Landing gear proximity sensor state detection method and system based on inductance value change rate

Abstract

The present application relates to the technical field of proximity sensor state detection, and discloses a landing gear proximity sensor state detection method and system based on inductance value change rate. The method obtains current and historical T period inductance values of the landing gear proximity sensor, constructs an inductance value vector, and generates an inductance value change rate vector based on the difference between adjacent sampling period inductance values. The number of elements in the change rate vector falling into the proximity determination interval group and the number of elements falling into the away determination interval group are counted respectively, and the proximity state determination condition and the away state determination condition are determined in combination with the current period inductance value and the inductance value threshold. When the proximity condition is met, the proximity state is output, when the away condition is met, the away state is output, and when neither condition is met, the last determination state is maintained. The scheme is used for landing gear position detection, can reduce the dependence of fixed inductance value conversion points on installation precision and in-place position, improve state output stability, maintenance adaptability and in-place vicinity anti-jitter capability, and is suitable for deployment control, position indication and in-place monitoring.

Description

Technical Field

[0001] This invention relates to the field of proximity sensor condition detection technology, and more specifically to a landing gear proximity sensor condition detection method and system based on the rate of change of inductance value. Background Technology

[0002] The landing gear position detection and retraction control system uses landing gear proximity sensors to detect the position status of each structure of the landing gear, performs logical processing based on the position status, and outputs landing gear retraction control signals. The status acquisition of the proximity sensors is directly related to the landing gear retraction function, position status indication, and positioning status monitoring, therefore, stable and reliable proximity and distance status determination results are required.

[0003] 1. Landing gear proximity sensor status detection typically uses a fixed inductance value transition point. The control system compares the collected proximity sensor inductance value with the preset transition point. When the collected inductance value is higher than the proximity transition point, a proximity state is determined; when the collected inductance value is lower than the distance transition point, a distance state is determined. This method is simple, but the state switching is highly dependent on the physical location of the transition point.

[0004] 2. During long-term use and maintenance of the landing gear, the sensor installation position, the gap between the target and the sensor sensing surface, and the structural positioning may shift. If the fixed inductance value conversion point is still relied upon, the landing gear may not stably cross the conversion point when it moves into position, making the status output more sensitive to installation accuracy and the structural position after maintenance.

[0005] 3. Mechanical vibration and sampling jitter may also exist near the landing gear in position. Single points near the fixed transition point are prone to boundary flipping, making it difficult to fully reflect the target's movement direction and continuous changing trend relative to the sensor's sensing surface.

[0006] 4. While basic solutions such as single-point comparison and inductive signal processing exist in related technologies, a complete state determination mechanism for landing gear proximity sensors has not yet been formed. In particular, the combination relationship between continuous window rate of change statistics, approach / distance bidirectional interval counting, current cycle inductance value conditions, and the maintenance of the previous determination state still has room for improvement. Summary of the Invention

[0007] When landing gear proximity sensors use a fixed inductance value transition point for state determination, they are highly dependent on sensor installation accuracy, structural maintenance changes, and the stability of the landing point in crossing the transition point. To address this issue, this invention provides a landing gear proximity sensor state detection method and system based on the inductance value change rate.

[0008] To achieve the above-mentioned objectives, the present invention provides the following technical solution.

[0009] A landing gear proximity sensor state detection method based on the rate of change of inductance includes: Obtain the current and historical T-cycle inductance values ​​of the landing gear proximity sensor and construct an inductance value vector; Generate an inductance rate of change vector based on the inductance value vector; The proximity determination condition is determined by the number of elements in the inductance value change rate vector that fall into the proximity determination interval group and the current period inductance value. The distance determination condition is determined by the number of elements in the inductance value change rate vector that fall into the distance determination interval group and the current period inductance value. When the approach state determination condition is met, the approach state is output; when the distance state determination condition is met, the distance state is output; when neither the approach state determination condition nor the distance state determination condition is met, the previous determination state is maintained.

[0010] Preferably, the inductance value vector includes the current period inductance value and multiple historical period inductance values ​​arranged in chronological order of sampling time, and the inductance value change rate vector includes a sequence of difference values ​​between inductance values ​​of adjacent sampling periods.

[0011] Preferably, the proximity determination condition includes: the number of elements in the inductance value change rate vector that fall into at least one proximity change rate sub-interval in the proximity determination interval group is not less than a quantity threshold, and the current period inductance value is greater than the inductance value threshold.

[0012] Preferably, the distance-away state determination condition includes: the number of elements in the inductance value change rate vector that fall into at least one distance-away change rate sub-interval in the distance-away determination interval group is not less than a quantity threshold, and the current period inductance value is less than the inductance value threshold.

[0013] Preferably, the proximity determination interval group includes at least one proximity rate of change sub-interval, which is set based on the trend of inductance value change when the target moves from far to near the sensor sensing surface; the distance determination interval group includes at least one distance rate of change sub-interval, which is set based on the trend of inductance value change when the target moves from near to far the sensor sensing surface.

[0014] Preferably, the proximity determination interval group, the distance determination interval group, the quantity threshold, and the inductance value threshold are preset based on physical sensor calibration data. The physical sensor calibration data includes the relationship between the target gap and the inductance value, as well as the rate of change trend obtained by the difference in inductance values ​​between adjacent calibration points.

[0015] Preferably, the approaching state is maintained when the previous determination state is an approaching state and the distance determination state condition is not met, and the distance determination state is maintained when the previous determination state is a distanced state and the approach determination state condition is not met.

[0016] Preferably, the approach state or the distance state is output to at least one of landing gear retraction control, position indication, or position status monitoring.

[0017] This invention also discloses a landing gear proximity sensor state detection system based on the rate of change of inductance, comprising: The inductance value acquisition module is configured to acquire the current and historical T-cycle inductance values ​​of the landing gear proximity sensor and construct an inductance value vector; The rate of change calculation module is configured to generate an inductance value rate of change vector based on the inductance value vector. The state determination module is configured to determine the approaching state determination condition by the number of elements in the inductance value change rate vector that fall into the approaching determination interval group and the current period inductance value, and to determine the far-away state determination condition by the number of elements in the inductance value change rate vector that fall into the far-away determination interval group and the current period inductance value. The status output module is configured to output a near state when the near state determination condition is met, output a far state when the far state determination condition is met, and maintain the previous determination state when neither the near state determination condition nor the far state determination condition is met.

[0018] Preferably, the sensor status detection system is located in the landing gear retraction and extension control system, or in the control unit that is communicatively connected to the landing gear proximity sensor.

[0019] Beneficial effects Compared with the prior art, the beneficial effects of the present invention are reflected in the following aspects.

[0020] 1. This invention constructs a window using the current and historical T-cycle inductance values ​​and generates an inductance value change rate vector. The state determination is no longer solely determined by whether the current cycle inductance value crosses the transition point, but rather by utilizing the continuous inductance value change trend caused by the target gap change during landing gear movement.

[0021] 2. This invention employs both near-judgment interval groups and far-judgment interval groups, and counts the number of elements falling into the corresponding interval in the inductance value change rate vector. The requirement for consistency of multiple elements within this window helps to reduce the impact of occasional sampling jitter on state switching.

[0022] 3. This invention uses the rate of change interval group count and the current period inductance value condition together for approach state determination and distance state determination, avoiding reliance on the rate of change trend or the current period inductance value alone, so that the state output is simultaneously constrained by the motion direction trend and the current period inductance value boundary. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating a landing gear proximity sensor state detection method based on inductance value change rate provided in a preferred embodiment of the present invention. Figure 2 This is a schematic diagram of a landing gear proximity sensor state detection system based on the rate of change of inductance value provided in a preferred embodiment of the present invention. Figure 3 This is a schematic diagram illustrating the relationship between the target gap and the inductance value in a preferred embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the trend of the inductance value change rate when the target moves from far to near, according to a preferred embodiment of the present invention. Figure 5 This is a schematic diagram illustrating the trend of the inductance value change rate as the target moves from near to far, according to a preferred embodiment of the present invention. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are used to illustrate the technical solution of the present invention and do not limit the present invention to a specific sensor model, control unit model or parameter value.

[0025] Example 1 like Figure 1 As shown, this embodiment is executed in a scenario where a landing gear proximity sensor works in conjunction with a landing gear retraction and extension control system. The landing gear proximity sensor is used to detect the positional state of the landing gear structure. When the landing gear moves, the target relative to the sensor sensing surface changes in distance, moving from far to near or from near to far. The control unit reads the inductance value of the landing gear proximity sensor according to the sampling period and outputs the approach or departure status according to the following steps.

[0026] In practical deployment, proximity sensors can be installed near the landing gear position detection point. The target moves with the landing gear mechanism, causing a change in the gap relative to the sensor's sensing surface. The inductance value received by the control unit reflects this gap change. This inductance value is not used as the sole basis for state switching, but rather is included in a data window consisting of the current and historical periods.

[0027] The state detection process in this embodiment is executed cyclically in each sampling cycle. After the inductance value of the current cycle enters the window, the control unit generates an inductance value change rate vector, and then performs determinations in both the approach and departure states. The output results can be sent to landing gear retraction control, position indication, or position monitoring logic. The above logic links are used to illustrate the control applications of the state detection results and do not limit the specific control unit model or interface type.

[0028] The control unit can use the inductance value output by the proximity sensor as a periodic input. Before entering the state determination, this input is first organized into a data window with a clear time sequence. Each inductance value within the window corresponds to a sampling period, which facilitates maintaining time direction consistency in subsequent differential calculations.

[0029] Step S1: Obtain the current and historical T-cycle inductance values ​​of the landing gear proximity sensor and construct the inductance value vector.

[0030] In this step, the control unit obtains the current period inductance value l during the current sampling period. t The system reads the historical inductance values ​​from previous sampling periods. These historical inductance values ​​are arranged in chronological order of sampling time, bringing the newer historical periods closer to the sampling time. t The earlier historical cycle is located at the end of the window.

[0031] In one specific embodiment, the inductance vector L is represented by the following formula:

[0032] in, Represents the inductance value vector; Indicates the inductance value for the current cycle; This represents the inductance value of the previous sampling period; This represents the inductance value from the two sampling cycles preceding the current cycle; This represents the historical period inductance value at the end of the current window; This represents the length parameter of the historical sampling window.

[0033] During periodic operation, the new current cycle inductance value is written to the window header. Historical cycle inductance values ​​within the original window are updated sequentially according to sampling time, maintaining their chronological relationship relative to the current cycle. Historical values ​​at the end of the window are no longer considered in the current cycle's determination after being updated. This sliding update method ensures that the inductance value vector for each cycle corresponds to the current landing gear motion state.

[0034] T is used to limit the number of historical periods involved in trend judgment. The specific value of T can be predetermined based on the sensor sampling period, landing gear movement speed, and state switching response requirements. In some preferred embodiments, T can be selected as 10 periods; this value is used to describe the setting method of the window length and does not limit the present invention to a specific control unit or a specific landing gear movement speed.

[0035] When the window is updated, the control unit can save the previous decision state corresponding to the current window. This previous decision state is not involved in the calculation of the inductance value vector L, but it is used for state maintenance in step S5. In this way, the data window is used to describe the change in inductance value, and the previous decision state is used to describe the history of state output; the two play different roles in the control flow.

[0036] Before the window is formed, if the historical inductance values ​​collected are insufficient to form the required inductance value vector, the control unit continues to collect inductance values ​​from subsequent sampling periods. Once the inductance value vector meets the window length requirement, subsequent rate of change calculations and state determination are performed. This process ensures the integrity of the data window involved in the determination and does not alter the switching rules between near and far states.

[0037] Step S2: Generate an inductance rate of change vector based on the inductance value vector.

[0038] In this step, the control unit performs differential analysis on the inductance values ​​of adjacent sampling periods in the inductance value vector L to obtain the inductance value change rate vector L'. This vector is used to express the trend of inductance value change caused by the change in target gap during landing gear movement.

[0039] In one specific embodiment, the inductance rate of change vector L' is represented by the following formula: ; Where L' represents the inductance rate vector; This represents the difference between the current inductance value and the inductance value in the previous sampling period. This represents the difference between the previous sampling period and the sampling period before that. This represents the difference between the inductance values ​​of two adjacent sampling periods at the end of the window.

[0040] The aforementioned differential value sequence reflects the change in inductance value between adjacent sampling periods. When the sampling period is fixed or can be considered fixed, the differential value can serve as a representation of the rate of change of inductance value. Compared to comparing the inductance value of the current period alone, the differential value sequence can reflect the direction and continuity of inductance value change over multiple periods. The determination of whether the state is close to or far from the current period is jointly determined by this trend and the inductance value of the current period.

[0041] In this embodiment, the inductance value change rate vector L' is represented by the difference value sequence between inductance values ​​in adjacent sampling periods, and is used for subsequent approach and distance state determination.

[0042] Step S3: Determine the proximity state determination condition based on the number of elements in the inductance value change rate vector that fall into the proximity determination interval group and the current period inductance value.

[0043] like Figure 3 As shown, there is a relationship between the target gap and the inductance value as the gap changes. When the target moves closer to the sensor sensing surface from a distance, the sensor inductance value increases as the gap decreases. Based on this relationship and the rate of change trend obtained from the difference in inductance values ​​between adjacent calibration points, proximity judgment interval groups, inductance value thresholds, and quantity thresholds can be preset.

[0044] like Figure 4 As shown, when the target moves from far to near, the rate of change of inductance exhibits a trend that matches the approach process. The closer the target is to the sensor's sensing surface, the more significant the change in inductance. When the target moves to near the limit position, the gap tends to stabilize, and the rate of change of inductance tends to zero. Mechanical vibration and sampling jitter may exist near the target's position, and a single rate of change falling within a certain range is insufficient to stably represent the approach state.

[0045] In this embodiment, the proximity determination interval group may include at least one proximity rate of change sub-interval. The control unit counts the number of elements in the inductance value change rate vector L' that fall into any proximity rate of change sub-interval in the proximity determination interval group, and compares this number of elements with a quantity threshold ρ. Simultaneously, the control unit determines the current period inductance value l. t Is it greater than the inductance threshold θ?

[0046] The proximity judgment interval group is used to filter elements with a rate of change that matches the trend of movement from far to near. The quantity threshold ρ is used to require a sufficient number of trend-consistent elements within the window. The inductance value threshold θ is used to constrain the judgment boundary that the inductance value of the current cycle has entered the proximity side. The three work together to avoid making state switching based on the instantaneous change of a single sampling point.

[0047] When the number of elements in the inductance rate of change vector L' that fall into the proximity judgment interval group is not less than the quantity threshold ρ, the change trend within the window meets the proximity direction requirement. Current period inductance value l t When the inductance value is greater than the inductance threshold θ, the current cycle inductance value meets the requirement of approaching the side boundary. When both requirements are met simultaneously, the proximity state determination condition is satisfied.

[0048] The proximity judgment interval group, quantity threshold ρ, and inductance value threshold θ can be preset based on the relationship between the target gap and the inductance value. This can be achieved by utilizing... Figure 3 The gap-inductance trend shown, and Figure 4 The trend of the rate of change from far to near is shown. Each parameter is used to express the trend range and the judgment boundary, and can be fine-tuned according to the physical calibration data and actual working conditions. This embodiment does not impose further limitations.

[0049] Regarding the parameter relationships, one or more sub-intervals of the rate of change in the proximity judgment interval group define the screening range of elements with the rate of change in the proximity direction. ρ defines the number of elements within the window that need to meet this screening range. θ defines the state boundary of the current period inductance value. This hierarchical setting avoids mixing trend judgment, quantity statistics, and the current period inductance value boundary into a single threshold comparison.

[0050] Step S4: Determine the distance determination condition based on the number of elements in the inductance value change rate vector that fall into the distance determination interval group and the current period inductance value.

[0051] like Figure 5 As shown, the sensor inductance gradually decreases as the target moves away from the sensor's sensing surface. The further the target moves away from the sensor's sensing surface, the greater the rate of change in inductance, matching the trend of the moving away process. When the target moves to a position where it is completely detached, the inductance tends to be at a low level, and the rate of change in inductance tends to be zero.

[0052] In this step, the distance determination interval group may include at least one distance rate of change sub-interval. The control unit counts the number of elements in the inductance value change rate vector L' that fall into any distance rate of change sub-interval in the distance determination interval group and compares this number of elements with a quantity threshold ρ. Simultaneously, the control unit determines the current period inductance value l. t Is it less than the inductance threshold θ?

[0053] The distance judgment interval group is used to filter rate-of-change elements that match the trend from near to far. The quantity threshold ρ is still used in the distance judgment to constrain trend consistency within the window. Current period inductance value l t When the inductance value is less than the inductance threshold θ, it indicates that the current cycle inductance value is already at the judgment boundary of the far-away side. This current cycle inductance value condition, together with the count of the rate of change interval group, forms the basis for the judgment of the far-away state.

[0054] When the number of elements in the inductance rate of change vector L' that fall outside the decision interval is greater than the threshold ρ, the trend within the window satisfies the requirement of moving away from the decision interval. Current period inductance value l t When the inductance value is less than the inductance threshold θ, the current cycle inductance value meets the requirement of being far from the side boundary. When both requirements are met simultaneously, the condition for determining the far-from-the-boundary state is satisfied.

[0055] The distance from the judgment interval group, the quantity threshold ρ, and the inductance threshold θ can be preset based on the relationship between the target gap and the inductance value. This can be achieved by utilizing... Figure 3The gap-inductance trend shown, and Figure 5 The trend of the rate of change from near to far is shown. The specific values ​​of the above parameters can be determined based on the preset calibration results, sampling period, and landing gear movement process.

[0056] Regarding the parameter relationships, one or more far-from-the-decision interval sub-intervals within the far-from-the-decision interval group define the filtering range for elements with far-from-the-decision-rate-of-change-direction. This filtering range corresponds to different motion directions than the near-the-decision interval group. The quantity threshold ρ is still used to constrain trend consistency within the window, and the inductance value threshold θ is still used to constrain the inductance value boundary of the current period.

[0057] Step S5: Output the approach state when the approach state determination condition is met, and output the distance state when the distance state determination condition is met.

[0058] If neither the proximity condition nor the distance condition is met, the previous condition is maintained.

[0059] In this step, the control unit updates the sensor status based on the determination results of steps S3 and S4. If the proximity determination condition is met, the control unit outputs a proximity status. If the distance determination condition is met, the control unit outputs a distance status. This output can be used as the sensor status input in the landing gear position status determination.

[0060] If neither the proximity state determination condition nor the distance state determination condition is met, the control unit does not immediately change the current output, but maintains the previous determination state. If the previous determination state is a proximity state and the distance state determination condition is not met, the control unit maintains the proximity state. If the previous determination state is a distance state and the proximity state determination condition is not met, the control unit maintains the distance state.

[0061] When combined with the rate of change interval group counting, this state-holding method can reduce frequent switching caused by vibrations near the position and sampling jitter. This state-holding method is embedded in the state determination process, which consists of the inductance value rate of change vector, bidirectional decision interval group, quantity threshold, and current cycle inductance value condition.

[0062] The output of the approach or departure status can be provided to at least one of landing gear retraction control, position indication, or position status monitoring. The above output purpose is used to illustrate the application of the status detection results in the landing gear control scenario, and does not change the determination rules defined in steps S1 to S5.

[0063] During the periodic execution of this embodiment, the control unit enters the next sampling cycle after completing one state output or state hold. When the next sampling cycle arrives, the new current cycle inductance value enters the inductance value vector, and the historical cycle inductance values ​​in the original window are updated in the order of sampling time. Then, steps S1 to S5 are repeated.

[0064] The aforementioned periodic execution method ensures that the status output is continuously updated as the landing gear moves. Approach direction determination, departure direction determination, and the previous determination status are all completed within the same control flow. This periodic execution method can complete status updates based on existing proximity sensor inductance values.

[0065] Example 2 like Figure 2 As shown, this embodiment provides a landing gear proximity sensor state detection system based on the rate of change of inductance value. This system can be installed in the landing gear retraction and extension control system, or in a control unit that is communicatively connected to the landing gear proximity sensor.

[0066] The sensor state detection system includes an inductance value acquisition module, a rate of change calculation module, a state determination module, and a state output module. Each module can be implemented by software tasks, hardware logic, or a combination of both within the same control unit.

[0067] In the system data stream, the inductance value acquisition module is located on the proximity sensor data input side. The rate of change calculation module is located on the window data processing side. The state determination module is located on the determination parameter calling side. The state output module is located on the control state output side. This data stream is... Figure 2 The module arrows correspond to each other.

[0068] The inductance value acquisition module obtains the current and historical T-cycle inductance values ​​from the landing gear proximity sensor and constructs an inductance value vector. This module receives the current cycle inductance value from the landing gear proximity sensor and maintains a window of historical cycle inductance values ​​arranged in chronological order of sampling time. Once the window meets the length requirement, the inductance value acquisition module outputs the inductance value vector L to the rate of change calculation module.

[0069] In one implementation, the inductance value acquisition module can update the window content in each sampling period. The inductance value of the current period enters the beginning of the window, and the inductance values ​​of previous periods move towards the end of the window with each sampling period. The L output by this module contains both the current state information and the basis of changes over the most recent several historical periods.

[0070] The rate of change calculation module generates an inductance value rate of change vector based on the inductance value vector. This module performs a difference operation on the inductance values ​​in adjacent sampling periods within the inductance value vector L to obtain the inductance value rate of change vector L'. The rate of change calculation module can update L' once in each sampling period, allowing the state determination module to obtain a rate of change window synchronized with the current period.

[0071] The L' output from the rate of change calculation module does not directly indicate whether the state is approaching or far away. This vector serves as intermediate data and enters the state determination module. The state determination module then combines the approach determination interval group, the far-away determination interval group, the quantity threshold ρ, and the inductance value threshold θ to make a determination.

[0072] The L' output by the rate of change calculation module serves as intermediate data. The state determination module uses this intermediate data, along with the proximity determination interval group, the distance from the determination interval group, the quantity threshold ρ, and the inductance value threshold θ, to generate a determination result. The rate of change calculation result only expresses the trend of inductance value change; the state output is still determined by subsequent determination conditions.

[0073] The state determination module determines the approaching state determination condition based on the number of elements in the inductance value change rate vector that fall into the approaching determination interval group and the current period inductance value. The module also determines the far-away state determination condition based on the number of elements in the inductance value change rate vector that fall into the far-away determination interval group and the current period inductance value.

[0074] The state determination module can read pre-set proximity determination interval groups, distance determination interval groups, quantity threshold ρ, and inductance value threshold θ. The condition determination for the proximity direction and distance direction is completed separately within this module. The determination result is output to the state output module, rather than directly replacing the final state output.

[0075] In terms of module execution relationships, the state determination module receives L' and the current cycle inductance value l. t For the approach direction, this module counts the number of elements falling into the approach determination interval group and determines l. t Is it greater than the inductance threshold θ? For the direction of departure, this module counts the number of elements falling into the departure judgment interval group and determines l. t Is it less than the inductance threshold θ?

[0076] The status output module outputs an approach status when the approach status determination condition is met. It outputs a distance status when the distance status determination condition is met. If neither condition is met, the status output module retains the previous determination status. This module can send the output status to the landing gear retraction control logic, position indication logic, or position status monitoring logic.

[0077] The status output module can also save the previous judgment state for use in the next sampling period. If the current period does not form a switching condition for approaching or moving away from the state, the status output module uses the previous judgment state. In this way, the data relationship between system modules remains consistent with the method steps in Embodiment 1.

[0078] In one deployment configuration, the sensor status detection system is integrated into the landing gear retraction and extension control system. The landing gear retraction and extension control system obtains the inductance values ​​from the landing gear proximity sensors and internally performs inductance value vector maintenance, rate of change calculation, status determination, and status output. This deployment configuration allows the landing gear retraction and extension control system to directly obtain the approach or departure status.

[0079] In another deployment method, the sensor status detection system is housed in a control unit that communicates with the landing gear proximity sensors. After completing status detection, this control unit outputs the proximity or distance status to the higher-level landing gear retraction / extension control, position indication, or landing status monitoring device. This deployment method is suitable for scenarios where the sensor status detection function is configured as an independent control logic.

[0080] Regardless of the deployment method used, the system retains the inductance value window, rate of change vector, proximity judgment interval group, distance judgment interval group, quantity threshold, inductance value threshold, and previous judgment state. These data or parameters collectively support the state detection process.

[0081] The module names in the above system embodiments are used to describe the data processing boundaries. The modules can be connected through data caching or data transfer relationships between software tasks. As long as the data flow still sequentially passes through inductance value window construction, inductance value change rate vector generation, bidirectional interval counting, current period inductance value condition judgment, and state maintenance output, the technical solution of this invention can be implemented.

[0082] In the implementation of module merging, the inductance value acquisition module and the rate of change calculation module can be completed by the same cycle task. In the implementation of module splitting, the state determination module and the state output module can also be completed by the determination task and the output task, respectively. The above merging or splitting does not change the processing order of steps S1 to S5 in the method embodiment.

[0083] Experimental Example To verify the correspondence between the target gap change and the inductance value of the proximity sensor, and to determine the proximity judgment interval group, the distance judgment interval group, the inductance value threshold, and the quantity threshold, this experimental example conducted a physical calibration experiment on a proximity sensor sample.

[0084] In this experimental example, the sensing surface of the proximity sensor is positioned opposite the target. At the start of calibration, the target and the sensing surface of the proximity sensor are in a state of full coverage, and the target gap in this state is recorded as 0 mm. Subsequently, the target is gradually moved along an axis away from the sensing surface of the proximity sensor, and the inductance value output by the proximity sensor is recorded at different target gap positions. The unit of inductance value is mH. The correspondence between the target gap and the inductance value obtained during calibration is used to plot... Figure 3 .

[0085] Table 1 below lists Figure 3 The curve showing the relationship between target gap and inductance value is a representative set of calibration data. Figure 3 Based on calibration data ranging from 0 mm to 12 mm, Table 1 lists representative data covering the proximal, near-limit, intermediate, and distal regions.

[0086] Table 1 Representative Calibration Data of Target Gap and Inductance Value

[0087] From Table 1 and Figure 3 It can be seen that in this experimental example, as the target gap increased from 0 mm to 12 mm, the inductance value of the proximity sensor decreased from 9.2232 mH to 4.8773 mH. The inductance value is larger when the target is closer to the proximity sensor sensing surface and smaller when the target is farther away from the proximity sensor sensing surface. This calibration relationship can be used as the basis for determining the inductance threshold θ.

[0088] In this experimental example, the inductance value in the distanced state was also recorded as 4.8725 mH. This distanced state inductance value is a reference inductance value when the target is in a distanced or out-of-target state, and is not used as a reference. Figure 3 The coordinates of the continuous gap curve from 0 mm to 12 mm.

[0089] To obtain the rate of change characterization value used for determining the approach and distance states, the inductance values ​​of adjacent calibration points are differentially processed. Specifically, for the case where the target moves from near to far, the inductance value of the next calibration point is subtracted from the inductance value of the previous calibration point, and the difference result is multiplied by 1000 and characterized in μH; for the case where the target moves from far to near, the corresponding positive differential characterization value is obtained in the opposite direction of movement. Figure 4 The trend of the rate of change of the target as it moves from far to near is shown. Figure 5 The rate of change of the target as it moves from near to far is shown.

[0090] Table 2 below lists the difference characterization values ​​corresponding to some adjacent calibration points. The difference characterization values ​​in Table 2, from nearest to farthest, are used to illustrate... Figure 5 The negative rate of change trend in the data, represented by the difference values ​​from far to near, is used to illustrate... Figure 4 The positive rate of change trend in the data.

[0091] Table 2 Characterization values ​​of inductance difference between adjacent calibration points

[0092] From Table 2, Figure 4 and Figure 5 It can be seen that when the target moves from far to near, the difference in inductance between adjacent calibration points is positive; when the target moves from near to far, the difference in inductance between adjacent calibration points is negative. When the target gap changes slowly or the target is in a stable position, the difference value approaches zero. Therefore, based on the sign and value range of the difference value, we can set up a near-judgment interval group and a far-judgment interval group respectively.

[0093] Based on the above calibration results, in one parameter setting method, the window period T used for trend judgment is set to 10 periods, and the quantity threshold ρ is set to 0.8T. When T is 10 periods, at least 8 rate-of-change elements falling into the corresponding judgment interval group can be used as a trend consistency condition. The quantity threshold ρ is used to require a sufficient number of same-direction rate-of-change elements within the window to reduce the impact of fluctuations in a single sampling point on state switching.

[0094] In this experimental example, based on the difference characterization values ​​shown in Table 2 and Figure 4 The trend of change rate from far to near, as shown, allows the proximity judgment interval group to be set up to include a first proximity change rate sub-interval and a second proximity change rate sub-interval. The first proximity change rate sub-interval is from 10 uH to 15 uH, and the second proximity change rate sub-interval is from 35 uH to 40 uH. Based on the difference characterization values ​​shown in Table 2 and... Figure 5 The trend of change rate from near to far can be set to include a first far-away change rate sub-interval and a second far-away change rate sub-interval, wherein the first far-away change rate sub-interval is -15 uH to -10 uH and the second far-away change rate sub-interval is -40 uH to -35 uH.

[0095] Based on the inductance value distribution shown in Table 1, the inductance threshold θ can be set as an intermediate inductance value. In one setting, the inductance threshold θ is 5 mH; when the inductance value is expressed in uH, θ can be expressed as 5000 uH. Therefore, in the proximity determination, the control unit can make a judgment by combining the number of elements in the proximity determination interval group and whether the current period inductance value is greater than θ; in the distance determination, the control unit can make a judgment by combining the number of elements in the distance determination interval group and whether the current period inductance value is less than θ.

[0096] The parameters T, ρ, proximity judgment interval group, distance judgment interval group, and inductance threshold θ mentioned above are parameter settings obtained based on the calibration data of this experimental example. In practical applications, these parameters can be recalibrated or fine-tuned according to the proximity sensor model, landing gear installation position, target gap range, sampling period, and landing gear movement speed.

[0097] In one implementation, the proximity and distance determination process corresponding to this experimental example is executed under the condition that the proximity sensor is not determined by the independent fault diagnosis logic to be disconnected, stuck, stopped midway, data lost, or otherwise faulty. When the independent fault diagnosis logic outputs a fault result, the control system can stop or disable the proximity and distance determination process in this embodiment.

Claims

1. A landing gear proximity sensor state detection method based on the rate of change of inductance, characterized in that, include: Obtain the current and historical T-cycle inductance values ​​of the landing gear proximity sensor and construct an inductance value vector; Generate an inductance rate of change vector based on the inductance value vector; The proximity determination condition is determined by the number of elements in the inductance value change rate vector that fall into the proximity determination interval group and the current period inductance value. The distance determination condition is determined by the number of elements in the inductance value change rate vector that fall into the distance determination interval group and the current period inductance value. When the approach state determination condition is met, the approach state is output; when the distance state determination condition is met, the distance state is output; when neither the approach state determination condition nor the distance state determination condition is met, the previous determination state is maintained.

2. The landing gear proximity sensor state detection method based on the rate of change of inductance value according to claim 1, characterized in that: The inductance value vector includes the current period inductance value and multiple historical period inductance values ​​arranged in order of sampling time, and the inductance value change rate vector includes a sequence of difference values ​​between inductance values ​​of adjacent sampling periods.

3. The landing gear proximity sensor state detection method based on the rate of change of inductance value according to claim 1, characterized in that: The proximity state determination conditions include: the number of elements in the inductance value change rate vector that fall into at least one proximity change rate sub-interval in the proximity determination interval group is not less than a quantity threshold, and the current period inductance value is greater than the inductance value threshold.

4. The landing gear proximity sensor state detection method based on the rate of change of inductance value according to claim 1, characterized in that: The conditions for determining the distance from the state include: the number of elements in the inductance value change rate vector that fall into at least one distance change rate sub-interval in the distance determination interval group is not less than a quantity threshold, and the current period inductance value is less than the inductance value threshold.

5. The landing gear proximity sensor state detection method based on the rate of change of inductance value according to claim 3 or 4, characterized in that: The proximity determination interval group includes at least one proximity rate of change sub-interval, which is set based on the trend of inductance value change when the target moves from far to near the sensor sensing surface; the distance determination interval group includes at least one distance rate of change sub-interval, which is set based on the trend of inductance value change when the target moves from near to far the sensor sensing surface.

6. The landing gear proximity sensor state detection method based on the rate of change of inductance value according to claim 3 or 4, characterized in that: The proximity determination interval group, the distance determination interval group, the quantity threshold, and the inductance value threshold are preset based on physical sensor calibration data. The physical sensor calibration data includes the relationship between the target gap and the inductance value, as well as the rate of change trend obtained from the difference in inductance values ​​between adjacent calibration points.

7. The landing gear proximity sensor state detection method based on the rate of change of inductance value according to claim 1, characterized in that: When the previous determination state is an approaching state and the determination condition for the far-away state is not met, the approaching state is maintained; when the previous determination state is a far-away state and the determination condition for the approaching state is not met, the far-away state is maintained.

8. The landing gear proximity sensor state detection method based on the rate of change of inductance value according to claim 1, characterized in that: The approach status or the distance status is output to at least one of landing gear retraction control, position indication, or position status monitoring.

9. A landing gear proximity sensor state detection system based on the rate of change of inductance, characterized in that, include: The inductance value acquisition module is configured to acquire the current and historical T-cycle inductance values ​​of the landing gear proximity sensor and construct an inductance value vector; The rate of change calculation module is configured to generate an inductance value rate of change vector based on the inductance value vector. The state determination module is configured to determine the approaching state determination condition by the number of elements in the inductance value change rate vector that fall into the approaching determination interval group and the current period inductance value, and to determine the far-away state determination condition by the number of elements in the inductance value change rate vector that fall into the far-away determination interval group and the current period inductance value. The status output module is configured to output a near state when the near state determination condition is met, output a far state when the far state determination condition is met, and maintain the previous determination state when neither the near state determination condition nor the far state determination condition is met.

10. The landing gear proximity sensor state detection system based on the rate of change of inductance value according to claim 9, characterized in that: The sensor status detection system is installed in the landing gear retraction and extension control system, or in the control unit that is communicatively connected to the landing gear proximity sensor.

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