Full-speed-domain aircraft wheel speed sensor

Abstract

The invention discloses a full-speed-domain aircraft wheel speed sensor, and belongs to the technical field of aircraft wheel speed sensors. Comprising a rotor assembly and a stator assembly which are coaxially arranged, the rotor assembly comprises a permanent magnet ring, and the permanent magnet ring is installed on an airplane wheel bearing end cover through a supporting seat; the stator assembly comprises Hall circuit boards, and the two Hall circuit boards are symmetrically installed on the two opposite sides of the inner edge of the wheel shaft through a supporting shell. The axial positions of the permanent magnet ring and the Hall circuit board are the same; the Hall circuit board comprises a circuit board, and a switch type Hall chip, a linear Hall chip and an electric connector which are installed on the circuit board. The switch type Hall chip is used for detecting a pulse signal when the airplane wheel rotates at a high speed, and the linear Hall chip is used for detecting a continuous magnetic field signal when the airplane wheel rotates at a low speed; and the phase difference of the two signals judges forward and reverse rotation of the wheel. According to the method, the full-speed-domain detection precision, the environmental adaptability and the reliability are remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft wheel speed sensors, and particularly relates to a full-speed-range aircraft wheel speed sensor. Background Art

[0002] The main function of an aircraft wheel speed sensor is to measure the wheel speed of the aircraft during takeoff roll. When the aircraft lands or aborts takeoff, in order to ensure safety and obtain the maximum braking effect, reduce the takeoff roll distance of the aircraft, and at the same time avoid tire bursting on dry concrete or skidding on wet or icy runways and reduce tire wear, it is necessary to monitor the wheel speed of the aircraft during takeoff roll in real time to prevent tire lock-up and skidding.

[0003] Currently, the widely used wheel speed sensor is a magnetoelectric wheel speed sensor. The wheel drives the sensor shaft to rotate through a fork transmission device, and outputs an approximate sine wave signal. The frequency of this signal is proportional to the wheel speed. Although this wheel speed sensor has the advantages of simple maintenance and convenient disassembly, this contact transmission method that drives the sensor shaft to rotate through a fork transmission device will inevitably cause mechanical wear during long-term operation, reducing the reliability of the equipment. In addition, the wheel speed sensor in this invention only generates a single alternating sine signal and cannot complete the detection and judgment of the forward and reverse rotation of the wheel.

[0004] Currently, the publicly disclosed non-contact wheel speed sensors have the advantages of small size and light weight, but their reliability cannot be guaranteed under the influence of light-blocking substances such as oil stains and fog or complex working conditions. Summary of the Invention

[0005] Technical Problems to be Solved

[0006] In order to avoid the deficiencies of the prior art, the present invention provides a full-speed-range aircraft wheel speed sensor, which significantly improves the full-speed-range detection accuracy, environmental adaptability and reliability through the collaborative layout of dual Hall chips, the optimization of the built-in structure and the high-density magnetic pole design.

[0007] The technical solution of the present invention is: a full-speed-range aircraft wheel speed sensor, including a rotor assembly and a stator assembly arranged coaxially, wherein the rotor assembly is fixed to the aircraft wheel bearing end cover, and the stator assembly is fixed to the inner edge of the wheel axle; the rotor assembly includes a permanent magnet ring, and the permanent magnet ring is installed on the aircraft wheel bearing end cover through a support seat; the stator assembly includes Hall circuit boards, and two Hall circuit boards are symmetrically installed on the opposite sides of the inner edge of the wheel axle through a support housing; and the axial positions of the permanent magnet ring and the Hall circuit boards are the same;

[0008] The Hall circuit board includes a circuit board and a switch-type Hall chip, a linear Hall chip, and an electrical connector mounted thereon. Two switch-type Hall chips form a group, and two linear Hall chips form a group, presenting a rectangular array as a whole. The switch-type Hall chip group and the linear Hall chip group are arranged in parallel along the axis with an axial spacing of 5 mm. The offset distance between two switch-type Hall chips and the offset distance between two linear Hall chips are both 50% of the single-pole width of the permanent magnet ring. The switch-type Hall chip is used to detect the pulse signal when the wheel rotates at high speed, and the linear Hall chip is used to detect the continuous magnetic field signal when the wheel rotates at low speed. And the phase difference between the two signals is used to judge the forward and reverse rotation of the wheel.

[0009] A further technical solution of the present invention is that the permanent magnet ring is magnetized with double poles on the end face, with 36 poles evenly distributed circumferentially, 18 pairs of N and S poles, and the gap between the pole surface and the Hall chip is 2 mm.

[0010] A further technical solution of the present invention is that the permanent magnet ring is made of samarium cobalt material.

[0011] A further technical solution of the present invention is that the switch-type Hall chip and its peripheral circuit form a switch-type Hall monitoring unit for the high-speed acquisition scenario of the aircraft. The rising edge or falling edge of the two signals is captured by the pulse capture module of the microcontroller to obtain the time interval between adjacent edges, and the wheel speed is calculated by combining the longitudinal layout offset of the Hall element and using the conversion relationship between the number of poles and the mechanical-electrical angle.

[0012] The linear Hall chip and its peripheral circuit form a linear Hall monitoring unit for the low-speed acquisition requirement scenario of the aircraft. The two signals are synchronously collected by the ADC module of the microcontroller to obtain discretized sine waveform data. The phase difference between the two signals is calculated by methods such as the quadrature demodulation algorithm and the arctangent function, and the phase difference is converted into a time interval. The wheel speed is calculated by combining the longitudinal layout offset of the Hall element and using the conversion relationship between the number of poles and the mechanical-electrical angle.

[0013] The working thresholds of the switch-type Hall monitoring unit and the linear Hall monitoring unit are demarcated by the ground speed of the aircraft at 20 km / h.

[0014] A further technical solution of the present invention is the switching mechanism of the switch-type Hall monitoring unit and the linear Hall monitoring unit: a smooth transition is achieved by the weighted fusion algorithm when the ground speed of the aircraft approaches the switching threshold, and the expression is as follows:

[0015]

[0016] In the formula, V linear is the acquisition value of the linear Hall monitoring unit, V switch is the acquisition value of the switch-type Hall monitoring unit, w is the inertial weight coefficient, Vout is the output value after fusion;

[0017] When the ground speed v of the aircraft ≤ 18 km / h, it completely relies on the linear Hall monitoring unit; when the ground speed v of the aircraft ≥ 22 km / h, it completely relies on the switch-type Hall monitoring unit; when in the transition range of 18 km / h to 22 km / h, the weight coefficient gradually relies on the linear Hall monitoring unit as the ground speed of the aircraft decreases.

[0018] A further technical solution of the present invention is that: the circuit board is embedded in the support housing through a slot, and the electrical connector is connected to the circuit board through pins to achieve dual-redundancy signal output.

[0019] A further technical solution of the present invention is that: the electrical connector outputs two independent square wave signals and two sine signals. The square wave signals are used for high-speed speed calculation, and the sine signals are used for low-speed speed calculation. And the two signals judge the forward and reverse rotation through the phase difference.

[0020] A further technical solution of the present invention is that: the switch-type Hall monitoring unit captures two square wave signals with a phase difference of 1 / 4 cycle in real time through the pulse capture module of the microcontroller in the circuit board. By monitoring the edge trigger timing of the two signals in real time and observing the edge order of the pilot signal, the forward and reverse rotation directions of the wheel are identified; the specific judgment process is as follows:

[0021] When the edge of signal A appears earlier than the edge of signal B, and the time difference is about 1 / 4 cycle, it is determined to be forward rotation; when the edge of signal B appears earlier than the edge of signal A, and the time difference is about 3 / 4 cycle, it is determined to be reverse rotation.

[0022] A further technical solution of the present invention is that: the linear Hall monitoring unit synchronously samples the two sine signals through the high-resolution ADC module of the microcontroller in the circuit board. By observing the timing sequence of the zero-crossing points of the two signals, the forward and reverse rotation directions of the wheel are determined; the specific judgment process is as follows: when the zero-crossing point of signal C appears earlier than signal D, it is determined to be forward rotation; otherwise, it is determined to be reverse rotation.

[0023] A further technical solution of the present invention is that: the support housing is of a circular ring structure, and notches are opened on both symmetric sides of its circumference for installing two Hall circuit boards respectively.

[0024] A speed measurement method for a full-speed-range aircraft wheel speed sensor:

[0025] When the ground speed of the aircraft ≥ 22 km / h, the switch-type Hall monitoring unit is enabled, and the square wave signal output by it is used to calculate the rotation speed through the pulse time interval.

[0026] When the ground speed of the aircraft is in the transition range of 18 km / h to 22 km / h, the switched Hall monitoring unit and the linear Hall monitoring unit operate in parallel, and smooth transition is achieved through the weighted fusion algorithm;

[0027] When the ground speed of the aircraft ≤ 18 km / h, the linear Hall monitoring unit is enabled, and the sine signal output by it is used to obtain the rotational speed through analog-to-digital conversion and electrical angle calculation;

[0028] The forward or reverse rotation of the wheel is judged according to the phase difference direction of the two signals.

[0029] Beneficial effects

[0030] The beneficial effects of the present invention are as follows: Through non-contact Hall sensing, dual-chip collaborative layout and built-in lightweight design, this technical solution comprehensively solves the core defects of existing sensors in aspects such as mechanical wear, environmental adaptability, volume and weight, full-speed range accuracy, and direction detection. Its innovation is not only reflected in the optimization of the hardware structure, but also through intelligent algorithms (such as weighted fusion and phase difference calculation) to achieve breakthroughs in functions and performance, providing reliable technical guarantees for the safe landing, efficient braking and preventive maintenance of the aircraft. The specific effect analysis is as follows:

[0031] 1. The present invention adopts non-contact Hall sensing design, abandons the mechanical transmission structure (such as fork and rotating shaft) of traditional magnetoelectric sensors, and eliminates the wear risk during long-term use. Comparative tests show that the sensor life is increased by more than 3 times, and the failure rate is reduced by 80%.

[0032] 2. The detection method based on the Hall effect of the present invention is not affected by optical interferences such as oil stains, fog, and dust, and has higher signal stability than photoelectric sensors (CN111337703A) in wet runway and high humidity environments.

[0033] 3. The built-in structure of the present invention integrates the sensor inside the wheel axle, reducing the space occupation by 50% and the weight by 40%, meeting the lightweight requirements of aircraft, and having significant advantages compared with external Hall sensors (CN106940381A).

[0034] 4. The present invention adopts a dual Hall chip collaborative design. The switched Hall chip supports high-speed detection, and the linear Hall chip realizes low-speed precise acquisition. Through the 20 km / h threshold and the weighted fusion algorithm (transition range 18 - 22 km / h), smooth switching between high and low speeds is ensured. When the ground speed of the aircraft approaches the 20 km / h threshold, the microcontroller starts the dual monitoring units to collect the wheel speed in parallel, and uses the weighted fusion algorithm for the collected values to reduce the speed fluctuation near the switching threshold to within ±1 km / h.

[0035] 5. The present invention determines and selects the direction by using the 1 / 4 - cycle phase difference between two signals: at high speeds, the direction is determined by the timing of the square - wave edges (rising edge / falling edge); at low speeds, the direction is determined by the order of the zero - crossing points of the sine signal; the direction recognition is accurate, avoiding the misjudgment problem of traditional single - signal sensors.

[0036] 6. The present invention adopts a dual - redundancy design to improve the fault - tolerance ability. Dual - Hall circuit boards are symmetrically installed in the support housing. When any component fails, the signal output can still be guaranteed, and the system redundancy reaches 100%, meeting the aviation - level reliability standard.

[0037] 7. The linear Hall monitoring unit of the present invention can monitor the magnetic flux condition of the permanent - magnet ring in real time, warning of the risk of pole degradation, increasing the maintenance efficiency of ground crew by more than 40%, and avoiding in advance the chain - failure of the wheel anti - skid braking system caused by pole degradation. Description of the Drawings

[0038] Figure 1 In (a), it is a schematic diagram of the installation position of the aircraft wheel speed sensor of the present invention inside the landing - gear shaft;

[0039] Figure 1 In (b), it is an axonometric view of the aircraft wheel speed sensor of the present invention;

[0040] Figure 2 In (a), it is an exploded view of the stator component of the aircraft wheel speed sensor of the present invention;

[0041] Figure 2 In (b), it is a sectional view of the stator component of the aircraft wheel speed sensor of the present invention;

[0042] Figure 3 In (a), it is an exploded view of the rotor component of the aircraft wheel speed sensor of the present invention;

[0043] Figure 3 In (b), it is a sectional view of the rotor component of the aircraft wheel speed sensor of the present invention;

[0044] Figure 4 It is a flow - chart block diagram of the collaborative work and switching of the dual - monitoring unit of the present invention.

[0045] Description of the Reference Numerals: 1. Wheel bearing end - cover; 2. Rotor assembly; 3. Stator assembly; 4. Screw; 5. Support housing; 6. Switch - type Hall chip; 7. Linear Hall chip; 8. Hall circuit board; 9. Pin; 10. Electrical connector; 11. Slot; 12. Permanent - magnet ring; 13. Screw; 14. Screw; 15. Screw; 16. Support seat; 17. Fixed end - face; 18. Outer half - hub; 19. Screw. Detailed Embodiment

[0046] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0047] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] CN 102495228 A disclosed in the prior art, the invention patent discloses a permanent magnet wheel speed sensor, in which the permanent magnet is pressed into the magnetic steel seat through the coil frame, and radial and axial movement is prevented by the positioning pin and the retaining ring. When the shaft rotates under the drive of the wheel, it rotates with the rotor assembly. As the rotor teeth and the stator teeth are relatively staggered, the magnetic resistance between the teeth continues to change, the magnetic flux changes, and a sinusoidal voltage signal is induced on the coil assembly. The wheel rotation speed can be obtained by identifying the frequency information of the voltage signal. Although the wheel speed sensor has the advantages of simple maintenance and easy disassembly, this contact transmission method that drives the sensor shaft to rotate through the fork transmission device will inevitably cause mechanical wear during long-term operation, reducing the reliability of the equipment. In addition, the wheel speed sensor in the invention only generates a single alternating sinusoidal signal, which cannot complete the forward and reverse detection and judgment of the wheel.

[0049] With the vigorous development of sensing technology, some non-contact wheel speed sensors have been proposed in recent years. The invention patent with announcement number CN 111337703A discloses a photoelectric speed sensor for aircraft brake system. The invention receives and transmits light through a photoelectric encoder switch, and obtains the wheel rotation speed by identifying the switching frequency information. Although the wheel speed sensor in the invention has the advantages of small size and light weight, its reliability cannot be guaranteed under the influence of light-shielding objects such as oil, fog or complex working conditions. The invention patent with announcement number CN 106940381A discloses an aircraft wheel data acquisition device and speed measurement method. The 72 Hall sensors in the invention are evenly distributed on the outer side of the wheel rim circumference. Through the gap magnetic field changes of the four permanent magnet rings, the Hall sensors induce pulse signals, and the wheel rotation speed is identified by judging the time difference of the pulse signals of adjacent Hall sensors. Although the wheel speed sensing system in the invention has strong anti-interference ability and can detect and judge the forward and reverse rotation of the wheel, the external Hall wheel speed sensor in the invention has the problems of large size and heavy weight. In addition, when the wheel rotates at a low speed, it is difficult to quickly and accurately collect the pulse switch quantity generated by the gap between the permanent magnet rings to identify the wheel speed.

[0050] In order to overcome the problems in the prior art of mechanical wear and inability to identify the forward and reverse rotation of the wheel in the contact transmission mode of the magnetoelectric wheel speed sensor; the photoelectric wheel speed sensor is easily affected by the environment and has low reliability; the external Hall wheel speed sensor is large in size and heavy in weight, the present invention proposes a built-in full-speed range aircraft wheel speed sensor based on the Hall effect, the sensor has the advantages of small size, light weight, high reliability, easy installation and disassembly, dynamic switching of dual monitoring units through speed threshold, and taking into account the advantages of low-speed and high-speed acquisition accuracy, etc., and is suitable for various working conditions and environmental requirements of aircraft wheel speed sensors.

[0051] The full-speed range aircraft wheel speed sensor comprises a coaxially arranged rotor assembly and a stator assembly, wherein the rotor assembly is fixed to the wheel bearing end cover, and the stator assembly is fixed to the inner edge of the wheel axle; the characteristic is that: the rotor assembly comprises a permanent magnet ring, and the permanent magnet ring is mounted on the wheel bearing end cover through a support seat; the stator assembly comprises a Hall circuit board, and two Hall circuit boards are symmetrically mounted on opposite sides of the inner edge of the wheel axle through a support shell; and the axial positions of the permanent magnet ring and the Hall circuit board are the same;

[0052] The Hall circuit board includes a circuit board, a switch-type Hall chip, a linear Hall chip, and an electrical connector mounted thereon. Two switch-type Hall chips form a group, and two linear Hall chips form a group, presenting a rectangular array as a whole. The switch-type Hall chip group and the linear Hall chip group are connected in parallel along the axis, and the axial spacing is 5 mm. The offset distance between two switch-type Hall chips and the offset distance between two linear Hall chips are both 50% of the single magnetic pole width of the permanent magnet ring. The switch-type Hall chip is used to detect the pulse signal when the wheel rotates at high speed, and the linear Hall chip is used to detect the continuous magnetic field signal when the wheel rotates at low speed. And the phase difference of the two signals is used to judge the forward and reverse rotation of the wheel.

[0053] The aircraft wheel speed sensor of the present invention is a non-contact Hall sensing system, which completely avoids the mechanical wear problem of the magnetoelectric wheel speed sensor in the publication number CN102495228A. In addition, the aircraft wheel speed sensor of the present invention is based on the Hall effect and has stronger environmental adaptability than the optoelectronic wheel speed sensor described in the publication number CN 111337703A, and can work stably under complex working conditions such as oil pollution and high humidity.

[0054] The aircraft wheel speed sensor of the present invention is an installation structure inside the wheel shaft. Compared with the external Hall wheel speed sensor in the publication number CN 106940381A, the space occupancy is reduced by 50% and the weight is reduced by 40%, in order to meet the requirements of aircraft lightweight and compactness.

[0055] The present invention significantly improves the accuracy and reliability of wheel speed detection through a segmented signal acquisition mechanism in low-speed and high-speed scenarios. In the low-speed working condition, the linear Hall monitoring unit uses high-resolution synchronous sampling to reduce the acquisition error rate. In the high-speed working condition, the switch-type Hall monitoring unit avoids signal jitter caused by wear during the high-speed mechanical transmission of the wheel. Based on the collaborative work of the dual monitoring units and the 20 km / h dynamic switching design, the speed detection range of the present invention is expanded by 10% compared with the publication number CN 106940381A, realizing high-precision full-speed coverage of the wheel speed.

[0056] The following further analyzes the above technical solutions in combination with the drawings and examples:

[0057] In one embodiment, referring to Figure 1 As shown, a full-speed aircraft wheel speed sensor mainly consists of a stator component and a rotor component. The rotor component includes a support seat, a permanent magnet ring, and screws, etc. The stator component includes a support housing, a Hall circuit board, and screws, etc., and the Hall circuit board includes a circuit board, an electrical connector, an outer housing, and screws, etc.

[0058] Preferably, referring to Figure 3As shown, the support base 16 is designed with light weight; and the support base 16 is connected to the wheel bearing end cover 1 by screws 15; the permanent magnet ring 12 is connected to the fixed end face 17 of the support base 16 by screws 13. Since the wheel bearing end cover 1 is connected to the outer half hub 18 by screws 13, it rotates together with the wheel assembly when the wheel assembly rotates.

[0059] Preferably, referring to Figure 2 As shown, the stator component 3 is fixed inside the landing gear shaft with screws 14 and remains relatively stationary with the landing gear shaft; the Hall circuit board 8 is fixed in the internal slot 11 of the support housing 5 with screws 4 and is in the same axial plane as the permanent magnet 12 of the rotor component 2. Two identical Hall circuit boards are installed at symmetrical positions of the support housing 5 to form a dual redundancy. The electrical connector 10 is fixed to the end of the support housing 5 with screws 19 and is connected to the Hall circuit board 8 through the pin 9.

[0060] Specifically, referring to Figure 2 As shown in (a) of , the circuit board of the Hall circuit board 8 is provided with a switched Hall chip 6, a linear Hall chip 7 and their respective peripheral circuits. The switched Hall chip 6 and its several peripheral circuits form a switched Hall monitoring unit; the linear Hall chip 7 and its several peripheral circuits form a linear Hall monitoring unit;

[0061] The electrical connector of the Hall circuit board assembly supplies power to the devices in the circuit board to realize the communication of commands, data and fault information between the circuit board and the aircraft anti-skid braking system.

[0062] The switched Hall monitoring unit in the circuit board is mainly used for high-speed acquisition scenarios such as aircraft landing or aborted takeoff. The rising edge or falling edge of two signals is captured by the pulse capture module of the microcontroller, and the time interval between adjacent edges is obtained. Combining the longitudinal layout offset of the Hall element and using the conversion relationship between the number of magnetic poles and the mechanical-electrical angle, the wheel speed is calculated. By real-time monitoring the edge trigger timing of the two signals and observing the edge order of the pilot signal, the rotation direction (forward or reverse) of the wheel is identified.

[0063] The linear Hall monitoring unit in the circuit board is mainly used for low-speed acquisition requirement scenarios such as aircraft taxiing at low speed on the runway, tractor migration or engine reverse thrust reverse. The two signals are synchronously acquired by the ADC module of the microcontroller to obtain discretized sine wave data. The phase difference between the two signals is calculated by methods such as quadrature demodulation algorithm and arctangent function, and the phase difference is converted into a time interval. Combining the longitudinal layout offset of the Hall element and using the conversion relationship between the number of magnetic poles and the mechanical-electrical angle, the wheel speed is calculated. By observing the timing sequence of the zero-crossing points of the two signals, the rotation direction (forward or reverse) of the wheel is determined.

[0064] When the ground speed of the aircraft approaches the switching threshold of 20 km / h, the microcontroller activates the dual monitoring unit to collect wheel speeds in parallel. The weighted fusion algorithm is used to output the final speed value to achieve smooth switching. In addition, the linear Hall monitoring unit can monitor the magnetic field strength of the permanent magnet ring throughout its life cycle.

[0065] Preferably, the circuit board size of the Hall circuit board 8 is designed to be 5 mm * 10 mm. The two switch-type Hall chips are longitudinally offset by 2 mm, which is half of the width of a single magnetic pole of the permanent magnet ring 12. The two linear Hall chips are longitudinally offset by 2 mm, which is half of the width of a single magnetic pole of the permanent magnet ring 12. The switch-type Hall chips and the linear Hall chips are horizontally spaced 5 mm apart. Both the switch-type Hall chips and the linear Hall chips are in SOT23 surface mount packages, and the gap between the package surface and the surface of the permanent magnet ring 12 is 2 mm.

[0066] The ground speed threshold of the aircraft is set at 20 km / h, which is lower than the anti-skid failure critical speed of 25 km / h, to avoid the risk of mis-switching of the dual monitoring unit caused by sudden changes in speed during the wheel anti-skid braking stage. The entire monitoring unit establishes real-time data communication with the wheel anti-skid braking system through the electrical connector 10 to ensure the coordinated control of the state parameters of each unit and the braking system.

[0067] The switching mechanism of the dual monitoring unit of the system achieves a smooth transition through the weighted fusion algorithm when the ground speed of the aircraft approaches the switching threshold, that is, the switching of the speed acquisition method is achieved through the following formula:

[0068]

[0069] In the formula, V linear is the acquisition value of the linear Hall monitoring unit, V switch is the acquisition value of the switch-type Hall monitoring unit, w is the inertial weight coefficient, and V out is the output value after fusion.

[0070] When the ground speed v of the aircraft ≤ 18 km / h, it completely relies on the linear Hall monitoring unit; when the ground speed v of the aircraft ≥ 22 km / h, it completely relies on the switch-type Hall monitoring unit; when in the transition interval (18 km / h to 22 km / h), the weight coefficient gradually relies on the linear Hall monitoring unit as the ground speed of the aircraft decreases.

[0071] Specifically, the switch-type Hall monitoring unit captures the rising or falling edges of two square wave signals (SignalA, SignalB) in real time through the pulse capture module of the microcontroller in the circuit board 8, and calculates the wheel speed by measuring the time interval between the edges, combined with the longitudinal offset of the Hall element 6, the number of magnetic poles, and the conversion relationship between the mechanical - electrical angle.

[0072] Specifically, the permanent magnet ring 12 is magnetized with double poles on the end face, with 36 magnetic poles and 18 pairs of N and S magnetic poles. Thus, the conversion relationship between the magnetic-mechanical and electrical angles can be obtained as 1° mechanical angle = 18° electrical angle. Since the two square wave signals (with the Hall elements arranged longitudinally) designed in the present invention have a phase difference of 1 / 4 cycle, 4 edges (rising edges and falling edges) can be detected in each electrical cycle, and the resolution can be improved through frequency doubling, that is, the number of pulses per mechanical cycle is 18×4 = 72. By combining the measured time interval Δt between adjacent pulses, the rotational speed of the wheel can be calculated. Combining with the rolling radius of the wheel, the linear speed of the wheel can be calculated. In addition, when the edge of Signal A appears earlier than the edge of Signal B and the time difference is approximately 1 / 4 cycle, it is determined as forward rotation; when the edge of Signal B appears earlier than the edge of Signal A and the time difference is approximately 3 / 4 cycle, it is determined as reverse rotation.

[0073] The linear Hall monitoring unit synchronously samples the two sine signals (Signal C and Signal D) through the high-resolution ADC module of the microcontroller in the circuit board 8 and obtains the discretized sine waveform data. After performing quadrature mixing and low-pass filtering on Signal C and Signal D respectively using the quadrature demodulation algorithm, the real and imaginary parts of the fundamental wave components are extracted. By performing the arctangent function calculation on the real and imaginary parts of the fundamental wave components, the phase difference between the two signals can be obtained; the corresponding time interval Δt can be calculated through the time difference between the zero-crossing points or characteristic points of the two signals. Combining with the conversion relationship between the mechanical and electrical angles (1° mechanical angle = 18° electrical angle), the rotational speed of the wheel can be calculated. Combining with the rolling radius of the wheel, the linear speed of the wheel can be calculated. In addition, when the zero-crossing point (such as the rising edge) of Signal C appears earlier than Signal D, it is determined as forward rotation; otherwise, it is determined as reverse rotation.

[0074] While the linear Hall monitoring unit of the present invention realizes the speed measurement task in the low-speed acquisition scenario of the wheel, it also undertakes the function of health monitoring of the permanent magnet ring 12. By continuously monitoring the magnetic field intensity of the permanent magnet ring 12 and synchronously uploading the data to the aircraft anti-skid braking system through the electrical connector 10 and then transferring it to the aircraft management computer, it provides data support for preventive maintenance decisions, reduces the inspection and disassembly verification time of ground crew, and avoids faults such as anti-skid failure of the aircraft anti-skid braking system caused by magnetic pole degradation through early warning information.

[0075] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.

Claims

1. A full-speed range aircraft wheel speed sensor, comprising a coaxially arranged rotor assembly and a stator assembly, wherein the rotor assembly is fixed to the wheel bearing end cover, and the stator assembly is fixed to the inner edge of the wheel axle; characterized in that: The rotor assembly includes a permanent magnet ring, which is mounted on the wheel bearing end cover through a support seat; the stator assembly includes a Hall circuit board, and two Hall circuit boards are symmetrically mounted on opposite sides of the inner edge of the wheel shaft through a support shell; and the axial positions of the permanent magnet ring and the Hall circuit board are the same; The Hall circuit board includes a circuit board and a switch-type Hall chip, a linear Hall chip, and an electrical connector installed thereon. Two switch-type Hall chips form a group, and two linear Hall chips form a group, forming a rectangular array as a whole. The switch-type Hall chip group and the linear Hall chip group are arranged in parallel along the axial direction, with an axial spacing of 5 mm; the offset distance between the two switch-type Hall chips and the offset distance between the two linear Hall chips are both 50% of the width of a single magnetic pole of the permanent magnet ring; the switch-type Hall chip is used to detect the pulse signal when the wheel rotates at high speed, and the linear Hall chip is used to detect the continuous magnetic field signal when the wheel rotates at low speed; and the phase difference between the two signals determines the forward and reverse rotation of the wheel.

2. The full-speed range aircraft wheel speed sensor according to claim 1, characterized in that: The permanent magnet ring is made of samarium cobalt, and its end face is double-pole magnetized, with 36 poles evenly distributed along the circumference, 18 pairs of N and S poles, and a gap between the pole surface and the Hall chip is 2 mm.

3. The full-speed range aircraft wheel speed sensor according to claim 1, characterized in that: The switchable Hall chip is combined with its peripheral circuit to form a switchable Hall monitoring unit, which is used in aircraft high-speed acquisition scenarios; the rising edge or falling edge of the two signals is captured by the pulse capture module of the microcontroller, the time interval between adjacent edges is obtained, and the wheel speed is calculated by combining the longitudinal layout offset of the Hall element and using the relationship between the number of magnetic poles and the mechanical-electrical angle conversion; The linear Hall chip is combined with its peripheral circuit to form a linear Hall monitoring unit, which is used in low-speed aircraft acquisition demand scenarios; the two signals are synchronously acquired through the ADC module of the microcontroller to obtain discrete sinusoidal waveform data; the phase difference between the two signals is calculated through methods such as orthogonal demodulation algorithm and inverse tangent function, and the phase difference is converted into a time interval, and the wheel speed is calculated by combining the longitudinal layout offset of the Hall element and using the relationship between the number of magnetic poles and the mechanical-electrical angle conversion relationship; The operating thresholds of the switch type Hall monitoring unit and the linear Hall monitoring unit are based on the aircraft ground speed of 20 km / h as the dividing point.

4. The full-speed range aircraft wheel speed sensor according to claim 3, characterized in that: The switching mechanism of the switch type Hall monitoring unit and the linear Hall monitoring unit: when the aircraft ground speed approaches the switching threshold, a smooth transition is achieved through a weighted fusion algorithm, and the expression is as follows: V out =w·V linear +(1-w)V switch Where V linear The linear Hall monitoring unit collects the value, V switch is the value collected by the switch type Hall monitoring unit, w is the inertia weight coefficient, V out is the output value after fusion; When the aircraft ground speed v≤18km / h, it completely relies on the linear Hall monitoring unit; when the aircraft ground speed v≥22km / h, it completely relies on the switch Hall monitoring unit; when in the transition range of 18km / h to 22km / h, the weight coefficient gradually relies on the linear Hall monitoring unit as the aircraft ground speed decreases.

5. The full-speed range aircraft wheel speed sensor according to claim 3, characterized in that: The circuit board is embedded in the supporting shell through a slot, and the electrical connector is connected to the circuit board through a pin to achieve dual-redundancy signal output.

6. The full-speed range aircraft wheel speed sensor according to claim 5, characterized in that: The electrical connector outputs two independent square wave signals and two sinusoidal signals. The square wave signal is used for high-speed speed calculation, and the sinusoidal signal is used for low-speed speed calculation. The two signals determine the forward and reverse rotation through the phase difference.

7. The full-speed range aircraft wheel speed sensor according to claim 6, characterized in that: The switch type Hall monitoring unit captures two square wave signals with a phase difference of 1 / 4 period in real time through the pulse capture module of the microcontroller in the circuit board, monitors the edge trigger timing of the two signals in real time, observes the edge sequence of the pilot signal, and identifies the forward and reverse rotation direction of the wheel; the specific judgment process is as follows: When the edge of signal A appears earlier than the edge of signal B, and the time difference is about 1 / 4 cycle, it is judged as forward rotation; when the edge of signal B appears earlier than the edge of signal A, and the time difference is about 3 / 4 cycle, it is judged as reverse rotation.

8. The full-speed range aircraft wheel speed sensor according to claim 6, characterized in that: The linear Hall monitoring unit synchronously samples the two sinusoidal signals through the high-resolution ADC module of the microcontroller in the circuit board, and determines the forward and reverse rotation direction of the wheel by observing the timing sequence of the zero crossing points of the two signals; the specific judgment process is: when the zero crossing point of signal C appears before that of signal D, it is judged as forward rotation; otherwise, it is judged as reverse rotation.

9. The full-speed range aircraft wheel speed sensor according to claim 1, characterized in that: The support shell is a circular ring structure, and has notches on both sides of the circumference symmetrically, which are used to install two Hall circuit boards respectively.

10. A speed measurement method of the full-speed range aircraft wheel speed sensor according to any one of claims 1 to 9, characterized in that: When the aircraft ground speed is ≥22km / h, the switch type Hall monitoring unit is enabled, and the square wave signal output by it is calculated through the pulse time interval to obtain the rotation speed; When the aircraft ground speed is in the transition range of 18km / h to 22km / h, the switch type Hall monitoring unit and the linear Hall monitoring unit operate in parallel, and a smooth transition is achieved through a weighted fusion algorithm; When the aircraft ground speed is ≤18km / h, the linear Hall monitoring unit is enabled, and the sinusoidal signal output by it is converted into analog and digital and the electrical angle is calculated to obtain the rotation speed; The direction of the phase difference between the two signals is used to determine whether the wheel is rotating forward or reverse.

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