the amplifier is connected to the first output end of the optical sensor chip, the output end of the amplifier is connected to the first input end of the analog-to-digital conversion module, the input end of the comparator is connected to the second output end of the optical sensor chip, and the output end of the comparator is connected to the second input end of the single-turn analysis module, wherein:

the amplifier is used for amplifying the main code channel sine and cosine analog signals, the cursor code channel sine and cosine analog signals and the segment code channel sine and cosine analog signals, and sending the amplified main code channel sine and cosine analog signals, cursor code channel sine and cosine analog signals and the segment code channel sine and cosine analog signals to the analog-to-digital conversion module;

the comparator is used for performing waveform conversion processing on the main code channel sine and cosine analog signal and the vernier code channel sine and cosine analog signal to obtain a first orthogonal square wave and a second orthogonal square wave, and sending the first orthogonal square wave and the second orthogonal square wave to the single-turn analysis module through a second output end of the optical sensing chip;

or the optical sensing chip comprises a comparator and an amplifier, and a second output end of the optical sensing chip is connected to the single-circle analysis module, wherein:

the amplifier is used for amplifying the main code channel sine and cosine analog signals, the cursor code channel sine and cosine analog signals and the segment code channel sine and cosine analog signals, and transmitting the amplified main code channel sine and cosine analog signals, cursor code channel sine and cosine analog signals and the segment code channel sine and cosine analog signals to the analog-to-digital conversion module through the first output end of the optical sensing chip;

the comparator is used for performing waveform conversion processing on the main code channel sine and cosine analog signal and the vernier code channel sine and cosine analog signal to obtain a first orthogonal square wave and a second orthogonal square wave, and the first orthogonal square wave and the second orthogonal square wave are sent to the single-turn analysis module through the second output end of the optical sensing chip.

Optionally, the servo controller further comprises an RS485 bus, wherein the I/O interface of the single-turn analysis module is used for transmitting the single-turn absolute position information and the count value of the number of rotations to the servo controller through the RS485 bus.

The utility model also proposes a servo system comprising an encoder as described above.

According to the technical scheme, the optical sensing chip is used for converting the received optical signals into the main code channel sine and cosine analog signals, the cursor code channel sine and cosine analog signals and the section code channel sine and cosine analog signals, the analog-to-digital conversion module is used for carrying out analog-to-digital conversion processing on the three groups of sine and cosine analog signals to obtain the main code channel sine and cosine digital signals, the cursor code channel sine and cosine digital signals and the section code channel sine and cosine digital signals, the single-turn analysis module is used for carrying out parallel processing on the main code channel sine and cosine digital signals, the cursor code channel sine and cosine digital signals and the section code channel sine and cosine digital signals based on a cursor principle, single-turn absolute position information is obtained through analysis, the delay time of outputting the single-turn absolute position information by a servo system is greatly reduced, and the dynamic response speed of the servo system is improved.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a first embodiment of an optical encoder according to the present utility model;

FIG. 2 is a schematic diagram of a second embodiment of an optical encoder according to the present utility model;

FIG. 3 is a schematic diagram showing the electrical angles of the main track and the cursor track of the optical encoder and the distance of one rotation of the optical encoder;

FIG. 4 is a diagram showing the absolute position information of a single turn output by the optical encoder and the distance of one turn of the optical encoder;

FIG. 5 is a schematic diagram of three sets of sine and cosine digital signals generated by the optical encoder and the distance of one rotation of the optical encoder.

Reference numerals illustrate:

reference numerals	Name of the name	Reference numerals	Name of the name
				1	Optical sensing chip	2	Amplifier
3	Comparator with a comparator circuit	4	Analog-to-digital conversion module
				5	Single-circle analysis module	6	TMR chip
7	exclusive-OR gate circuit	8	Voltage monitoring module
				9	Multi-turn analysis module	10	RS485 bus

The achievement of the objects, functional features and advantages of the present utility model will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present utility model are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

In the present utility model, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" as it appears throughout is meant to include three side-by-side schemes, for example, "a and/or B", including a scheme, or B scheme, or a scheme that is satisfied by both a and B. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present utility model.

As shown in fig. 1, a schematic structural diagram of a first embodiment of an optical encoder of the present utility model, which may be installed in a servo motor of a servo system, is suitable for closed-loop control of the servo motor.

The optical encoder in this embodiment may include an optical sensing chip 1, an analog-to-digital conversion module 4 and a single-turn analysis module 5, where a first output end of the optical sensing chip 1 is connected to a first input end of the analog-to-digital conversion module 4, and an output end of the analog-to-digital conversion module 4 is electrically connected to the first input end of the single-turn analysis module 5. Wherein: the optical encoder comprises a code disc, wherein a main code channel, a vernier code channel and a section code channel which are arranged along the measuring direction are arranged on the code disc, each code channel consists of light-transmitting and light-non-transmitting sector areas which are alternately arranged, one side of the code disc is provided with a light source, the other side of the code disc is correspondingly provided with the optical sensing chip 1, and the optical sensing chip 1 is used for receiving light transmitted or reflected by the code disc, converting optical signals into electric signals and outputting sine and cosine analog signals; that is, the optical sensing chip 1 is configured to convert the received optical signal into a main code channel sine and cosine analog signal, a cursor code channel sine and cosine analog signal, and a segment code channel sine and cosine analog signal; the analog-to-digital conversion module 4 is configured to convert the main code channel sine and cosine analog signals, the cursor code channel sine and cosine analog signals, and the segment code channel sine and cosine analog signals (as shown in fig. 5, the ordinate in fig. 5 is the sine and cosine analog signals, and the abscissa is the distance of one rotation of the optical encoder) into main code channel sine and cosine digital signals, cursor code channel sine and cosine digital signals; the single-circle analysis module 5 is used for processing the main code channel sine and cosine digital signals, the cursor code channel sine and cosine digital signals and the segment code channel sine and cosine digital signals in parallel based on the vernier principle by utilizing a hardware logic controller, and analyzing to obtain single-circle absolute position information.

It should be noted that, the optical encoder includes 3 code tracks: the outer ring (main code channel) has n lines, the middle ring (vernier code channel) has n-1 lines, and the inner ring (section code channel) has n-m lines; and the score lines on the main track typically satisfy the power of 2 data, such as 256, 512, 1024, etc. The phase difference of the run code track to the main code track is uniquely determined over the optical encoder distance, and the phase difference of the segment code track to the main code track is periodically varied over the optical encoder distance. The optical encoder is divided into a plurality of large sections by the periodic phase difference of the segment code channel to the main code channel to obtain a coarse code, and the sub-coarse code and the fine code are obtained by combining the phase difference of the stream mark code channel to the main code channel, so that the current position information can be accurately combined.

After the optical encoder provided by the embodiment carries out analog-to-digital conversion on the sine and cosine signals of the main code channel, the cursor code channel and the segment code channel, a hardware logic controller can be utilized to process the sine and cosine digital signals of the main code channel, the cursor code channel and the segment code channel in parallel based on the cursor principle, single-circle absolute position information is obtained through analysis, the delay time of outputting the single-circle absolute position information by the servo system is greatly reduced, and the dynamic response speed of the servo system is improved.

It should be noted that, in this embodiment, analysis of a single-circle absolute position can be implemented based on the vernier principle, so that the optical encoder can obtain the position information rotated by the servo motor without passing through a zero point, and compared with the case of adopting the MCU (Microcontroller Unit, micro control unit) to perform position analysis, the present embodiment can analyze the original analog information of three groups of six optical encoders at the same time based on the vernier principle because of longer position feedback delay of the encoder caused by the logic of MCU serial processing, and quickly output the position information, and control the output delay to be within 1us at the lowest, thereby improving the response speed of the servo system.

Wherein the hardware logic controller may comprise: FPGA (field programmable logic control array), CPLD (complex programmable logic device) or ASIC (application specific integrated circuit chip). It should be understood, of course, that other possible hardware logic controllers or hardware integrated circuits are also possible, and specifically may be determined according to practical situations, which is not limited by the embodiments of the present disclosure.

In one embodiment, the method for analyzing and obtaining single-circle absolute position information based on the vernier principle includes:

determining the phase angle of the main code channel sine and cosine digital signals, the phase angle of the cursor code channel sine and cosine digital signals and the phase angle of the segment code channel sine and cosine digital signals;

subtracting the phase angle of the sine and cosine digital signals of the main code channel from the phase angle of the sine and cosine digital signals of the cursor code channel to obtain the phase difference of the sine and cosine digital signals of the main code channel and the sine and cosine digital signals of the cursor code channel;

subtracting the phase angle of the main code channel sine and cosine digital signal from the phase angle of the segment code channel sine and cosine digital signal to obtain the phase difference of the main code channel sine and cosine digital signal and the segment code channel sine and cosine digital signal;

calculating to obtain a first coding value based on the phase difference between the sine and cosine digital signals of the main code channel and the sine and cosine digital signals of the cursor code channel;

calculating a second coding value based on the phase difference between the main code channel sine and cosine digital signals and the segment code channel sine and cosine digital signals;

and splicing the high N bits of the first code value with the low S bits of the second code value to obtain single-circle absolute position information.

The method for determining the phase angle of the sine and cosine digital signal of the main code channel comprises the following steps: the tangent is obtained by dividing the main code channel sine digital signal and the main code channel cosine digital signal, and then the phase angle is obtained by the arc tangent. The process of determining the phase angle of the sine and cosine digital signal of the cursor code channel and the phase angle of the sine and cosine digital signal of the segment code channel is the same as the process of determining the phase angle of the sine and cosine digital signal of the main code channel, and will not be described again here.

The digital angle (first code value) of the phase difference between the main code channel sine and cosine digital signal and the section code channel sine and cosine digital signal can be obtained by performing interpolation subdivision on the main code channel sine and cosine digital signal, the section code channel sine and cosine digital signal and the section code channel sine and cosine digital signal.

Wherein N is the length of data bits obtained by subdivision of the run code channel, and S is the length of data bits obtained by subdivision of the segment code channel. For example, when the number of grids corresponding to the main code track, the cursor code track and the segment code track is 1024, 1023 and 992 respectively, N is equal to 5,S and is equal to 5; when the number of grids corresponding to the main code channel, the cursor code channel and the segment code channel is 512, 511 and 496 respectively, N is equal to 4, and S is equal to 5; when the number of grids corresponding to the main code channel, the cursor code channel and the segment code channel is 2048, 2047 and 2016 respectively, N is equal to 5,S and is equal to 6.

Taking the number of grids corresponding to the main code channel, the cursor code channel and the segment code channel as 1024, 1023 and 992 respectively as an example for explanation. Because a group of sine and cosine digital signals of each code channel can be resolved to obtain a group of 360-degree electrical angles, the main code channel, the vernier code channel and the segment code channel can respectively generate 1024, 1023 and 992 electrical angles of 0-360 degrees. As shown in fig. 3, the ordinate in fig. 3 is an electrical angle, and the abscissa is a distance by which the optical encoder rotates one turn. Namely, between the X-th grids of each code disc which are identical with each other, a phase difference value with a unique fixed range is arranged to realize the identification of the absolute position, and the principle is the same as that of a vernier caliper. For example, the phase difference range between the X-th grid of the main code track and the X-th grid of the cursor code track is: (2 pi/1024) (X-1) < theta (2 pi/1024) X. That is, absolute position information of 10-bit resolution can be obtained by the main track and the run-length track. However, in order to reduce the requirement of the precision of the servo system and the processing difficulty of the code tracks in the code disc, 992 grid section code tracks are also introduced. And acquiring low 5-bit position information in the absolute position information with 10-bit resolution through the main code channel and the segment code channel, and splicing the low 5-bit position information with the high 5-bit position information in the absolute position information with 10-bit resolution acquired through the main code channel and the cursor code channel to acquire final absolute position information, namely acquiring single-circle absolute position information. As shown in fig. 4, the ordinate in fig. 4 is the number of tracks, and the abscissa is the distance by which the optical encoder rotates one turn.

Further, the analog-to-digital conversion module 4 in the present embodiment may be a 16-bit resolution analog-to-digital conversion module 4. It will be understood, of course, that other analog-to-digital conversion modules with lower or higher resolution are also possible, and in particular, may be determined according to practical situations, which is not limited in the embodiments of the present disclosure.

In this embodiment, the high 5-bit position information in the absolute position information obtained through the main code track and the cursor code track is spliced with the low 5-bit position information in the absolute position information obtained through the main code track and the segment code track, so that the error tolerance of the absolute position information of a single loop is improved from 2pi\1022 to 2pi\31, and the resolution of the analog-to-digital conversion module 4 is 16 bits, so that the resolution of the optical encoder can reach 26 bits, and the accuracy of the servo system is further improved.

Further, the conversion rate of the analog-to-digital conversion module 4 in the embodiment is 2M when performing analog-to-digital conversion, so that the data output delay time is reduced, the delay time of outputting single-circle absolute position information by the servo system is further reduced, and the dynamic response speed of the servo system is improved.

In this embodiment, after receiving the main code channel sine and cosine digital signal, the run-length code channel sine and cosine digital signal, and the section code channel sine and cosine digital signal, the single-loop analysis module 5 may store the main code channel sine and cosine digital signal, the run-length code channel sine and cosine digital signal, and the section code channel sine and cosine digital signal through RAM (random access memory) before parallel processing, so as to prevent data loss.

In this embodiment, the first output end of the analog-to-digital conversion module 4 and the first input end of the single-turn parsing module 5 may be connected through an SPI (serial peripheral interface ) interface.

In the present embodiment, a comparator 3 and an amplifier 2 are also included. Wherein, as shown in fig. 2, the comparator 3 and the amplifier 2 may be integrated in the photo-sensing chip 1. In some embodiments, the comparator 3 and the amplifier 2 may also be provided separately, not integrated in the photo-sensing chip 1. The specific determination may be determined according to the actual situation, and the embodiment of the present specification is not limited thereto.

In one embodiment, when the comparator 3 and the amplifier 2 are integrated in the optical sensor chip 1, the amplifier 2 is configured to amplify the main code channel sine and cosine analog signal, the cursor code channel sine and cosine analog signal, and the segment code channel sine and cosine analog signal, and send the amplified main code channel sine and cosine analog signal, cursor code channel sine and cosine analog signal, and the segment code channel sine and cosine analog signal to the analog-to-digital conversion module 4 through the first output end of the optical sensor chip 1. The comparator 3 is configured to perform waveform conversion processing on the main code channel sine and cosine analog signal and the cursor code channel sine and cosine analog signal, obtain a first orthogonal square wave and a second orthogonal square wave, and send the first orthogonal square wave and the second orthogonal square wave to the single-ring analysis module 5 through the second output end of the optical sensing chip 1. The single-turn analysis module 5 can calculate to obtain a count value of the main code channel according to the first orthogonal square wave, and can verify whether the count of the main code channel is correct or not according to the second orthogonal square wave, so that PWM closed-loop adjustment between the optical sensing chip 1 and the single-turn analysis module 5 is realized.

In one embodiment, when the comparator 3 and the amplifier 2 are separately provided, the input terminal of the amplifier 2 is connected to the first output terminal of the optical sensing chip 1, the output terminal of the amplifier 2 is connected to the first input terminal of the analog-to-digital conversion module 4, the input terminal of the comparator 3 is connected to the second output terminal of the optical sensing chip 1, and the output terminal of the comparator 3 is connected to the second input terminal of the single-turn analysis module 5.

Specifically, in this embodiment, as shown in fig. 2, the system may further include an RS485 bus 10, where the RS485 bus 10 is connected to (an I/O interface of) an output end of the single-turn parsing module 5, and the single-turn parsing module 5 transmits single-turn absolute position information to the servo controller through the RS485 bus 10.

The optical encoder can realize the output of single-turn ground-insulation position information and the output of count values of a plurality of turns. As shown in fig. 2, besides the optical sensor chip 1, the analog-to-digital conversion module 4, the single-turn analysis module 5, the comparator 3, the amplifier 2 and the RS485 bus 10, the optical sensor further comprises a TMR chip 6, wherein a first output end of the TMR chip 6 is electrically connected with a third input end of the single-turn analysis module 5, wherein:

the TMR chip 6 (magnetic switch sensor chip) is used to generate a measurement signal when the optical encoder rotates one turn and transmit it to the single-turn parsing module 5;

the single-turn analysis module 5 is further configured to count the number of rotations of the optical encoder based on the received measurement signal when the optical encoder is in a normal power supply state.

The measurement signal generated by TMR chip 6 when the optical encoder rotates one turn may be a pulse signal.

In this embodiment, the method may further include: the first output end of the TMR chip 6 is electrically connected with the first input end of the multi-turn analysis module 9, the second output end of the TMR chip 6 is electrically connected with the input end of the multi-turn analysis module 7, and the output end of the multi-turn analysis module 9 is electrically connected with the second input end of the multi-turn analysis module 7, wherein:

the TMR chip 6 is also used to generate a measurement signal and transmit it to the exclusive or gate 7 when the optical encoder rotates one revolution;

the TMR chip 6 is also used to generate a measurement signal when the optical encoder rotates one turn and transmit it to the multi-turn parsing module 9;

the exclusive or gate circuit 7 is used for generating an excitation signal based on the measurement signal, and outputting the excitation signal to wake up for the multi-turn analysis module 9;

the multi-turn analysis module 9 is configured to count the number of turns of the optical encoder based on the received measurement signal after being awakened when the optical encoder is in a normal power supply state or in a power failure state.

Wherein, the multi-turn analysis module 9 is an MCU (micro controller).

In this embodiment, the exclusive or gate 7 may include a two-input exclusive or gate. When the measurement signal output by the TMR chip 6 when the optical encoder rotates one turn is a high level signal, the input of the input terminal of the exclusive or gate 7 which is not connected to the TMR chip 6 is a low level signal; when the measurement signal output by the TMR chip 6 at one rotation of the optical encoder is a low level signal, the input of the input terminal of the exclusive or gate 7 not connected to the TMR chip 6 is a high level signal.

When the optical encoder is in a normal power supply state (5V is powered on), the single-turn analysis module 5 and the multi-turn analysis module 9 can both count the number of rotations of the optical encoder.

The present embodiment may further include: the voltage monitoring module 8, the input of voltage monitoring module 8 is connected with the power supply input of the analysis module 9 of multiturn, the output of voltage monitoring module 8 and the second input electric connection of analysis module 9 of multiturn, the output of analysis module 9 of multiturn is connected to the fourth input of analysis module 5 of single circle, wherein:

the voltage monitoring module 8 is configured to output a pulse signal to the multi-ring analysis module 9 when it is monitored that the voltage at the power supply input end of the multi-ring analysis module 9 is greater than or equal to a first preset threshold, where the pulse signal is used to wake up the multi-ring analysis module;

the multi-turn analysis module 9 is configured to send the number of rotations of the optical encoder currently counted to the single-turn analysis module 5 after receiving the pulse signal.

In this embodiment, the first preset threshold may be a rated power supply voltage of the optical encoder, and a voltage at the power supply input end of the multi-turn analysis module 9 being greater than or equal to the first preset threshold indicates that the optical encoder is in a normal power supply state, at this time, the voltage monitoring module 8 outputs a pulse signal to the multi-turn analysis module 9, where the pulse signal is used to wake up the multi-turn analysis module 9.

In this embodiment, when the voltage monitoring module 8 monitors that the voltage at the power supply input end of the multi-turn parsing module 9 is less than the first preset threshold (5V), it outputs a low level signal to the multi-turn parsing module 9, or does not output a signal, so that the multi-turn parsing module 9 enters into a low power consumption mode. When the multi-turn parsing module 9 enters the low power mode, it can only execute the process: when the excitation signal input from the exclusive or circuit is received, the number of rotations of the optical encoder is counted based on the received measurement signal, and the counted number of rotations of the optical encoder cannot be transmitted to the single-turn analysis module 5.

When the voltage monitoring module 8 monitors that the voltage at the power supply input end of the multi-turn analysis module 9 is greater than or equal to a first preset threshold (5V), a high-level pulse signal is output to the multi-turn analysis module 9, so that the multi-turn analysis module 9 enters a working mode from a low-power consumption mode, and at the moment, the multi-turn analysis module 9 normally executes a process of counting the number of rotation turns of the optical encoder based on the received counting signal and sends the counted number of rotation turns of the optical encoder in the low-power consumption mode to the single-turn analysis module 5. In addition, it should be further noted that, when the voltage monitoring module 8 monitors that the voltage of the power supply input terminal of the multi-turn parsing module 9 is smaller than the first preset threshold (5V), that is, the optical encoder is in the power-down state, the single-turn parsing module 5 no longer receives the count signal of the TMR chip 6. By means of the above-described voltage monitoring module 8, the power consumption of the optical encoder can be reduced.

Further, when the multi-turn analysis module 9 enters a low power consumption mode, the power consumption is only 2-4uA, so that the service life of the battery power supply with 26mAh electric quantity can reach more than 10 years, and the service life of the power supply battery is effectively prolonged.

It should be noted that when the optical encoder is in the power-down state, the counting of multiple circles is completed in the multiple-circle analysis module 9, but the integration of multiple circles and single circle data and the data transmission of the RS485 bus 10 are completed in the single-circle analysis module 5, so that the delay time is shortened, the delay time of outputting single circle absolute position information by the servo system is further reduced, and the dynamic response speed of the servo system is improved.

Specifically, in this embodiment, the output end of the multi-ring parsing module 9 is connected to the fourth input end of the single-ring parsing module 5 through an SPI interface.

The utility model also proposes a servo system comprising an optical encoder as described above. The optical encoder has a specific structure referring to the above embodiments, and because the present servo system adopts all the technical solutions of all the embodiments, at least has all the beneficial effects brought by the technical solutions of the embodiments, which are not described in detail herein.

The foregoing description of the preferred embodiments of the present utility model should not be construed as limiting the scope of the utility model, but rather should be understood to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the utility model as defined by the following description and drawings or any application directly or indirectly to other relevant art(s).

Claims

1. The utility model provides an optical encoder, its characterized in that includes optical sensing chip, analog-to-digital conversion module, single-circle analysis module and RS485 bus, optical sensing chip's first output is connected to analog-to-digital conversion module's first input, analog-to-digital conversion module's output with single-circle analysis module's first input electric connection, wherein:

the single-circle analysis module is used for processing the main code channel sine and cosine digital signals, the cursor code channel sine and cosine digital signals and the segment code channel sine and cosine digital signals in parallel based on a vernier principle by utilizing a hardware logic controller, and analyzing to obtain single-circle absolute position information;

and the I/O interface of the single-turn analysis module is used for transmitting the single-turn absolute position information to a servo controller through the RS485 bus.

2. The optical encoder of claim 1, further comprising a TMR chip having a first output electrically connected to a third input of the single turn resolution module, wherein:

3. The optical encoder of claim 2 further comprising a multi-turn resolution module and an exclusive-or circuit, wherein the first output of the TMR chip is further electrically connected to the first input of the multi-turn resolution module, the second output of the TMR chip is electrically connected to the input of the exclusive-or circuit, and the output of the exclusive-or circuit is electrically connected to the second input of the multi-turn resolution module, wherein:

the TMR chip is also used for generating a measurement signal when the optical encoder rotates for one circle and transmitting the measurement signal to the multi-circle analysis module;

4. The optical encoder of claim 3, further comprising a voltage monitoring module, an input of the voltage monitoring module being connected to a power supply input of the multi-turn resolution module, an output of the voltage monitoring module being electrically connected to a second input of the multi-turn resolution module, an output of the multi-turn resolution module being connected to a fourth input of the single-turn resolution module, wherein:

5. The optical encoder of claim 4 wherein the output of the multi-turn resolution module is connected to the fourth input of the single-turn resolution module via an SPI interface.

6. The optical encoder of claim 1 wherein the first output of the analog-to-digital conversion module is connected to the first input of the single-turn resolution module via an SPI interface.

7. The optical encoder of claim 1 wherein the hardware logic controller comprises: FPGA, CPLD or ASIC.

8. The optical encoder of claim 1, further comprising a comparator and an amplifier, an input of the amplifier being connected to a first output of the optical sensing chip, an output of the amplifier being connected to a first input of the analog-to-digital conversion module, an input of the comparator being connected to a second output of the optical sensing chip, an output of the comparator being connected to a second input of the single-turn resolution module, wherein:

9. The optical encoder of claim 1, wherein the I/O interface of the single-turn parsing module is further configured to transmit a count of the number of rotations to a servo controller via the RS485 bus.

10. A servo system comprising an optical encoder as claimed in any one of claims 1 to 8.