Angular position sensor

Abstract

The invention provides an angular position sensor, which comprises a rotor fixed on a central shaft of a sensing target and synchronously rotating with the sensing target; the stator and the rotor are coaxially arranged at an interval; the sensing part comprises a signal processing unit as well as an inductive sensing assembly and a magnetoelectric sensing assembly which are respectively in communication connection with the signal processing unit, and the signal processing unit is used for receiving and processing sensing information of the inductive sensing assembly to generate absolute angle position information; the processor is also used for receiving and processing sensing information of the magnetoelectric sensing assembly to generate rotation turns and rotation direction information; when the sensing part is in a normal working mode, the signal processing unit, the inductive sensing assembly and the magnetoelectric sensing assembly all work normally; in the low power consumption mode, only the signal processing unit and the magnetoelectric sensing assembly keep working. According to the invention, while high-precision absolute angle position measurement is considered, the number of turns can be recorded and stored under the condition of long-time power failure.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to an angle position sensor. Background Art

[0002] With the rapid development of industrial automation, robotics, new energy vehicles, and medical equipment, high-precision absolute angle position sensors are used as core measurement components, and their performance directly affects the system control accuracy and reliability. Especially in scenarios where power outages are frequent and position information needs to be maintained continuously, such as the rotation scanning of medical CT machines, power outage recovery of industrial robotic arms, environmental adaptability of wind turbines, and anti-pinch safety control of rail transit train doors, the sensor must not only achieve high-precision single-turn angle measurement, but also have a multi-turn cumulative counting function, and maintain the counting data through a backup power supply during a power outage to avoid downtime losses or safety accidents caused by recalibration.

[0003] In the prior art, the angle position sensor detects the angle by generating and receiving signals through the excitation coil and the receiving coil respectively. For example, when the angular position between the rotor coil and the stator coil in the sensor changes, the inductance will change and then be converted into an electrical signal. The angle position sensor has the advantages of high reliability, high precision, compact structure and low cost, but the power consumption of the inductive sensor is high and it cannot meet the long-term working requirements when powered by a battery, so it is mostly used in an environment with stable power supply.

[0004] On the other hand, magnetoelectric sensors measure angles by detecting changes in magnetic fields. For example, a magnet is installed on a rotating shaft, and the Hall element detects changes in the direction of the magnetic field to measure the angle. This type of sensor usually has a simple structure. Although it has low power consumption, it has poor accuracy and is not friendly to environments with large magnetic field interference. Therefore, it is more commonly used in scenarios where accuracy requirements are not too high but data needs to be saved for a long time in the event of a power outage.

[0005] Therefore, it is difficult to achieve both high precision and low power consumption in the existing inductive solution, and there is also an essential conflict between low power consumption and high precision in the magnetoelectric solution. Summary of the invention

[0006] The object of the present invention is to provide an angular position sensor which can achieve high-precision absolute angular position measurement while meeting the requirements of recording and storing the number of turns in the event of a long power outage.

[0007] In order to achieve the above object, the present invention provides an angular position sensor, comprising:

[0008] A rotor, fixed on the central axis of the sensing target and rotating synchronously with the sensing target;

[0009] A stator is coaxially arranged with the rotor and has a spacing therebetween;

[0010] The sensing part includes a signal processing unit, an inductive sensing component, and a magnetoelectric sensing component that are respectively communicatively connected to the signal processing unit. The signal processing unit is configured to receive and process the sensing information of the inductive sensing component to generate the absolute angular position information of the sensing target within one rotation period, and is further configured to receive and process the sensing information of the magnetoelectric sensing component to generate the number of rotation turns and the rotation direction information of the sensing target;

[0011] The sensing part has a normal operation mode and a low power consumption mode. In the normal operation mode, the signal processing unit, the inductive sensing component, and the magnetoelectric sensing component all operate normally; in the low power consumption mode, only the signal processing unit and the magnetoelectric sensing component remain operational.

[0012] Optionally, the stator includes an upper-layer PCB board and a lower-layer PCB board. The upper-layer PCB board is disposed on the lower-layer PCB board and the two are communicatively connected. The signal processing unit is disposed on the upper-layer PCB board.

[0013] Optionally, a number of positioning holes are correspondingly provided on the upper-layer PCB board and the lower-layer PCB board.

[0014] Optionally, the inductive sensing component includes a conductive target disposed on the rotor, and an excitation coil and a receiving coil disposed on the lower-layer PCB board. The signal processing unit is configured to control the excitation coil to generate an excitation magnetic field and process the induced voltage generated by the receiving coil to generate the absolute angular position information.

[0015] Optionally, the receiving coil includes a sine receiving coil and a cosine receiving coil. The conductive target includes a first conductive target adapted to the sine receiving coil and a second conductive target adapted to the cosine receiving coil.

[0016] Optionally, the lower-layer PCB board is a multi-layer PCB board. The excitation coil and the receiving coil are arranged in sequence along the thickness direction on the lower-layer PCB board and are arranged in parallel.

[0017] Optionally, the magnetoelectric sensing component includes a magnet disposed on the rotor and at least two Hall sensors disposed on the upper-layer PCB board. The signal processing unit is configured to process the induced pulses generated by the Hall sensors to generate the number of rotation turns and the rotation direction information of the sensing target.

[0018] Optionally, there are two Hall sensors, which are symmetrically arranged on the same diameter of the upper-layer PCB board.

[0019] Optionally, the minimum distance between the magnet of the magnetoelectric sensor assembly and the conductive target of the inductive sensor assembly on the rotor is between 1.5 mm and 2 mm.

[0020] Optionally, the sensing part enters the normal working mode when it is stably powered by an external power supply, and enters the low power consumption mode when it is temporarily powered by a backup battery.

[0021] The present invention provides an angle position sensor, which has at least one of the following beneficial effects:

[0022] 1) It has different working modes under different power supply conditions. Under stable power supply conditions, it can simultaneously obtain the absolute angle position information of the sensing target within a rotation cycle as well as the number of rotations and the rotation direction information. When only the backup battery is powered, it enters the low power consumption mode and only records the number of rotations and the rotation direction. After the normal power supply is restored, it can read the number of rotation changes of the sensing target during the power outage, and realize the multi-turn counting and memory function under power outage. This configuration can take into account the high-precision absolute angle position measurement while meeting the requirements of the number of rotations recording and storage under long-term power outages;

[0023] 2) By using two PCB boards to install the sensing elements of the inductive sensor component and the magnetoelectric sensor component respectively, a staggered layout in space is achieved, avoiding mutual interference in a highly compact space. At the same time, one signal processing unit can meet the requirements of both functions, which greatly reduces the size and economic cost of the sensor and is very suitable for miniaturized application scenarios;

[0024] 3) It solves the technical problem that high-precision, high-resolution sensors cannot record and save the number of turns information in the case of long-term power outages. It also solves the technical problem that some sensors are sensitive to magnetic field interference and require a compact size. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0026] Figure 1 A top three-dimensional schematic diagram of the angle position sensor provided in the first embodiment of the present invention;

[0027] Figure 2 A three-dimensional schematic diagram of the bottom of the angle position sensor provided in the first embodiment of the present invention;

[0028] Figure 3 A structural block diagram of the sensing part provided in the first embodiment of the present invention when the external power supply is normal;

[0029] Figure 4It is a structural block diagram of the sensing part under the temporary power supply of the backup battery provided by Embodiment 1 of the present invention;

[0030] Figure 5 It is a schematic diagram of the execution steps of the sensing part provided by Embodiment 1 of the present invention under different power supply conditions;

[0031] Figure 6 It is a planar schematic diagram of the lower-layer PCB board provided by Embodiment 1 of the present invention;

[0032] Figure 7 It is a planar schematic diagram of the rotor provided by Embodiment 1 of the present invention;

[0033] Figure 8 It is a planar schematic diagram of the upper-layer PCB board provided by Embodiment 1 of the present invention;

[0034] In the drawings:

[0035] 100 - Rotor; 200 - Stator; 210 - Upper-layer PCB board; 220 - Lower-layer PCB board; 230 - Positioning hole; 300 - Signal processing unit; 400 - Inductive sensing component; 410 - Conductive target; 411 - First conductive target; 412 - Second conductive target; 420 - Excitation coil; 430 - Receiving coil; 431 - Sine receiving coil; 432 - Cosine receiving coil; 500 - Magnetoelectric sensing component; 510 - Magnet; 520 - Hall sensor. Detailed implementation manners

[0036] To make the objectives, advantages and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are in a very simplified form and all use non-precise scales, only for conveniently and clearly assisting in explaining the objectives of the embodiments of the present invention. To make the objectives, features and advantages of the present invention more obvious and understandable, please refer to the accompanying drawings. It should be noted that the structures, scales, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any modification of the structure, change of the proportional relationship or adjustment of the size, under the condition of being the same or approximate to the effects that the present invention can produce and the objectives that can be achieved, should still fall within the scope that the technical content disclosed by the present invention can cover.

[0037] As used in the present invention, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. As used in the present invention, the term "or" is generally used in the sense of including "and / or" unless the context clearly dictates otherwise. As used in the present invention, the term "several" is generally used in the sense of including "at least one" unless the context clearly dictates otherwise. As used in the present invention, the term "at least two" is generally used in the sense of including "two or more" unless the context clearly dictates otherwise. In addition, the terms "first", "second", "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third" may explicitly or implicitly include one or at least two of such features.

[0038] In the description of the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed" shall be construed broadly. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Please refer to Figure 1 - Figure 2 , this embodiment provides an angular position sensor, comprising:

[0040] A rotor 100, fixed on the central axis of the sensing target and rotating synchronously with the sensing target;

[0041] A stator 200, coaxially arranged with the rotor 100 and having a spacing;

[0042] A sensing part, comprising a signal processing unit 300, an inductive sensing component 400 and a magnetoelectric sensing component 500 which are respectively communicatively connected with the signal processing unit 300. The signal processing unit 300 is configured to receive and process the sensing information of the inductive sensing component 400 to generate the absolute angular position information of the sensing target within one rotation period, and is further configured to receive and process the sensing information of the magnetoelectric sensing component 500 to generate the number of rotation cycles and the rotation direction information of the sensing target;

[0043] The sensing part has a normal working mode and a low power consumption mode. In the normal working mode, the signal processing unit 300, the inductive sensing component 400 and the magnetoelectric sensing component 500 all work normally; in the low power consumption mode, only the signal processing unit 300 and the magnetoelectric sensing component 500 remain working.

[0044] As Figure 3 - Figure 5 shown, the angular position sensor provided in this embodiment has different working modes under different power supply conditions. Under the power supply of a stable power source (such as a motor controller), the signal processing unit 300, the inductive sensing component 400, and the magnetoelectric sensing component 500 all work normally. The inductive sensing component 400 is used to obtain the absolute angular position information of the sensing target within one rotation period, and the magnetoelectric sensing component 500 is used to obtain the number of rotations and the rotation direction information of the sensing target. The combination of the two generates the core function of a high-precision multi-turn absolute value sensor. When only powered by a backup battery, the sensing part enters the low-power mode, the inductive sensing component 400 stops working, and the magnetoelectric sensing component 500 remains working. At this time, only the number of rotations and the rotation direction are recorded. After the normal power supply is restored, the change information of the number of rotations of the sensing target during the power-off process can be read, realizing the multi-turn counting and memory functions under power-off conditions.

[0045] The present invention integrates the inductive sensing component 400 and the magnetoelectric sensing component 500 in an angular position sensor, taking into account high-precision absolute angular position measurement while satisfying the number-of-rotation recording and preservation under long-term power-off conditions.

[0046] In this embodiment, the stator 200 includes an upper-layer PCB board 210 and a lower-layer PCB board 220. The upper-layer PCB board 210 is disposed on the lower-layer PCB board 220 and the two are communicatively connected. The signal processing unit 300 is disposed on the upper-layer PCB board 210. By using two PCB boards to separately install the sensing elements of the inductive sensing component 400 and the magnetoelectric sensing component 500, an interleaved layout in space is achieved, avoiding mutual interference in a highly compact space. At the same time, configuring one signal processing unit 300 can meet the requirements of both functions, which greatly reduces the size and economic cost of the sensor and is very suitable for miniaturized application scenarios.

[0047] In this embodiment, the signal processing unit 300 is, for example, an AC475X series chip developed by Daoxin Technology.

[0048] Preferably, a plurality of positioning holes 230 are correspondingly provided on the upper-layer PCB board 210 and the lower-layer PCB board 220. The positioning holes 230 are used to ensure the positioning and installation of the upper-layer PCB board 210 and the lower-layer PCB board 220, improving the matching accuracy between the two. The positioning holes 230 can be fixedly connected through fasteners such as bolts. The present invention does not impose any restrictions on the number and distribution mode of the positioning holes 230. In this embodiment, the positioning holes 230 are three and are evenly distributed along the circumferential direction of the upper and lower-layer PCB boards 220.

[0049] Please refer to Figure 6 - Figure 7, the inductive sensing component 400 includes a conductive target 410 disposed on the rotor 100, and an excitation coil 420 and a receiving coil 430 disposed on the lower-layer PCB board 220. The signal processing unit 300 is used to control the excitation coil 420 to generate an excitation magnetic field, and process the induced voltage generated by the receiving coil 430 to generate absolute angle position information.

[0050] The working principle of the inductive sensing component 400 provided in this embodiment will be described below.

[0051] The signal processing unit 300 is used to control the excitation coil 420 to generate an excitation magnetic field. The receiving coil 430 does not generate an induced voltage in the excitation magnetic field generated by the excitation coil 420 due to its special structure. After adding a conductive target 410 directly opposite to the receiving coil 430, the conductive target 410 will generate eddy currents in the alternating magnetic field generated by the excitation coil 420, and the eddy currents will generate a new alternating magnetic field, which will cause the receiving coil 430 to generate an induced voltage. Therefore, as long as the receiving coil 430 is wound into a specific shape and matched with a conductive target 410 of a corresponding shape, the receiving coil 430 can generate an induced voltage that is a sine-cosine function relationship with the rotation angle of the sensing target, and then after being processed by the signal processing unit 300, high-precision single-turn absolute value angle position information can be generated.

[0052] It should be noted that Figure 1 and Figure 2 do not show the excitation coil 420, the receiving coil 430 and the conductive target 410. When the stator 200 and the rotor 100 are coaxially installed, the conductive target 410 is located directly below the receiving coil 430, and a suitable distance is maintained between the stator 200 and the rotor 100 to ensure the accuracy of the multi-turn absolute value angle position information.

[0053] In this embodiment, as Figure 6 - Figure 7 shown, the receiving coil 430 includes a sine receiving coil 431 and a cosine receiving coil 432, and the conductive target 410 includes a first conductive target 411 adapted to the sine receiving coil 431 and a second conductive target 412 adapted to the cosine receiving coil 432.

[0054] Preferably, the lower-layer PCB board 220 is a multi-layer PCB board, and the excitation coil 420 and the receiving coil 430 are arranged in sequence along the thickness direction and are arranged in parallel on the lower-layer PCB board 220, so that the coil volume and production cost can be greatly reduced.

[0055] Please refer to Figure 2 and Figure 8The magnetoelectric sensing assembly 500 includes a magnet 510 disposed on the rotor 100 and at least two Hall sensors 520 disposed on the upper PCB board 210. The signal processing unit 300 is used to process the induction pulses generated by the Hall sensor 520 to generate the number of rotations and rotation direction information of the sensing target.

[0056] The working principle of the magnetoelectric sensor assembly 500 provided in this embodiment is described below.

[0057] The magnet 510 fixed on the rotor 100 rotates synchronously with the sensing target, and generates an induction pulse every time it passes through one of the Hall sensors 520. The number of rotations and the rotation direction information of the sensing target can be generated by combining the pulse sequence of at least two Hall sensors 520 and calculating by the signal processing unit 300. Since the power consumption of the magnetoelectric induction component is extremely low at the microampere level, combined with the microampere low power consumption mode of the dedicated chip, it can work for at least 2 years under the power supply condition of a small backup battery.

[0058] In this embodiment, there are two Hall sensors 520 and they are symmetrically placed on the same diameter of the upper PCB board 210 . The two Hall sensors 520 correspond to the zero point and the 180° point of the rotation angle respectively.

[0059] Preferably, the minimum distance between the magnet 510 of the magnetoelectric sensor assembly 500 and the conductive target 410 of the inductive sensor assembly 400 on the rotor 100 is between 1.5 mm and 2 mm. It is understandable that the conductive target 410 and the magnet 510 should be kept at a certain distance to avoid mutual influence of the magnetic fields of the two. The present invention can control the distance between the two within 2 mm without mutual interference through reasonable spatial layout.

[0060] In summary, the embodiments of the present invention provide an angle position sensor that integrates an inductive sensor component and a magnetoelectric sensor component into one angle position sensor. The sensor has different working modes under different power supply conditions. Under stable power supply conditions, the sensor can simultaneously obtain the absolute angle position information of the sensing target within a rotation cycle as well as the number of rotations and the rotation direction information. When only the backup battery is used for power supply, the sensor enters a low power consumption mode and only records the number of rotations and the rotation direction. After the normal power supply is restored, the sensor can read the number of rotation changes of the sensing target during the power outage, thereby realizing the multi-turn counting and memory function under power outage conditions. Such a configuration can take into account high-precision absolute angle position measurement while meeting the requirements of number of rotation recording and preservation under long-term power outage conditions.

[0061] The above are only the preferred embodiments of the present invention and do not impose any restrictive effect on the present invention. Any person skilled in the art, within the scope of the technical solution of the present invention, makes any form of equivalent substitution or modification and other changes to the technical solution and technical content disclosed by the present invention, which are all within the content of the technical solution of the present invention and still fall within the protection scope of the present invention.

Claims

1. An angular position sensor, characterized in that, Including: A rotor, fixed on the central axis of the sensing target and rotating synchronously with the sensing target; A stator, coaxially arranged with the rotor and having a spacing; A sensing part, including a signal processing unit, an inductive sensing component and a magnetoelectric sensing component respectively communicatively connected to the signal processing unit. The signal processing unit is configured to receive and process the sensing information of the inductive sensing component to generate the absolute angular position information of the sensing target within one rotation period, and is also configured to receive and process the sensing information of the magnetoelectric sensing component to generate the number of rotation turns and the rotation direction information of the sensing target; The sensing part has a normal working mode and a low-power consumption mode. In the normal working mode, the signal processing unit, the inductive sensing component and the magnetoelectric sensing component all work normally; In the low-power consumption mode, only the signal processing unit and the magnetoelectric sensing component remain working.

2. The angular position sensor according to claim 1, wherein The stator includes an upper-layer PCB board and a lower-layer PCB board. The upper-layer PCB board is arranged on the lower-layer PCB board and the two are communicatively connected. The signal processing unit is arranged on the upper-layer PCB board.

3. The angular position sensor according to claim 2, characterized in that, A plurality of positioning holes are correspondingly arranged on the upper-layer PCB board and the lower-layer PCB board.

4. The angular position sensor according to claim 2, characterized in that, The inductive sensing component includes a conductive target arranged on the rotor, and an excitation coil and a receiving coil arranged on the lower-layer PCB board. The signal processing unit is configured to control the excitation coil to generate an excitation magnetic field and process the induced voltage generated by the receiving coil to generate the absolute angular position information.

5. The angular position sensor according to claim 4, characterized in that, The receiving coil includes a sine receiving coil and a cosine receiving coil. The conductive target includes a first conductive target adapted to the sine receiving coil and a second conductive target adapted to the cosine receiving coil.

6. The angular position sensor according to claim 4, wherein, The lower-layer PCB board is a multi-layer PCB board. The excitation coil and the receiving coil are arranged in sequence along the thickness direction and arranged in parallel on the lower-layer PCB board.

7. The angular position sensor according to claim 2, wherein, The magnetoelectric sensing component includes a magnet arranged on the rotor and at least two Hall sensors arranged on the upper-layer PCB board. The signal processing unit is configured to process the induced pulses generated by the Hall sensors to generate the number of rotation turns and the rotation direction information of the sensing target.

8. The angular position sensor according to claim 7, characterized in that, There are two Hall sensors and they are symmetrically arranged on the same diameter of the upper-layer PCB board.

9. The angular position sensor according to claim 7, characterized in that, The minimum distance between the magnet of the magnetoelectric sensing component and the conductive target of the inductive sensing component on the rotor is between 1.5 mm and 2 mm.

10. The angular position sensor according to claim 1, characterized in that, When the sensing part is stably powered by an external power supply, it enters the normal working mode. When the sensing part is temporarily powered by a backup battery, it enters the low-power consumption mode.

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