Eddy current sensor double-coil structure and eddy current sensor

Abstract

The invention discloses an eddy current sensor double-coil structure and an eddy current sensor, the eddy current sensor double-coil structure comprises a first coil group and a second coil group, the first coil group and the second coil group are configured on a PCBA circuit board, the first coil group comprises a first transmitting coil and a first receiving coil group, and the second coil group comprises a second transmitting coil and a second receiving coil; the second coil group comprises a second transmitting coil and a second receiving coil group; the first receiving coil group and the second receiving coil group have the same receiving radius and are positioned on the inner sides of the first transmitting coil and the second transmitting coil; and each receiving coil of the first receiving coil group and the second receiving coil group is of a closed circular structure formed by a curve taking a trigonometric function as a deformation basis. And under the same rotation area, the receiving area can be increased, so that the precision and the anti-interference performance of the eddy current sensor are obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of angle measurement sensors, and in particular relates to a double-coil structure of an eddy current sensor and an eddy current sensor. Background Art

[0002] The dual-coil eddy current sensor is used to detect the rotation angle and position of the metal rotor. Compared with the single-coil eddy current sensor, it has a more reliable and safer system due to the addition of a redundant system. The overall product consists of a PCBA circuit board, epoxy glue and a plastic shell. The PCBA circuit mainly consists of a coil part, a signal processing part and an output part. The coil part can be divided into two sets of coils, and any set of coils consists of 1 transmitting coil and 2 receiving coils.

[0003] The schematic diagram of the double coil structure of the eddy current sensor and the corresponding target rotor in the prior art is shown in the attached figure. Figure 1 and attached Figure 2 As shown, 1-1 is the transmitting coil of the first set of coils, 1-2 is the receiving coil 1 of the first set of coils, 1-3 is the receiving coil 2 of the first set of coils, 1-4 is the transmitting coil of the second set of coils, 1-5 is the receiving coil 1 of the second set of coils, and 1-6 is the receiving coil 2 of the second set of coils. 1-7 is the induction area of ​​the outer ring coil, 1-8 is the induction area of ​​the inner ring coil, 1-9 is the through-shaft mounting hole, and 1-10 is the outer edge of the target wheel rotor.

[0004] The application scenario of the existing dual-coil coil solution is a low-speed encoder, which is mainly used for robot rotation angle and position detection and cannot be applied to high-speed rotation scenarios. The requirements for the installation shaft and the surrounding environment are high, and a thicker installation shaft requires a wider range of installation environments. In addition, the design requirements for the target wheel rotor are also high, and it is necessary to design the inner and outer double-layer target wheel rotors according to the arrangement of the coil groups inside and outside the rotor. The target wheel rotors in the prior art mostly use PCB rotors-etching copper foil on the copper-clad board to form the copper foil into the shape of the target wheel. The durability is weak and the strength is low. Even if a metal stamping or casting target wheel is used, the strength requirements for high-speed rotation cannot be met due to the large perforation area on the target wheel. Summary of the invention

[0005] To solve the above problems, the purpose of the present invention is to provide an eddy current sensor double coil structure and an eddy current sensor, which can increase the receiving area under the same rotation area, thereby significantly improving the accuracy and anti-interference ability of the eddy current sensor.

[0006] The technical solution provided by the present invention is: an eddy current sensor double coil structure, comprising: A first coil group and a second coil group, wherein the first coil group and the second coil group are configured on a PCBA circuit board, the first coil group includes a first transmitting coil and a first receiving coil group, and the second coil group includes a second transmitting coil and a second receiving coil group; The first receiving coil group and the second receiving coil group have the same receiving radius and are both located inside the first transmitting coil and the second transmitting coil. Each receiving coil of the first receiving coil group and the second receiving coil group presents a closed circular structure formed by a curve with a trigonometric function as a deformation basis.

[0007] Preferably, the first transmitting coil is a multi-layer structure, configured on different conductive layers of the PCBA circuit board, and adjacent layer structures of the first transmitting coil are connected through conductive holes; the second transmitting coil is a multi-layer structure, configured on different conductive layers of the PCBA circuit board, and adjacent layer structures of the first transmitting coil are connected through conductive holes.

[0008] Preferably, the first transmitting coil is a single-layer structure, and is configured on a conductive layer of the PCBA circuit board; the second transmitting coil is a single-layer structure, and is configured on a conductive layer of the PCBA circuit board.

[0009] Preferably, the first transmitting coil and the second transmitting coil are configured on different conductive layers of the PCBA circuit board, and the first transmitting coil and the second transmitting coil overlap in the projection direction, or the second transmitting coil routing is within the spiral gap of the projection of the first transmitting coil.

[0010] Preferably, the PCBA circuit board is a multi-layer board, each conductive layer of the PCBA circuit board is uniquely configured with a partial structure of the first transmitting coil or the second transmitting coil, the first transmitting coil and the second transmitting coil do not overlap each other in the projection direction, the conductive wire of each layer structure of the first transmitting coil extends in a spiral shape, and the conductive wire of each layer structure of the second transmitting coil extends in a spiral shape in the projection direction in the gap between each layer structure of the first transmitting coil.

[0011] Preferably, the first receiving coil group includes a first receiving coil and a second receiving coil, the second receiving coil group includes a third receiving coil and a fourth receiving coil, the first receiving coil and the second receiving coil have the same shape parameters and are rotationally symmetric about a geometric center, and the third receiving coil and the fourth receiving coil have the same shape parameters and are rotationally symmetric about the geometric center.

[0012] Preferably, a relative phase shift angle between the first receiving coil and the second receiving coil is equal to a relative phase shift angle between the third receiving coil and the fourth receiving coil.

[0013] Preferably, the first receiving coil group and the second receiving coil group are in a rotationally symmetrical relationship about the geometric center, and the rotation angle is 0 degree to 360 degrees.

[0014] Preferably, a relative phase shift angle between the first receiving coil and the second receiving coil is not equal to a relative phase shift angle between the third receiving coil and the fourth receiving coil.

[0015] Based on the same inventive concept, this embodiment also provides an eddy current sensor, comprising any of the double-coil structures described above.

[0016] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: The present invention realizes the fusion of the radial positions of the first receiving coil group and the second receiving coil group by configuring the first receiving coil group and the second receiving coil group as a closed circular structure composed of a curve with the same receiving radius and a deformation based on a trigonometric function, and at the same time makes full use of the radial distance between the first transmitting coil and the first receiving coil group to arrange the second transmitting coil, so that the first coil group and the second coil group occupy as little space as possible in the radial direction, so that a larger receiving area can be obtained under the same rotation area, and the accuracy and anti-interference performance of the eddy current sensor are effectively improved. In addition, the solution of the present invention can use the target wheel rotor of the single coil group solution, so as to save the design time and manufacturing cost of the entire device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein: Figure 1 It is a schematic diagram of the double coil structure of the eddy current sensor in the prior art; Figure 2 It is a schematic diagram of a target rotor corresponding to the double-coil structure of an eddy current sensor in the prior art; Figure 3 This is a schematic diagram of the double-coil structure of the eddy current sensor of the present invention; Figure 4 Schematic diagram of the target rotor corresponding to the double-coil structure of the eddy current sensor.

[0018] Description of Reference Numerals 2-1: first transmitting coil; 2-2: first receiving coil; 2-3: second receiving coil; 2-4: second transmitting coil; 2-5: third receiving coil; 2-6: fourth receiving coil; 2-7: target wheel rotor; 2-8: through-shaft area of ​​target wheel rotor. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise ratios, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0020] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0021] First embodiment like Figure 3 As shown, this embodiment provides an eddy current sensor double coil structure, including: A first coil group and a second coil group, wherein the first coil group and the second coil group are configured on a PCBA circuit board, the first coil group includes a first transmitting coil and a first receiving coil group, and the second coil group includes a second transmitting coil and a second receiving coil group; The first receiving coil group and the second receiving coil group have the same receiving radius and are both located inside the first transmitting coil and the second transmitting coil. Each receiving coil of the first receiving coil group and the second receiving coil group presents a closed circular structure formed by a curve with a trigonometric function as a deformation basis.

[0022] The technical solution of this embodiment realizes the fusion of the radial positions of the first receiving coil group and the second receiving coil group by configuring the first receiving coil group and the second receiving coil group as a closed circular structure composed of a curve with the same receiving radius and a deformation based on a trigonometric function, and at the same time, makes full use of the radial distance between the first transmitting coil and the first receiving coil group to arrange the second transmitting coil, so that the first coil group and the second coil group occupy as little space as possible in the radial direction, so that a larger receiving area can be obtained under the same rotation area, and the accuracy and anti-interference performance of the eddy current sensor are effectively improved. In addition, in the dual coil group solution of the prior art, since the hollowed-out part of the rotor accounts for too large a proportion, the strength cannot meet the requirements of high-speed rotation. The solution of this embodiment can be used as follows: Figure 4 The target wheel rotor of the single coil group solution shown can save the design time and manufacturing cost of the entire device. Using the technical solution of this embodiment, in some embodiments, the receiving area can be significantly increased by 126.8% under the same rotation area.

[0023] Here, the "receiving coil is a closed circular structure formed by a curve based on the deformation of a trigonometric function" is further explained to express the shape of the receiving coil more clearly. Figure 3 The receiving coil is a curve connected end to end with a trigonometric function as the deformation basis and the whole presents a closed circular structure.

[0024] Preferably, the first transmitting coil is a multi-layer structure, configured on different conductive layers of the PCBA circuit board, and adjacent layer structures of the first transmitting coil are connected through conductive holes; the second transmitting coil is a multi-layer structure, configured on different conductive layers of the PCBA circuit board, and adjacent layer structures of the first transmitting coil are connected through conductive holes.

[0025] In this embodiment, when the PCBA circuit board is a multi-layer board, the space of each conductive layer of the PCBA circuit board can be fully utilized, and the first transmitting coil and the second transmitting coil can be arranged in the multi-layer conductive layers to fully meet the design requirements.

[0026] Preferably, the first transmitting coil is a single-layer structure, and is configured on a conductive layer of the PCBA circuit board; the second transmitting coil is a single-layer structure, and is configured on a conductive layer of the PCBA circuit board.

[0027] In this embodiment, when the PCBA circuit board is a single layer, see Figure 3 The first transmitting coil is in a vortex shape with a radius gradually increasing from the inside to the outside, and the second transmitting coil is also in a vortex shape with a radius gradually increasing from the inside to the outside. The wire of the second transmitting coil is arranged between the gaps of the wire of the first transmitting coil and extends along them. Similarly, the wire of the first transmitting coil can also be understood as being arranged between the gaps of the wire of the second transmitting coil and extending along them. This solution can make full use of the space of each conductive layer of the PCBA circuit board.

[0028] Preferably, the first transmitting coil and the second transmitting coil are configured on different conductive layers of the PCBA circuit board, and the first transmitting coil and the second transmitting coil overlap in the projection direction, or the second transmitting coil routing is within the spiral gap of the projection of the first transmitting coil.

[0029] In this embodiment, since the first transmitting coil and the second transmitting coil are configured on different conductive layers of the PCBA circuit board, the first transmitting coil and the second transmitting coil can be overlapped in the projection direction, and the second transmitting coil can be routed within the spiral gap projected by the first transmitting coil, thereby meeting space utilization while improving design flexibility.

[0030] Preferably, the PCBA circuit board is a multi-layer board, each conductive layer of the PCBA circuit board is uniquely configured with a partial structure of the first transmitting coil or the second transmitting coil, the first transmitting coil and the second transmitting coil do not overlap each other in the projection direction, the conductive wire of each layer structure of the first transmitting coil extends in a spiral shape, and the conductive wire of each layer structure of the second transmitting coil extends in a spiral shape in the projection direction in the gap between each layer structure of the first transmitting coil.

[0031] In the technical solution of this embodiment, the first transmitting coil and the second transmitting coil are arranged in different wire layers of the PCBA circuit board. Preferably, the first transmitting coil and the second transmitting coil do not overlap in the projection direction, which makes the engineering production process easier and is beneficial to improving the yield of the product.

[0032] Preferably, the first receiving coil group includes a first receiving coil and a second receiving coil, the second receiving coil group includes a third receiving coil and a fourth receiving coil, the first receiving coil and the second receiving coil have the same shape parameters and are rotationally symmetric about a geometric center, and the third receiving coil and the fourth receiving coil have the same shape parameters and are rotationally symmetric about the geometric center.

[0033] In this embodiment, since the receiving coil is a closed circular structure, and the closed circular structure extends in a spiral shape in the direction of its arc, it is possible to achieve a staggered arrangement of the four receiving coils in the radial space, and configure them to have the same receiving radius, thereby improving the utilization efficiency of the radial space. For the same group of receiving coils, the same shape parameters are configured, and the shape parameters mentioned here include but are not limited to the spiral direction, spiral radius, spiral slope, spiral period, spiral number of turns, etc., to match the target wheel rotor parameters, which can reduce the error of the sensor and improve the accuracy.

[0034] Preferably, a relative phase shift angle between the first receiving coil and the second receiving coil is equal to a relative phase shift angle between the third receiving coil and the fourth receiving coil.

[0035] In this embodiment, based on the previous embodiment, the relative phase shift angle between the first receiving coil and the second receiving coil is configured to be equal to the relative phase shift angle between the third receiving coil and the fourth receiving coil, so that the double-coil structure has better rotational symmetry, which is more conducive to the design and implementation of subsequent calculation programs.

[0036] Furthermore, the first receiving coil group and the second receiving coil group are in a rotationally symmetrical relationship about the geometric center, and the rotation angle is 0 degree to 360 degrees.

[0037] In this embodiment, based on the previous embodiment, since the relative phase shift angle between the first receiving coil and the second receiving coil is equal to the relative phase shift angle between the third receiving coil and the fourth receiving coil, it is only necessary to rotate the first receiving coil group or the second receiving coil group as a whole by an angle of 0 to 360 degrees according to the design. The design is simple, and is also conducive to the design and implementation of subsequent programs, thereby reducing the product development cycle.

[0038] Preferably, a relative phase shift angle between the first receiving coil and the second receiving coil is not equal to a relative phase shift angle between the third receiving coil and the fourth receiving coil.

[0039] In this embodiment, the relative phase shift angle in the first receiving coil group is designed to be different from the relative phase shift angle in the second receiving coil group, which can match special requirements in engineering design and is flexible and convenient.

[0040] Based on the same inventive concept, this embodiment also provides an eddy current sensor, comprising any of the double-coil structures described above.

[0041] The technical solution of this embodiment realizes the fusion of the radial positions of the first receiving coil group and the second receiving coil group by configuring the first receiving coil group and the second receiving coil group as a closed circular structure with the same receiving radius, and at the same time makes full use of the radial distance between the first transmitting coil and the first receiving coil group to arrange the second transmitting coil, so that the first coil group and the second coil group occupy as little space as possible in the radial direction, so that a larger receiving area can be obtained under the same rotation area, and the accuracy and anti-interference performance of the eddy current sensor are effectively improved. In addition, in the dual coil group solution of the prior art, since the hollowed-out part of the rotor accounts for too large a proportion, the strength cannot meet the requirements of high-speed rotation. The solution of this embodiment can be used as follows Figure 4 The target wheel rotor of the single coil group solution shown can save the design time and manufacturing cost of the entire device. Using the technical solution of this embodiment, in some embodiments, the receiving area can be significantly increased by 126.8% under the same rotation area.

[0042] Those skilled in the art can clearly understand that, for the sake of convenience and brevity in description, the identification content specifically executed by the above-described system and device can refer to the corresponding process in the aforementioned method embodiment.

[0043] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the protection scope of the present invention.

Claims

1. A double coil structure of an eddy current sensor, characterized in that: include: A first coil group and a second coil group, wherein the first coil group and the second coil group are configured on a PCBA circuit board, the first coil group includes a first transmitting coil and a first receiving coil group, and the second coil group includes a second transmitting coil and a second receiving coil group; The first receiving coil group and the second receiving coil group have the same receiving radius and are both located inside the first transmitting coil and the second transmitting coil. Each receiving coil of the first receiving coil group and the second receiving coil group presents a closed circular structure formed by a curve with a trigonometric function as a deformation basis.

2. The double coil structure of the eddy current sensor according to claim 1, characterized in that: The first transmitting coil is a multi-layer structure, configured on different conductive layers of the PCBA circuit board, and adjacent layer structures of the first transmitting coil are connected through conductive holes; the second transmitting coil is a multi-layer structure, configured on different conductive layers of the PCBA circuit board, and adjacent layer structures of the first transmitting coil are connected through conductive holes.

3. The double coil structure of the eddy current sensor according to claim 1, characterized in that: The first transmitting coil is a single-layer structure and is configured on a conductive layer of the PCBA circuit board. The second transmitting coil is a single-layer structure and is configured on a conductive layer of the PCBA circuit board.

4. The double coil structure of the eddy current sensor according to claim 1, characterized in that: The first transmitting coil and the second transmitting coil are configured on different conductive layers of the PCBA circuit board, and the first transmitting coil and the second transmitting coil overlap in the projection direction, or the second transmitting coil routing is within the spiral gap of the projection of the first transmitting coil.

5. The double coil structure of the eddy current sensor according to claim 1, characterized in that: The PCBA circuit board is a multi-layer board, and each conductive layer of the PCBA circuit board is uniquely configured with a partial structure of the first transmitting coil or the second transmitting coil, the first transmitting coil and the second transmitting coil do not overlap each other in the projection direction, the conductive wire of each layer structure of the first transmitting coil extends in a spiral shape, and the conductive wire of each layer structure of the second transmitting coil extends in a spiral shape in the projection direction in the gap between each layer structure of the first transmitting coil.

6. The double coil structure of the eddy current sensor according to claim 1, characterized in that: The first receiving coil group includes a first receiving coil and a second receiving coil, the second receiving coil group includes a third receiving coil and a fourth receiving coil, the first receiving coil and the second receiving coil have the same shape parameters and are rotationally symmetric about a geometric center, and the third receiving coil and the fourth receiving coil have the same shape parameters and are rotationally symmetric about the geometric center.

7. The double coil structure of the eddy current sensor according to claim 6, characterized in that: A relative phase shift angle between the first receiving coil and the second receiving coil is equal to a relative phase shift angle between the third receiving coil and the fourth receiving coil.

8. The double coil structure of the eddy current sensor according to claim 7, characterized in that: The first receiving coil group and the second receiving coil group are in a rotationally symmetrical relationship about the geometric center, and the rotation angle is 0 degree to 360 degrees.

9. The double-coil structure of the eddy current sensor according to claim 6, characterized in that: A relative phase shift angle between the first receiving coil and the second receiving coil is not equal to a relative phase shift angle between the third receiving coil and the fourth receiving coil.

10. An eddy current sensor, characterized in that: The double coil structure comprises any one of claims 1 to 9.

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