An automatic calibration method for switching points based on landing gear inductive proximity sensors

Abstract

This invention discloses an automatic calibration method for the transition point based on a landing gear inductive proximity sensor, comprising the following steps: S1, establishing a standard variation curve for the proximity sensor, and obtaining the distance between the proximity transition point and the fully approached attitude point, and the hysteresis distance between the far-from-the-transition point and the proximity transition point under the standard installation position of the proximity sensor; S2, obtaining the inductance value of the fully approached attitude point, and obtaining the offset between the standard reference point and the offset reference point based on the inductance value of the fully approached attitude point and the standard variation curve; S3, obtaining the offset variation curve based on the offset between the standard reference point and the offset reference point; S4, calibrating the transition point of the proximity sensor based on the offset variation curve, the distance between the proximity transition point and the fully approached attitude point under the standard installation position of the proximity sensor, and the hysteresis distance between the far-from-the-transition point and the proximity transition point.

Description

Technical Field

[0001] This invention belongs to the field of proximity sensor position detection technology, specifically relating to an automatic calibration method for the transition point based on a landing gear inductive proximity sensor. Background Technology

[0002] Currently, inductive proximity sensors are primarily used in aircraft landing gear position detection and retraction control units for position detection, and a fixed inductance value is typically set for the proximity sensor transition point. The advantage of this method is its simplicity and ease of implementation; the landing gear control system only needs to collect the current real-time inductance value and compare it with the set standard transition point inductance value to determine the current landing gear attitude. Using the landing gear's fully approached attitude point as a reference point, a proximity sensor inductance change characteristic curve is established. If the proximity sensor's position shifts, the reference point of the characteristic curve will change, resulting in a shift in the actual physical position corresponding to the standard transition point inductance value.

[0003] In practical applications, proximity sensors are subject to human error during installation on the landing gear structure, and significant vibrations often occur during landing gear retraction and extension. These environmental factors frequently cause proximity sensor position shifts. Continuing to use a fixed standard inductance value as the switching point under these circumstances will lead to a deviation in the landing gear attitude switching point, potentially causing the landing gear retraction and extension control unit to misidentify the landing gear attitude switching state. When a proximity sensor switching point shift occurs, manual recalibration and reinstallation are often performed. This method is not only inefficient but can also affect flight missions and flight safety in special environments. Currently, there are no effective measures to address this problem.

[0004] In traditional landing gear position detection systems, the proximity sensor is set with a fixed inductance value as the switching point. When the proximity sensor is offset from its installation position on the aircraft or when the landing gear vibrates and causes the sensor position to shift, the switching point will also shift accordingly. This will cause the landing gear to shift its state switching position during the retraction and extension process, which may lead to the landing gear control system misidentifying the landing gear state. Summary of the Invention

[0005] To address the aforementioned shortcomings in the prior art, this invention provides an automatic calibration method for the switching point based on a landing gear inductive proximity sensor, which solves the problem of switching point offset caused by sensor installation errors, position shifts due to the operating environment, and other factors.

[0006] To achieve the aforementioned objectives, the present invention employs the following technical solution: an automatic calibration method for the transition point based on a landing gear inductive proximity sensor, comprising the following steps:

[0007] S1. Establish the standard change curve of the proximity sensor, and obtain the distance between the proximity transition point and the fully approached attitude point and the hysteresis distance between the distance transition point and the proximity transition point under the standard installation position of the proximity sensor.

[0008] S2. Obtain the inductance value of the point that is close to the attitude point. Based on the inductance value of the point that is close to the attitude point and the standard change curve, obtain the offset between the standard reference point and the offset reference point.

[0009] S3. Obtain the change curve after offset based on the offset between the standard reference point and the offset reference point;

[0010] S4. Based on the change curve after offset, the distance between the proximity transition point and the fully approach attitude point under the standard installation position of the proximity sensor, and the hysteresis distance between the far transition point and the proximity transition point, calibrate the transition point of the proximity sensor.

[0011] Further: S1 specifically refers to:

[0012] Install the proximity sensor in a standard position, take the fully approach attitude point as the origin of the coordinate system, establish a standard change curve for the proximity sensor, obtain the distance between the proximity transition point and the fully approach attitude point based on the inductance value of the proximity transition point, and obtain the hysteresis distance between the distance transition point and the proximity transition point based on the inductance value of the distance transition point.

[0013] Specifically, the standard variation curve is a function curve of the inductance value of the standard proximity sensor versus the displacement distance.

[0014] Further: In step S2, the method for obtaining the inductance value that is perfectly close to the attitude point is as follows:

[0015] Obtain the proximity sensor inductance value when the landing gear is retracted to the fully approached attitude point, and use it as the inductance value at the fully approached attitude point.

[0016] Further: In step S4, the method for calibrating the transition point of the proximity sensor is specifically as follows:

[0017] Based on the change curve after offset, the distance between the proximity transition point and the fully approach attitude point under the standard installation position of the proximity sensor, and the hysteresis distance between the far-from transition point and the proximity transition point, the actual proximity transition point inductance value and the far-from transition point inductance value after offset are calculated. Based on the actual proximity transition point inductance value and the far-from transition point inductance value after offset, the actual proximity transition point and the far-from transition point after offset are obtained, and the transition point of the proximity sensor is calibrated.

[0018] Further: Calculate the actual proximity switching point inductance value L after the offset. B The specific expression is:

[0019]

[0020] In the formula, d2 is the curve showing the change after offset, and d2 is the distance between the proximity transition point and the full proximity attitude point in the standard installation position of the proximity sensor.

[0021] Further: Calculate the actual inductance value L far from the switching point after the offset. C The specific expression is:

[0022]

[0023] In the formula, d3 is the hysteresis distance between the far-from conversion point and the near-from conversion point in the standard installation position of the proximity sensor.

[0024] The beneficial effects of this invention are as follows:

[0025] (1) The breakthrough of this invention compared with the prior art lies in the fact that: in traditional landing gear position detection systems, the proximity sensor is set with a fixed inductance value as the switching point. When the proximity sensor's installation position on the aircraft shifts, the switching point will also shift accordingly, causing the landing gear's state switching position to shift during the retraction and extension process, which may lead to the landing gear control system misidentifying the landing gear state. The automatic switching point calibration method proposed in this invention can automatically calibrate the shifted inductance value of the switching point after the proximity sensor's installation position shifts, while ensuring that the physical position of the switching point remains unchanged. Thus, even when the sensor's installation position shifts, or the sensor's position shifts due to landing gear vibration, the physical position of the landing gear attitude state switching point remains constant.

[0026] (2) The method proposed in this invention only needs to detect the inductance value after the landing gear is fixed to the fully approaching position point to realize the calibration of the transition point. The landing gear control system can calibrate the offset in real time according to the fixed point inductance value after the landing gear is retracted and positioned each time, thereby realizing the automatic calibration of the transition point of the proximity sensor. Attached Figure Description

[0027] Figure 1 This is a flowchart of an automatic calibration method for the switching point based on a landing gear inductive proximity sensor, according to the present invention.

[0028] Figure 2 This is a schematic diagram of the proximity sensor switching point deviation of the present invention.

[0029] Figure 3 This is a schematic diagram of the function curve of inductance versus displacement of the proximity sensor of the present invention.

[0030] Figure 4 This is a schematic diagram of the proximity sensor switching point calibration of the present invention. Detailed Implementation

[0031] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0032] like Figure 1 As shown, in one embodiment of the present invention, an automatic calibration method for the transition point based on a landing gear inductive proximity sensor includes the following steps:

[0033] S1. Establish the standard change curve of the proximity sensor, and obtain the distance between the proximity transition point and the fully approached attitude point and the hysteresis distance between the distance transition point and the proximity transition point under the standard installation position of the proximity sensor.

[0034] S2. Obtain the inductance value of the point that is close to the attitude point. Based on the inductance value of the point that is close to the attitude point and the standard change curve, obtain the offset between the standard reference point and the offset reference point.

[0035] S3. Obtain the change curve after offset based on the offset between the standard reference point and the offset reference point;

[0036] S4. Based on the change curve after offset, the distance between the proximity transition point and the fully approach attitude point under the standard installation position of the proximity sensor, and the hysteresis distance between the far transition point and the proximity transition point, calibrate the transition point of the proximity sensor.

[0037] Specifically, S1 is:

[0038] Install the proximity sensor in a standard position, take the fully approached attitude point A as the origin of the coordinate system, establish the standard change curve of the proximity sensor, obtain the distance between the proximity transition point and the fully approached attitude point based on the inductance value of the proximity transition point, and obtain the hysteresis distance between the distance transition point and the proximity transition point based on the inductance value of the distance transition point.

[0039] Specifically, the standard variation curve is a function curve of the inductance value of the standard proximity sensor versus the displacement distance.

[0040] In this embodiment, the principle of the automatic conversion point calibration method of the present invention is as follows:

[0041] A schematic diagram of the proximity sensor switching point deviation of the present invention is shown below. Figure 2As shown, X1 is the standard proximity sensor mounting position, X2 is the actual proximity sensor mounting position with installation errors, and the traditional proximity sensor switching point uses a fixed inductance value as the switching point, which is the approach state switching point after offset. C' is the distance state switching point after offset, and D is the completely distance attitude point, used to indicate that the landing gear is in a completely distanced state. Figure 2 In the standard proximity sensor installation position X1, the proximity switching point B and the distance switching point C are determined by the inductance value, that is, the inductance value at the proximity switching point is [value missing]. The inductance value away from the switching point is Establish a coordinate system with the point A that is almost perfectly close to the attitude point as the origin, as follows: Figure 3 The curve showing the change between displacement distance and proximity sensor inductance value is shown. The corresponding standard installation position is close to the conversion point at a distance of 100 km. When the actual installation position of the proximity sensor deviates from the standard position The corresponding actual distance to the conversion point is d2, and the displacement deviation between the two is Δd2. Similarly, the displacement deviation between the points far from the conversion point is Δd3.

[0042] In practical use, proximity sensors are subject to installation errors. Using a traditional fixed inductance value as the switching point can cause switching point drift, which may lead to false alarms about the attitude transition status during landing gear retraction and extension. Therefore, it is necessary to ensure that the proximity switching point B and the distance switching point C remain fixed in the actual use scenario to achieve automatic calibration of the proximity sensor switching point.

[0043] In step S2, the method for obtaining the inductance value that is very close to the attitude point is as follows:

[0044] Obtain the proximity sensor inductance value when the landing gear is retracted to the fully approached attitude point, and use it as the inductance value at the fully approached attitude point.

[0045] In this embodiment, as Figure 4 As shown, Δd1 is the difference between the actual installation position and the standard position of the proximity sensor, where:

[0046]

[0047] In the formula, d1 represents the distance between the proximity sensor and the fully approached attitude point in the standard mounting position, and d2 represents the distance between the proximity sensor and the fully approached attitude point in the actual mounting position. Δd1 > 0 indicates that the actual mounting position is closer to point A relative to the standard position, and Δd1 < 0 indicates that the actual mounting position is farther from point A relative to the standard position. To ensure that the conversion point remains unchanged after the actual mounting position shifts, i.e.:

[0048]

[0049] When the actual installation position of the proximity sensor shifts, the inductance change curve changes accordingly in the original coordinate system. In practical applications, directly measuring the installation offset Δd1 introduces human measurement errors, and since the proximity sensor is installed inside the landing gear structure, it is difficult to achieve accurate measurement. Therefore, this invention directly measures the proximity sensor inductance value L0 when the landing gear is retracted to the fully approached attitude point A through the landing gear control system, and uses it as the inductance value of the fully approached attitude point.

[0050] According to the standard variation curve The difference between the offset origin and the origin in the standard coordinate system can be indirectly derived, i.e., the offset d0 between the standard reference point and the offset reference point, Δd1 = -d0. The inductance change curve after offset is the inductance change curve under the standard installation position of the proximity sensor. Let function That is, the inductance change curve after offset is like Figure 3 The curve showing the inductance change after the proximity sensor's installation position is offset is shown.

[0051] The actual inductance value at the proximity switching point after offset is Where d2 is the set standard distance between the approach transition point and the fully approach pose point. The actual inductance value after offset from the transition point is... Where d3 is the set hysteresis distance between the near-conversion point and the far-conversion point.

[0052] In step S4, the method for calibrating the transition point of the proximity sensor is as follows:

[0053] Based on the change curve after offset, the distance between the proximity transition point and the fully approach attitude point under the standard installation position of the proximity sensor, and the hysteresis distance between the far-from transition point and the proximity transition point, the actual proximity transition point inductance value and the far-from transition point inductance value after offset are calculated. Based on the actual proximity transition point inductance value and the far-from transition point inductance value after offset, the actual proximity transition point and the far-from transition point after offset are obtained, and the transition point of the proximity sensor is calibrated.

[0054] Calculate the actual proximity switching point inductance value L after the offset. B The specific expression is:

[0055]

[0056] In the formula, d2 is the curve showing the change after offset, and d2 is the distance between the proximity transition point and the full proximity attitude point in the standard installation position of the proximity sensor.

[0057] Calculate the actual inductance value L far from the switching point after the offset. C The specific expression is:

[0058]

[0059] In the formula, d3 is the hysteresis distance between the far-from conversion point and the near-from conversion point in the standard installation position of the proximity sensor.

[0060] The beneficial effects of this invention are as follows: Compared with the prior art, the breakthrough of this invention lies in the fact that in traditional landing gear position detection systems, the proximity sensor is set with a fixed inductance value as the switching point. When the proximity sensor's installation position on the aircraft shifts, the switching point will also shift accordingly, causing the landing gear's state switching position to shift during the retraction and extension process. This may lead to the landing gear control system misidentifying the landing gear state. The automatic switching point calibration method proposed in this invention can automatically calibrate the shifted inductance value of the switching point after the proximity sensor's installation position shifts, while ensuring that the physical position of the switching point remains unchanged. Therefore, even when the sensor's position shifts due to factors such as sensor installation position shift or landing gear vibration causing sensor position shift, the physical position of the landing gear attitude state switching point remains constant.

[0061] The method proposed in this invention only needs to detect the inductance value after the landing gear is in position and fully close to the pose point to achieve the calibration of the transition point. The landing gear control system can calibrate the offset in real time according to the inductance value of the fixed point after each landing gear retraction and positioning, thereby realizing the automatic calibration of the transition point of the proximity sensor.

[0062] In the description of this invention, it should be understood that the terms "center," "thickness," "upper," "lower," "horizontal," "top," "bottom," "inner," "outer," and "radial," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying the relative importance or the number of technical features implicitly specified. Therefore, a feature defined by "first," "second," and "third" may explicitly or implicitly include one or more of that feature.

Claims

1. A method of automatic calibration of a transition point for an inductive proximity sensor based on a landing gear, characterized in that, Includes the following steps: S1. Establish the standard change curve of the proximity sensor, and obtain the distance between the proximity transition point and the fully approached attitude point and the hysteresis distance between the distance transition point and the proximity transition point under the standard installation position of the proximity sensor. S2. Obtain the inductance value of the point that is close to the attitude point. Based on the inductance value of the point that is close to the attitude point and the standard change curve, obtain the offset between the standard reference point and the offset reference point. S3. Obtain the change curve after offset based on the offset between the standard reference point and the offset reference point; S4. Based on the change curve after offset, the distance between the proximity transition point and the fully approach attitude point under the standard installation position of the proximity sensor, and the hysteresis distance between the far transition point and the proximity transition point, calibrate the transition point of the proximity sensor.

2. The method of automatic calibration of the transition point of a landing gear inductive proximity sensor according to claim 1, characterized in that, Specifically, S1 is: Install the proximity sensor in a standard position, take the fully approach attitude point as the origin of the coordinate system, establish a standard change curve for the proximity sensor, obtain the distance between the proximity transition point and the fully approach attitude point based on the inductance value of the proximity transition point, and obtain the hysteresis distance between the distance transition point and the proximity transition point based on the inductance value of the distance transition point. Specifically, the standard variation curve is a function curve of the inductance value of the standard proximity sensor versus the displacement distance.

3. The automatic calibration method for the transition point based on the landing gear inductive proximity sensor according to claim 1, characterized in that, In step S2, the method for obtaining the inductance value that is very close to the attitude point is as follows: Obtain the proximity sensor inductance value when the landing gear is retracted to the fully approached attitude point, and use it as the inductance value at the fully approached attitude point.

4. The automatic calibration method for the transition point based on the landing gear inductive proximity sensor according to claim 1, characterized in that, In step S4, the method for calibrating the transition point of the proximity sensor is as follows: Based on the change curve after offset, the distance between the proximity transition point and the fully approach attitude point under the standard installation position of the proximity sensor, and the hysteresis distance between the far-from transition point and the proximity transition point, the actual proximity transition point inductance value and the far-from transition point inductance value after offset are calculated. Based on the actual proximity transition point inductance value and the far-from transition point inductance value after offset, the actual proximity transition point and the far-from transition point after offset are obtained, and the transition point of the proximity sensor is calibrated.

5. The automatic calibration method for the transition point based on the landing gear inductive proximity sensor according to claim 4, characterized in that, calculating the actual proximity transition point inductance value L after the offset B The expression for the actual proximity transition point inductance value L after the offset is given by: In the formula, d2 is the curve showing the change after offset, and d2 is the distance between the proximity transition point and the full proximity attitude point in the standard installation position of the proximity sensor.

6. The automatic calibration method for the transition point based on the landing gear inductive proximity sensor according to claim 5, characterized in that, calculating the actual remote conversion point inductance value L after the offset C The expression is specifically: In the formula, d3 is the hysteresis distance between the far-from conversion point and the near-from conversion point in the standard installation position of the proximity sensor.

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