Encoder and processor thereof

Abstract

The embodiment of the invention relates to the field of encoders, and discloses an encoder and a processor thereof. The encoder comprises: a code disc; the absolute code channel and the incremental code channel are arranged on the code disc; the absolute code channel is arranged to be a symmetrical graph which is used for enabling light rays penetrating through the absolute code channel to be linearly changed; the fixed grating corresponds to the code channel; the fixed grating is used for cooperating with the code disc to generate a sinusoidal signal. According to the encoder provided by the invention, the problems of complex encoding mode and poor PD universality of an absolute photoelectric encoder are solved, the encoding mode is at least simple, the PD universality can be improved, a multi-turn counting function is added on the premise that the number of code channels is not increased, and the miniaturization of the encoder is facilitated.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of encoders, and in particular to an encoder and a processor thereof. Background Art

[0002] The photoelectric encoder is an angle measuring device that integrates optics, mechanics and electronics. It converts optical signals into electrical signals through mechanical structures and signal processing circuits, thereby achieving direct or indirect measurement of various physical quantities such as angular displacement, position and speed.

[0003] The encoding method of the absolute encoder determines that different angle positions have different digital codes, and the code for each angle is unique. At present, the encoding method of the absolute encoder usually adopts Gray code and M code, but these two codes have the problems of complex coding and poor PD (PD (Photodiode) refers to photodiode) universality. In order to achieve multiple turns, multiple turns of code channels need to be added, which makes the manufacturing process complicated. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to at least provide an encoder and a processor thereof, which can at least solve the problems of complex encoding method of absolute photoelectric encoders and poor versatility of PDs, and at least achieve a simple encoding method, improve the versatility of PDs, and add a multi-turn counting function without increasing the number of code channels, which is conducive to the miniaturization of the encoder.

[0005] To solve the above technical problem, at least one embodiment of the present application provides an encoder, including:

[0006] Code disk;

[0007] An absolute code track and an incremental code track are provided on the code disk; the absolute code track is provided as a symmetrical pattern for making the light passing through the absolute code track change linearly;

[0008] And a fixed grating corresponding to the code disc; the fixed grating is used to cooperate with the code disc to generate a sinusoidal signal.

[0009] At least one embodiment of the present application also provides a signal processor for an encoder, comprising: a detector for detecting the optical signals of the absolute code track and the incremental code track in the encoder as described above and outputting a detection signal; and a controller for performing multi-turn and absolute position value calculations on the detection signal output by the detector.

[0010] Compared with the prior art, the encoder and processor provided in the embodiments of the present application adopt a symmetrical pattern that can make the light passing through the absolute code channel change linearly, thereby realizing linear change of light intensity, and at the same time combining with a fixed grating to realize signal sinusoidalization, so that every time the moving grating selects a circle, the signal output changes by one sinusoidal period, and the absolute position of a single circle can be obtained, so that multi-circle counting can be performed; in addition, since graphical single-cycle linear encoding is adopted, the absolute fixed grating has no grating pitch limitation, which can enhance the strength of the photosensitive signal and improve the stability of the absolute signal.

[0011] In addition, the absolute code track includes a first absolute code track and a second absolute code track; the first absolute code track, the incremental code track and the second absolute code track are arranged in parallel on the code disk.

[0012] In addition, the engraved lines of the incremental code channel are evenly distributed and alternate between light and dark.

[0013] In addition, when the number of coding bits of the first absolute code channel and the second absolute code channel is N, the number of scales of the incremental code channel is 2. N .

[0014] In addition, the shape of the absolute code channel is a symmetrical figure whose area changes linearly.

[0015] In addition, the absolute code is any one of a symmetrical triangle, a fan or a quadrilateral.

[0016] In addition, the fixed grating includes a third absolute code channel, a sinusoidal code channel and a fourth absolute code channel arranged in parallel; the third absolute code channel is used to detect the first absolute code channel; the fourth absolute code channel is used to detect the second absolute code channel; the sinusoidal code channel is composed of N sectors connected in sequence in the circumferential direction, and its position corresponds to the incremental code channel setting; wherein the areas of the N sectors vary in a sinusoidal function in the circumferential direction.

[0017] In addition, center lines of the third absolute code track, the sinusoidal code track and the fourth absolute code track are located on the same straight line.

[0018] In addition, the signal processor further comprises:

[0019] a signal amplifier connected to the detector;

[0020] and an analog-to-digital converter connected to the signal amplifier;

[0021] The controller is connected to the analog-to-digital converter and is used to calculate multiple turns and absolute position values ​​of the detection signal that has been amplified by the signal amplifier and converted by the analog-to-digital converter in sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0023] Figure 1 is a schematic diagram of the structure of a code disk in an encoder provided according to an embodiment of the present invention;

[0024] Figure 2 is a schematic structural diagram of a fixed grating in an encoder provided according to an embodiment of the present invention;

[0025] Figure 3 is a schematic diagram of an encoder outputting a sinusoidal signal according to an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of the connection relationship of a signal processor provided according to an embodiment of the present invention.

[0027] In the figure: 1a, first absolute code channel; a, incremental code channel; 2a, second absolute code channel; b, sine code channel; 1b, third absolute code channel; 2b, fourth absolute code channel. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it can be understood by those skilled in the art that in the embodiments of the present invention, many technical details are provided to enable readers to better understand the present invention. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present invention can be implemented.

[0029] In order to facilitate understanding of the embodiments of the present application, relevant content about the absolute encoder is first introduced here.

[0030] A photoelectric encoder is an angle measuring device that integrates optics, mechanics and electronics. It converts optical signals into electrical signals through mechanical structures and signal processing circuits, thereby achieving direct or indirect measurement of various physical quantities such as angular displacement, position and speed.

[0031] The encoding method of the absolute encoder determines that different angle positions have different digital codes, and the code for each angle is unique. At present, the encoding method of the absolute encoder usually adopts Gray code and M code, but these two codes are complex. The code channels of Gray code and M code are composed of fixed-length translucent or opaque lines arranged in the measurement direction. The two are arranged in different ways, the grating pitch of the moving grating is inconsistent, and the fixed grating will have a different design, resulting in PD (PD (Photodiode) refers to photodiode) is not universal, that is, the PD has poor universality. In addition, in order to achieve multiple turns, multiple turns of code channels need to be added, which makes the structure of the code disk and the fixed grating complex and troublesome to manufacture.

[0032] Embodiment 1:

[0033] An embodiment of the present invention relates to an encoder, specifically an absolute value encoder.

[0034] Compared with the prior art, the embodiments of the present invention adopt a symmetrical figure that can make the light passing through the absolute code channel change linearly, thereby realizing linear change of light intensity, and at the same time combining with a fixed grating to realize signal sinusoidalization, so that every time the moving grating selects a circle, the signal output changes by one sinusoidal period, and then the absolute position of a single circle can be obtained, so that multi-circle counting can be performed; in addition, since a graphical single-cycle linear encoding is adopted, the absolute fixed grating has no grating pitch limitation, which can enhance the strength of the photosensitive signal and improve the stability of the absolute signal.

[0035] The implementation details of the encoder of this embodiment are described in detail below. The following content is only provided for easy understanding of the implementation details and is not necessary for implementing this solution.

[0036] An embodiment of the present invention provides an encoder, comprising: a code disk and a fixed grating, and an absolute code track and an incremental code track a arranged on the code disk;

[0037] The absolute code track is set as a symmetrical figure for making the light passing through the absolute code track change linearly; the fixed grating is used to cooperate with the code disk to generate a sinusoidal signal. Specifically, the shape of the absolute code track is a symmetrical figure with a linearly changing area, so that the light passing through the absolute code track changes linearly.

[0038] like Figure 1 As shown, specifically, the absolute code track includes an absolute code track 1a and a second absolute code track 2a; the first absolute code track 1a, the incremental code track a and the second absolute code track 2a are arranged in parallel on the code disk; by arranging each code track in parallel, it is convenient to read the position information of each code track at the same time, and achieve high-speed operation and high-resolution and high-precision working requirements. Among them, the first absolute code track 1a and the second absolute code track 2a have the same shape, and the phase difference between the two is 90°. Further, when the code disk is circular, the first code track 1a and the second code track 2a are arranged radially along the circumference of the code disk.

[0039] When the number of code bits of the first absolute code channel 1a and the second absolute code channel 2a is N, the number of scales of the incremental code channel a is 2. N ; and the engraved lines of the incremental code channel a are evenly distributed, with light and dark alternating. Therefore, since the absolute code channel in the code disk adopts graphical single-cycle linear encoding, it is beneficial to increase the width of the absolute window, ensure the light sensitivity of the PD, and improve the stability of the absolute signal.

[0040] In this embodiment, the first absolute code track 1a and the second absolute code track 2a are both symmetrical figures, and the area of ​​the symmetrical figures when rotating is monotonically increasing or monotonically decreasing, so that after the code disk rotates, the light passing through the first absolute code track 1a and the second absolute code track 2a changes linearly, so that the linearly changing light signal corresponds to the position value one by one, and the position value can be interpreted. Optionally, the absolute code disk is any one of a symmetrical triangle, a fan, or other symmetrical figures with linearly changing areas; as shown in the figure, the absolute code track is arranged by taking a symmetrical triangle as an example.

[0041] Further, such as Figure 1 and 2 As shown, the fixed grating includes a third absolute code channel 1b, a sinusoidal code channel b and a fourth absolute code channel 2b arranged in parallel; the third absolute code channel 1b is used to detect the first absolute code channel 1a; the fourth absolute code channel 2b is used to detect the second absolute code channel 2a; the sinusoidal code channel b is composed of N sectors connected in sequence in the circumferential direction, and its position corresponds to the incremental code channel a; wherein the areas of the N sectors vary in a sinusoidal function in the circumferential direction. Specifically, the structure of the fixed grating can refer to the fixed grating structure in the prior art application with announcement number CN109827599A. At the same time, other fixed grating structures that can generate sinusoidal signals should also fall within the scope of this specification. By detecting the first absolute code channel 1a through the third absolute code channel 1b and the second absolute code channel 2a through the fourth absolute code channel 2b, a sinusoidal signal with a phase deviation of 90° can be generated, such as Figure 3 As shown in the figure, signal lines A and B show that the encoder can generate a period of sinusoidal signal for each rotation of the encoder, and this signal is used to subdivide the absolute signal.

[0042] In the embodiment of the present application, the central angle of each sector ring is θ / n, that is, the central angle corresponding to the sinusoidal code channel is divided into n equal parts. During the design, it is only necessary to consider distributing the area of ​​each sector ring according to the law of the sinusoidal function. The scheme is easy to implement and convenient to process, and the electrical signal obtained through photoelectric conversion will be closer to the sinusoidal signal.

[0043] Specifically, the center lines of the third absolute code track 1b, the sinusoidal code track b and the fourth absolute code track 2b are located on the same straight line, thereby ensuring that no phase deviation occurs when detecting each code track, thereby improving the accuracy of absolute code encoding.

[0044] The encoder provided in this embodiment adopts a symmetrical pattern that can make the light passing through the absolute code channel change linearly, thereby realizing linear change of light intensity. At the same time, it is combined with a fixed grating to realize signal sinusoidalization, so that every time the moving grating rotates one circle, the signal output changes one sinusoidal period, and the absolute position of a single circle can be obtained, so that multi-circle counting can also be performed; in addition, since graphical single-cycle linear encoding is adopted, the absolute fixed grating has no grating pitch limit, which can enhance the strength of the photosensitive signal and improve the stability of the absolute signal.

[0045] Embodiment 2

[0046] The embodiment of the present invention further provides a signal processor of an encoder, see Figure 4 As shown, the signal processor includes a detector, a signal amplifier, a comparator, an analog-to-digital converter, and a controller. In this embodiment, the detector can detect the optical signal of the encoder provided in the first embodiment, so that the single-turn absolute encoding can be directly obtained by subdividing the sinusoidal analog signal of the single code channel. The encoding method is simple, the number of absolute code channels is small, and its graphical single-cycle linear encoding improves the stability of the absolute signal, improves the versatility of the PD, and has a multi-turn code channel function.

[0047] Specifically, the input end of the signal amplifier is connected to the detector, and the output end is connected to the analog-to-digital converter; the output end of the analog-to-digital converter is connected to the controller, the detector is used to detect the encoder as described in Example 1 and output the detection signal, and the controller is used to perform multi-turn and absolute position value calculation on the detection signal that has been amplified by the signal amplifier and converted by the analog-to-digital converter. Among them, the analog-to-digital converter is Figure 4 The A / D module in the figure, the controller is the MCU module.

[0048] In this embodiment, the detector includes a first detector, a second detector and a third detector. The signal processor also includes a comparator, and two signal amplifiers are configured, wherein the first detector and the second detector are both connected to one of the signal amplifiers and the comparator, and the third detector is only connected to the other signal amplifier.

[0049] Among them, the first detector and the second detector are used to detect and output the electrical signal of the absolute code channel in the encoder, and there are two sets of differential analog signal outputs. The output signal is amplified and compared at the same time. The amplified signal is digitized by the corresponding analog-to-digital converter and sent to the controller for arc tangent to obtain a rough absolute position value; the signal processed by the comparator is two sets of square wave signals with a phase difference of 90°, which are sent to the controller for multi-turn counting and direction identification. Since there is only one cycle of square wave signal in one turn, it can ensure the stability of multi-turn counting under low power consumption.

[0050] The third detector is used to detect and output the electrical signal of the incremental code channel in the encoder, and there are two sets of differential analog signal outputs. The output signal is digitized by the corresponding analog-to-digital converter after passing through the amplifier, and sent to the controller for arc tangent to obtain the precise subdivision position value.

[0051] The controller realizes multi-turn and absolute position value calculation, can combine its multi-turn and absolute position values ​​to obtain the final absolute position value, and communicates with the encoder driver.

[0052] In this embodiment, the detector is a photoelectric detector that can detect the light signal on the code disk.

[0053] It should be understood that the expressions "mechanism", "device", "component" and the like used in this application are only a method for distinguishing different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the word can be replaced by other expressions.

[0054] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for realizing the present invention, and in practical applications, the technical features of the above-mentioned embodiments can be arbitrarily combined. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification, and various changes can be made in form and details without departing from the spirit and scope of the present invention.

Claims

1. An encoder, characterized in that: include: Code disk; An absolute code track and an incremental code track are provided on the code disk; the absolute code track is provided as a symmetrical pattern for making the light passing through the absolute code track change linearly; And a fixed grating corresponding to the code disc; the fixed grating is used to cooperate with the code disc to generate a sinusoidal signal.

2. The encoder according to claim 1, characterized in that The absolute code track includes a first absolute code track and a second absolute code track; the first absolute code track, the incremental code track and the second absolute code track are arranged in parallel on the code disk.

3. The encoder according to claim 1 or 2, characterized in that The engraved lines of the incremental code channel are evenly distributed and alternate between light and dark.

4. The encoder according to claim 2, characterized in that When the number of coded bits of the first absolute code channel and the second absolute code channel is N, the number of scales of the incremental code channel is 2 N .

5. The encoder according to claim 1, characterized in that The shape of the absolute code channel is a symmetrical figure whose area changes linearly.

6. The encoder according to claim 5, characterized in that The absolute code channel is any one of a symmetrical triangle, a fan or a quadrilateral.

7. The encoder according to claim 2, characterized in that The fixed grating includes a third absolute code channel, a sinusoidal code channel and a fourth absolute code channel arranged in parallel; the third absolute code channel is used to detect the first absolute code channel; the fourth absolute code channel is used to detect the second absolute code channel; the sinusoidal code channel is composed of N sectors connected in sequence in the circumferential direction, and its position corresponds to the incremental code channel setting; wherein the areas of the N sectors vary in a sinusoidal function in the circumferential direction.

8. The encoder according to claim 7, characterized in that The center lines of the third absolute code track, the sinusoidal code track and the fourth absolute code track are located on the same straight line.

9. A signal processor for an encoder, characterized in that: include: A detector for detecting the optical signals of the absolute code track and the incremental code track in the encoder according to any one of claims 1 to 8 and outputting a detection signal; And a controller for calculating multiple turns and absolute position values ​​of the detection signal output by the detector.

10. The signal processor of an encoder according to claim 9, characterized in that: Also includes: a signal amplifier connected to the detector; and an analog-to-digital converter connected to the signal amplifier; The controller is connected to the analog-to-digital converter and is used to calculate multiple turns and absolute position values ​​of the detection signal that has been amplified by the signal amplifier and converted by the analog-to-digital converter in sequence.

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