Proximity sensor resolving system and method for undercarriage folding and unfolding system

Abstract

The invention discloses a proximity sensor resolving system for an undercarriage folding and unfolding system. The resolving system comprises an inductance measurement module, a signal processing module, a signal generation module, a main control module, a temperature compensation module and a bus communication module. A plurality of groups of inductance values are acquired through the inductance measuring instrument and the resolving system, and the inductance measurement value of the proximity sensor is calibrated, so that the inductance value resolved by the resolving system is prevented from being subjected to measurement result errors caused by unstable parameters of contact resistance, parasitic inductance and parasitic capacitance of a measurement line, a connector and the like; the problems that an existing proximity sensor is complex in circuit structure and calculation process, low in calculation speed and low in accuracy are effectively solved. The invention further provides a proximity sensor resolving method for the undercarriage folding and unfolding system.

Description

Technical Field

[0001] The invention relates to a position indication technology for an aircraft landing gear retracting and extending system, in particular to a proximity sensor solution system and method for the landing gear retracting and extending system. Background Art

[0002] The proximity sensor is a non-contact sensor that can reduce the mechanical damage rate and extend the mechanical life. It is widely used in the landing gear retraction and extension system of large aircraft. The proximity sensor of the landing gear retraction and extension system is generally inductive. The collected inductance value needs to be calculated by the solution unit to accurately determine the current position of the landing gear, thereby providing an action basis for the retraction / extension control system of the landing gear. The basic principle of the proximity sensor is to use the change in the position between the sensor itself and the target to cause the change in the induced inductance value, which can be introduced into the back-end processing for measurement and processing. Since the inductance value of the proximity sensor is generally small, the change at the approach / distance point is even smaller, which is not easy to measure, and is easily interfered by external factors to cause measurement errors. Among them, the equivalent cable impedance between the proximity sensor and the retraction and extension control box and the ambient temperature have a greater impact on the measurement, which will cause errors in the solution results. However, the general inductance measurement method often has a complex circuit structure and calculation process, slow solution speed, low solution accuracy, and poor stability. Therefore, how to design a proximity sensor solution solution with simple structure, high real-time performance and high measurement accuracy has become a technical problem that needs to be solved urgently. Summary of the invention

[0003] The present invention aims to provide a proximity sensor solution system for a landing gear retraction and extension system. The solution system has high real-time performance and high measurement accuracy, thereby improving the accuracy and real-time performance of inductive proximity sensor signals.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a proximity sensor solution system, the system comprising:

[0005] The inductance measurement module comprises a proximity sensor and a sampling resistor, wherein one end of the sampling resistor is connected to one end of the inductance coil of the proximity sensor;

[0006] The signal processing module includes an amplifier, a bandpass filter and an analog-to-digital conversion circuit. The amplifier includes a first amplifier and a plurality of second amplifiers. The second amplifier is used to amplify the voltage U at both ends of the proximity sensor. L And the voltage U across the sampling resistor R , the second amplifier is connected to the analog-to-digital conversion circuit, and one end of the bandpass filter is connected to the other end of the sampling resistor;

[0007] A signal generating module, used for generating a signal source required by the proximity sensor solving system, so that the proximity sensor has inductance, the signal generating module comprises a signal generator, one end of the signal generator is connected to one end of the first amplifier, and the other end of the first amplifier is connected to the other end of the bandpass filter;

[0008] A main control module, including a signal calculation module and an inductance calibration module, wherein the signal calculation module is used to calculate the inductance measurement value L of the proximity sensor, and the inductance calibration module is used to calibrate the inductance measurement value L of the proximity sensor. The main control module is also used for signal frequency setting and modification, data acquisition and temperature compensation algorithm calculation, and the main control module is connected to the other end of the signal generator and the analog-to-digital conversion circuit respectively; the signal generation module also includes a signal frequency setting and modification unit of the main control module;

[0009] A temperature compensation module, used for temperature compensation of the proximity sensor solution system, so as to eliminate the influence of the sampling resistor and the inductance equivalent impedance of the proximity sensor and the ambient temperature on the inductance value measurement;

[0010] The bus communication module is used to receive the control signal of the host computer and report the approaching / distance status calculated by the solving system to the host computer in the form of bus.

[0011] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization:

[0012] In one preferred embodiment, the inductance measurement module adopts an LCR bridge method, and the sampling resistor adopts a precision detection resistor.

[0013] In one preferred embodiment, the data acquisition of the main control module includes the voltage U across the two ends of the proximity sensor L And the voltage U across the sampling resistor R Collection of.

[0014] In one preferred embodiment, the temperature compensation module includes a temperature sensor and a temperature compensation algorithm calculation unit of the main control module, and the temperature sensor is connected to the main control module.

[0015] In one of the preferred embodiments, the bus communication module is also used to transmit the inductance value measured by the inductance measuring instrument to the inductance calibration module through the bus.

[0016] Based on the same concept, the present invention also provides a method for calculating the inductance value using the proximity sensor calculation system, and the calculation method comprises the following steps:

[0017] Inductance calibration:

[0018] a1), through the inductance measuring instrument and the proximity sensor solution system, the inductance calibration module respectively collects two inductance values ​​under the same target gap; the target gap is the distance gap between the target and the proximity sensor when the target moves toward the proximity sensor; the inductance measurement value of the inductance measuring instrument is recorded as the reference inductance value;

[0019] a2), changing the target gap several times, and repeating step a1) accordingly, to obtain multiple sets of inductance values ​​of two acquisition modes;

[0020] a3), performing quadratic polynomial fitting on the multiple groups of inductance values ​​of the two acquisition methods to obtain a calibration quadratic term formula, and writing the calibration quadratic term formula into the program of the inductance value calibration module;

[0021] Inductance measurement:

[0022] b1), the main control module collects the voltage U at both ends of the proximity sensor L and the voltage across the sampling resistor U R ,

[0023] b2), the signal analysis module analyzes the voltage U at both ends of the proximity sensor L and the voltage across the sampling resistor U R , calculate and obtain the inductance measurement value L of the proximity sensor;

[0024] b3), the inductance measurement value L of the proximity sensor is transmitted to the inductance calibration module in which the calibration quadratic term formula has been written, to obtain a calibrated inductance measurement value.

[0025] In one preferred embodiment, in step a3), excel is used to process multiple sets of inductance values ​​of the two acquisition methods to obtain the calibration quadratic term formula L m =aL 2 +bL+c; where L m is the calibration value of the inductance measurement value L of the proximity sensor, a is a constant, b is a constant, and c is a constant.

[0026] In one preferred embodiment, the step b2) of calculating the inductance measurement value L of the proximity sensor specifically includes the following steps: comparing the voltage U across the proximity sensor L and the voltage across the sampling resistor U R The phase difference θ is calculated according to the voltage U at both ends of the proximity sensor. L , the voltage U across the sampling resistor R and the phase difference θ, the actual inductance value L is calculated.

[0027] In one preferred embodiment, the calculation formula of the inductance measurement value L of the proximity sensor is as follows:

[0028]

[0029] The calculation formula of the phase difference θ is as follows:

[0030]

[0031] Wherein, R1 is the sampling resistance value, R is the equivalent resistance value of the inductance measurement module, and f is the inductance frequency.

[0032] Compared with the prior art, the beneficial effects of the present invention are: the proximity sensor solution system provided by the present invention has high real-time performance and high measurement accuracy, improves the accuracy and real-time performance of the inductive proximity sensor signal, and effectively solves the problems of complex circuit structure and calculation process, slow solution speed and low accuracy of the existing proximity sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of a proximity sensor solution system according to Embodiment 1 of the present invention;

[0034] Figure 2 It is a signal calculation flow chart of the proximity sensor calculation system of embodiment 1 of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0036] Example 1

[0037] This embodiment provides a proximity sensor solution system for a landing gear retraction and extension system. The solution system includes an inductance measurement module, a signal processing module, a signal generation module, a main control module, a temperature compensation module and a bus communication module.

[0038] The inductance measurement module includes a proximity sensor and a sampling resistor, wherein one end of the sampling resistor is connected to one end of the inductance coil of the proximity sensor;

[0039] The signal processing module includes an amplifier, a bandpass filter and an analog-to-digital conversion circuit. The amplifier includes a first amplifier and a plurality of second amplifiers. The second amplifier is used to amplify the voltage U at both ends of the proximity sensor. L And the voltage U across the sampling resistor R , the second amplifier is connected to the analog-to-digital conversion circuit, and one end of the bandpass filter is connected to the other end of the sampling resistor;

[0040] The signal generating module generates a sine wave signal with a pure spectrum and programmable frequency and phase, which is used to generate the signal source required by the proximity sensor solution system. The signal generating module includes a signal generator, one end of the signal generator is connected to one end of the first amplifier, and the other end of the first amplifier is connected to the other end of the bandpass filter;

[0041] The main control module includes a signal calculation module and an inductance calibration module. The signal calculation module is used to calculate the inductance measurement value L of the proximity sensor. The inductance calibration module is used to calibrate the inductance measurement value L of the proximity sensor. The main control module is also used for signal frequency setting and modification, data acquisition and temperature compensation algorithm calculation. The main control module is connected to the other end of the signal generator and the analog-to-digital conversion circuit respectively; the signal generation module also includes a signal frequency setting and modification unit of the main control module;

[0042] The temperature compensation module is used for temperature compensation of the proximity sensor solution system;

[0043] The bus communication module is used to receive the control signal of the host computer and report the approach / distance state after the solution system is solved to the host computer in the form of a bus. In this embodiment, the bus communication module can receive the control signal of the host computer through the RS422 communication interface, and report the approach / distance state after the solution system is solved in the form of a bus. The bus communication module can also realize software update and debugging without disassembly through the RS232 communication interface, which can save maintenance and debugging time.

[0044] The proximity sensor solution system uses the signal generator to generate a sine wave excitation source, so that current flows through the inductor coil of the proximity sensor, and the inductor generates a magnetic field, and the magnitude of the inductance value is affected by the magnetic resistance of the magnetic circuit where the inductor coil of the proximity sensor is located. That is, when the target moves toward the proximity sensor, the change in the gap between the target and the proximity sensor will cause the magnetic resistance of the inductor circuit of the proximity sensor to change: when the target is close to the proximity sensor, the inductance value increases, and vice versa. Therefore, the proximity / distance state of the proximity sensor can be obtained by measuring the change in inductance.

[0045] The greater the voltage across the proximity sensor inductor, the higher the sampling accuracy of the solution system. It is necessary to maximize the voltage across the proximity sensor inductor and ensure that the sampling resistor is not damaged due to excessive power consumption. Therefore, the solution system further selects a precision detection resistor as a sampling resistor connected in series to the detection circuit, and the inductance measurement module adopts an LCR bridge method.

[0046] Furthermore, the data acquisition of the main control module includes the voltage U at both ends of the proximity sensor L And the voltage U across the sampling resistor R Collection of.

[0047] As the circuit works longer, the temperature of components such as resistors in the circuit will change, causing changes in their resistance values. Since the calculation of the inductance value is related to the resistance value, it will eventually affect the calculation result of the inductance value. The temperature compensation module eliminates the increased temperature through the temperature compensation algorithm, ensuring that the temperature increases but the resistance value remains unchanged, and the final calculated inductance value is not affected.

[0048] Furthermore, the temperature compensation module includes a temperature sensor and a temperature compensation algorithm calculation unit of the main control module, and the temperature sensor is connected to the main control module. The temperature compensation module collects the temperature between PCB boards in real time through the temperature sensor and performs temperature compensation to effectively eliminate the influence of sampling resistance, inductor equivalent cable impedance and ambient temperature on inductance value measurement.

[0049] The inductance calibration module collects multiple sets of inductance values ​​through the inductance measuring instrument and the solution system, and calibrates the inductance measurement value of the proximity sensor, ensuring that the inductance value solved by the solution system is free from the measurement error caused by unstable parameters such as contact resistance, parasitic inductance and parasitic capacitance of the measurement line and connector. Therefore, further, the bus communication module is also used to transmit the inductance value measured by the inductance measuring instrument to the inductance calibration module through the bus.

[0050] When the gap between the target and the proximity sensor changes, the approach and distance state of the target is determined by the change of the calibrated inductance value.

[0051] Figure 1 In, R L is the equivalent resistance of the proximity sensor.

[0052] Example 2

[0053] This embodiment provides a proximity sensor solution method for a landing gear retraction and extension system, and the implementation steps are as follows:

[0054] Inductance calibration:

[0055] a1), through the inductance measuring instrument and the proximity sensor solution system, the inductance calibration module respectively collects two inductance values ​​under the same target gap; the target gap is the distance gap between the target and the proximity sensor when the target moves toward the proximity sensor; the inductance measurement value of the inductance measuring instrument is recorded as the reference inductance value;

[0056] a2), changing the target gap several times, and repeating step a1) accordingly, to obtain multiple sets of inductance values ​​of two acquisition modes;

[0057] a3), performing quadratic polynomial fitting on the multiple groups of inductance values ​​of the two acquisition methods to obtain a calibration quadratic term formula, and writing the calibration quadratic term formula into the program of the inductance value calibration module;

[0058] Inductance measurement:

[0059] b1), the main control module collects the voltage U at both ends of the proximity sensor L and the voltage across the sampling resistor U R ,

[0060] b2), the signal analysis module analyzes the voltage U at both ends of the proximity sensor L and the voltage across the sampling resistor U R , calculate and obtain the inductance measurement value L of the proximity sensor;

[0061] b3), the inductance measurement value L of the proximity sensor is transmitted to the inductance calibration module in which the calibration quadratic term formula has been written, to obtain a calibrated inductance measurement value.

[0062] The inductance measuring instrument and the proximity sensor solution system are both used to measure the inductance value. The inductance tester has high accuracy and is the preferred inductance value measurement device in ground testing. However, due to factors such as the large size of the inductance tester, the lack of an interface for interaction with the host computer, and the inability to ensure electromagnetic compatibility, the inductance tester is not the preferred measurement device on the machine body. Therefore, it is necessary to develop a proximity sensor solution system, and it is expected that the accuracy of the developed proximity sensor solution system can be comparable to that of the inductance tester. Therefore, in this embodiment, the inductance value measured by the inductance tester is used as the reference inductance value.

[0063] In this embodiment, the calibration quadratic term formula between the multiple groups of inductance values ​​of the two acquisition methods is obtained through Excel, and the step a3) specifically includes the following steps:

[0064] s1, open Excel, input multiple sets of inductance values ​​of the two acquisition methods, and the multiple sets of inductance values ​​of each acquisition method are a column of values;

[0065] s2, select two columns of data, select "Insert Chart", "All Chart Types";

[0066] s3. In the "Insert Chart" dialog box, select "Scatter Chart", select the first one in "Scatter Chart", and click "OK";

[0067] s4, generating a graph, wherein the graph displays scattered points, wherein the abscissa is the inductance measurement value L of the proximity sensor, and the ordinate is the inductance measurement value of the inductance measuring instrument;

[0068] s5, select one of the scattered points, right-click, and select "Add Trend Line";

[0069] s6. In the "Trend Line Options" dialog box, select "Trend Forecast / Regression Analysis Type", "Polynomial", select 2 for "Sequence", continue to select "Show Formula", and click "Close";

[0070] s7, the trend line and quadratic term formula of the scattered points are displayed in Excel, and the quadratic term formula is the calibration quadratic term formula.

[0071] In step s7), the calibration quadratic term formula can be expressed as L m =aL 2 +bL+c, where L m is the calibration value of the inductance measurement value L of the proximity sensor, a is a constant, b is a constant, and c is a constant.

[0072] In the step b2), the inductance measurement value L of the proximity sensor is calculated, which specifically includes the following steps: comparing the voltage U at both ends of the proximity sensor L and the voltage across the sampling resistor U R The phase difference θ is calculated according to the voltage U at both ends of the proximity sensor. L , the voltage U across the sampling resistor R and the phase difference θ, and calculate the inductance measurement value L of the proximity sensor. The calculation formula of the inductance measurement value L of the proximity sensor is as follows:

[0073]

[0074] The calculation formula of the phase difference θ is as follows:

[0075]

[0076] Wherein, R1 is the sampling resistance value, R is the equivalent resistance value of the inductance measurement module, and f is the inductance frequency.

[0077] Example 3

[0078] In this embodiment, the main control module is ZYNQ7020, which combines the processing power of the ARM processor and the flexibility of the FPGA; the signal generator is AD9833; the first amplifier is OP07; the bandpass filter is a third-order passive low-pass filter; the second amplifier is GS8054;

[0079] The host computer sends control instructions through the RS422 bus, controls the excitation source signal generator AD9833 to send a fixed sine wave frequency signal through the main control module ZYNQ7020, and obtains the signal of the required amplitude and frequency of the inductance of the proximity sensor through the first amplifier OP07 and the bandpass filter.

[0080] The main control module collects the voltage U at both ends of the proximity sensor L and the voltage across the sampling resistor U R , is amplified by the second amplifier into a voltage signal that can be collected by the ADC chip ADS131M02, and then the ADC chip ADS131M02 performs analog-to-digital conversion to convert the collected voltage signal U L , U R The signal is then transmitted to the FPGA acquisition channel, and then transmitted to the signal analysis unit (ARM processor) through the FPGA acquisition channel for analysis, and the U L and the U R The phase difference θ, then according to the U L 、The U R and the phase difference θ, and calculate the inductance measurement value L of the proximity sensor.

[0081] The temperature sensor collects the temperature between PCB boards in real time and uploads it to the FPGA, and performs temperature compensation calculation in the FPGA to ensure that the inductance value output by the solution system is not affected by the sampling resistor, the inductor equivalent cable impedance and the ambient temperature change.

[0082] Through the inductance measuring instrument and the solution system, the inductance calibration module collects multiple sets of inductance values ​​L si , L i Among them, L si is the i-th group of inductance values ​​collected by the inductance tester, 1≤i≤n, and n is the number of groups of collected inductance values. si and L i Perform quadratic fitting to obtain the calibration quadratic term formula L m =aL 2 +bL+c, where L mis the calibration value of the inductance measurement value L of the proximity sensor. The calibration quadratic term formula is written into the inductance calibration module to ensure that the inductance value output through the bus is the calibrated inductance value during subsequent inductance measurement.

[0083] In this embodiment, the real-time performance of the calculation system is no more than 10 ms (milliseconds), the real-time performance of multi-channel simultaneous measurement is also guaranteed to be no more than 10 ms (milliseconds), and the inductance value measurement accuracy reaches ±0.01 mH (millihenry).

[0084] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A proximity sensor solution system, characterized in that: The solution system comprises: The inductance measurement module comprises a proximity sensor and a sampling resistor, wherein one end of the sampling resistor is connected to one end of the inductance coil of the proximity sensor; The signal processing module includes an amplifier, a bandpass filter and an analog-to-digital conversion circuit. The amplifier includes a first amplifier and a plurality of second amplifiers. The second amplifier is used to amplify the voltage U at both ends of the proximity sensor. L And the voltage U across the sampling resistor R , the second amplifier is connected to the analog-to-digital conversion circuit, and one end of the bandpass filter is connected to the other end of the sampling resistor; A signal generating module, used for generating a signal source required by the proximity sensor solving system, wherein the signal generating module comprises a signal generator, one end of the signal generator is connected to one end of the first amplifier, and the other end of the first amplifier is connected to the other end of the bandpass filter; A main control module, including a signal calculation module and an inductance calibration module, wherein the signal calculation module is used to calculate the inductance measurement value L of the proximity sensor, and the inductance calibration module is used to calibrate the inductance measurement value L of the proximity sensor. The main control module is also used for signal frequency setting and modification, data acquisition and temperature compensation algorithm calculation, and the main control module is connected to the other end of the signal generator and the analog-to-digital conversion circuit respectively; the signal generation module also includes a signal frequency setting and modification unit of the main control module; A temperature compensation module, used for temperature compensation of the proximity sensor solution system; The bus communication module is used to receive the control signal of the host computer and report the approaching / distance status calculated by the solving system to the host computer in the form of bus.

2. The proximity sensor solution system according to claim 1, characterized in that: The inductance measurement module adopts an LCR bridge method, and the sampling resistor adopts a precision detection resistor.

3. The proximity sensor solution system according to claim 1, characterized in that: The data acquisition of the main control module includes the voltage U at both ends of the proximity sensor L And the voltage U across the sampling resistor R Collection of.

4. The proximity sensor solution system according to claim 1, characterized in that: The temperature compensation module includes a temperature sensor and a temperature compensation algorithm calculation unit of the main control module, and the temperature sensor is connected to the main control module.

5. The proximity sensor solution system according to claim 1, characterized in that: The bus communication module is also used to transmit the inductance value measured by the inductance measuring instrument to the inductance calibration module through the bus.

6. A method for calculating inductance using the proximity sensor calculation system according to any one of claims 1 to 5, characterized in that: The solution method comprises the following steps: Inductance calibration: a1), through the inductance measuring instrument and the proximity sensor solution system, the inductance calibration module respectively collects two inductance values ​​under the same target gap; the inductance measurement value of the inductance measuring instrument is recorded as the reference inductance value; a2), changing the target gap several times, and repeating step a1) accordingly, to obtain multiple sets of inductance values ​​of two acquisition modes; a3), performing quadratic polynomial fitting on the multiple groups of inductance values ​​of the two acquisition methods to obtain a calibration quadratic term formula, and writing the calibration quadratic term formula into the program of the inductance value calibration module; Inductance measurement: b1), the main control module collects the voltage U at both ends of the proximity sensor L and the voltage U across the sampling resistor R , b2), the signal analysis module analyzes the voltage U at both ends of the proximity sensor L and the voltage U across the sampling resistor R , calculate and obtain the inductance measurement value L of the proximity sensor; b3), the inductance measurement value L of the proximity sensor is transmitted to the inductance calibration module in which the calibration quadratic term formula has been written, to obtain a calibrated inductance measurement value.

7. The proximity sensor solution method according to claim 6, characterized in that: In the step a3), the multiple sets of inductance values ​​of the two acquisition methods are processed using Excel to obtain the calibration quadratic term formula L m =aL 2 +bL+c; where L m is the calibration value of the inductance measurement value L of the proximity sensor, a is a constant, b is a constant, and c is a constant.

8. The proximity sensor solution method according to claim 6, characterized in that: The step b2) of calculating the inductance measurement value L of the proximity sensor specifically includes the following steps: comparing the voltage U across the proximity sensor L and the voltage across the sampling resistor U R The phase difference θ is calculated according to the voltage U at both ends of the proximity sensor. L , the voltage U across the sampling resistor R and the phase difference θ, and calculate the inductance measurement value L of the proximity sensor.

9. The proximity sensor solution method according to claim 8, characterized in that: The calculation formula of the inductance measurement value L of the proximity sensor is as follows: The calculation formula of the phase difference θ is as follows: Wherein, R1 is the sampling resistance value, R is the equivalent resistance value of the inductance measurement module, and f is the inductance frequency.

Images