CN220708412U

CN220708412U - Slit part, photoelectric encoder, servo motor and servo system

Info

Publication number: CN220708412U
Application number: CN202321849678.8U
Authority: CN
Inventors: 熊方圆
Original assignee: Suzhou Inovance Technology Co Ltd
Current assignee: Suzhou Inovance Technology Co Ltd
Priority date: 2022-12-30
Filing date: 2023-07-14
Publication date: 2024-04-02
Anticipated expiration: 2033-07-14

Abstract

The embodiment of the present specification provides a slit portion, a photoelectric encoder, a servo motor, and a servo system, wherein the slit portion is applied to the photoelectric encoder, the slit portion includes: the first absolute slit array is provided with first bright and dark patterns which are formed at equal intervals along the measuring direction and have equal widths and area changes of bright stripes in the first bright and dark patterns so as to realize absolute position calculation of the photoelectric encoder. In the embodiment of the present disclosure, since the bright stripes in the first bright-dark pattern have equal widths and areas that change, the intensities of the corresponding light signals transmitted through the bright stripes or reflected by the bright stripes also change, so that the intensities of the reflected or transmitted light signals are positively correlated with the areas of the bright stripes irradiated by the current light source, so that the current absolute position can be uniquely calculated by using one slit array, and the volume of the slit portion is effectively reduced.

Description

Slit part, photoelectric encoder, servo motor and servo system

Technical Field

The embodiment of the specification relates to the technical field of encoders, in particular to a slit part, a photoelectric encoder, a servo motor and a servo system.

Background

The photoelectric encoder is a sensor for converting mechanical geometric displacement on an output shaft into pulse or digital quantity through photoelectric conversion, and consists of a light source, an optical code disc (or grating ruler) and a photoelectric receiving array. The optical code disc or the grating ruler can be carved with a plurality of slit arrays, and each slit array needs a photoelectric receiving array corresponding to the slit array. The light emitted by the light source irradiates the code disc, so that the code disc reflects or transmits the light information modulated by the light and dark stripes in the slit array, and the photoelectric receiving array can receive the light information and convert the light information into an electric signal, thereby calculating the current position information.

In the prior art, the resolution modes adopted by the absolute photoelectric encoder mainly comprise two modes: the digital coding resolving mode and the vernier resolving mode, wherein the reliability of the digital coding resolving mode is higher, but the digital coding resolving mode usually needs two or more absolute value slit arrays to realize reliable resolving of absolute positions, and the digital coding resolving mode is used for realizing subdivision of higher dividing line numbers to improve resolving precision, so that additional increment slit arrays are also needed to be added. That is, the prior art generally needs to use 3 or more slit arrays to realize high-precision absolute position calculation, but the scheme of using a plurality of slit arrays is limited in volume and cannot be applied to a small encoder.

Therefore, the technical scheme in the prior art can not realize high-precision absolute position calculation by means of the single absolute value slit array.

In view of the above problems, no effective solution has been proposed at present.

Disclosure of Invention

The embodiment of the specification provides a slit part, a photoelectric encoder, a servo motor and a servo system, so as to solve the problem that high-precision absolute position calculation cannot be realized by means of a single absolute value slit array in the prior art.

The present specification embodiments provide a slit portion applied to an optical-electrical encoder, the slit portion including: the first absolute slit array is provided with first bright-dark patterns which are formed at equal intervals along the measuring direction according to a first interval, and bright stripes in the first bright-dark patterns are equal in width and area, so that absolute position calculation of the photoelectric encoder is realized.

The embodiments of the present specification also provide an optical-electrical encoder, including: a slit portion comprising: a first absolute slit array having first bright-dark patterns formed at equal intervals along a measurement direction at a first pitch, bright stripes in the first bright-dark patterns being equal in width and varying in area to achieve absolute position resolution of the photoelectric encoder; a light source for emitting measurement light to the slit portion; the first absolute light receiving array is arranged opposite to the slit part and is used for receiving the measuring light reflected or transmitted by the first absolute slit array, generating an absolute sine and cosine signal by sensing the light quantity change of the measuring light, and the absolute sine and cosine signal is used for resolving the absolute position.

The embodiment of the specification also provides a servo motor, which comprises: a rotary-type motor in which a rotor rotates with respect to a stator, or a linear motor in which a mover moves with respect to a stator; and the photoelectric encoder is used for detecting at least one of the position, the speed and the acceleration of the rotor or the rotor.

The embodiment of the specification also provides a servo system, which comprises: a rotary-type motor in which a rotor rotates with respect to a stator, or a linear motor in which a mover moves with respect to a stator; the photoelectric encoder detects at least one of a position, a speed, and an acceleration of the rotor or the mover; and the controller is used for controlling the rotary motor or the linear motor according to the detection result fed back by the photoelectric encoder.

The embodiment of the present specification provides a slit portion, which may be provided with a first absolute slit array for modulating light irradiated from a light source, and the first absolute slit array may have first bright-dark patterns formed at equal intervals of a first pitch in a measurement direction. The first light and dark patterns are equal in width and area, so that the intensity of the light signal transmitted through the light stripes or reflected by the light stripes is correspondingly changed due to the change of the areas of the light stripes, the intensity of the reflected or transmitted light signal is stronger when the area of the light stripes is larger, and the absolute sine and cosine signal amplitude generated by the first absolute light receiving array for receiving the reflected or transmitted light signal is correspondingly larger, so that the amplitude of the generated absolute sine and cosine signal is positively correlated with the area of the light stripes irradiated by the current light source, and the current absolute position can be uniquely calculated by determining the absolute sine and cosine signal amplitude by utilizing one slit array. Further, the volume of the slit portion can be effectively reduced, and the slit portion can be applied to a small-sized encoder.

Drawings

The accompanying drawings, which are included to provide a further understanding of embodiments of the present specification, are incorporated in and constitute a part of this specification and do not limit the embodiments of the present specification. In the drawings:

FIG. 1 is a schematic diagram of a servo system provided in accordance with an embodiment of the present disclosure;

fig. 2 is a schematic view of a slit portion provided according to an embodiment of the present specification;

fig. 3 is another schematic view of a slit portion provided according to an embodiment of the present disclosure;

FIG. 4 is a schematic view of a first shading pattern provided according to an embodiment of the present disclosure;

FIG. 5 is another schematic view of a first shading pattern provided according to an embodiment of the present disclosure;

fig. 6 is a schematic structural view of a reflective photoelectric encoder applied to a rotary electric machine according to an embodiment of the present specification;

fig. 7 is a schematic structural view of a transmissive photoelectric encoder applied to a rotary electric machine according to an embodiment of the present specification;

fig. 8 is a schematic structural view of a transmissive photoelectric encoder applied to a linear motor according to an embodiment of the present disclosure;

fig. 9 is a schematic structural view of a reflective photoelectric encoder applied to a linear motor according to an embodiment of the present disclosure;

Fig. 10 is a schematic diagram of a correspondence relationship between a light receiving element and a first bright-dark pattern according to an embodiment of the present disclosure;

fig. 11 is another schematic diagram of a correspondence relationship between a light receiving element and a first bright-dark pattern according to an embodiment of the present disclosure;

FIG. 12 is a schematic diagram of an absolute sine and cosine signal provided according to an embodiment of the present disclosure;

fig. 13 is a circuit topology diagram of a sinusoidal signal processing unit provided according to an embodiment of the present specification;

fig. 14 is a schematic view showing a structure of a bipolar magnet in a linear encoder according to an embodiment of the present disclosure;

fig. 15 is a schematic view showing a structure of a bipolar magnet in a rotary encoder according to an embodiment of the present disclosure;

FIG. 16 is a schematic diagram of an absolute sine and cosine signal and a reference signal according to an embodiment of the present disclosure;

FIG. 17 is a schematic view of a reference slot array provided in accordance with an embodiment of the present disclosure;

FIG. 18 is a schematic diagram of a reference signal provided in accordance with an embodiment of the present disclosure;

fig. 19 is a schematic structural view of an optical-electrical encoder provided according to an embodiment of the present disclosure;

FIG. 20 is a schematic diagram of an absolute pattern formed using numerical encoding according to an embodiment of the present disclosure;

FIG. 21 is a schematic diagram of a comparison of an incremental slot array with a first absolute slot array provided in accordance with an embodiment of the present disclosure;

fig. 22 is a schematic structural view of an optical-electrical encoder provided according to an embodiment of the present specification.

Detailed Description

The principles and spirit of the embodiments of the present specification will be described below with reference to several exemplary implementations. It should be understood that these embodiments are presented merely to enable one skilled in the art to better understand and implement the present description embodiments and are not intended to limit the scope of the present description embodiments in any way. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

Those skilled in the art will appreciate that the implementations of the embodiments of the present description may be implemented as a system, apparatus, method, or computer program product. Accordingly, the present disclosure may be embodied in the following forms, namely: complete hardware, complete software (including firmware, resident software, micro-code, etc.), or a combination of hardware and software.

While the flow described below includes a number of operations occurring in a particular order, it should be apparent that these processes may include more or fewer operations, which may be performed sequentially or in parallel (e.g., using a parallel processor or a multi-threaded environment).

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

The present embodiment provides a slit portion, a photoelectric encoder, a servo motor, and a servo system, which are applicable to related products such as a linear motor, a rotary motor, and the like, for detecting at least one of a position of the motor, a speed of the motor M (which may also be referred to as a rotational speed, an angular velocity, and the like), and an acceleration of the motor M (which may also be referred to as a rotational acceleration, an angular acceleration, and the like). Of course, it will be appreciated that it is also applicable to other possible devices or apparatus, such as: the robot and the like may be specifically determined according to actual conditions, and the embodiment of the present specification is not limited thereto.

In a possible implementation scenario, the photoelectric encoder provided in the embodiments of the present disclosure may be preferably applied to a servo system, for example, a rotating motor, and the servo system may be as shown in fig. 1. The servo system may include: servo motor 600 and controller 300. Servo motor 600 may include rotary motor 100 and photoelectric encoder 200. A servo system (servo mechanism) may be an automatic control system that enables an output controlled amount of an object's position, orientation, state, etc. to arbitrarily change following an input target (or a given value), servo motor 600 may refer to a motor including an encoder to follow a command of a control signal.

In this embodiment, the rotary electric machine 100 and the photoelectric encoder 200 may be mounted coaxially, and the photoelectric encoder 200 may determine the current position, speed, or acceleration at which the rotary electric machine 100 actually operates by detecting the position of the rotary electric machine shaft (rotor), and output detection data representing the position, which may be an absolute position as described below, to the controller.

In this embodiment, the controller calculates a deviation according to a given value of the upper computer and detection data fed back from the photoelectric encoder 200, and adjusts a control amount according to the deviation, thereby obtaining a control signal and transmitting the control signal to the rotating electric machine 100 to control the rotating electric machine 100 to rotate according to the adjusted control signal.

Noun interpretation:

1. slit portion 210: the slit portion 210 is a slit array formed by weaving light and shade at intervals on an opaque substrate according to a preset coding mode, and the slit array can be used for modulating light irradiated by a light source. When applied to a rotary electric machine, the slit portion 210 may be a circular code wheel; when applied to a linear motor, the slit portion 210 may be a linear type grating. Of course, the slit portion 210 is not limited to the above example, and may take other possible forms, and those skilled in the art may make other modifications in light of the technical spirit of the embodiments of the present disclosure, but it should be covered in the protection scope of the embodiments of the present disclosure as long as the functions and effects achieved are the same as or similar to those of the embodiments of the present disclosure.

2. The slit array may be engraved with a plurality of slits, and a "slit" is a region formed in the slit portion 210 and having an effect of reflecting (including reflection type diffraction), transmitting (including transmission type diffraction), or the like on light emitted from the light source. The plurality of slits may form a predetermined bright-dark pattern in the measurement direction, thereby constituting a slit array. Slits that transmit light in a transmissive encoder may be referred to as bright stripes and slits that do not transmit light or that transmit light less may be referred to as dark stripes; the reflective slit in the reflective encoder may be referred to as a bright stripe, the non-reflective or low reflective slit may be referred to as a dark stripe, and the definition of bright stripe and dark stripe are opposite, and may be specifically determined according to the actual situation, which is not limited in the embodiments of the present disclosure.

An absolute slit array may refer to a slit array in which the position of a slit illuminated by a current light source may be uniquely determined in a complete measurement period according to a light signal reflected or transmitted by the slit, and the absolute position may be calculated from the solution. The absolute position is a position of the slit portion 210 with respect to an origin in one circle, and one origin is provided in one circle of the absolute slit array, and an absolute pattern is formed with the origin as a reference.

The incremental slit array may be a slit array that is repeated at regular intervals, where the intervals are intervals between bright stripes in the incremental slit array, and each bright stripe is passed by the light source to generate a light-shade change of the light, and each light-shade change may be converted into a count pulse, so as to obtain an incremental position. The incremental slit array does not have a zero point, the incremental position is a relative displacement, and the absolute position can be obtained by accumulating the relative displacement based on the zero point. The incremental slit array can realize a high-precision position calculation as compared with the absolute slit array.

3. The light source 220 may be a point light source for illuminating light to the slit array, and the light emitted by the light source 220 may be parallel light or divergent light, and in some embodiments, may be LED (Light Emitting Diode ). It will be understood, of course, that other possible light source types may be used, and specifically may be selected according to actual requirements, and specifically may be selected according to actual situations, which is not limited by the embodiment of the present disclosure.

4. The light receiving array includes a plurality of light receiving elements arranged in a measurement direction for receiving light reflected or transmitted by the slit array and converting the received light signal into an electrical signal. The light receiving element is a photosensitive element, for example: photodiodes, phototriodes, etc. may of course also be used, and in particular may be determined according to practical situations, which is not limited in this embodiment of the present disclosure.

Referring to fig. 2 and 3, the present embodiment may provide a slit portion 210, and the slit portion 210 may implement absolute position calculation using a single slit array. The slit portion 210 may include: a first absolute slit array 211, the first absolute slit array 211 having first bright-dark patterns formed at equal intervals along a measurement direction, bright stripes in the first bright-dark patterns being equal in width and varying in area to achieve absolute position resolution of the photoelectric encoder.

In the present embodiment, the slit portion 210 may be provided with a first insulation slit array 211, and the first insulation slit array 211 may be used to modulate light irradiated by a light source. The first insulating slit array 211 may be engraved with a plurality of slits, and the plurality of slits may be arranged at equal intervals along the measurement direction to form a first bright-dark pattern.

In the present embodiment, the measurement direction may be a movement direction of the object to be measured when optically measured, and when the object to be measured is a rotary motor, the measurement direction may coincide with a circumferential direction around the motor shaft as a central axis; when the object to be measured is a linear motor, the measurement direction may coincide with the direction in which the linear motor linearly moves.

In this embodiment, the first bright-dark pattern may have a plurality of bright stripes and dark stripes, the dark stripes and the bright stripes being alternately arranged in sequence, the first pitch X ₁ The width of the dark stripe may be indicated, the width of the stripe may be indicated, or the widths of the dark stripe and the bright stripe may be indicated. Correspondingly, the equal intervals may represent equal widths of dark stripes in the first bright-dark pattern, or equal widths of bright stripes in the first bright-dark pattern, which may be specifically determined according to practical situations, and the embodiment of the present specification is not limited thereto.

In this embodiment, the width of the bright stripe may be equal to the width of the dark stripe, and in some embodiments, the width of the bright stripe may not be equal to the width of the dark stripe, which may be specifically determined according to practical situations, and this embodiment is not limited in this specification.

In the present embodiment, the plurality of bright stripes may be arranged at a first pitch X in the measuring direction ₁ The first light and dark patterns are formed by equidistant arrangement, namely, the dark stripes are arranged at a first interval X ₁ Arranged at equal width, where the first distance X ₁ Is the width of the dark stripe; alternatively, a plurality of dark fringes can be measured at a first pitch X in the measurement direction ₁ The first bright and dark patterns are formed by equidistant arrangement, namely, the bright stripes are arranged according to a first interval X ₁ Arranged at equal width, where the first distance X ₁ Is the width of the dark stripe. Of course, the width of both the bright and dark stripes can be set to X ₁ Other variations will occur to those skilled in the art upon a reading of the teachings of the present embodiments, and it is intended to cover within the scope of the present embodiments all such variations and modifications as come within the meaning and range of equivalents of the invention.

In the present embodiment, the first interval X ₁ The smaller the subdivision accuracy is, the higher the accuracy of the absolute position obtained by the calculation is. The first interval X ₁ May be a value greater than 0, for example: 0.12 mm, 0.2 mm, 1 mm, 1.35 mm, 8.6 mm, 1.1 cm, etc., and may be specifically determined according to practical situations, which are not limited in the embodiment of the present specification.

In this embodiment, since the bright stripes are equally wide and the areas of the first bright-dark patterns are changed, the change of the bright stripe areas correspondingly changes the intensities of the light signals transmitted through the bright stripes or reflected by the bright stripes, the larger the bright stripe areas are, the stronger the intensities of the reflected or transmitted light signals are, and correspondingly, the larger the amplitudes of the absolute sine and cosine signals output by the first absolute light receiving array 231 after the conversion processing are, so that the amplitudes of the absolute sine and cosine signals finally output by the first absolute light receiving array 231 are positively correlated with the areas of the bright stripes irradiated by the current light source, and therefore, the absolute position can be calculated according to the amplitudes of the absolute sine and cosine signals finally output by the first absolute light receiving array 231.

In one embodiment, the bright stripe in the first bright-dark pattern may have at least one variation period.

In this embodiment, when the first bright-dark pattern has a change period, in a complete measurement period, the light source irradiates the first absolute slit array 211 to linearly change the intensity of the light signal reflected or transmitted by the first bright-dark pattern, and correspondingly, the amplitude of the absolute sine and cosine signal output by the first absolute light receiving array after the conversion process also linearly changes, and each absolute sine and cosine signal amplitude uniquely corresponds to one absolute position, so that the absolute position calculation can be realized by using one absolute slit array.

In this embodiment, the area or length of the bright stripes in each variation period may not be repeatedly varied, that is, the area of the bright stripes in each variation period may be different (the number of bright stripes in each variation period may be different), or the trend of variation of the area of the bright stripes in each variation period may be different. It will be understood, of course, that the area of the bright stripes in the first bright-dark pattern may also be periodically and repeatedly changed, i.e. the area of each change period is the same, and the trend of the change in the area of the bright stripes in each change period is the same. The specific determination may be determined according to the actual situation, and the embodiment of the present specification is not limited thereto.

In the present embodiment, the first bright-dark pattern may also have a plurality of variation periods. In the case where the first bright-dark pattern has a plurality of variation periods, the variation trend of the bright-stripe area in each variation period may be different, for example: the bright stripes are equal in width, the bright stripe length is increased from 0.1 cm to 0.9 cm in the first change period, the bright stripe length is increased from 1 cm to 1.5 cm in the second change period, and the like, so that the area of each bright stripe is unique, and the position of the bright stripe irradiated by the light source can be uniquely calculated in one measurement period, and the absolute position is obtained. Of course, the arrangement of the first bright-dark pattern is not limited to the above examples, and other modifications may be made by those skilled in the art in light of the technical spirit of the embodiments of the present disclosure, but it should be covered within the protection scope of the embodiments of the present disclosure as long as the functions and effects achieved are the same or similar to those of the embodiments of the present disclosure.

In this embodiment, the area of each variation period may also be different, that is, the number of bright stripes in each variation period may be different, and specifically, may be designed according to the actual situation, which is not limited in this embodiment of the present disclosure.

In the present embodiment, an example of the slit portion 210 when applied to a linear motor is given in fig. 2, the slit portion 210 in fig. 2 is a grid scale, and the first absolute slit array 211 is arranged in the measurement direction shown in the figure. In the transmissive scheme, in fig. 2, the gray stripes are high-transmission regions, the white regions are non-transmission regions (or low-transmission regions), the light emitted by the light source irradiates the first absolute slit array 211, the light incident on the white regions is blocked from passing through (or passes through a small amount of) the first absolute slit array 211, and the light incident on the gray stripes can smoothly pass through the first absolute slit array 211 and finally irradiate on the first absolute light receiving array 231. In the reflective scheme, in fig. 2, the white area is a low reflection area, the gray stripe is a high reflection area, most of the light emitted by the light source irradiates the white area of the first absolute slit array 211 to be absorbed, only a small amount of the light is reflected back, most of the light incident on the gray stripe is reflected back, and the reflected light irradiates the first absolute light receiving array 231.

The width of the dark stripe in FIG. 2 may be X ₁ The width of the bright stripes can be Y ₁ The first interval may be X ₁ In some embodiments, X ₁ Can be equal to Y ₁ . The width direction may be a measurement direction, and the length of each bright stripe along the measurement direction corresponds to the width of each bright stripe.

In the present embodiment, fig. 3 shows an example of the slit portion 210 when applied to a rotary electric machine, the slit portion 210 in fig. 3 is a code wheel, the radius of the code wheel is R, and the origin O of the code wheel is connected to the rotation shaft of the machine to drive the code wheel to rotate in the measurement direction shown in the figure. The first absolute slit array 211 is formed as an annular array centered on the origin O of the code wheel, in the transmissive scheme, the gray stripes are high-transmission areas, the white areas are non-transmission areas (or low-transmission areas), the light emitted from the light source irradiates the first absolute slit array 211, the light incident into the white areas is blocked and cannot pass (or passes a small amount of) the first absolute slit array 211, and the light incident into the gray stripes can smoothly pass through the first absolute slit array 211 and finally irradiate the first absolute light receiving array 231. In the reflective scheme, in fig. 3, the white area is a low reflection area, the gray stripe is a high reflection area, most of the light emitted by the light source irradiates the white area of the first absolute slit array 211 to be absorbed, only a small amount of the light is reflected back, most of the light incident on the gray stripe is reflected back, and the reflected light irradiates the first absolute light receiving array 231.

The first absolute slit array 211 in fig. 3 has two periods of variation: the first absolute slit array 211 is not limited to the example shown in the drawings, and other modifications may be made by those skilled in the art in light of the technical spirit of the embodiments of the present disclosure, so long as the functions and effects implemented by the first absolute slit array are the same as or similar to those of the embodiments of the present disclosure.

The width of the dark stripe in FIG. 3 may be X ₁ The width of the bright stripes can be Y ₁ The first interval may be X ₁ In some embodiments, X ₁ Can be equal to Y ₁ . The width direction may be a measurement direction, and the length of each bright stripe along the measurement direction corresponds to the width of each bright stripe.

In this embodiment, the shape of the slit array and the rule of change in the length of the bright stripes may be adjusted according to the actual application scene, the shape and the area of the corresponding light receiving array may be changed according to the selection of the light source 220 and the distance relationship between the light source 220 and the slit array, and the embodiment of the present disclosure is not limited to this specific embodiment.

From the above description, it can be seen that the following technical effects are achieved in the embodiments of the present specification: the slit portion may be provided with a first absolute slit array, which may be used to modulate light irradiated by the light source, and the first absolute slit array may have first bright-dark patterns formed at first pitches equally spaced along the measurement direction. Since the bright stripes in the first bright-dark pattern have equal widths and areas vary, the absolute position of the photoelectric encoder can be calculated. The change of the area of the bright stripes can cause the intensity of the light signal transmitted through the bright stripes or reflected by the bright stripes to correspondingly change, the larger the area of the bright stripes is, the stronger the intensity of the reflected or transmitted light signal is, so that the amplitude of the generated absolute sine-cosine signal is positively correlated with the area of the bright stripes irradiated by the current light source, and the current absolute position can be uniquely calculated by utilizing a slit array through the change of the intensity of the induced light signal. Further, the volume of the slit portion can be effectively reduced, and the slit portion can be applied to a small-sized encoder.

In one embodiment, the shape of the bright stripe may include: of course, the shape of the bright stripe is not limited to the above examples, and other modifications are possible by those skilled in the art in light of the technical spirit of the embodiments of the present specification, but it should be covered within the scope of the embodiments of the present specification as long as the functions and effects achieved are the same or similar to those of the embodiments of the present specification.

In this embodiment, the shapes of the plurality of bright stripes in the same slit array may be the same or different, and may be specifically determined according to practical situations, which is not limited in this embodiment.

In one embodiment, the area of the bright stripes in the first bright-dark pattern may be periodically changed according to a sine wave trend, or the area of the bright stripes in the first bright-dark pattern may be periodically changed according to a triangular wave trend.

In the present embodiment, since the widths of the bright stripes in the first bright-dark pattern are equal, the variation in the bright stripe area can be equivalent to the variation in the bright stripe length.

In this embodiment, as shown in fig. 4, the lengths of bright and dark stripes in the first bright-dark pattern may be periodically changed according to a sine wave or cosine wave trend, where 0-90 ° may be regarded as a change period when the lengths are periodically changed according to a sine-cosine trend, or 0-180 ° may be regarded as a change period. When 0-180 degrees are regarded as a change period, the area of the same bright stripe corresponds to two different positions, so that the change trend (increasing or decreasing) of the length of the current bright stripe can be judged to determine the current interval, and the current absolute position can be uniquely calculated.

In this embodiment, as shown in fig. 5, the lengths of bright stripes in the first bright-dark pattern may be periodically changed in accordance with the triangular wave trend. It will be understood, of course, that the lengths of the bright stripes in the first bright-dark pattern may also be periodically changed according to other possible trends, for example, may be periodically changed according to an exponential trend, and specifically may be designed according to the actual situation, which is not limited in this embodiment of the present disclosure.

Based on the same inventive concept, there is also provided in the embodiments of the present specification an optical-electrical encoder that can be used to achieve the resolution of absolute position using a single slit array. The above photoelectric encoder may include: slit portion 210, light source 220, and first absolute light receiving array 231, wherein,

the slit part 210 may include a first absolute slit array 211, the first absolute slit array 211 having first bright-dark patterns formed at equal intervals along the measurement direction at a first pitch, bright stripes in the first bright-dark patterns being equal in width and varying in area to achieve absolute position resolution of the photoelectric encoder.

The light source 220 emits measurement light to the slit portion 210;

the first absolute light receiving array 211 is disposed opposite to the slit portion 210, the first absolute light receiving array 211 is configured to receive the measurement light reflected or transmitted by the first absolute slit array 211, and generate an absolute sine and cosine signal by sensing a change in the light quantity of the measurement light, and the absolute sine and cosine signal is configured to resolve the absolute position.

In this embodiment, the specific implementation manner and effect of the slit portion 210 may be explained in comparison with the above embodiment, and will not be described herein.

In the present embodiment, fig. 3 shows an example of the slit portion 210 when applied to a rotary electric machine, the slit portion 210 in fig. 3 is a code wheel, the radius of the code wheel is R, and the origin O of the code wheel is connected to the rotation shaft of the machine to drive the code wheel to rotate in the measurement direction shown in the figure. The first absolute slit array 211 is formed as an annular array centered on the origin O of the code wheel. In the transmissive scheme, in fig. 3, the gray stripes are high-transmission regions, the white regions are non-transmission regions (or low-transmission regions), the light emitted by the light source irradiates the first absolute slit array 211, the light incident on the white regions is blocked from passing through (or passes through a small amount of) the first absolute slit array 211, and the light incident on the gray stripes can smoothly pass through the first absolute slit array 211 and finally irradiate on the first absolute light receiving array 231. In the reflective scheme, in fig. 3, the white area is a low reflection area, the gray stripe is a high reflection area, most of the light emitted by the light source irradiates the white area of the first absolute slit array 211 to be absorbed, only a small amount of the light is reflected back, most of the light incident on the gray stripe is reflected back, and the reflected light irradiates the first absolute light receiving array 231.

In the present embodiment, the reflective photoelectric encoder may be configured as shown in fig. 4 when applied to a rotary electric machine, in which the slit portion 210 is connected to a rotation shaft of the electric machine to drive the slit portion 210 to rotate along with the rotation shaft of the electric machine, thereby realizing detection of the position of the electric machine. The first absolute slit array 211 is disposed on the slit portion 210, and the first absolute light receiving array 231 is disposed opposite to the slit portion 210, and the first absolute light receiving array 231 is configured to receive measurement light reflected when the light source irradiates the first absolute slit array 211.

In this embodiment, the light source 220 and the first absolute light receiving array 231 may be integrated in one photocell chip, so that a certain space may be saved. Of course, the light source 220 may also be disposed independently of the photocell chip, with the first absolute light receiving array 231 disposed therein. In the reflective scheme, the light source 220 may be disposed at a side of the slit portion 210 near the first absolute light receiving array 231 when independent; in the transmissive scheme, the first absolute light receiving array 231 and the light source may be disposed on both sides of the slit portion 210 when the light source 220 is independent, and specific positions may be determined according to actual requirements through the light path design, which is not limited in the embodiment of the present disclosure.

In this embodiment, one light source 220 may be provided, however, in order to ensure light intensity and reliability, a plurality of light sources may be provided redundantly, and the plurality of light sources may be provided at intervals along the measurement direction, which may be specifically determined according to practical situations, and this embodiment is not limited thereto.

In the present embodiment, the light source 220 may irradiate at least a part of the slit array, and the first absolute light receiving array 231 may be disposed opposite to the slit portion 210 in order to receive the measurement light reflected or transmitted by the first absolute slit array 211. In some embodiments, in order to accurately sense the light quantity change of the transmitted or reflected measurement light, the first absolute light receiving array 231 may be disposed opposite to the slit portion 210 in parallel, or may be disposed at an included angle therebetween, which may be specifically determined according to practical situations, and the embodiments herein are not limited thereto.

In the present embodiment, since the bright stripe and the bright stripe in the first bright-dark pattern have the same width and the area changes, the absolute position of the photoelectric encoder can be calculated. The change of the bright stripe area can cause the intensity of the light signal transmitted through the bright stripe or reflected by the bright stripe to also change periodically, the larger the bright stripe area is, the stronger the intensity of the reflected or transmitted light signal is, and correspondingly, the larger the amplitude of the absolute sine and cosine signal generated by the first absolute light receiving array 231 for receiving the reflected or transmitted light signal is, so that the amplitude of the absolute sine and cosine signal generated by the first absolute light receiving array 231 is positively correlated with the area of the bright stripe irradiated by the current light source, and the current absolute position can be calculated by determining the amplitude of the absolute sine and cosine signal output by the first absolute light receiving array 231.

In one embodiment, the reflective photoelectric encoder applied to the rotary electric machine may have a structure in which the slit portion 210 is connected with the rotation shaft of the electric machine as shown in fig. 6 to drive the slit portion 210 to rotate following the rotation shaft of the electric machine, thereby achieving detection of the position of the electric machine. The first absolute slit array 211 is disposed on the slit portion 210, and the light source 220 and the first absolute light receiving array 231 are integrated into one photocell chip, which is disposed opposite to the slit portion 210, and the first absolute light receiving array 231 is used for receiving the measurement light reflected when the light source irradiates the first absolute slit array 211.

The light source 220 and the first absolute light receiving array 231 are illustrated in fig. 6 as being integrated into one photocell chip, and in some embodiments, the light source may be disposed separately from the photocell chip, and the specific position may be determined by the light path design according to actual requirements, which is not limited in this embodiment of the present disclosure.

In one embodiment, the transmission type photoelectric encoder applied to the rotary electric machine may have a structure in which the slit portion 210 is connected with the rotation shaft of the electric machine as shown in fig. 7 to drive the slit portion 210 to rotate following the rotation shaft of the electric machine, thereby achieving detection of the position of the electric machine. The first absolute slit array 211 is disposed on the slit portion 210, the first absolute light receiving array 231 and the light source 220 are disposed on both sides of the slit portion 210, respectively, the first absolute light receiving array 231 and the light source 220 are disposed opposite to each other, and the first absolute light receiving array 231 is configured to receive measurement light transmitted when the light source irradiates the first absolute slit array 211.

In this embodiment, a lens may be further disposed between the light source 220 and the slit portion 210, so as to focus the light emitted from the light source 220, and avoid inaccurate measurement results caused by scattering of the light.

In one embodiment, the structure of the transmissive photoelectric encoder when applied to a linear motor may be such that the slit portion 210 moves linearly in the measurement direction as shown in fig. 8. The first absolute slit array 211 is disposed on the surface of the slit portion 210, the first absolute light receiving array 231 and the light source 220 are disposed on two sides of the slit portion 210, respectively, the first absolute light receiving array 231 and the light source 220 are disposed opposite to each other, and the first absolute light receiving array 231 is configured to receive measurement light transmitted when the light source irradiates the first absolute slit array 211.

In one embodiment, the structure of the reflective photoelectric encoder when applied to a linear motor may be such that the slit portion 210 moves linearly in the measurement direction as shown in fig. 9. The first absolute slit array 211 is disposed on the surface of the slit portion 210, the light source 220 and the first absolute light receiving array 231 are integrated into a photocell chip, the photocell chip is disposed opposite to the slit portion 210, and the first absolute light receiving array 231 is used for receiving the measuring light reflected when the light source irradiates the first absolute slit array 211.

The light source 220 and the first absolute light receiving array 231 are illustrated in fig. 9 as being integrated on a photocell chip, and in some embodiments, the light source may be disposed independently of the photocell chip, and the specific position may be determined by the light path design according to actual requirements, which is not limited in this embodiment of the present disclosure.

From the above description, it can be seen that the following technical effects are achieved in the embodiments of the present specification: the slit part may be provided with a first absolute slit array, which may have first bright-dark patterns formed at equal intervals along a measurement direction at a first pitch, and a first absolute light receiving array disposed opposite to the slit part, the first absolute light receiving array being configured to receive measurement light reflected or transmitted by the light source irradiated to the first absolute slit array, and generate an absolute sine-cosine signal by sensing a light quantity change of the measurement light. Since the bright stripes in the first bright-dark pattern are equal in width and change in area, the change of the bright stripe area can enable the intensity of the light signal transmitted through the bright stripes or reflected by the bright stripes to correspondingly change, the larger the bright stripe area is, the stronger the intensity of the reflected or transmitted light signal is, and correspondingly, the larger the amplitude of the absolute sine and cosine signal generated by the first absolute light receiving array for receiving the reflected or transmitted light signal is, so that the amplitude of the absolute sine and cosine signal generated by the first absolute light receiving array is positively correlated with the area of the bright stripes irradiated by the current light source, and the current absolute position can be calculated by determining the amplitude of the absolute sine and cosine signal output by the first absolute light receiving array.

In one embodiment, the first absolute light receiving array 231 may have a plurality of light receiving elements arranged along the measurement direction, and four adjacent light receiving elements of the plurality of light receiving elements may be used to receive the measurement light reflected or transmitted by a set of bright-dark fringes in the first bright-dark pattern; the set of absolute sine and cosine signals generated by the four adjacent light receiving elements may include: a first sine current signal Isin+, a first cosine current signal Icos+, a second sine current signal Isin-, and a second cosine current signal Icos-.

In this embodiment, a group of 4 light receiving elements adjacent to the first absolute light receiving array 231 may be used, and the light receiving elements may convert the sensed light signal into an electrical signal to output, and the same signal may be connected together to output to the post-amplifying circuit, corresponding to a group of bright and dark fringes (one bright fringe and one dark fringe) of the first bright and dark pattern projected on the first absolute light receiving array 231.

In this embodiment, two light receiving elements are used to correspond to one bright stripe and one dark stripe, respectively, so that sine-cosine current signals with a phase difference of 180 degrees can be generated, and the effects of common mode noise and even harmonics can be eliminated. It will of course be appreciated that in some embodiments more or fewer light receiving elements may be used to receive a set of light and dark stripe reflected or transmitted measurement light, for example: and receiving the measuring light reflected or transmitted by a group of bright and dark fringes in the first bright and dark pattern by using 2 light receiving elements, or receiving the measuring light reflected or transmitted by a group of bright and dark fringes in the first bright and dark pattern by using 8 light receiving elements. 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, in a linear application scenario, as shown in fig. 10, the correspondence between the light-receiving elements and the first bright-dark pattern may be that the dark stripe portion corresponds to the first absolute slit array 211, the light stripe portion corresponds to the first absolute light-receiving array 231, and the light-receiving elements selected in the box in fig. 10 are a group of four light-receiving elements, and the first sine current signal isin+, the first cosine current signal icos+, the second sine current signal Isin-, and the second cosine current signal Icos-are respectively output from left to right.

In one embodiment, in the application scenario of the rotation type, as shown in fig. 11, the corresponding relationship between the light-receiving element and the first bright-dark pattern may be that the dark stripe portion corresponds to the first absolute slit array 211, the light stripe portion corresponds to the first absolute light-receiving array 231, and the corresponding relationship between the first absolute light-receiving array 231 and the first absolute slit array 211 when the first absolute light-receiving array 231 moves relative to the first absolute slit array 211 is exemplarily shown in fig. 11 at two different positions. The frame-selected light receiving elements are a group of four light receiving elements, and the first sine current signal Isin+, the first cosine current signal Icos+, the second sine current signal Isin-and the second cosine current signal Icos-are respectively output from left to right.

In one embodiment, taking the first absolute slit array 211 in fig. 10 as an example, when the first absolute slit array 211 moves from right to left relative to the first absolute light receiving array 231, a set of four light receiving elements may generate an absolute sine and cosine signal as shown in fig. 12, where a set of bright and dark fringes corresponds to a periodic sine and cosine signal. For ease of understanding, only one sine current signal Isin and one cosine current signal Icos are exemplarily shown in fig. 12, and it can be seen from the graph that the amplitude of the sine and cosine signals corresponds to the trend of the area of the bright stripe.

In one embodiment, the photoelectric encoder 200 may further include: a first absolute signal processing unit 410 electrically connected to the first absolute light receiving array 231, wherein the first absolute signal processing unit 410 includes a sine signal processing unit 411, a cosine signal processing unit 412, and a displacement resolving unit 413; wherein,

the sinusoidal signal processing unit 411 is configured to determine a first sinusoidal voltage signal vsin+ and a second sinusoidal voltage signal Vsin "based on the first sinusoidal current signal isin+ and the second sinusoidal current signal Isin-;

the cosine signal processing unit 412 is configured to determine a first cosine voltage signal vcos+ and a second cosine voltage signal Vcos "based on the first cosine current signal icos+ and the second cosine current signal Icos-;

The displacement calculating unit 413 is configured to determine the magnitudes of the set of absolute sine and cosine signals according to the first sinusoidal voltage signal vsin+, the second sinusoidal voltage signal Vsin-, the first cosine voltage signal vcos+ and the second cosine voltage signal Vcos-, and calculate the target displacement in the current variation period based on the obtained feature information set and the magnitudes; the characteristic information set is used for representing the corresponding relation between the area of bright stripes in the first bright-dark pattern and displacement in a change period.

In this embodiment, the sine signal processing unit 411, the cosine signal processing unit 412, and the displacement resolving unit 413 may be implemented based on a hardware circuit, may be implemented based on a software algorithm, may be implemented in a manner of combining soft and hard, and may be specifically determined according to the actual situation, which is not limited in this embodiment of the present disclosure.

In one example of the present embodiment, the sinusoidal signal processing unit 411 may be implemented as a hardware circuit as shown in fig. 13, where the light receiving element inputs the generated first cosine current signal icos+ and second cosine current signal Icos-into two high gain transimpedance amplifiers (Transimpedance amplifier, TIA) respectively, the high gain transimpedance amplifiers TIA are used to amplify the current information into voltage signals, and the converted two voltage signals The number is input to a fully differential amplifier (Fully differential amplifiers, FDA) to eliminate the influence of common mode noise and even harmonics, and a first sinusoidal voltage signal Vsin+ and a second sinusoidal voltage signal Vsin-are obtained. Wherein I is _bias For bias current, V _{ref_TIA} Reference voltage for TIA of high gain transimpedance amplifier, V _{ref_FDA} Is the reference voltage of the fully differential amplifier FDA, R _n 、R _f 、R _t For the resistor, a specific resistance value may be designed according to practical situations, and the embodiment of the present specification is not limited thereto.

In this embodiment, the cosine signal processing unit 412 may process the cosine signal by using the same circuit as shown in fig. 13, and the repetition is not repeated.

In this embodiment, the first sine voltage signal vsin+ and the second cosine voltage signal vcos+ output from the sine signal processing unit 411 and the cosine signal processing unit 412 may be directly output to a processor (for example, MCU, FPGA) to perform absolute position calculation by software, the first sine voltage signal vsin+ and the second sine voltage signal Vsin-are subtracted to obtain a sine signal, the first cosine voltage signal vcos+ and the second cosine voltage signal Vcos-are subtracted to obtain a cosine signal, the amplitude of the absolute sine and cosine signals may be obtained by squaring and re-squaring the sine and cosine signals, and then the current target displacement may be determined according to the correspondence between the area of the bright and dark stripe and the displacement in one variation period in the first bright and dark pattern.

In this embodiment, the feature information set may include a plurality of key value pairs, and each key value pair may include a displacement corresponding to an area of one bright stripe in one variation period. It will be understood, of course, that the above feature information set may be a curve or a formula obtained by fitting, and specifically may be determined according to practical situations, which is not limited in the embodiment of the present disclosure.

In this embodiment, in the case of only one change period, or other possible cases, the calculated target displacement may be the current absolute position, which may be specifically determined according to the actual situation, which is not limited in this embodiment of the present specification.

In this embodiment, the displacement resolving unit 413 may also be implemented in hardware, for example: the displacement resolving unit 413 is composed of a subtractor, an amplifier, an adder, and the like, and achieves the resolving of the target displacement. Of course, the implementation manner of the displacement calculation unit 413 is not limited to the above example, and other modifications may be made by those skilled in the art in light of the technical spirit of the embodiments of the present disclosure, and all the functions and effects implemented by those skilled in the art should be covered in the protection scope of the embodiments of the present disclosure as long as they are the same as or similar to the embodiments of the present disclosure.

In one embodiment, the change period may be plural, and the photoelectric encoder may further include: the hall device comprises a hall element 500, at least one bipolar magnet 600 and a reference signal processing part 510, wherein the bipolar magnet 600 is arranged opposite to the hall element 500, and the magnetic pole change point of the bipolar magnet 600 is arranged corresponding to the junction point of two adjacent change periods; the hall element 500 is configured to detect a change in magnetic pole when moving in the measuring direction with respect to the bipolar magnet 600, and output a reference signal; the reference signal processing unit is electrically connected to the hall element 500, and is configured to determine, according to the reference signal, a change period of the first bright-dark pattern currently irradiated by the light source, and output a determination result.

In this embodiment, since the optical signal is always continuously changed, and in consideration of the resolving precision and the multi-range universality, a multi-period repetitive pattern is often adopted in the design of the slit array, that is, the changing period is multiple, and at this time, the amplitude of the same absolute sine and cosine signal is not corresponding to the unique displacement, and it is necessary to distinguish the same amplitude from different displacement by means of an auxiliary code channel or an auxiliary sensing device.

In the present embodiment, a hall element 500, at least one bipolar magnet 600, and a reference signal processing section 510 may be provided. The magnetic pole changing points of the bipolar magnet 600 may be disposed corresponding to the boundary points of two adjacent changing periods, and when the magnetic field changes, the magnetic pole changing points indicate that the magnetic pole changing points have moved from one changing period to another, so that the current changing period can be confirmed by detecting the change of the magnetic field.

In the present embodiment, the hall element 500 is a semiconductor magneto-electric device, and the hall element 500 operates by using the hall effect, and can be used to detect a magnetic field and a change thereof, and when the hall element 500 detects a change in the magnetic field, the level of an output reference signal changes. Accordingly, the reference signal processing unit 510 can determine the change period of the first bright-dark pattern currently irradiated by the light source according to the level change of the output reference signal

In this embodiment, the hall element 500 may be a bipolar latch hall element, but other possible devices may be used, and the specific may be determined according to practical situations, which is not limited in this embodiment.

In the present embodiment, the bipolar magnet may be rectangular, circular, oval, or any other possible shape, and may be specifically determined according to the actual situation, which is not limited in the examples in the present specification.

In the present embodiment, the hall element 500 and the bipolar magnet 600 may be replaced with other sensor devices, and the sensor devices may be specifically determined according to actual situations, and the embodiment is not limited thereto.

In the present embodiment, since the reference signal output from the hall element 500 has an incremental function, the reference signal can be used to perform a more accurate relative position calculation, thereby realizing a high-accuracy absolute position calculation.

In one embodiment, in the case where the photoelectric encoder 200 is a linear encoder, the number of the bipolar magnets 600 may be equal to the number of the variation periods, the bipolar magnets 600 may be spaced along the measurement direction, and the magnetic poles of two adjacent bipolar magnets 600 may be opposite to each other; in the case where the photoelectric encoder 200 is a rotary encoder, the bipolar magnet 600 is disposed at the center of the slit 210.

In the present embodiment, in order to accurately detect the number of the change periods in which the first bright-dark pattern irradiated by the light source is currently located, the number of the bipolar magnets 600 may be equal to the number of the change periods.

In the case where the photoelectric encoder 200 is a linear encoder, as shown in fig. 14, the bipolar magnets 600 may be disposed such that the hall element 500 may be moved in synchronization with the first absolute light receiving array 231, the bipolar magnets 600 are disposed on the moving path of the hall element 500, two of the bipolar magnets 600 are disposed at the switching positions of the changing periods, and the poles of the adjacent two of the bipolar magnets 600 are disposed opposite to each other, and the mounting directions are left N, right S, and left S, right N, respectively. The two bipolar magnets 600 and the first absolute slit array 211 are jointly installed on a stator or a rotor of the linear motor, and the hall element 500 and the first absolute light receiving array 231 are installed on the stator or the rotor of the linear motor, so that when the bipolar magnets 600 and the first absolute slit array 211 move relative to the first absolute light receiving array 231 and the hall element 500, the level switching point of the hall element 500 is a two-interval switching point, and the current interval can be judged by the output level of the hall element 500. Only a part of the bipolar magnets 600 are cut out in fig. 14, and more bipolar magnets 600 can be provided in practical application, and the details can be determined according to practical situations.

In the present embodiment, in order to save the volume, in the case where the photoelectric encoder 200 is a rotary encoder, the bipolar magnet 600 is provided at the center of the slit portion 210. In some embodiments, the bipolar magnet 600 may be integrally formed with the slit portion 210, or may be disposed independently of the slit portion 210, which is not limited in this specification according to the actual situation.

In the case where the photoelectric encoder 200 is a rotary encoder, as shown in fig. 15, the bipolar magnet 600 may be installed in the center of the slit portion 210, and the magnetic pole switching position of the bipolar magnet 600 is aligned with the interval switching position of the variation period during installation, so that when the bipolar magnet 600 and the first absolute slit array 211 rotate relative to the first absolute light receiving array 231 and the hall element 500, the hall element 500 level switching point is ensured to be the two interval switching point, and the current interval can be determined by the output level of the hall element 500.

In one embodiment, as shown in fig. 16, the absolute sine and cosine signals output by the first absolute light receiving array 231 and the reference signals output by the hall element 500 may be signal diagrams corresponding to the first absolute slit array 211 with 32 lines in fig. 16, and the switching points of the reference signal levels correspond to the switching points of the 8 th and 9 th period absolute sine and cosine signals and the switching points of the 23 th and 24 th period absolute sine and cosine signals. Wherein, a group of bright and dark stripes corresponds to a periodic sine and cosine signal.

While fig. 15 illustrates 2 periods of change, the manner of the bipolar magnet 600 is not limited to the above example, and other modifications may be made by those skilled in the art in light of the technical spirit of the embodiments of the present disclosure, and all the functions and effects achieved are intended to be covered by the protection scope of the embodiments of the present disclosure as long as they are the same as or similar to the embodiments of the present disclosure.

In one embodiment, the variation period may be plural, and the slit part 210 may further include a reference slit array 212, where the reference slit array 212 has a second bright-dark pattern formed at equal intervals along the measurement direction, and an intersection point of bright-dark fringes in the second bright-dark pattern is aligned with an intersection point of two adjacent variation periods, and the second interval is greater than the first interval. Correspondingly, the photoelectric encoder 200 may further include: a reference light receiving array 232 and a reference signal processing section 510; the reference light receiving array 232 is configured to receive the measurement light reflected or transmitted by the reference slit array 212, and generate a reference signal; the reference signal processing unit 510 is electrically connected to the reference light receiving array 232, and the reference signal processing unit 510 is configured to determine, according to the reference signal, a change period of the first bright-dark pattern currently irradiated by the light source, and output a determination result.

In this embodiment, the length of the second pitch may be equal to the length of one variation period, and the widths of the bright and dark fringes in the second light and dark pattern may be equal to the second pitch, and the boundary point of the bright and dark fringes in the second light and dark pattern is aligned with the boundary point of two adjacent variation periods, so that it may be determined, by detecting the light and dark variation of the second light and dark pattern, what variation period the first light and dark pattern irradiated by the light source is located at.

In the present embodiment, since the reference slit array 212 has an incremental function, the reference slit array 212 can be used to perform a more accurate relative position calculation, thereby realizing a highly accurate absolute position calculation.

In one embodiment, the arrangement of the reference slit array 212 may be as shown in fig. 17, the light-dark stripe switching point of the reference slit array 212 is aligned with the interval switching position of the variation period, the reference light receiving array 232 may be a photodiode, the reference signal generated by the reference light receiving array 232 is output to the post-amplifying circuit, the reference signal may be amplified into a voltage signal by the high gain transimpedance amplifier, and then is output as a high-low level signal by the comparator and a fixed reference level, when the reference slit array 212 moves from right to left relative to the reference light receiving array 232, the amplified voltage signal output by the reference light receiving array 232 and the reference signal finally output after comparison may be as shown in fig. 18.

In one embodiment, the photoelectric encoder 200 may further include: an absolute position resolving unit 440, where the absolute position resolving unit 440 is electrically connected to the first absolute signal processing unit 410 and the reference signal processing unit 510, and is configured to resolve a first absolute position according to the determination result and the target displacement.

In this embodiment, the target displacement is used to represent the absolute position in a change period, and the determination result is used to represent the change period in which the first bright-dark pattern illuminated by the light source is currently located, so that the current first absolute position can be determined by combining the determination result and the target displacement.

In an embodiment, when the optical encoder 200 is a rotary encoder, as shown in fig. 19, the optical encoder 200 may be integrated with the light source 220, the reference light receiving array 232, and the first absolute light receiving array 231 in one photocell chip as illustrated in fig. 19, and in some embodiments, the light source may also be separately provided, which may be specifically determined according to practical situations, and this embodiment is not limited to this embodiment.

In one embodiment, the slit part 210 may further include: a second absolute slit array 213 and a third absolute slit array 214, the second absolute slit array 213 having a first absolute pattern formed along the measurement direction, and the third absolute slit array 214 having a second absolute pattern formed along the measurement direction.

In this embodiment, in order to improve the accuracy of the absolute position calculation, the second absolute slit array 213 and the third absolute slit array 214 may be provided, and each of the second absolute slit array 213 and the third absolute slit array 214 may be used alone to calculate the absolute position, and the absolute position calculated by the second absolute slit array 213 and the third absolute slit array 214 may be calibrated with the absolute position calculated by the first absolute slit array 211, thereby realizing the absolute position calculation with higher accuracy.

In the present embodiment, the actual slit arrays may have a deviation due to technical limitations such as a process, and thus the second absolute slit array 213 and the third absolute slit array 214 may be provided redundantly, so that high-precision absolute position calculation may be achieved using three absolute slit arrays. It will be understood, of course, that in some embodiments, only two absolute slit arrays may be provided, and in particular, may be determined according to practical situations, which is not limited in this embodiment of the present disclosure.

In this embodiment, the second absolute pattern and the third absolute pattern may include bright and dark areas, and the bright and dark area arrangement rule may be determined by a digital coding method, and the digital coding method may include: m-sequence coding, gray code, etc.

In this embodiment, the absolute pattern formed by the numerical coding method can be shown in fig. 20, and it can be seen from the figure that the change of the bright and dark areas is irregular and accords with the rule of the numerical coding, so that the current absolute position can be uniquely determined in one measurement period based on the absolute pattern.

In the present embodiment, the absolute pattern may refer to a pattern in which the position of the slit is uniquely determined in one measurement period. For example: the origin may be set at a proper angular position of the slit array, and an absolute pattern may be formed with reference to the origin. The absolute position refers to an angular position of the current position with respect to the origin in one measurement period, and the absolute position is unique in one measurement period.

In one embodiment, the photoelectric encoder 200 may further include: a second absolute light receiving array 233 and a third absolute light receiving array 234, the second absolute light receiving array 233 and the third absolute light receiving array 234 being disposed opposite to the slit portion 210, wherein the second absolute light receiving array 233 is configured to receive the measurement light reflected or transmitted by the second absolute slit array 213 and generate a first absolute signal; the third absolute light receiving array 234 is configured to receive the measurement light reflected or transmitted by the third absolute slit array 214 and generate a second absolute signal; the absolute sine and cosine signals are used for selecting one of the first absolute signal and the second absolute signal as a target absolute signal, the target absolute signal is used for calculating a second absolute position, and the change period of the first bright and dark pattern irradiated by the light source at present is judged.

In the present embodiment, the second absolute light receiving array 233 and the third absolute light receiving array 234 may be disposed opposite to the second absolute slit array 213 and the third absolute slit array 214, respectively, to receive the measurement light reflected or transmitted when the light source 220 irradiates the second absolute slit array 213 and the third absolute slit array 214.

In the present embodiment, since the second absolute slit array 213 and the third absolute slit array 214 are provided redundantly, only one of the data can be selected for calculation at the time of actual calculation. The absolute slit arrays with higher precision at different angular positions may be identical, for example, due to factors such as process: the deviation of the second absolute slit array 213 is smaller at 60 °, at which time the signal output by the second absolute light receiving array 233 may be selected for resolving the absolute position.

In this embodiment, the test may be performed before shipping, the absolute signals output by the first absolute light receiving array 231, the second absolute light receiving array 233 and the third absolute light receiving array 234 in one measurement period may be obtained, and the obtained three absolute signals are compared with the three standard signals corresponding to the three absolute signals, so as to determine the correspondence between the absolute sine and cosine signals output by the first absolute light receiving array 231 and the absolute signals output by the second absolute light receiving array 233 and the third absolute light receiving array 234, obtain a correspondence data set, and select one of the first absolute signal and the second absolute signal as the target absolute signal according to the correspondence data set.

In this embodiment, after the corresponding relation data set is obtained by testing, the corresponding relation data set may be stored at a preset position of the encoder, so that the corresponding relation data set may be obtained in time during operation. The corresponding relation data set may be a key value pair, a curve, a formula obtained by fitting, or the like, and may specifically be determined according to actual situations, which is not limited in the embodiment of the present specification.

In this embodiment, the second absolute position may further assist in determining the change period of the first bright-dark pattern currently irradiated by the light source 220, so as to obtain a determination result, and thus, the determination result and the absolute sine-cosine signal output by the first absolute light receiving array 231 may be combined to calculate another absolute position.

In this embodiment, the first absolute slit array 211, the second absolute slit array 213 and the third absolute slit array 214 that use digital codes can be used to effectively increase the subdivision capability of the digital code resolving mode, and solve the problem that resolving using digital signal codes is often limited in size.

In the present embodiment, the number and specific form of the absolute slit array using digital coding are not limited, and may be a barcode track or more, for example: only the second absolute slit array 213 or only the third absolute slit array 214 may be provided, or the second absolute slit array 213 and the third absolute slit array 214 may be provided, and further absolute slit arrays may be provided. As long as the absolute slit array can be set to meet different variation periods corresponding to the same amplitude of the first absolute slit array 211, other variations are possible by those skilled in the art in light of the technical spirit of the embodiments of the present disclosure, and all the functions and effects implemented by the absolute slit array are the same as or similar to those of the embodiments of the present disclosure, which are included in the protection scope of the embodiments of the present disclosure.

It will of course be appreciated that other possible ways of determining the correspondence of the target absolute signal to the first absolute signal and the second absolute signal may be used, for example: the method of using the absolute sine and cosine signals to select one of the first absolute signal and the second absolute signal as the target absolute signal is not limited to the above example, and other modifications are possible by those skilled in the art in light of the technical spirit of the embodiments of the present specification, but all the functions and effects implemented by the method are the same as or similar to those of the embodiments of the present specification, and are encompassed in the protection scope of the embodiments of the present specification.

In one embodiment, the slit part 210 may further include: an incremental slit array 215, the incremental slit array 215 having a third bright-dark pattern formed at a third pitch equally spaced along the measurement direction, wherein the third pitch is smaller than the first pitch.

In the present embodiment, a higher score number of the incremental slit array 215 may be further provided to accomplish a higher accuracy of the low position calculation, and the incremental slit array 215 may have a third bright-dark pattern formed at a third pitch interval along the measurement direction. The third pitch being smaller than the first pitch indicates that the scribing accuracy of the incremental slit array 215 is higher than that of the first absolute slit array 211, and thus the resolved first absolute position can be subdivided by the incremental track, thereby obtaining a higher-accuracy absolute position.

In the present embodiment, the third bright-dark pattern may be a pattern that is regularly repeated at a third pitch, and the absolute position cannot be calculated by itself using the third absolute pattern, but in general, the third bright-dark pattern can represent the position with higher accuracy than the absolute pattern.

In the present embodiment, a rotary encoder is taken as an example of the reticle accuracy: within one 360 degrees, the number of lines of the first absolute slit array 211 is 512 (512 bright and dark stripes), the number of lines of the incremental slit array 215 is 1024 (1024 bright and dark stripes), the more the number of lines, the smaller the pitch of the bright and dark stripes, and the higher the progress of the corresponding solution to the obtained position.

In this embodiment, the comparison of the incremental slit array 215 and the first absolute slit array 211 can be as shown in fig. 21, and it can be seen from fig. 21 that the distribution of bright stripes in the incremental slit array 215 is more dense than the first absolute slit array 211. Of course, the arrangement of the incremental slot array 215 and the first absolute slot array 211 is not limited to the above examples, and other modifications may be made by those skilled in the art in light of the technical spirit of the present embodiment, and it should be understood that the present embodiment is also encompassed by the present embodiment as long as the functions and effects achieved are the same as or similar to those of the present embodiment.

In this embodiment, the slit portion 210 may be provided with the incremental slit array 215 and the first absolute slit array 211, or may be provided with the incremental slit array 215, the second absolute slit array 213, the third absolute slit array 214 and the first absolute slit array 211, which of course is understood that more or less slit arrays may be designed according to actual needs, and the present invention is not limited to the above examples, and those skilled in the art may make other changes in light of the technical spirit of the embodiments of the present invention, but all the functions and effects that are achieved are covered by the protection scope of the embodiments of the present invention as long as they are the same as or similar to the embodiments of the present invention.

In this embodiment, the embodiment of the incremental slit array 215 and the first absolute slit array 211 may be combined with the embodiment of the reference slit array 212 and the embodiment of the hall element 500 to realize the absolute position resolution, and may be specifically determined according to the actual situation, which is not limited in this embodiment.

In one embodiment, the photoelectric encoder 200 may further include: and an incremental light receiving array 235, the incremental light receiving array 235 being disposed opposite to the slit portion 210, wherein the incremental light receiving array 235 is configured to receive the measurement light reflected or transmitted by the incremental slit array 235 and generate an incremental signal for resolving an incremental position.

In this embodiment, the incremental light receiving array 235 may be disposed opposite to the incremental slit array 235, and is configured to receive the measurement light reflected or transmitted by the incremental slit array 235 irradiated by the light source 220.

In the present embodiment, the positional relationship between the incremental light receiving array 235 and the first absolute light receiving array 231 may correspond to the positional relationship between the first absolute slit array 211 and the incremental slit array 215 on the slit portion 210, and may be specifically designed according to the actual optical path, which is not limited in the present embodiment.

In one embodiment, as shown in fig. 22, the photoelectric encoder 200 may further include: a signal selecting unit 400, a first absolute signal processing unit 410, a second absolute signal processing unit 420, an incremental signal processing unit 430, and an absolute position resolving unit 440, wherein input ends of the signal selecting unit 400 are electrically connected to output ends of the first absolute light receiving array 231, the second absolute light receiving array 233, and the third absolute light receiving array 234, respectively, and are used for selecting one of the first absolute signal and the second absolute signal as a target absolute signal based on the absolute sine and cosine signal; the input end of the second absolute signal processing unit 420 is electrically connected to the output end of the signal selecting unit 400, and is configured to obtain the second absolute position according to the target absolute signal; the input end of the first absolute signal processing unit 410 is electrically connected to the output ends of the first absolute light receiving array 231 and the second absolute signal processing unit 233, and is configured to determine, according to the second absolute position, a change period of the first bright-dark pattern currently illuminated by the light source, and calculate to obtain a first absolute position according to a determination result and an absolute sine-cosine signal output by the first absolute light receiving array 231; the input end of the increment signal processing part 430 is electrically connected with the output end of the increment light receiving array 235, and is used for calculating an increment position according to the increment signal; the input end of the absolute position resolving unit 440 is electrically connected to the output ends of the first absolute signal processing unit 410 and the incremental signal processing unit 430, and is configured to subdivide the first absolute position by using the incremental position to obtain a target absolute position.

In this embodiment, 4 slit arrays may be provided, including three absolute slit arrays and one incremental slit array, and correspondingly, 4 light receiving arrays may be provided. The light source 220 and the 4 light receiving arrays are illustrated in fig. 22 as being integrated into one photocell chip, although the light source 220 may be provided independently in some embodiments. In addition, the 4 light receiving arrays are not limited to the arrangement shown in fig. 22, and other modifications are possible by those skilled in the art in light of the technical spirit of the embodiments of the present disclosure, but all the functions and effects achieved by the embodiments are included in the protection scope of the embodiments of the present disclosure as long as they are the same or similar to the embodiments of the present disclosure.

In this embodiment, the target absolute position can be obtained by the following steps:

step S101: selecting one of the first absolute signal and the second absolute signal as a target absolute signal by using the absolute sine and cosine signals output from the first absolute light receiving array 231;

step S103: the target absolute signal is utilized to complete the high-order absolute position calculation to obtain a second absolute position;

step S104: distinguishing different change periods corresponding to the same amplitude of the absolute sine and cosine signals by using the second absolute position to obtain a judging result;

Step S106: according to the judging result and the absolute sine and cosine signal, intermediate position absolute position and low position solution can be carried out to obtain a first absolute position

Step S107: the increment signal output by the increment light receiving array 235 can be utilized to complete the calculation of the lower position with higher precision, so as to obtain the increment position;

step S108: the first absolute position may be subdivided using incremental positions to obtain a target absolute position, thereby obtaining a high accuracy absolute position.

In the present embodiment, for the absolute position calculation of 26 bits, the high order may refer to 17-26 bits, and the high order may use the second absolute slit array 233 or the third absolute slit array 234; the middle bits may be 9-18 bits, the middle bits may be the bits that complete the resolution using first absolute slit array 211, the lower bits may be 1-10 bits, and the lower bits may be the bits that complete the resolution by means of more finely divided incremental slit array 235.

In the present embodiment, the second absolute signal processing unit 420 may send the second absolute position obtained by the calculation to the absolute position calculating unit 440, and the reference for determining the target absolute position may be specifically selected according to the actual situation, which is not limited in the present embodiment.

In the present embodiment, the signal selecting unit 400, the first absolute signal processing unit 410, the second absolute signal processing unit 420, the incremental signal processing unit 430, and the absolute position resolving unit 440 may be only a split expression based on the abstraction of the data processing logic, and may not represent an actual hardware module, and the "selecting unit" or the "processing unit" or the "resolving unit" may implement a combination of software and/or hardware for a predetermined function. In some embodiments, four paths of signals output by the 4 light receiving arrays may be directly input to a processor for performing an operation, which may be specifically determined according to practical situations, and the embodiments of the present disclosure are not limited to this.

In this embodiment, the steps may be processed in parallel, or processed in series, or the sequence may be changed adaptively, which is not limited to the above example, and other modifications may be made by those skilled in the art in light of the technical spirit of the embodiments of the present disclosure, but all the functions and effects implemented by the steps are included in the protection scope of the embodiments of the present disclosure as long as they are the same as or similar to the embodiments of the present disclosure.

In one embodiment, the output end of the second absolute signal processing unit is electrically connected to the input end of the absolute position resolving unit, and the absolute position resolving unit is further configured to perform mutual calibration by using the first absolute position and the second absolute position.

In this embodiment, since the intermediate position calculation result according to the determination result and the absolute sine and cosine signal partially overlaps with the high position calculation result of the second absolute position, the determination result and the high position calculation result can be mutually calibrated, and the reliability of the encoder calculation result can be improved.

In this embodiment, if there is a difference between the first absolute position and the second absolute position, it is indicated that there may be an error, and at this time, calibration may be performed by the determined error, and the specific calibration manner may be determined according to the actual situation, which is not limited in this embodiment of the present disclosure.

Based on the same inventive concept, a servo motor is also provided in the embodiments of the present disclosure, and the servo motor 600 may include: a rotary-type motor in which a rotor rotates with respect to a stator, or a linear motor in which a mover moves with respect to a stator; and the above-mentioned photoelectric encoder 200 for detecting at least one of a position, a speed, and an acceleration of the rotor or the mover.

Since the principle of the servo motor 600 for solving the problem is similar to that of the photoelectric encoder 200, the implementation of the servo motor 600 can be referred to the embodiment of the photoelectric encoder 200, and the repetition is omitted.

Based on the same inventive concept, embodiments of the present disclosure further provide a servo system, where the servo system includes: a rotary-type motor in which a rotor rotates with respect to a stator, or a linear motor in which a mover moves with respect to a stator; an electro-optical encoder 200 that detects at least one of a position, a speed, and an acceleration of the rotor or the mover; and a controller 300 for controlling the rotary motor or the linear motor according to the detection result fed back by the photoelectric encoder.

Since the principle of solving the problem by the servo system is similar to that of the photoelectric encoder 200, the implementation of the servo system can be referred to the embodiment of the photoelectric encoder 200, and the repetition is omitted.

It will be apparent to those skilled in the art that the modules or steps of the embodiments described above may be implemented in a general purpose computing device, they may be concentrated on a single computing device, or distributed across a network of computing devices, they may alternatively be implemented in program code executable by computing devices, so that they may be stored in a storage device for execution by computing devices, and in some cases, the steps shown or described may be performed in a different order than herein, or they may be separately fabricated into individual integrated circuit modules, or multiple modules or steps within them may be fabricated into a single integrated circuit module. Thus, embodiments of the present specification are not limited to any specific combination of hardware and software.

Although the present description provides the method operational steps as described in the above embodiments or flowcharts, more or fewer operational steps may be included in the method, either on a routine or non-inventive basis. In steps where there is logically no necessary causal relationship, the execution order of the steps is not limited to the execution order provided in the embodiments of the present specification. The described methods, when performed in an actual apparatus or an end product, may be performed sequentially or in parallel (e.g., in a parallel processor or multithreaded environment) as shown in the embodiments or figures.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the embodiments of the specification should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

The above description is only of the preferred embodiments of the present embodiments and is not intended to limit the present embodiments, and various modifications and variations can be made to the present embodiments by those skilled in the art. Any modification, equivalent replacement, improvement, or the like made within the spirit and principles of the embodiments of the present specification should be included in the protection scope of the embodiments of the present specification.

Claims

1. A slit portion for use in an optoelectronic encoder, the slit portion comprising: the first absolute slit array is provided with first bright-dark patterns which are formed at equal intervals along the measuring direction according to a first interval, and bright stripes in the first bright-dark patterns are equal in width and area, so that absolute position calculation of the photoelectric encoder is realized.

2. The slit portion of claim 1, wherein the bright stripe shape comprises: rectangular, fan-shaped or trapezoidal.

3. The slit portion of claim 1, wherein bright stripes in the first bright-dark pattern have at least one period of variation.

4. The slit portion according to claim 1, wherein an area of the bright-dark pattern varies according to a sine wave trend or an area of the bright-dark pattern varies according to a triangular wave trend.

5. An optoelectronic encoder, comprising:

a slit portion comprising: a first absolute slit array having first bright-dark patterns formed at equal intervals along a measurement direction at a first pitch, bright stripes in the first bright-dark patterns being equal in width and varying in area to achieve absolute position resolution of the photoelectric encoder;

A light source for emitting measurement light to the slit portion;

the first absolute light receiving array is arranged opposite to the slit part and is used for receiving the measuring light reflected or transmitted by the first absolute slit array, generating an absolute sine and cosine signal by sensing the light quantity change of the measuring light, and the absolute sine and cosine signal is used for resolving the absolute position.

6. The photoelectric encoder according to claim 5, wherein the first absolute light receiving array has a plurality of light receiving elements arranged along the measurement direction, and four adjacent light receiving elements of the plurality of light receiving elements are configured to receive the measurement light reflected or transmitted by a set of bright-dark fringes in the first bright-dark pattern; wherein,

the set of absolute sine and cosine signals generated by the four adjacent light receiving elements comprises: first sinusoidal current signal I _sin+ First cosine current signal I _cos+ Second sinusoidal current signal I _sin- Second cosine current signal I _cos- 。

7. The optoelectronic encoder of claim 6, further comprising: the first absolute signal processing part is electrically connected with the first absolute light receiving array and comprises a sine signal processing unit, a cosine signal processing unit and a displacement resolving unit; wherein,

The sinusoidal signal processing unit is used for being based on the first sinusoidal current signal I _sin+ Second sinusoidal current signal I _sin- Determining a first sinusoidal voltage signal V _sin+ Second sinusoidal voltage signal V _sin- ；

The cosine signal processing unit is used for based on the first cosine current signal I _cos+ Second cosine current signal I _cos- Determining a first cosine voltage signal V _cos+ A second cosine voltage signal V _cos- ；

The displacement resolving unit is used for resolving the first sinusoidal voltage signal V _sin+ Second sinusoidal voltage signal V _sin -, a first cosine voltage signal V _cos+ And a second cosine voltage signal V _cos- Determining the amplitude of the set of absolute sine and cosine signals, and calculating the target displacement in the current change period based on the acquired characteristic information set and the amplitude; the characteristic information set is used for representing the corresponding relation between the area of bright stripes in the first bright-dark pattern and displacement in a change period.

8. The optoelectronic encoder of claim 7, wherein the bright stripes in the first bright-dark pattern have a plurality of periods of variation, the optoelectronic encoder further comprising: the Hall device comprises a Hall element, at least one bipolar magnet and a reference signal processing part, wherein the bipolar magnet is arranged opposite to the Hall element,

The magnetic pole change points of the bipolar magnet are correspondingly arranged with the junction points of two adjacent change periods;

the Hall element is used for detecting magnetic pole change when moving along the measuring direction relative to the bipolar magnet and outputting a reference signal;

the reference signal processing part is electrically connected with the Hall element and is used for judging which change period the first bright-dark pattern irradiated by the light source is positioned at present according to the reference signal and outputting a judging result.

9. The photoelectric encoder according to claim 8, wherein in the case where the photoelectric encoder is a linear encoder, the number of the bipolar magnets is equal to the number of the variation cycles, the bipolar magnets are arranged at intervals in the measurement direction, and magnetic poles of adjacent two bipolar magnets are arranged opposite to each other;

in the case where the photoelectric encoder is a rotary encoder, the bipolar magnet is provided at the center of the slit portion.

10. The photoelectric encoder according to claim 7, wherein bright stripes in the first bright-dark pattern have a plurality of variation periods, the slit portion further includes a reference slit array having second bright-dark patterns formed at equal intervals along the measurement direction,

The juncture of the light and shade stripes in the second light and shade pattern is aligned with the juncture of two adjacent variation periods, and the second interval is larger than the first interval;

correspondingly, the photoelectric encoder further comprises: a reference light receiving array and a reference signal processing section;

the reference light receiving array is used for receiving the measuring light reflected or transmitted by the reference slit array and generating a reference signal;

the reference signal processing part is electrically connected with the reference light receiving array and is used for judging the change period of the first bright-dark pattern irradiated by the light source according to the reference signal and outputting a judging result.

11. The photoelectric encoder according to claim 8 or 10, further comprising an absolute position resolving section electrically connected to the first absolute signal processing section and the reference signal processing section for resolving a first absolute position based on the determination result and the target displacement.

12. The photoelectric encoder according to claim 5, wherein the slit portion further includes: a second absolute slit array having a first absolute pattern formed along the measurement direction, and a third absolute slit array having a second absolute pattern formed along the measurement direction.

13. The optoelectronic encoder of claim 12, further comprising: a second absolute light receiving array and a third absolute light receiving array, which are disposed opposite to the slit portion, wherein,

the second absolute light receiving array is used for receiving the measuring light reflected or transmitted by the second absolute slit array and generating a first absolute signal;

the third absolute light receiving array is used for receiving the measuring light reflected or transmitted by the third absolute slit array and generating a second absolute signal;

the absolute sine and cosine signals are used for selecting one of the first absolute signal and the second absolute signal as a target absolute signal, the target absolute signal is used for calculating a second absolute position, and the change period of the first bright and dark pattern irradiated by the light source at present is judged.

14. The photoelectric encoder of claim 13, wherein the slit portion further comprises: an incremental slit array having a third bright-dark pattern formed at a third pitch equal interval along the measurement direction, wherein the third pitch is smaller than the first pitch.

15. The photoelectric encoder of claim 5 or 14, further comprising: an incremental light receiving array disposed opposite to the slit portion, wherein,

the incremental light receiving array is configured to receive measurement light reflected or transmitted by the incremental slit array and generate an incremental signal that is used to resolve the incremental position.

16. The optoelectronic encoder of claim 15, further comprising: a signal selection section, a first absolute signal processing section, a second absolute signal processing section, an incremental signal processing section, and an absolute position resolving section, wherein,

the input end of the signal selection part is respectively and electrically connected with the output ends of the first absolute light receiving array, the second absolute light receiving array and the third absolute light receiving array, and is used for selecting one of the first absolute signal and the second absolute signal as a target absolute signal based on the absolute sine and cosine signal;

the input end of the second absolute signal processing part is electrically connected with the output end of the signal selecting part and is used for obtaining a second absolute position according to the target absolute signal solution;

The input end of the first absolute signal processing part is electrically connected with the first absolute light receiving array and the output end of the second absolute signal processing part, and is used for judging which change period the first bright-dark pattern irradiated by the light source is positioned at present by utilizing the second absolute position, and obtaining a first absolute position by calculating according to a judging result and the absolute sine-cosine signal;

the input end of the increment signal processing part is electrically connected with the output end of the increment light receiving array and is used for calculating an increment position according to the increment signal;

the absolute position resolving part is electrically connected with the input ends of the first absolute signal processing part and the increment signal processing part, and is used for subdividing the first absolute position by utilizing the increment position to obtain a target absolute position.

17. The photoelectric encoder of claim 16, wherein an output of the second absolute signal processing portion is electrically connected to an input of the absolute position resolving portion, the absolute position resolving portion further configured to perform mutual calibration using the first absolute position and the second absolute position.

18. A servo motor, the servo motor comprising:

a rotary-type motor in which a rotor rotates with respect to a stator, or a linear motor in which a mover moves with respect to a stator; and

the photoelectric encoder of any of claims 5-17, for detecting at least one of a position, a velocity, and an acceleration of the rotor or the mover.

19. A servo system, the servo system comprising:

a rotary-type motor in which a rotor rotates with respect to a stator, or a linear motor in which a mover moves with respect to a stator;

the photoelectric encoder of any of claims 5-17, which detects at least one of a position, a velocity, and an acceleration of the rotor or the mover; and

and the controller is used for controlling the rotary motor or the linear motor according to the detection result fed back by the photoelectric encoder.