High-resolution hybrid photoelectric encoder and signal processing method thereof

Abstract

The invention provides a high-resolution hybrid photoelectric encoder, and the encoder comprises an encoding medium which is provided with an incremental code channel and an absolute code channel, and the incremental code channel is composed of K pairs of periodic light and shade alternate scribed lines which are uniformly distributed; the absolute code channel has a pseudo-random property and is composed of K / N coding scribed lines; the optical system comprises a light source and an optical assembly and projects light rays of the light source to the coding media in a transmission or reflection mode; a detection element for receiving an optical signal emitted from the light source and formed by transmission or reflection through the encoding medium; the detection element comprises an incremental light receiving device array used for receiving incremental code channel optical signals of the coding media; the absolute light receiving device array is used for receiving absolute code channel optical signals of the coding media; the signal processing system comprises an incremental signal processing channel and an absolute signal processing channel; and the data processing unit comprises a storage module and a decoding operation module. The invention also provides a signal processing method realized by adopting the hybrid photoelectric encoder.

Description

Technical Field

[0001] This invention relates to the field of photoelectric measurement and sensor technology, and in particular to a hybrid photoelectric encoder structure and its decoding method that can achieve ultra-high resolution under large-size photoelectric detector conditions. Background Technology

[0002] Photoelectric encoders are crucial position feedback components in modern precision motion control systems. Their performance directly affects the positioning accuracy and control stability of the system, and therefore they are widely deployed in industrial applications with strict dynamic performance requirements, such as industrial robots, CNC machine tools, and high-precision servo systems.

[0003] As modern equipment manufacturing continues to upgrade towards higher precision and efficiency, the market is placing increasingly stringent demands on encoder resolution. In a typical hybrid photoelectric encoder, the encoding medium generally has two sets of parallel grating tracks: one set is the absolute code track, composed of non-periodic bright and dark stripes, each line representing a unique absolute position code; the other set is the incremental code track, composed of periodically evenly arranged bright and dark periodic lines used to generate orthogonal sinusoidal signals. Generally, one absolute code track line spatially corresponds to a pair of bright and dark periodic lines on the incremental code track. In this traditional design, the absolute code track acquires absolute position information, and the incremental code track acquires relative position information. The total system resolution can theoretically be obtained by adding the number of bits in the absolute code track and the number of bits in the incremental code track. Therefore, traditional techniques primarily increase the number of bits in the absolute code track by continuously reducing the physical size of the absolute code track detection element, thereby improving the overall resolution. However, this approach has encountered significant limitations in practice: First, the minimum size of the detection element is physically limited by semiconductor process nodes and cannot be reduced indefinitely; second, an excessively small photosensitive area reduces signal energy and exacerbates noise interference, leading to a deterioration in the overall signal-to-noise ratio of the system. Furthermore, extremely small detectors are difficult to manufacture and complex to package, resulting in a significant increase in production costs.

[0004] Therefore, breaking through the current resolution limit without completely relying on detector miniaturization has become a major technical bottleneck that urgently needs to be solved in this field. Summary of the Invention

[0005] The technical problem this invention aims to solve is to provide a new encoder structure and decoding method based on existing photodetector manufacturing processes, enabling the achievement of resolutions such as 29 bits or even higher without significantly reducing the detector size. The technical solution is as follows: A high-resolution hybrid photoelectric encoder, comprising: The encoding medium has incremental code channels and absolute code channels. The incremental code channels consist of K pairs of periodically alternating bright and dark etched lines that are evenly distributed. The absolute code channels have pseudo-random properties and consist of K / N coded etched lines, where N is an integer greater than 1, K>N and K / N is an integer. One coded etched line of the absolute code channel corresponds spatially to N pairs of periodically alternating bright and dark etched lines of the incremental code channel. An optical system, including a light source and optical components, projects light from the light source onto the coded medium by transmission or reflection; A detection element is used to receive light signals emitted from a light source and formed by transmission or reflection through an encoding medium. The detection element includes: an incremental light-receiving device array for receiving incremental code track light signals from the encoding medium; and an absolute light-receiving device array for receiving absolute code track light signals from the encoding medium. The absolute light-receiving device array is arranged as follows: for a scribed stripe of an absolute code track on the encoding medium, M photodetector receiving units are configured in the corresponding photosensitive area, forming a group, called a group of M absolute light-receiving devices, where M is an integer and N>M≥1. All photodetector receiving units in the absolute light-receiving device array simultaneously and independently receive absolute code track light signals. The signal processing system includes an incremental signal processing channel and an absolute signal processing channel. The incremental signal processing channel is equipped with an incremental signal readout circuit and a Q-bit incremental signal analog-to-digital converter, which is used to convert the optical signal of the incremental photodetector array into an electrical signal, and amplify and subdivide it to obtain incremental position information. The absolute signal processing channel is equipped with an absolute signal readout circuit and an absolute signal analog-to-digital converter, which is used to convert the optical signal of the absolute photodetector array into an electrical signal, and process and calculate it to obtain an absolute position code. The data processing unit includes a storage module and a decoding and computation module.

[0006] Furthermore, the electrical signal characteristics of the absolute light-receiving device output are as follows: For a group of M absolute light-receiving devices corresponding to a single scribe line of the absolute code track, when all M absolute light-receiving devices are on the bright scribe line of the absolute code track, the output electrical signal is high; when all M absolute light-receiving devices are on the dark scribe line, the output electrical signal is low; when all M absolute light-receiving devices are in the transition zone between bright and dark scribe lines of the absolute code track, only one of the M absolute light-receiving devices has an output signal between high and low levels, and as the encoding medium rotates, this output signal exhibits an edge characteristic from high to low or from low to high, and the edge duration of this output signal is N / M incremental signal cycles, while the output signals of the other absolute light-receiving devices are high or low.

[0007] This invention also provides a signal processing method implemented using the above-described encoder, including... The following operations are performed during the system initialization and calibration phase: For each group of M absolute light-receiving devices, for output signals with edge characteristics, the periodic edge of the incremental code channel is used as the synchronous trigger signal. The absolute code channel sample and hold circuit samples the voltage of the output signal. Under the triggering of a stable incremental periodic edge, the edge of the output signal is divided into N / M voltage partitions. The sampled voltage values ​​are converted into digital signals by an absolute signal analog-to-digital converter and stored in the storage unit as partition reference voltages. Perform the following operations during the system's operation phase: S1, High-order absolute code acquisition: Calculate (log2K-log2N) and round the result up to get T. The absolute code channel of the encoded medium has T bits of absolute position information. The absolute position information of T bits is directly acquired by the photodetector receiving unit in the absolute light receiving device array and used as the high-order absolute position information. S2, Median Absolute Code Acquisition: Calculate log2M and round the result up to obtain S. Scan the output voltage of all absolute light-receiving devices in real time, identify the only photodetector receiving unit with edge characteristics in the M absolute light-receiving device array corresponding to a scribe line stripe of the absolute code track at the same time, and parse the median absolute position information of S bits accordingly. S3, Low-order absolute code acquisition: Calculate (log2N-log2M) and round up the result to obtain V. The output voltage of all absolute receiving units will be scanned in real time. The instantaneous sampling voltage of the photodetector receiving unit with edge characteristics will be compared with the pre-stored partition reference voltage to determine its partition and output the low-order absolute position information of V bits. S4, Obtain the complete absolute position code: Combine the T-bit high-order absolute code, S-bit middle-order absolute code and V-bit low-order absolute code into a complete absolute position code of log2K bits; S5, Obtaining Incremental Position Encoding: The incremental signal analog-to-digital converter is a Q-bit high-precision analog-to-digital converter, used to synchronously sample and quantize the four orthogonal sinusoidal signals output by the incremental code channel, and to perform interpolation subdivision within one incremental signal period through arctangent operation or lookup table method to obtain the relative position information of Q bits.

[0008] Furthermore, it also includes obtaining complete location information encoding: combining the complete absolute location encoding with the Q-bit relative location information to output high-resolution location data totaling (T+S+V+Q) bits.

[0009] Compared with the prior art, the beneficial effects of the present invention are: Breaking through technological bottlenecks: Traditional photoelectric encoder technology requires shrinking detector size to improve resolution. This invention, through a new signal decoding architecture, shifts the core of resolution improvement from "mechanical miniaturization" to "intelligent signal analysis," making it possible to achieve ultra-high resolution (29 bits and above) on mature, larger-sized detectors. This not only reduces reliance on cutting-edge semiconductor processes but also significantly reduces the process limitations, manufacturing difficulties, packaging challenges, and high costs caused by excessively small detector sizes, achieving a performance leap at the same process node. A new performance benchmark has been proposed: by combining "absolute code channel segmented decoding" with "incremental code channel high-multiplication interpolation", a resolution level of 29-bit absolute position has been achieved, providing higher-order perception capabilities for high-precision servo control and advanced manufacturing, and realizing excellent comprehensive performance. High signal-to-noise ratio and stability: Thanks to the larger photosensitive area of ​​the detector, the system captures stronger signals and significantly improves anti-interference ability, ensuring long-term reliability and measurement consistency in harsh industrial environments such as vibration and temperature fluctuations. It provides greater design flexibility: the parameterized design of "N" and "M" makes this invention a scalable design paradigm, which can flexibly adjust the resolution index according to the cost and performance requirements of different application scenarios, thus expanding the application spectrum of the product. High fault tolerance and easy maintenance: The larger detector size means lower sensitivity to contamination such as dust and scratches, improving the overall lifespan and environmental adaptability; It opens up a feasible path to reduce costs and increase efficiency: By empowering hardware with algorithms, it achieves performance indicators that were previously only achievable with top-tier processes at a lower manufacturing cost, breaking the traditional dilemma that "high performance inevitably means high cost", and has high commercial value and market competitiveness. Attached Figure Description

[0010] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation of the present invention.

[0011] Figure 1 This is an explanatory diagram illustrating an example of a simplified configuration of a photoelectric encoder system. Figure 2 This is a partial schematic diagram illustrating an example of an encoded media. Figure 3 This is a partially enlarged schematic diagram illustrating an example of an encoded medium. Figure 4 This is an illustrative diagram showing a partial structure of a photoelectric encoder and the signals it generates. Figure 5 This is a block diagram illustrating an example of the calibration stage in a photoelectric encoder signal processing scheme. Figure 6 This is a block diagram illustrating an example of the working stages in a photoelectric encoder signal processing scheme. Figure 7 These are other illustrative diagrams showing a simplified configuration of a photoelectric encoder system. Figure 8 This is a partial schematic diagram illustrating other instances of encoded media. Detailed Implementation

[0012] The basic technical solution of the present invention will be described below.

[0013] This invention provides a novel high-resolution hybrid photoelectric encoder structure, the structure of which consists of: 1) The encoding medium is equipped with incremental code tracks and absolute code tracks. The incremental code tracks consist of K pairs of periodically alternating bright and dark etched lines that are evenly distributed; the absolute code tracks have pseudo-random properties and are composed of K / N specific coded etched lines (N is an integer greater than 1, K>N and K / N is an integer); one etched line of the absolute code track corresponds spatially to N pairs of bright and dark etched lines of the incremental code track. 2) An optical system, including a light source and optical components, projects light from the light source onto the encoding medium by transmission or reflection; 3) A detection element for receiving optical signals emitted from a light source and formed by transmission or reflection through the encoding medium. The detection element includes: an incremental light-receiving device array for receiving incremental code track optical signals of the encoding medium; and an absolute light-receiving device array for receiving absolute code track optical signals of the encoding medium. 4) The signal processing system includes an incremental signal processing channel and an absolute signal processing channel. The incremental signal processing channel is equipped with an incremental signal readout circuit and a high-precision Q-bit analog-to-digital converter (Q is an integer greater than 1) to convert the optical signal of the incremental photodetector array into an electrical signal, and then amplify and subdivide it to obtain high-precision incremental position information. The absolute signal processing channel is equipped with an absolute signal readout circuit and an absolute signal analog-to-digital converter (ADC) to convert the optical signal of the absolute photodetector array into an electrical signal, and then process and calculate it to obtain the absolute position code. 5) Data processing unit, including storage module and decoding and operation module.

[0014] 2. The arrangement of the absolute light-receiving device array is as follows: For a single etched line of the absolute code track on the encoding medium, M (M is an integer, and N>M≥1) photodetector receiving units are configured within its corresponding photosensitive area, forming a group. All photodetector receiving units in the absolute light-receiving device array simultaneously and independently receive the absolute code track optical signal.

[0015] 3. The electrical signal characteristics of the absolute light-receiving device output are as follows: For a group of M absolute light-receiving devices corresponding to one etched line of the absolute code track, when all the light-receiving devices in the group are on the bright etched line of the absolute code track, the output electrical signal is high; when all the light-receiving devices in the group are on the dark etched line, the output electrical signal is low; when the group of light-receiving devices is in the transition zone between bright and dark etched lines of the absolute code track, only one of the M absolute light-receiving devices has an output signal between high and low levels, and as the encoding medium rotates, this output signal exhibits an edge characteristic from high to low or from low to high, while the output signals of the other light-receiving devices are either high or low. Since one etched line of the absolute code track corresponds to N pairs of bright and dark etched lines of the incremental code track, and M absolute light-receiving devices are configured for one etched line of the absolute code track, the edge duration of this output signal is N / M (N / M is an integer, and N / M > 1) incremental signal cycles.

[0016] 4. A signal processing method for a high-resolution hybrid photoelectric encoder, comprising the following steps: Perform the following operations during the system initialization and calibration phase: For each group of M absolute light-receiving devices, the output signal is located at the edge. Since the edge duration is N / M incremental signal cycles, the periodic edge of the incremental code channel is used as the synchronous trigger signal. The absolute code channel sample-and-hold circuit samples the voltage of the output signal. Under the trigger of a stable incremental periodic edge, the signal edge is divided into N / M voltage partitions. The sampled voltage values ​​are converted into digital signals by an absolute signal analog-to-digital converter and stored in the memory unit as partition reference voltages.

[0017] Perform the following operations during the system's operation phase: 1) High-order absolute code acquisition: The absolute code channel of the encoded medium has absolute position information of (log2K-log2N) bits (rounding up the calculation result). The absolute position information of (log2K-log2N) bits is directly acquired by each receiving unit in the absolute light receiving device array and used as the high-order absolute position information. 2) Median absolute code acquisition: Scan the output voltage of all absolute receiving units in real time, identify the only receiving unit in the edge region at the same time among the M receiving units corresponding to a scribe line stripe of the absolute code track, and parse the median absolute position information of log2M bits (round the calculation result up).

[0018] 3) Low-order absolute code acquisition: Real-time scanning of the output voltage of all absolute receiving units, comparing the instantaneous sampled voltage of the receiving unit in the edge region with the pre-stored partition reference voltage to determine its partition, and outputting (log2N-log2M) bits of low-order absolute position information (rounded up).

[0019] 4) Obtain the complete absolute position code: Combine the (log2K-log2N) bit high-order absolute code, the log2M bit middle-order absolute code, and the (log2N-log2M) bit low-order absolute code into a complete log2K bit absolute position code (round all calculation results up).

[0020] 5) Obtaining incremental position code: The incremental signal analog-to-digital converter is a Q-bit (Q is an integer greater than 1) high-precision analog-to-digital converter, used to synchronously sample and quantize the four orthogonal sinusoidal signals output by the incremental code channel, and to perform interpolation subdivision within one incremental signal period by arctangent operation or lookup table method to obtain the relative position information of Q bits.

[0021] Obtain complete location information encoding: Combine the log2K bits of complete absolute location encoding with the Q bits of relative location information to output a total of (log2K+Q) bits of high-resolution location data (round all calculation results up).

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] like Figure 1 The diagram shown illustrates a structural embodiment of the photoelectric encoder, which is a transmissive structure. Its core components include a rotating code disk, a light source, a photodiode photosensitive array, and a signal processing circuit. These components work together to achieve high-precision absolute position detection. The code disk has pseudo-random absolute code tracks 100 and incremental code tracks 110. The receiving element includes an absolute photosensitive array 120 and an incremental photosensitive array 130. When the code disk rotates with the rotating shaft, light emitted from the light source passes through the light-transmitting area of ​​the code disk and illuminates the photodiode photosensitive array, causing a change in the light intensity received by the receiving element. The receiving element converts this change in light intensity into a current signal, which is then processed by the signal processing circuit. Figure 1 The structure of a transmissive photoelectric encoder is shown, but the technical solution proposed in this invention can be used for both transmissive and reflective photoelectric encoders.

[0024] like Figure 2The diagram shown is a partial schematic of an embodiment of the encoding medium, including an absolute code track 100 and an incremental code track 110. The absolute code track uses pseudo-random sequence encoding and is composed of several striped lines arranged in a pattern, with each rotation position corresponding to a unique pseudo-random code combination; the incremental code track is composed of uniformly distributed periodic bright and dark lines.

[0025] like Figure 3 The diagram shown is a partial schematic of an embodiment of the encoding medium. In this embodiment, N is set to 4, and one scribe line of the absolute code track 100 corresponds to 16 pairs of light and dark stripe scribe lines of the incremental code track 110.

[0026] like Figure 4 The image shows a photoelectric encoder scheme according to the first embodiment of the present invention. In this embodiment, K is set to 15, Q to 14, N to 4, and M to 2. In the encoding medium, each absolute code track 100 corresponds to 16 pairs of incremental bright and dark etched lines, and each absolute etched line 100 corresponds to 4 absolute detection elements 121-124. When the encoding medium 100 and 110 rotate relative to the detection elements, when the absolute code track etched line is bright, the light-receiving device corresponding to the absolute code track receives the light signal from the encoding medium, and the generated current signal increases; when the absolute code track etched line is dark, the current signal generated by the light-receiving device corresponding to the absolute code track decreases. In this embodiment, the dark-to-light etched lines of the absolute code track 100 pass sequentially through absolute code track detection elements 121-124. Detection element 121 generates an electrical signal as shown in Figure 421, detection element 122 generates an electrical signal as shown in Figure 422, detection element 123 generates an electrical signal as shown in Figure 423, and detection element 124 generates an electrical signal as shown in Figure 424. Electrical signals 421-424 have the edge characteristics shown in the figure. The incremental code track detection element receives the optical signal from the encoding medium 110 and generates a periodic sinusoidal signal 410. The rising edge time length of the absolute signals 421-424 corresponds to four periods of the incremental signals 410.

[0027] like Figure 5 The diagram illustrates the calibration stage of the signal processing scheme in the first embodiment of the present invention. Its purpose is to provide partition voltages for low-order absolute code discrimination during the operational stage. The calibration stage involves the following steps: After the pseudo-random absolute code channel signal passes through the signal amplification circuit 510, the absolute code channel sample-and-hold circuit 520 samples the edge voltage of the absolute code channel under stable incremental periodic edge triggering, using the periodic edge of the incremental code channel as the synchronous trigger signal. The sampled voltage is converted into a digital signal by the absolute signal analog-to-digital converter 530 and stored in the storage unit 540 as a partition reference voltage.

[0028] like Figure 6The diagram shows the working stage of the signal processing scheme in the first embodiment of the present invention, the purpose of which is to obtain the final 29-bit angle information encoding. The working stage of the photoelectric encoder scheme relies on the partitioned reference voltage pre-stored in the calibration stage. Absolute position calculation is achieved through segmented decoding (high bit + middle bit + low bit), combined with high-multiplication interpolation of the incremental code, to output a total resolution of 29 bits. The steps of the working stage are as follows: 1) The current signal of the absolute code channel detection element is sampled in real time by the absolute code channel signal amplifier circuit 510 and then sent to the absolute signal sample and hold circuit 520 for digitization. The signal is then sent to the absolute signal analog-to-digital converter 530 to obtain an 11-bit high-order absolute code, which corresponds to the coarse position of the absolute code channel. 2) Based on the results of the absolute signal analog-to-digital converter, the system monitors the signals of the four detection elements corresponding to the absolute reticle lines in the digital logic 650 module, such as... Figure 4 As shown, at most one signal is on the rising edge or falling edge at any given time. Therefore, the detection element corresponding to the signal located on the edge is identified and encoded to obtain a 2-bit absolute code. 3) In the digital logic 650 module, for the detected signal voltage at the edge, it is compared one by one with the partition reference voltage pre-stored in the memory 540 during the calibration stage to determine its subdivision partition at the waveform edge and output a 2-bit low-order absolute code. 4) In the digital logic 650 module, the 11-bit high-order absolute code, the 2-bit middle-order absolute code, and the 2-bit low-order absolute code are combined to obtain a 15-bit absolute position code, which corresponds to the precise position of the absolute code channel. 5) The incremental code channel detection element receives the optical signal from the incremental code channel 120 and generates a periodic sine signal 130. The signal is then sent to the incremental signal high-precision analog-to-digital converter 670 via the incremental signal amplification circuit 660. The output 14-bit digital signal is sent to the digital logic 650 and subdivided into 14 bits within one incremental cycle through an interpolation algorithm to obtain the incremental position information.

[0029] 6) In the Digital Logic 650 module, the 15-bit absolute position code is combined with the 14-bit incremental interpolation code to obtain 29-bit high-resolution position data, which corresponds to the precise physical position of the encoded media.

[0030] In summary, the resolution of traditional absolute photoelectric encoders is mainly determined by a series of constraints such as the encoder's physical size, semiconductor process technology, and corresponding manufacturing costs. In contrast, the photoelectric encoder solution of this invention shifts the core factor determining resolution from "scale compression dependent on mechanical structure" to "intelligent analysis and reconstruction based on signal characteristics," thereby achieving ultra-high resolution positioning (not less than 29 bits) while maintaining the macroscopic size of the detector.

[0031] like Figure 7 As shown, the light source is on one side of the photodiode array. The light emitted by the light source passes through the encoding medium and is reflected onto the photodiode photosensitive array, where the light carrying the encoded information of the encoding medium is reflected. The photodiode converts the light signal into an electrical signal, which then enters the signal processing circuit.

[0032] like Figure 8 As shown, the encoding medium has absolute code tracks 100 and incremental code tracks 110. Incremental code tracks 110 consist of uniformly distributed, periodically alternating bright and dark etched lines. Absolute code tracks have pseudo-random properties and are composed of specific encoding etched lines, where each absolute code track etched line spatially corresponds to N pairs of incremental code track bright and dark etched lines (N is greater than 1 and is an integer). Other absolute code tracks 810 and other incremental code tracks 820 may also exist in the encoding medium.

Claims

1. A high-resolution hybrid photoelectric encoder, comprising: The encoding medium has incremental code channels and absolute code channels. The incremental code channels consist of K pairs of periodically alternating bright and dark etched lines that are evenly distributed. The absolute code channels have pseudo-random properties and are composed of K / N encoding etched lines, where N is an integer greater than 1, K>N and K / N is an integer. A single coding line in the absolute code track corresponds spatially to N pairs of periodic alternating bright and dark lines in the incremental code track; An optical system, including a light source and optical components, projects light from the light source onto the coded medium by transmission or reflection; A detection element is used to receive light signals emitted from a light source and formed by transmission or reflection through an encoding medium. The detection element includes: an incremental light-receiving device array for receiving incremental code track light signals from the encoding medium; and an absolute light-receiving device array for receiving absolute code track light signals from the encoding medium. The absolute light-receiving device array is arranged as follows: for a scribed stripe of an absolute code track on the encoding medium, M photodetector receiving units are configured in the corresponding photosensitive area, forming a group, called a group of M absolute light-receiving devices, where M is an integer and N>M≥1. All photodetector receiving units in the absolute light-receiving device array simultaneously and independently receive absolute code track light signals. The signal processing system includes an incremental signal processing channel and an absolute signal processing channel. The incremental signal processing channel is equipped with an incremental signal readout circuit and a Q-bit analog-to-digital converter, which is used to convert the optical signal of the incremental photodetector array into an electrical signal, and amplify and subdivide it to obtain incremental position information. The absolute signal processing channel is equipped with an absolute signal readout circuit and an absolute signal analog-to-digital converter, which is used to convert the optical signal of the absolute photodetector array into an electrical signal, and process and calculate it to obtain an absolute position code. The data processing unit includes a storage module and a decoding and computation module.

2. The high-resolution hybrid photoelectric encoder according to claim 1, characterized in that, The electrical signal characteristics of the output of the absolute light-receiving device are as follows: For a group of M absolute light-receiving devices corresponding to a single etched line of the absolute code track, when all M absolute light-receiving devices are on the bright etched line of the absolute code track, the output electrical signal is high; when all M absolute light-receiving devices are on the dark etched line, the output electrical signal is low; when the group of M absolute light-receiving devices is in the transition zone between bright and dark etched lines of the absolute code track, only one of the M absolute light-receiving devices has an output signal between high and low levels, and as the encoding medium rotates, the output signal exhibits an edge characteristic from high to low or from low to high, and the edge duration of the output signal is N / M incremental signal cycles, while the output signals of the other absolute light-receiving devices are high or low.

3. A signal processing method based on any one of claims 1 or 2, characterized in that, The following operations are performed during the system initialization and calibration phase: For each group of M absolute light-receiving devices, for output signals with edge characteristics, the periodic edge of the incremental code channel is used as the synchronous trigger signal. The absolute code channel sample and hold circuit samples the voltage of the output signal. Under the triggering of a stable incremental periodic edge, the edge of the output signal is divided into N / M voltage partitions. The sampled voltage values ​​are converted into digital signals by an absolute signal analog-to-digital converter and stored in the storage unit as partition reference voltages. Perform the following operations during the system's operation phase: S1, High-order absolute code acquisition: Calculate (log2K-log2N) and round the result up to get T. The absolute code channel of the encoded medium has T bits of absolute position information. The absolute position information of T bits is directly acquired by the photodetector receiving unit in the absolute light receiving device array and used as the high-order absolute position information. S2, Median Absolute Code Acquisition: Calculate log2M and round the result up to obtain S. Scan the output voltage of all absolute light-receiving devices in real time, identify the only photodetector receiving unit with edge characteristics in the M absolute light-receiving device array corresponding to a scribe line stripe of the absolute code track at the same time, and parse the median absolute position information of S bits accordingly. S3, Low-order absolute code acquisition: Calculate (log2N-log2M) and round up the result to obtain V. The output voltage of all absolute receiving units will be scanned in real time. The instantaneous sampling voltage of the photodetector receiving unit with edge characteristics will be compared with the pre-stored partition reference voltage to determine its partition and output the low-order absolute position information of V bits. S4, Obtain the complete absolute position code: Combine the T-bit high-order absolute code, S-bit middle-order absolute code and V-bit low-order absolute code into a complete absolute position code of log2K bits; S5, Obtaining Incremental Position Encoding: The incremental signal analog-to-digital converter is a Q-bit high-precision analog-to-digital converter, used to synchronously sample and quantize the four orthogonal sinusoidal signals output by the incremental code channel, and to perform interpolation subdivision within one incremental signal period through arctangent operation or lookup table method to obtain the relative position information of Q bits.

4. The signal processing method according to claim 3, characterized in that, It also includes obtaining complete location information encoding: combining the complete absolute location encoding with the Q-bit relative location information to output high-resolution location data totaling (T+S+V+Q) bits.

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