Mechanical multi-circle absolute time grating angular displacement sensor and measuring system

Abstract

The invention discloses a mechanical multi-circle absolute type time grating angular displacement sensor and a measuring system.The mechanical multi-circle absolute type time grating angular displacement sensor comprises a single-circle absolute type time grating assembly and a single-antipode absolute type time grating assembly, and the single-circle absolute type time grating assembly is used for measuring absolute angular displacement; the single-antipode absolute time grating assembly is used for multi-turn counting, and the single-turn absolute time grating assembly and the single-antipode absolute time grating angle assembly are in transmission connection through a multi-stage reduction gear set so as to realize measurement of multi-turn absolute angular displacement. According to the scheme, the single-circle absolute type time grating assembly and the single antipode absolute type time grating assembly are combined with the multistage reduction gear set for measurement, so that measurement of multi-circle absolute type angular displacement is realized, the reliability of signal feedback is improved, the problems of interference faced by the Wiegand principle, possible loss of parameters and the like are avoided, and the measurement accuracy is improved. And a high-precision angular displacement measurement function is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a mechanical multi-turn absolute time-grating angular displacement sensor and a measuring system. Background Art

[0002] Multi-turn absolute angular displacement sensors use the number of rotations to add the single-turn absolute angular displacement value to obtain the multi-turn absolute angular displacement value, which can provide a wider measurement range. Therefore, multi-turn absolute angular displacement sensors are widely used in applications that need to track multiple rotation cycles, such as wind turbines, motor control, etc. Due to its large measurement range, it does not need to find the zero point during installation, which simplifies the difficulty of installation and debugging, and is a hot topic in the research of absolute angular displacement sensors.

[0003] At present, multi-turn absolute angular displacement sensors mainly use electronic multi-turn to achieve multi-turn counting. Electronic multi-turn can be divided into two types: electronic multi-turn with battery memory and electronic multi-turn based on the Wiegand principle. However, the electronic multi-turn angular displacement sensor with battery memory has the probability of abnormal battery power supply or counter counting error. The electronic multi-turn angular displacement sensor using the Wiegand principle has problems such as fuzzy and unstable zero position, uncertainty in the size of Wiegand self-generated energy and micro-energy storage, and strong magnetic interference.

[0004] For example, the invention patent application with publication number CN 113008129 A discloses a multi-turn absolute time-grating angular displacement sensor, which uses a high-frequency clock pulse as a measurement reference, adopts parallel capacitor plates to construct an alternating electric field to perform displacement measurement in a time-sharing manner, and utilizes a Wiegand sensor module to measure the direction of rotation and the number of rotations, thereby realizing multi-turn absolute angular displacement measurement. However, the use of the Wiegand principle for multi-turn counting cannot avoid the above-mentioned problems such as line interference, storage failure, and counting errors caused by electrical or software reasons.

[0005] The reliability of angular displacement sensors is one of the key factors that determine their measurement accuracy and wide application. However, the size of Wiegand self-generated energy and micro-energy storage are uncertain, and there are potential risks such as strong magnetic interference, which will eventually lead to the risk of inaccurate measurement results. Summary of the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a mechanical multi-turn absolute time-grating angular displacement sensor and a measurement system that can effectively reduce external interference and effectively improve measurement accuracy.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A mechanical multi-turn absolute time grid angular displacement sensor comprises a single-turn absolute time grid component and a single-pole absolute time grid component. The single-turn absolute time grid component is used for measuring absolute angular displacement, and the single-pole absolute time grid component is used for multi-turn counting. The single-turn absolute time grid component and the single-pole absolute time grid angle component are connected by a multi-stage reduction gear set to achieve multi-turn absolute angular displacement measurement.

[0009] Preferably, the single-turn absolute time grid assembly includes a single-turn stator and a single-turn rotor, the single-turn absolute time grid assembly includes a single-turn stator and a single-turn rotor, the single-turn rotor is fixedly connected to the mechanical shaft, and the multi-stage reduction gear set includes a plurality of gears meshing with each other and having different numbers of teeth, wherein the driving gear in the multi-stage reduction gear set is used to rotate synchronously with the mechanical shaft, and the driven gear in the multi-stage reduction gear set is used to drive the single-turn rotor to rotate.

[0010] Preferably, it also includes a shell, the single-turn absolute time grid assembly and the single-pair time grid assembly are both located in the shell, and the single-turn stator and the single-pole stator are both fixedly connected to the shell, the single-turn stator is also fixedly connected to a mounting plate, the driving gear in the multi-stage reduction gear array is fixedly connected to the mechanical shaft, and the remaining gears are fixedly connected to the mounting plate, the single-pole rotor is also fixedly connected to a base with an internal gear, and the internal gear of the base is meshed with the driven gear in the multi-stage reduction gear set, so that the mechanical shaft drives the single-pole rotor to rotate after being decelerated by the multi-stage reduction gear.

[0011] Preferably, a printed circuit board is also fixedly connected to the single-turn stator, and the printed circuit board is fixedly connected to the mounting plate via positioning pins.

[0012] Preferably, the gap between the single-turn stator and the single-turn rotor is d1, and the gap between the single-pole stator and the single-pole rotor is d2.

[0013] Preferably, the multi-stage reduction gear set comprises a driving gear, a first driven gear and a second driven gear meshed in sequence, the driving gear is fixedly connected to the mechanical shaft, and the second driven gear meshes with an internal gear on the base.

[0014] Preferably, the single-turn stator comprises a first excitation electrode located in the outer ring and having N pairs of poles and a second excitation electrode located in the inner ring and having M pairs of poles, and the single-turn rotor comprises a first induction electrode corresponding to the first excitation electrode and a second induction electrode corresponding to the second excitation electrode;

[0015] The single-pole stator includes a third excitation electrode located in the outer ring and having a single pair of poles and a fourth excitation electrode located in the inner ring and having a single pair of poles. The single-pole rotor includes a third induction electrode corresponding to the third excitation electrode and a fourth induction electrode corresponding to the fourth excitation electrode.

[0016] Preferably, the current angular displacement θ to be measured of the single-turn absolute time grid component a The calculation formula is:

[0017] θ a =n i θ p1 +θ i =n m θ p +θ m

[0018] θ p1 =2π / N

[0019] θ p2 =2π / M

[0020] Where: θ p1 is the single-pole angular displacement of the outer ring of a single-turn rotor, θ p2 is the single-pole angular displacement of the inner ring of a single-turn rotor, n i is the maximum number of poles of the outer ring of a single-turn rotor at the current position, n m is the maximum number of poles of the inner ring of a single-turn rotor at the current position, θ i is the precise measurement value of the outer ring of the single-turn rotor in the current pole pair, θ m It is the precise measurement value of the inner ring of a single-turn rotor within the current pole pair.

[0021] Preferably, the maximum number of poles n of the outer ring of the single-turn rotor at the current position is i and the maximum number of poles n of the inner ring of a single-turn rotor at the current position m The calculation formulas are:

[0022]

[0023] Where: is the phase difference between the traveling wave signal output by the first induction electrode of the outer ring of the single-turn rotor and the reference signal, is the phase difference between the traveling wave signal output by the second induction electrode of the inner ring of the single-turn rotor and the reference signal. Using the above formula, the angle value of the single-turn time grid at any position can be obtained.

[0024] The single-pole absolute time grating assembly is the same as the single-turn absolute time grating assembly in terms of measurement principle and structure. Therefore, the single-pole absolute time grating assembly is also a natural absolute time grating, and its positioning principle is the same as that of the single-turn absolute time grating assembly. The single-pole absolute time grating assembly has only one pole within the range of 360°. If the maximum number of turns measured by the sensor is n, the maximum measurable angle corresponds to 2πn. The measured number of turns n is matched one by one with the whole circumference of the single-pole absolute time grating assembly. For every 1° rotation of the single-pole absolute time grating assembly, the single-turn absolute time grating assembly rotates n / 2π turns, and so on. Therefore, it can be obtained that the transmission ratio between the mechanical shaft and the base with the internal gear is n:1. The transmission ratio of the remaining driven gears can be designed according to this transmission ratio, so that the function of multi-turn counting can be realized while achieving absolute measurement.

[0025] A mechanical multi-turn absolute time grid angular displacement measurement system comprises a signal generating circuit, a signal processing circuit, an FPGA circuit and the above-mentioned mechanical multi-turn absolute time grid angular displacement sensor, wherein the signal generating circuit is respectively connected to the excitation end of the single-turn absolute time grid component and the excitation end of the single-pole absolute time grid component for sending an excitation signal to the single-turn absolute time grid component and the single-pole absolute time grid component, the signal output end of the single-turn absolute time grid component and the signal output end of the single-pole absolute time grid component are both connected to the signal amplifying circuit for communication, the signal amplifying circuit amplifies, filters and shapes the output signals of the single-turn absolute time grid component and the single-pole absolute time grid component and then sends them to the FPGA circuit, the FPGA circuit calculates the actual angle currently rotated according to the angle rotated by the single-turn absolute time grid component and the number of turns rotated by the single-pole absolute time grid component to realize the measurement of multi-turn absolute displacement.

[0026] Compared with the prior art, the mechanical multi-turn absolute time grid angular displacement sensor of the present invention is mainly composed of a single-turn absolute time grid component and a single-pole absolute time grid component. The two parts are connected to the mechanical shaft through a multi-stage reduction gear set. By reasonably setting the reduction ratio of the multi-stage reduction gear set, absolute positioning and calculation of the number of turns within a range of 360° can be achieved. Therefore, while the present solution uses a single-turn absolute time grid component to achieve absolute angular displacement measurement, it uses the transmission of the multi-stage reduction gear set and utilizes the natural absolute angular displacement sensor—the single-pole absolute time grid component to achieve multi-turn counting. By combining the single-turn absolute time grid component and the single-pole absolute time grid component with the multi-stage reduction gear set for measurement, the measurement of absolute multi-turn angular displacement is achieved, the reliability of signal feedback is improved, the interference problem faced by the Wiegand principle is avoided, and the effect of reducing external interference and improving measurement accuracy is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] AttachedFigure 1 It is a structural schematic diagram of the mechanical multi-turn absolute time-grid angular displacement sensor of the present invention;

[0028] Attached Figure 2 It is a structural schematic diagram of a single-turn absolute time-grating component in the mechanical multi-turn absolute time-grating angular displacement sensor of the present invention;

[0029] Attached Figure 3 It is a schematic diagram of the structure of the cooperation between the multi-stage reduction gear set and the internal gear in the mechanical multi-turn absolute time-grid angular displacement sensor of the present invention;

[0030] Attached Figure 4 It is a schematic diagram of the absolute positioning principle of a single-turn absolute time-grid component in the mechanical multi-turn absolute time-grid angular displacement sensor of the present invention;

[0031] Attached Figure 5 The system block diagram of the mechanical multi-turn absolute time-grating angular displacement measurement system of the present invention.

[0032] Explanation of the reference numerals: single-turn rotor 1, first induction electrode 101, second induction electrode 102, single-turn stator 2, first excitation electrode 201, second excitation electrode 202, mechanical shaft 3, printed circuit board 4, mounting plate 5, driving gear 6, first driven gear 7, second driven gear 8, base 9, single-pole rotor 10, single-pole stator 11, housing 12. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0034] It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invention product is usually placed when used, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In addition, the terms "horizontal", "vertical", etc. do not mean that the components are absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In view of the problems existing in the prior art using the electronic multi-turn counting method, a mechanical multi-turn absolute time-grid angular displacement sensor is provided in this specific embodiment. Figure 1 As shown, it includes a housing 12, a single-turn absolute time grid assembly, a single-pole absolute time grid assembly, a multi-stage reduction gear set and a mechanical shaft 3. The single-turn absolute time grid assembly, the single-pole absolute time grid assembly, the multi-stage reduction gear set and the mechanical shaft 3 are all located in the housing 12, wherein the single-turn absolute time grid assembly is used to measure absolute angular displacement, the single-pole absolute time grid assembly is used to count multiple turns, and the single-turn absolute time grid assembly and the single-pole absolute time grid angle assembly are connected by transmission via the multi-stage reduction gear set to achieve the measurement of multiple turns of absolute angular displacement.

[0036] In this specific embodiment, the single-turn absolute time grid assembly includes a single-turn stator 2 and a single-turn rotor 1, and the single-pole absolute time grid assembly includes a single-pole stator 11 and a single-pole rotor 10. The single-turn stator 2, the single-turn rotor 1, the single-pole stator 11, the single-pole rotor 10 and the mechanical shaft 3 are all coaxially arranged, and a fixed gap d1 is provided between the single-turn stator 2 and the single-turn rotor 1. Figure 2As shown, the single-turn stator 2 includes a first excitation electrode 201 located in the outer ring and having N pairs of poles and a second excitation electrode 202 located in the inner ring and having M pairs of poles, and the single-turn rotor 1 includes a first induction electrode 101 corresponding to the first excitation electrode 201 and a second induction electrode 102 corresponding to the second excitation electrode 202. The single-pole stator 11 includes a third excitation electrode located in the outer ring and having a single pair of poles and a fourth excitation electrode located in the inner ring and having a single pair of poles, and the single-pole rotor 10 includes a third induction electrode corresponding to the third excitation electrode and a fourth induction electrode corresponding to the fourth excitation electrode.

[0037] Specifically, the outer contour of the single-turn stator 2 is fixed on the housing 12, and a printed circuit board 4 (PCBA) is fixedly connected to the upper end of the single-turn stator 2. A mounting plate 5 is also provided above the printed circuit board 4. The mounting plate 5 and the printed circuit board 4 are fixedly connected by positioning pins, so that the single-turn stator 2, the printed circuit board 4 and the mounting plate 5 are fixedly connected together, and the single-turn rotor 1 is fixedly connected to the mechanical shaft 3. The upper end of the mechanical shaft 3 passes through the single-turn stator 2, the printed circuit board 4 and the mounting plate 5 in sequence and then extends from the upper end of the mounting plate 5. The single-turn stator 2, the printed circuit board 4 and the mounting plate 5 are all provided with corresponding holes for the mechanical shaft 3 to pass through and enable the mechanical shaft 3 to rotate freely. As the mechanical shaft 3 drives the single-turn rotor 1 to rotate synchronously, the single-turn absolute time grid assembly works, thereby realizing the acquisition of angle information within a range of 360° and realizing the absolute positioning function within a single turn.

[0038] The part of the mechanical shaft 3 extending out of the mounting plate 5 is connected to a multi-stage reduction gear set, which includes a plurality of gears meshing with each other and having different numbers of teeth, wherein the driving gear in the multi-stage reduction gear set is used to rotate synchronously with the mechanical shaft 3, and the driven gear is used to drive the single-pole rotor 10 to rotate. By setting the reduction ratio of the multi-stage reduction gear set, angle measurement in a wider range can be achieved. In this specific embodiment, as shown in the attached figure, Figure 3 As shown, the multi-stage reduction gear set includes a driving gear 6, a first driven gear 7 and a second driven gear 8 which are meshed in sequence, the driving gear 6 is fixedly connected to the mechanical shaft 3, the first driven gear 7 is meshed with the driving gear 6, the first driven gear 7 is meshed with the second driven gear 8, and the first driven gear 7 and the second driven gear 8 are both mounted on the mounting plate 5, so that the speed of the mechanical shaft 3 reaches the second driven gear 8 after multi-stage reduction.

[0039] In this specific embodiment, the single-pole stator 11 is fixedly connected to the housing 12, and the gap between the single-pole stator 11 and the single-pole rotor 10 is d2. The single-pole rotor 10 is also coaxially arranged and fixedly connected with the base 9 with an internal gear. The internal gear of the base 9 is meshed with the second driven gear 8, so that the mechanical shaft 3 drives the single-pole rotor 10 to rotate after being decelerated by the multi-stage reduction gear. In this specific embodiment, as shown in the attached Figure 3 As shown, the internal gear is meshed with the second driven gear 8. Since each gear stage has a corresponding integer multiple reduction ratio relationship with the previous gear stage and the mechanical shaft 3, when the mechanical shaft 3 rotates, the base 9 with the internal gear drives the single-pole rotor 10 to rotate through the gears step by step. Since the single-pole absolute time grid component has only one pole pair within the entire circumference, the single-turn absolute time grid component rotates n / 2π turns every time the single-pole absolute time grid component rotates 1°, so as to realize the multi-turn counting function.

[0040] The working principle of the single-turn absolute time grid component is explained below:

[0041] The principle of absolute positioning is similar to that of vernier caliper measurement. The current measurement value is calculated by combining the main scale and the sub-scale. The absolute time grating angular displacement sensor is a combination of N pairs of poles and M pairs of poles of incremental time grating angular displacement sensors. The N pairs of poles and M pairs of poles of incremental sensors are arranged in the outer circle and inner circle respectively. The inner circle electrodes are fixedly arranged and cannot be moved like a vernier caliper. However, the angle difference of the electrode arrangement position of each pair of poles relative to the outer circle electrodes is uniquely determined. By combining the inner and outer circle structures, absolute angular displacement measurement is achieved. Similarly, for a single pair of poles absolute time grating, its structure is the same as that of a single-circle absolute time grating, that is, only a single pair of poles of electrodes need to be arranged within the full 360° range to obtain a single pair of poles absolute time grating, forming a natural absolute angular displacement sensor.

[0042] The absolute positioning principle diagram of the single-turn absolute time grid component is as follows: Figure 4 Attached Figure 4 (a) is the measurement model of the rotor and rotor of the single-turn absolute time grid assembly, r1 and r2 represent the motion paths of the corresponding induction electrodes of the outer and inner rings of the single-turn rotor 1, respectively, θ a Represents the current angular displacement to be measured, and its calculation formula is:

[0043] θ a =nθ p1 +θ i =n m θ p2 +θ m

[0044] θ p1 =2π / N

[0045] θ p2 =2π / M

[0046] Where: θ p1 is the single-pole angular displacement of the outer ring of the single-turn rotor 1, θ p2 is the single-pole angular displacement of the inner ring of the single-turn rotor 1, n i is the maximum number of poles of the outer ring of the single-turn rotor 1 at the current position, nm is the maximum number of poles of the inner ring of the single-turn rotor 1 at the current position, θ i is the precise measurement value of the outer ring of the single-turn rotor 1 in the current pole pair, θ m It is the precise measurement value of the inner ring of the single-turn rotor 1 in the current pole pair. i and θ m The traveling wave signals of the outer ring and inner ring of the single-ring rotor are obtained through system processing.

[0047] n i and n m It can be obtained by the phase of the traveling wave signal of the inner and outer rings of the single-ring rotor 1. i θ p1 and n m θ p2 As a rough displacement, θ i and θ m As the precise displacement measured within the current pole.

[0048] The phase difference between the traveling wave signal output by the first induction electrode 101 on the outer ring of the single-turn rotor 1 and the reference signal (the reference signal is a square wave signal with the same frequency as the excitation signal, obtained by FPGA after clock multiplication) is used as The phase difference between the traveling wave signal output by the second induction electrode 102 of the inner ring of the single-turn rotor 1 and the reference signal is expressed as express, for and The relationship between phase difference and angular displacement is shown in the attached figure. Figure 4 As shown in (b). and It changes periodically from 0 to 2π. The relationship between the angular displacement and the Make the following transformations:

[0049]

[0050] After the above conversion, the phase difference of the traveling wave signal of the inner and outer circles of the single-turn absolute time grating component changes linearly from 0 to 2π. i and n m The largest integer that can be expressed using the rounding function is:

[0051]

[0052] Using the above method, the number of poles at any current position of the sensor can be determined, and the absolute angular displacement value at any position can be obtained according to the above formula.

[0053] In addition, this embodiment also provides a mechanical multi-turn absolute time-grid angular displacement measurement system, as shown in the attached Figure 5 As shown, it includes a signal generating circuit, a signal processing circuit, an FPGA circuit and the above-mentioned mechanical multi-turn absolute time grid angular displacement sensor. The signal generating circuit is respectively connected to the excitation end of the single-turn absolute time grid component and the excitation end of the single-pole absolute time grid component for sending excitation signals to the single-turn absolute time grid component and the single-pole absolute time grid component. The signal output end of the single-turn absolute time grid component and the signal output end of the single-pole absolute time grid component are both connected to the signal amplification circuit for communication. The signal amplification circuit amplifies, filters, and shapes the output signals of the single-turn absolute time grid component and the single-pole absolute time grid component and then sends them to the FPGA circuit. The FPGA circuit calculates the current actual angle according to the angle of the single-turn absolute time grid component and the number of turns of the single-pole absolute time grid component to achieve the measurement of multi-turn absolute displacement. The angle of the single-turn absolute time grid component plus the number of turns of the single-pole absolute time grid component are processed by the signal processing circuit and sent to the FPGA circuit for calculation to obtain the current actual angle.

[0054] Compared with the prior art, the mechanical multi-turn absolute time grid angular displacement sensor of the present invention is mainly composed of a single-turn absolute time grid component and a single-pole absolute time grid component. Among them, the single-turn absolute time grid component can realize the absolute positioning of the angular displacement sensor within the range of 360°, and the single-pole absolute time grid component is the same as the single-turn absolute time grid component in the measurement principle and structure, so the single-pole absolute time grid component is also a natural absolute time grid. At the same time, since the single-pole absolute time grid component has only one pole within the entire circumference, the single-turn absolute time grid component rotates n / 2π turns for every 1° rotation of the single-pole absolute time grid component, so the function of multi-turn counting can be realized while realizing absolute measurement. The two parts are connected to the mechanical shaft 3 through a multi-stage reduction gear set for transmission. By reasonably setting the reduction ratio of the multi-stage reduction gear set, absolute positioning and calculation of the number of turns within the range of 360° can be realized. Therefore, this solution uses a single-turn absolute time grating component to achieve absolute angular displacement measurement, and uses the transmission of a multi-stage reduction gear set to use a natural absolute angular displacement sensor - a single-pole absolute time grating component to achieve multi-turn counting. By combining the single-turn absolute time grating component and the single-pole absolute time grating component with a multi-stage reduction gear set for measurement, the absolute multi-turn angular displacement measurement is achieved, the reliability of signal feedback is improved, the interference problem faced by the Wiegand principle is avoided, and the effect of reducing external interference and improving measurement accuracy is achieved. This solution realizes multi-turn measurement of absolute time grating angular displacement sensors, provides a reference for more absolute multi-turn time grating solutions, and enriches the types of time grating products.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A mechanical multi-turn absolute time-grating angular displacement sensor, characterized in that: It comprises a single-turn absolute time grid component and a single-pole absolute time grid component. The single-turn absolute time grid component is used for measuring absolute angular displacement, and the single-pole absolute time grid component is used for multi-turn counting. The single-turn absolute time grid component and the single-pole absolute time grid angle component are connected by a multi-stage reduction gear set to realize the measurement of multi-turn absolute angular displacement.

2. The mechanical multi-turn absolute time-grating angular displacement sensor according to claim 1, characterized in that: The single-turn absolute time grid assembly includes a single-turn stator and a single-turn rotor, the single-turn absolute time grid assembly includes a single-turn stator and a single-turn rotor, the single-turn rotor is fixedly connected to the mechanical shaft, the multi-stage reduction gear set includes a plurality of gears meshing with each other and having different numbers of teeth, wherein the driving gear in the multi-stage reduction gear set is used to rotate synchronously with the mechanical shaft, and the driven gear in the multi-stage reduction gear set is used to drive the single-turn rotor to rotate.

3. The mechanical multi-turn absolute time-grating angular displacement sensor according to claim 2, characterized in that: It also includes a shell, the single-turn absolute time grid assembly and the single-pair time grid assembly are both located in the shell, and the single-turn stator and the single-pole stator are both fixedly connected to the shell, the single-turn stator is also fixedly connected to a mounting plate, the driving gear in the multi-stage reduction gear array is fixedly connected to the mechanical shaft, and the remaining gears are all fixedly connected to the mounting plate, the single-pole rotor is also fixedly connected to a base with an internal gear, and the internal gear of the base is meshed with the driven gear in the multi-stage reduction gear set, so that the mechanical shaft drives the single-pole rotor to rotate after being decelerated by the multi-stage reduction gear.

4. The mechanical multi-turn absolute time-grating angular displacement sensor according to claim 3, characterized in that: A printed circuit board is also fixedly connected to the single-turn stator, and the printed circuit board is fixedly connected to the mounting plate via positioning pins.

5. The mechanical multi-turn absolute time-grating angular displacement sensor according to claim 2, characterized in that: The gap between the single-turn stator and the single-turn rotor is d1, and the gap between the single-pole stator and the single-pole rotor is d2.

6. The mechanical multi-turn absolute time-grating angular displacement sensor according to claim 3, characterized in that: The multi-stage reduction gear set comprises a driving gear, a first driven gear and a second driven gear meshed in sequence, the driving gear is fixedly connected to the mechanical shaft, and the second driven gear meshes with an internal gear on the base.

7. The mechanical multi-turn absolute time-grating angular displacement sensor according to claim 2, characterized in that: The single-turn stator comprises a first excitation electrode located in the outer ring and having N pairs of poles, and a second excitation electrode located in the inner ring and having M pairs of poles, and the single-turn rotor comprises a first induction electrode corresponding to the first excitation electrode and a second induction electrode corresponding to the second excitation electrode; The single-pole stator includes a third excitation electrode located in the outer ring and having a single pair of poles and a fourth excitation electrode located in the inner ring and having a single pair of poles. The single-pole rotor includes a third induction electrode corresponding to the third excitation electrode and a fourth induction electrode corresponding to the fourth excitation electrode.

8. The mechanical multi-turn absolute time-grating angular displacement sensor according to claim 7, characterized in that: The current angular displacement θ to be measured of the single-turn absolute time grid component a The calculation formula is: i a =n i i p1 +θ i =n m i p2 +θ m i p1 =2π / N i p2 =2π / M Where: θ p1 is the single-pole angular displacement of the outer ring of a single-turn rotor, θ p2 is the single-pole angular displacement of the inner ring of a single-turn rotor, n i is the maximum number of poles of the outer ring of a single-turn rotor at the current position, n m is the maximum number of poles of the inner ring of a single-turn rotor at the current position, θ i is the precise measurement value of the outer ring of the single-turn rotor in the current pole pair, θ m It is the precise measurement value of the inner ring of a single-turn rotor within the current pole pair.

9. The mechanical multi-turn absolute time-grating angular displacement sensor according to claim 8, characterized in that: The maximum number of poles n of the outer ring of a single-turn rotor at the current position i and the maximum number of poles n of the inner ring of a single-turn rotor at the current position m The calculation formulas are: Where: is the phase difference between the traveling wave signal output by the first induction electrode of the outer ring of the single-turn rotor and the reference signal, It is the phase difference between the traveling wave signal output by the second induction electrode of the inner ring of the single-turn rotor and the reference signal.

10. A mechanical multi-turn absolute time-grating angular displacement measurement system, characterized in that: The invention comprises a signal generating circuit, a signal processing circuit, an FPGA circuit and the mechanical multi-turn absolute time grid angular displacement sensor as claimed in claim 1, wherein the signal generating circuit is respectively connected to the excitation end of the single-turn absolute time grid component and the excitation end of the single-pole absolute time grid component for sending an excitation signal to the single-turn absolute time grid component and the single-pole absolute time grid component, and the signal output end of the single-turn absolute time grid component and the signal output end of the single-pole absolute time grid component are both connected to the signal amplifying circuit for communication, and the signal amplifying circuit amplifies, filters and shapes the output signals of the single-turn absolute time grid component and the single-pole absolute time grid component and then sends them to the FPGA circuit, and the FPGA circuit calculates the actual angle currently rotated according to the angle rotated by the single-turn absolute time grid component and the number of turns rotated by the single-pole absolute time grid component to realize the measurement of multi-turn absolute displacement.

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