Successive approximation four-redundancy atmospheric parameter voting system and method

Abstract

Disclosed in the present invention are a successive approximation four-redundancy atmospheric parameter voting system and method. The method comprises the following steps: measuring the current total pressure and static pressure of an aircraft, and measuring some or all of the current total temperatures of the aircraft; collecting the total pressure and the static pressure, and collecting some or all of the total temperatures, so as to obtain four sets of atmospheric data parameters; determining the validity of each atmospheric data parameter in each set of atmospheric data parameters, performing atmospheric parameter voting according to a successive approximation four-redundancy voting algorithm, and calculating an atmospheric parameter voting value; using a fault tree analysis (FTA) method to perform system security analysis, and identifying bottom events in a fault tree; calculating a failure rate of each bottom event in the fault tree; and calculating the probability of pressure altitude / airspeed output error data. The present invention solves the problem of it being impossible for an original algorithm to eliminate abnormal data during four-redundancy parameter voting, thus affecting the reliability and integrity of voted atmospheric parameters, not being conducive to flight control, and even generating design defects endangering flight safety.

Description

A successive approximation four-redundant atmospheric parameter voting system and method Technical Field

[0001] The present invention belongs to the technical field of aerospace atmospheric data acquisition and processing, and in particular relates to a successive approximation type four-redundant atmospheric parameter voting system and method. Background Art

[0002] The atmospheric data system of civil airliners belongs to the airborne avionics system. It uses the principle of measuring air pressure and ambient temperature to measure the aircraft's altitude, speed and other parameters in real time. The atmospheric data system generally includes a probe that senses pressure, a sensor that measures temperature, a control unit that calculates atmospheric parameters, etc. Its parameters will be used by airborne systems such as the flight control system for flight control and flight mission management. It is crucial to aircraft safety and usually adopts a redundant system architecture.

[0003] The advantages of voting are to improve the reliability and safety of the system, reduce fault effects and fault transients, improve the consistency between channel signals, improve downstream device fault detection, reduce false alarms, and improve signal accuracy. The data processing method currently used by a certain type of passenger aircraft is to sort the four redundant parameters and calculate the difference between two adjacent values ​​and perform threshold judgment. The relationship between the interval value and the threshold is not considered. Therefore, the voting results cannot exclude some abnormal data and introduce unreliable parameters into the voting results, thereby affecting the reliability and integrity of the voting atmospheric parameters and bringing adverse factors to aircraft control.

[0004] Summary of the Invention

[0005] The present invention provides a successive approximation four-redundant atmospheric parameter voting system and method, which solves the problem that the original algorithm cannot exclude abnormal data during four-redundant parameter voting, thereby affecting the reliability and integrity of the voted atmospheric parameters, being detrimental to flight control, and even causing design defects that endanger flight safety.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: a successive approximation type four-redundant atmospheric parameter voting system, including an atmospheric data module ADM, an atmospheric data reference unit ADRU, an external probe and a sensor TATP;

[0007] The air data module ADM is used to collect and convert the total pressure and static pressure detected by the external probe and send them to the air data reference unit ADRU;

[0008] The atmospheric data reference unit ADRU is used to collect the total temperature sensed by the sensor TATP, determine the validity of the atmospheric data parameters, and perform atmospheric data voting to calculate the probability of the aircraft's current pressure altitude / airspeed outputting erroneous data;

[0009] The external probe is used to detect the current total pressure and static pressure of the aircraft;

[0010] The sensor TATP is used to detect the current total temperature of the aircraft.

[0011] The beneficial effects of the present invention are as follows: the atmospheric data voting system provided by the present invention has a built-in successive approximation four-redundancy atmospheric parameter voting algorithm, and adopts a gas path averaging and electrical averaging four-redundancy non-similar redundancy design, which can effectively suppress common mode failures of software and hardware and eliminate the impact of sideslip. Compared with traditional single-redundancy or dual-redundancy atmospheric data systems, the availability and integrity are higher, and the safety, function and performance requirements of high-safety aircraft platforms such as large passenger aircraft can be met.

[0012] Furthermore, the external probes include a total pressure probe PTP, a static pressure probe PSP and a full static pressure probe PSTP;

[0013] The total pressure probe PTP is used to detect the current total pressure of the aircraft;

[0014] The static pressure probe PSP is used to detect the current static pressure of the aircraft;

[0015] The total static pressure probe PSTP is used to detect the current total pressure and static pressure of the aircraft.

[0016] The present invention also provides a successive approximation four-redundancy atmospheric parameter voting method, comprising the following steps:

[0017] S1. Detect the current total pressure and static pressure of the aircraft through external probes, and detect part or all of the current total temperature of the aircraft through the TATP sensor;

[0018] S2. Collect total pressure and static pressure through the atmospheric data module ADM and send them to the atmospheric data reference unit ADRU. Also, collect part or all of the total temperature through the atmospheric data reference unit ADRU to obtain four sets of atmospheric data parameters.

[0019] S3. Determine the validity of each atmospheric data parameter in each set of atmospheric data parameters through the atmospheric data reference unit ADRU, and perform atmospheric parameter voting according to the successive approximation four-redundant voting algorithm built into the atmospheric data reference unit ADRU to calculate the atmospheric parameter voting value;

[0020] S4. Based on the voting values ​​of atmospheric parameters, the fault tree model FTA analysis method is used to perform system safety analysis and identify the bottom event of the fault tree;

[0021] S5. Statistics and records of errors are collected from the FRACAS database, and the failure rate of each fault tree bottom event is calculated based on the expected data.

[0022] S6. Based on the failure rate of each fault tree bottom event, calculate the probability of erroneous data output of pressure altitude / airspeed, and complete the atmospheric parameter voting for this cycle.

[0023] The beneficial effects of the present invention are as follows: atmospheric data parameters are obtained through external probes, atmospheric parameter voting values ​​are calculated according to the successive approximation four-redundant atmospheric parameter voting algorithm provided by the present invention, and then a fault tree model FTA analysis method is used to perform safety analysis, and the probability of erroneous data output of the pressure altitude / airspeed is calculated. This is much lower than the probability of erroneous data output of the pressure altitude / airspeed calculated by the traditional voting algorithm, and can exclude abnormal data, avoid introducing unreliable parameters into the voting results, improve the integrity of the voted atmospheric parameters, and be more conducive to aircraft control.

[0024] Furthermore, the specific steps of step S3 are:

[0025] S31. Determine the validity of each atmospheric data parameter in each set of atmospheric data parameters using the atmospheric data reference unit ADRU. If all four atmospheric data parameters are valid, calculate the atmospheric parameter voting value using the four-redundant atmospheric parameter voting algorithm in the successive approximation four-redundant voting algorithm and proceed to step S4. Otherwise, proceed to step S32.

[0026] S32. If three atmospheric data parameters are valid, the atmospheric parameter voting value is calculated according to the three-redundant atmospheric parameter voting in the successive approximation four-redundant voting algorithm, and the process proceeds to step S4. Otherwise, the process proceeds to step S33.

[0027] S33. If two atmospheric data parameters are valid, sort the two atmospheric data parameters in ascending order according to the double-redundancy atmospheric parameter voting in the successive approximation four-redundancy voting algorithm, calculate the atmospheric parameter voting value, and proceed to step S4. Otherwise, proceed to step S34.

[0028] S34. If only one atmospheric data parameter is valid, the single-redundancy atmospheric parameter voting in the successive approximation four-redundancy voting algorithm is used, and the valid atmospheric data parameter is used as the atmospheric parameter voting value, and the process proceeds to step S4; otherwise, the process proceeds to step S35.

[0029] S35. If all four atmospheric data parameters are invalid, the atmospheric parameter voting value of the previous period is used as the atmospheric parameter voting value, and the process goes to step S4.

[0030] The beneficial effects of the above further scheme are: through the successive approximation four-redundant atmospheric parameter voting algorithm, the system reliability can be effectively improved, the fault effect and fault transient can be reduced, the consistency between the signals of each channel can be improved, the fault detection of downstream devices can be improved, and false alarms can be reduced. In addition, the signal accuracy can be improved, abnormal data can be excluded, and unreliable parameters can be avoided from being introduced into the voting results, thereby improving the reliability and integrity of the voting atmospheric parameters and providing safer and more reliable atmospheric data parameters for aircraft control.

[0031] Furthermore, the specific steps of the four-redundant atmospheric parameter voting in step S31 are:

[0032] A1. Sort the four atmospheric data parameters in ascending order, including the minimum value X1, the second minimum value X2, the second maximum value X3, and the maximum value X4;

[0033] A2. Calculate the difference between the minimum value X1, the second minimum value X2, the second maximum value X3, and the maximum value X4, and get the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 , difference ΔX 21 and the difference ΔX 43 , and make logical judgments;

[0034] A3. If the difference ΔX 41 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A4, where SUM() represents a summation function;

[0035] A4. If the difference ΔX 41 Exceeds the threshold value, and the difference ΔX 31 and the difference ΔX 42 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A5;

[0036] A5. If the difference ΔX 41 and the difference ΔX 31 Both exceed the threshold value, and the difference ΔX 42 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A6;

[0037] A6、If the difference ΔX 41 and the difference ΔX 42 Both exceed the threshold value, and the difference ΔX 31 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A7;

[0038] A7, if the difference ΔX 41 , difference ΔX 31 and the difference ΔX 42 Both exceed the threshold value, and the difference ΔX 32 , difference ΔX 21 and the difference ΔX 43 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A8;

[0039] A8, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 and the difference ΔX 43 Both exceed the threshold value, and the difference ΔX 32 and the difference ΔX 21 If both values ​​do not exceed the threshold, the atmospheric parameter voting value V X =X2, otherwise, go to step A9;

[0040] A9, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 and the difference ΔX 21 Both exceed the threshold value, and the difference ΔX 32 and the difference ΔX 43 If both values ​​do not exceed the threshold, the atmospheric parameter voting value V X =X3, otherwise, go to step A10;

[0041] A10, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 21 and the difference ΔX 43 Both exceed the threshold value, and the difference ΔX 32 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A11;

[0042] A11, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 and the difference ΔX 32 Both exceed the threshold value, and the difference ΔX 21 and the difference ΔX 43 If the threshold is not exceeded, the voting fails and the atmospheric parameter voting value V X = voting value of atmospheric parameters in the previous period, otherwise, go to step A12;

[0043] A12, if the difference ΔX 41 , difference ΔX31 , difference ΔX 42 , difference ΔX 32 and the difference ΔX 43 Both exceed the threshold value, and the difference ΔX 21 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A13;

[0044] A13, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 and the difference ΔX 21 Both exceed the threshold value, and the difference ΔX 43 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A14;

[0045] A14, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 , difference ΔX 21 and the difference ΔX 43 If both exceed the threshold, the voting fails and the atmospheric parameter voting value V X = Voting value of atmospheric parameters in the previous period.

[0046] Furthermore, the specific steps of the three-redundant atmospheric parameter voting in step S32 are:

[0047] B1. Sort the three atmospheric data parameters in ascending order, including the minimum value X1', the middle value X2', and the maximum value X3';

[0048] B2. Calculate the difference between the minimum value X1', the middle value X2', and the maximum value X3', and get the difference ΔX 31 ', difference ΔX 32 ' and the difference ΔX 21 ', and make logical judgments;

[0049] B3, if the difference ΔX 31 'If the threshold is not exceeded, the atmospheric parameter voting value Otherwise, go to step B4, where SUM() represents a summation function;

[0050] B4, if the difference ΔX 31 'Exceeds the threshold value, and the difference ΔX 32 ' and the difference ΔX 21 'Does not exceed the threshold value, then the atmospheric parameter voting value V X=X2, otherwise, go to step B5;

[0051] B5, if the difference ΔX 31 ' and the difference ΔX 21 'All exceed the threshold value, and the difference ΔX 32 'If the threshold is not exceeded, the atmospheric parameter voting value Otherwise, go to step B6;

[0052] B6, if the difference ΔX 31 ' and the difference ΔX 32 'All exceed the threshold value, and the difference ΔX 21 'If the threshold is not exceeded, the atmospheric parameter voting value Otherwise, go to step B7;

[0053] B7, if the difference ΔX 31 ', difference ΔX 32 ' and the difference ΔX 21 'If both exceed the threshold, the voting fails and the atmospheric parameter voting value V X = Voting value of atmospheric parameters in the previous period.

[0054] Furthermore, the specific steps of the dual-redundancy atmospheric parameter voting in step S33 are:

[0055] C1. Sort the two atmospheric data parameters in ascending order, including the minimum value X1″ and the maximum value X2″;

[0056] C2. Calculate the difference between the minimum value X1″ and the maximum value X2″ to obtain the difference ΔX 21 ″, and make logical judgments;

[0057] C3, if the difference ΔX 21 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step C4, where SUM() represents a summation function;

[0058] C4, if the difference ΔX 21 If the threshold is exceeded, the voting fails and the atmospheric parameter voting value V X = Voting value of atmospheric parameters in the previous period.

[0059] Furthermore, the fault tree bottom events in step S4 include sensor drift X1, clock drift X2, common circuit failure X3, self-test circuit failure X4, power supply failure X5, frequency signal processing failure X6, sensor performance degradation X7, bus transmission failure X8, FPGA performance degradation X9, clock drift X10, common circuit failure X11, self-test circuit failure X12, FPGA performance degradation X13, CPU performance degradation X14, 429 communication failure X15 and power supply failure X16.

[0060] Furthermore, the probability of the pressure altitude / airspeed outputting erroneous data in step S5 is The calculation formula is:

[0061] in, Indicates that the pressure altitude / airspeed output is correct or lost. Indicates a redundancy in pressure altitude / airspeed outputting correct data or loss of data. Represents a redundant pressure altitude / airspeed output error data, and Xi represents the bottom event of the fault tree.

[0062] The beneficial effect of the above further solution is: by using the successive approximation type four-redundant atmospheric parameter voting algorithm, the difference between the four independent parameters is calculated, and the relationship between the difference and the voting threshold is judged by the successive approximation method from large to small, which can improve the efficiency of the algorithm. At the same time, the probability of the pressure altitude / airspeed output error data is obtained through failure analysis calculation. The compliance of the pressure altitude / airspeed output function in the air data system with respect to quantitative safety objectives can be demonstrated. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] FIG1 is a principle block diagram of the successive approximation four-redundant atmospheric parameter voting system of the present invention.

[0064] FIG2 is a flow chart of the successive approximation four-redundant atmospheric parameter voting method of the present invention. DETAILED DESCRIPTION

[0065] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

[0066] Example 1

[0067] As shown in FIG1 , the present invention provides a successive approximation type four-redundant atmospheric parameter voting and processing system, characterized in that it includes an atmospheric data module ADM, an atmospheric data reference unit ADRU, an external probe and a sensor TATP;

[0068] The air data module ADM is used to collect and convert the total pressure and static pressure detected by the external probe and send them to the air data reference unit ADRU;

[0069] The atmospheric data reference unit ADRU is used to collect the total temperature sensed by the sensor TATP, determine the validity of the atmospheric data parameters, and perform atmospheric data voting to calculate the probability of the aircraft's current pressure altitude / airspeed outputting erroneous data;

[0070] The external probe is used to detect the current total pressure and static pressure of the aircraft;

[0071] The sensor TATP is used to detect the current total temperature of the aircraft.

[0072] The external probes include a total pressure probe PTP, a static pressure probe PSP and a full static pressure probe PSTP;

[0073] The total pressure probe PTP is used to detect the current total pressure of the aircraft;

[0074] The static pressure probe PSP is used to detect the current static pressure of the aircraft;

[0075] The total static pressure probe PSTP is used to detect the current total pressure and static pressure of the aircraft.

[0076] In this embodiment 1, the atmospheric data module ADM is composed of functional modules such as a power supply module, a frequency signal processing module, a sensor module, a bus transceiver module, an FPGA module and a clock module. The power supply module is used for power supply, the frequency signal processing module is used for signal isolation and filtering, the sensor module is used to convert the pressure detected by the external probe into a frequency signal, the bus transceiver module is used for internal and external communication, the FPGA module is used for F / D conversion and bus transceiver control, and the clock module is used to provide a time reference.

[0077] The atmospheric data reference unit (ADRU) consists of functional modules such as a power supply module, a temperature acquisition module, an angle of attack acquisition module, a bus transceiver module, an FPGA module, a CPU module, and a clock module. The power supply module is used for power supply, the temperature acquisition module is used to collect the total temperature signal detected by the sensor TATP, the angle of attack acquisition module is used to collect angle of attack signals, the bus transceiver module is used for internal and external communication, the FPGA module is used for discrete quantity transceiver control, etc., the CPU module is used for signal sampling, detection, control, and solution, etc., and the clock module is used to provide a time reference.

[0078] The total pressure probe PTP, static pressure probe PSP and full static pressure probe PSTP in the external probes are all mechanical devices and do not contain signal circuits.

[0079] The sensor TATP detects the current total temperature of the aircraft through a platinum resistor.

[0080] In this first embodiment, the atmospheric data module (ADM) collects signals from the aircraft's current total pressure or static pressure detected by an external probe, converts the pressure signal into a frequency signal, and transmits it to the atmospheric data reference unit (ADRU). Simultaneously, the ADRU collects the aircraft's current total temperature signal detected by the sensor (TATP). The ADRU then uses some or all of the collected total and static pressures and total temperature as atmospheric data parameters. The ADRU then uses a successive approximation four-redundant atmospheric parameter voting method built into the ADRU to perform atmospheric parameter voting on the atmospheric data parameters. System safety analysis is then performed, and the probability of erroneous pressure, altitude, and airspeed output is determined.

[0081] At the same time, the system collects, calculates, votes and outputs atmospheric data parameters in a cycle of 20ms. When the vote in this cycle fails, the voting value of the previous cycle is output and the parameter flag is set to invalid.

[0082] Example 2

[0083] As shown in FIG2 , the present invention also provides a successive approximation four-redundant atmospheric parameter voting method, comprising the following steps:

[0084] S1. Detect the current total pressure and static pressure of the aircraft through external probes, and detect part or all of the current total temperature of the aircraft through the TATP sensor;

[0085] S2. Collect total pressure and static pressure through the atmospheric data module ADM and send them to the atmospheric data reference unit ADRU. Also, collect part or all of the total temperature through the atmospheric data reference unit ADRU to obtain four sets of atmospheric data parameters.

[0086] S3. Determine the validity of each atmospheric data parameter in each set of atmospheric data parameters through the atmospheric data reference unit ADRU, and perform atmospheric parameter voting according to the successive approximation four-redundant voting algorithm built into the atmospheric data reference unit ADRU to calculate the atmospheric parameter voting value;

[0087] S4. Based on the voting values ​​of atmospheric parameters, the fault tree model FTA analysis method is used to perform system safety analysis and identify the bottom event of the fault tree;

[0088] S5. Statistics and records of errors are collected from the FRACAS database, and the failure rate of each fault tree bottom event is calculated based on the expected data.

[0089] S6. Based on the failure rate of each fault tree bottom event, calculate the probability of erroneous data output of pressure altitude / airspeed, and complete the atmospheric parameter voting for this cycle.

[0090] In this second embodiment, a fault tree analysis (FTA) model is established. Using the successive approximation quadruple-redundant voting algorithm provided by the present invention, a top-down analysis is performed to determine the single fault or combination of faults that cause each failure state at a lower level, thereby determining the probability of the top event occurring—that is, the probability of erroneous pressure altitude / airspeed output data. Compared to correlation diagrams and Markov analysis, the FTA analysis method uses Boolean logic gates to demonstrate the relationship between fault effects and failure modes, intuitively demonstrating the design's compliance with quantitative safety objectives.

[0091] The specific steps of step S3 are:

[0092] S31. Determine the validity of each atmospheric data parameter in each set of atmospheric data parameters using the atmospheric data reference unit ADRU. If all four atmospheric data parameters are valid, calculate the atmospheric parameter voting value using the four-redundant atmospheric parameter voting algorithm in the successive approximation four-redundant voting algorithm and proceed to step S4. Otherwise, proceed to step S32.

[0093] S32. If three atmospheric data parameters are valid, the atmospheric parameter voting value is calculated according to the three-redundant atmospheric parameter voting in the successive approximation four-redundant voting algorithm, and the process proceeds to step S4. Otherwise, the process proceeds to step S33.

[0094] S33. If two atmospheric data parameters are valid, sort the two atmospheric data parameters in ascending order according to the double-redundancy atmospheric parameter voting in the successive approximation four-redundancy voting algorithm, calculate the atmospheric parameter voting value, and proceed to step S4. Otherwise, proceed to step S34.

[0095] S34. If only one atmospheric data parameter is valid, the single-redundancy atmospheric parameter voting in the successive approximation four-redundancy voting algorithm is used, and the valid atmospheric data parameter is used as the atmospheric parameter voting value, and the process proceeds to step S4; otherwise, the process proceeds to step S35.

[0096] S35. If all four atmospheric data parameters are invalid, the atmospheric parameter voting value of the previous period is used as the atmospheric parameter voting value, and the process goes to step S4.

[0097] In this embodiment 2, each redundancy atmospheric data parameter has a validity range. When performing the voting calculation, the validity of the atmospheric data parameters at each signal source will be judged, and the atmospheric data parameters outside the validity range will be removed and will not participate in the final voting calculation.

[0098] In addition, through the successive approximation four-redundant atmospheric parameter voting algorithm, the difference between the four independent parameters is calculated, and the relationship with the voting threshold is judged by successive approximation of the difference from large to small. Compared with the traditional voting algorithm, the algorithm running time can be reduced by 81.25%, thereby improving the algorithm efficiency.

[0099] Because when the difference between the maximum and minimum parameters is less than the threshold, the differences between other parameters must also be less than the threshold. Therefore, the judgment of the size of the differences between other parameters and the threshold can be omitted, thereby improving the efficiency of the algorithm.

[0100] The specific steps of the four-redundant atmospheric parameter voting in step S31 are:

[0101] A1. Sort the four atmospheric data parameters in ascending order, including the minimum value X1, the second minimum value X2, the second maximum value X3, and the maximum value X4;

[0102] A2. Calculate the difference between the minimum value X1, the second minimum value X2, the second maximum value X3, and the maximum value X4, and get the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 , difference ΔX 21 and the difference ΔX 43 , and make logical judgments;

[0103] A3. If the difference ΔX 41 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A4, where SUM() represents a summation function;

[0104] A4. If the difference ΔX 41 Exceeds the threshold value, and the difference ΔX 31 and the difference ΔX 42 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A5;

[0105] A5. If the difference ΔX 41 and the difference ΔX 31 Both exceed the threshold value, and the difference ΔX 42 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A6;

[0106] A6、If the difference ΔX 41 and the difference ΔX 42 Both exceed the threshold value, and the difference ΔX 31 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A7;

[0107] A7, if the difference ΔX 41 , difference ΔX 31 and the difference ΔX 42 Both exceed the threshold value, and the difference ΔX 32 , difference ΔX 21 and the difference ΔX 43 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A8;

[0108] A8, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 and the difference ΔX 43 Both exceed the threshold value, and the difference ΔX 32 and the difference ΔX 21 If both values ​​do not exceed the threshold, the atmospheric parameter voting value V X =X2, otherwise, go to step A9;

[0109] A9, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 and the difference ΔX 21 Both exceed the threshold value, and the difference ΔX 32 and the difference ΔX 43 If both values ​​do not exceed the threshold, the atmospheric parameter voting value V X =X3, otherwise, go to step A10;

[0110] A10, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 21 and the difference ΔX 43 Both exceed the threshold value, and the difference ΔX 32 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A11;

[0111] A11, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 and the difference ΔX 32 Both exceed the threshold value, and the difference ΔX 21and the difference ΔX 43 If the threshold is not exceeded, the voting fails and the atmospheric parameter voting value V X = voting value of atmospheric parameters in the previous period, otherwise, go to step A12;

[0112] A12, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 and the difference ΔX 43 Both exceed the threshold value, and the difference ΔX 21 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A13;

[0113] A13, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 and the difference ΔX 21 Both exceed the threshold value, and the difference ΔX 43 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A14;

[0114] A14, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 , difference ΔX 21 and the difference ΔX 43 If both exceed the threshold, the voting fails and the atmospheric parameter voting value V X = Voting value of atmospheric parameters in the previous period.

[0115] In this embodiment 2, the four-redundant atmospheric parameter voting algorithm outputs the atmospheric parameter voting value according to Table 1, and sorts the valid atmospheric data parameters in ascending order. Table 1 is a logic truth table for processing the four-redundant voting algorithm, where "0" in the truth table indicates that the difference does not exceed the threshold value, "1" indicates that the difference exceeds the threshold value, and "-" indicates that the difference is in any state compared with the threshold value.

[0116] Table 1

[0117] Among them, the difference ΔX 41 The difference between the maximum value X4 and the minimum value X1, the difference ΔX 31 The difference between the second largest value X3 and the minimum value X1, the difference ΔX 42 The difference between the maximum value X4 and the second minimum value X2, the difference ΔX 32 The difference between the second largest value X3 and the second smallest value X2, the difference ΔX21 is the difference between the next minimum value X2 and the minimum value X1, and the difference ΔX 43 It is the difference between the maximum value X4 and the second maximum value X3.

[0118] The specific steps of the three-redundant atmospheric parameter voting in step S32 are:

[0119] B1. Sort the three atmospheric data parameters in ascending order, including the minimum value X1', the middle value X2', and the maximum value X3';

[0120] B2. Calculate the difference between the minimum value X1', the middle value X2', and the maximum value X3', and get the difference ΔX 31 ', difference ΔX 32 ' and the difference ΔX 21 ', and make logical judgments;

[0121] B3, if the difference ΔX 31 'If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step B4, where SUM() represents a summation function;

[0122] B4, if the difference ΔX 31 'Exceeds the threshold value, and the difference ΔX 32 ' and the difference ΔX 21 'Does not exceed the threshold value, then the atmospheric parameter voting value V X =X2, otherwise, go to step B5;

[0123] B5, if the difference ΔX 31 ' and the difference ΔX 21 'All exceed the threshold value, and the difference ΔX 32 'If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step B6;

[0124] B6, if the difference ΔX 31 ' and the difference ΔX 32 'All exceed the threshold value, and the difference ΔX 21 'If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step B7;

[0125] B7, if the difference ΔX 31 ', difference ΔX 32 ' and the difference ΔX 21 'If both exceed the threshold, the voting fails and the atmospheric parameter voting value V X = Voting value of atmospheric parameters in the previous period.

[0126] In this embodiment 2, the triple-redundant atmospheric parameter voting algorithm outputs the atmospheric parameter voting value according to Table 2, and sorts the valid atmospheric data parameters in ascending order. Table 2 is a truth table of the triple-redundant voting algorithm processing logic, where "0" in the truth table indicates that the difference does not exceed the threshold value, "1" indicates that the difference exceeds the threshold value, and "-" indicates that the difference is in any state compared with the threshold value.

[0127] Among them, the difference ΔX 31 ' is the difference between the maximum value X3' and the minimum value X1', the difference ΔX 32 ' is the difference between the maximum value X3' and the middle value X2', the difference ΔX 21 ' is the difference between the middle value X2' and the minimum value X1'.

[0128] Table 2

[0129] The specific steps of dual-redundancy atmospheric parameter voting in step S33 are:

[0130] C1. Sort the two atmospheric data parameters in ascending order, including the minimum value X1″ and the maximum value X2″;

[0131] C2. Calculate the difference between the minimum value X1″ and the maximum value X2″ to obtain the difference ΔX 21 ″, and make logical judgments;

[0132] C3, if the difference ΔX 21 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step C4, where SUM() represents a summation function;

[0133] C4, if the difference ΔX 21 If the threshold is exceeded, the voting fails and the atmospheric parameter voting value V X = Voting value of atmospheric parameters in the previous period.

[0134] In this embodiment 2, the dual-redundancy atmospheric parameter voting algorithm outputs the atmospheric parameter voting value according to Table 3. Table 3 is a logic truth table for processing the triple-redundancy voting algorithm. In the truth table, "0" indicates that the difference does not exceed the threshold value, "1" indicates that the difference exceeds the threshold value, and "-" indicates that the difference is in any state compared with the threshold value.

[0135] Table 3

[0136] Among them, the difference ΔX 21 ″ is the difference between the maximum value X2″ and the minimum value X1″.

[0137] The fault tree bottom events in step S4 include sensor drift X1, clock drift X2, common circuit failure X3, self-test circuit failure X4, power supply failure X5, frequency signal processing failure X6, sensor performance degradation X7, bus transmission failure X8, FPGA performance degradation X9, clock drift X10, common circuit failure X11, self-test circuit failure X12, FPGA performance degradation X13, CPU performance degradation X14, 429 communication failure X15 and power supply failure X16.

[0138] In this embodiment 2, sensor drift X1, clock drift X2, common circuit failure X3, self-test circuit failure X4, power supply failure X5, frequency signal processing failure X6, sensor performance degradation X7, bus transmission failure X8, FPGA performance degradation X9, clock drift X10, common circuit failure X11, self-test circuit failure X12, FPGA performance degradation X13, CPU performance degradation X14, 429 communication failure X15, and power supply failure X16 are independent fault tree bottom events.

[0139] The probability of the pressure altitude / airspeed outputting erroneous data in step S5 The calculation formula is:

[0140] in, Indicates that the pressure altitude / airspeed output is correct or lost. Indicates a redundancy in pressure altitude / airspeed outputting correct data or loss of data. Indicates a redundant pressure altitude / airspeed output error data, and Xi represents the bottom event of the fault tree.

[0141] In this embodiment 2, the Fault Reporting, Analysis, and Corrective Action (FRACAS) database is used to collect statistics and record error occurrences. Combined with the reliability prediction data, the failure rate of each fault tree bottom event is calculated, as shown in Table 4. Table 4 shows the failure rate λ of each fault tree bottom event.

[0142] Table 4

[0143] Calculate the probability of erroneous data output of pressure altitude / airspeed based on the failure rate λ of each fault tree bottom event 1.023e -10 / FH, which can meet the requirement that the probability of occurrence of the main pressure altitude data of a certain type of passenger aircraft should be less than 1.0e -9 The safety requirements of / FH are compared with the probability of erroneous data output of pressure altitude / airspeed by the air data system voting algorithm that does not consider the relationship between interval value and threshold. 3.069e -10 / FH, probability of outputting incorrect altitude / airspeed data It is reduced by three times and improves the integrity of the system.

Claims

1. A successive approximation type four-redundant atmospheric parameter voting system, characterized in that: It includes the atmospheric data module ADM, the atmospheric data reference unit ADRU, the external probe and the sensor TATP; The atmospheric data module ADM is used to collect and convert the total pressure and static pressure detected by the external probe and send them to the atmospheric data reference unit ADRU; The atmospheric data reference unit ADRU is used to collect the total temperature sensed by the sensor TATP, to judge the validity of the atmospheric data parameters, and to vote on the atmospheric data to calculate the probability of the aircraft's current pressure altitude / airspeed outputting erroneous data; The external probe is used to detect the current total pressure and static pressure of the aircraft; The sensor TATP is used to detect the current total temperature of the aircraft.

2. The successive approximation type four-redundant atmospheric parameter voting system according to claim 1 is characterized in that: The external probes include a total pressure probe PTP, a static pressure probe PSP and a total static pressure probe PSTP; The total pressure probe PTP is used to detect the current total pressure of the aircraft; The static pressure probe PSP is used to detect the current static pressure of the aircraft; The total static pressure probe PSTP is used to detect the current total pressure and static pressure of the aircraft.

3. A successive approximation type four-redundancy atmospheric parameter voting method, characterized in that: The following steps are involved: S1. Detect the current total pressure and static pressure of the aircraft through an external probe, and detect part or all of the current total temperature of the aircraft through the sensor TATP; S2, collecting total pressure and static pressure through the atmospheric data module ADM, sending them to the atmospheric data reference unit ADRU, and collecting part or all of the total temperature through the atmospheric data reference unit ADRU to obtain four sets of atmospheric data parameters; S3, judge the validity of each atmospheric data parameter in each set of atmospheric data parameters through the atmospheric data reference unit ADRU, and use the successive approximation type four-redundancy table built in the atmospheric data reference unit ADRU The decision-making algorithm votes on the atmospheric parameters and calculates the voting values ​​of the atmospheric parameters; S4. According to the voting values ​​of atmospheric parameters, the fault tree model FTA analysis method is used to perform system safety analysis and identify the bottom events of the fault tree; S5. According to the FRACAS database, statistics and records of errors are collected and recorded, and the failure rate of each fault tree bottom event is calculated in combination with the expected data; S6. According to the failure rate of each fault tree bottom event, calculate the probability of pressure altitude / airspeed output erroneous data and complete the atmospheric parameter voting of this cycle.

4. The successive approximation type four-redundancy atmospheric parameter voting method according to claim 3 is characterized in that: The specific steps of step S3 are: S31, judging the validity of each atmospheric data parameter in each set of atmospheric data parameters through the atmospheric data reference unit ADRU, if all four atmospheric data parameters are valid, then calculating the atmospheric parameter voting value according to the four-redundant atmospheric parameter voting in the successive approximation four-redundant voting algorithm, and entering step S4, otherwise, entering step S32; S32, if three atmospheric data parameters are valid, then the atmospheric parameter voting value is calculated according to the three-redundant atmospheric parameter voting in the successive approximation four-redundant voting algorithm, and the process proceeds to step S4, otherwise, the process proceeds to step S33; S33, if two atmospheric data parameters are valid, then according to the double-redundancy atmospheric parameter voting in the successive approximation type four-redundancy voting algorithm, the two atmospheric data parameters are sorted in ascending order, and the atmospheric parameter voting value is calculated, and the process goes to step S4; otherwise, the process goes to step S34; S34. If only one atmospheric data parameter is valid, the single-redundancy atmospheric parameter voting in the successive approximation four-redundancy voting algorithm is used to take the valid atmospheric data parameter as the atmospheric parameter voting value, and the process proceeds to step S4; otherwise, the process proceeds to step S35. S35. If the four atmospheric data parameters are all invalid, the atmospheric parameter voting value of the previous period is used as the atmospheric parameter. Parameter voting value, and enter step S4.

5. The successive approximation type four-redundancy atmospheric parameter voting method according to claim 4 is characterized in that: The specific steps of the four-redundancy atmospheric parameter voting in step S31 are: A1. Sort the four atmospheric data parameters in ascending order, including the minimum value X1, the second minimum value X2, the second maximum value X3 and the maximum value X4; A2, calculate the difference between the minimum value X1, the second minimum value X2, the second maximum value X3 and the maximum value X4, and get the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 , difference ΔX 21 and the difference ΔX 43 , and make logical judgments; A3, if the difference ΔX 41 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, proceed to step A4, where SUM() represents a summation function; A4, if the difference ΔX 41 Exceeds the threshold value, and the difference ΔX 31 and the difference ΔX 42 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A5; A5. If the difference ΔX 41 and the difference ΔX 31 Both exceed the threshold value, and the difference ΔX 42 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A6; A6, if the difference ΔX 41 and the difference ΔX 42 Both exceed the threshold value, and the difference ΔX 31 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A7; A7, if the difference ΔX 41 , difference ΔX 31 and the difference ΔX 42 Both exceed the threshold value, and the difference ΔX 32 , difference ΔX 21 and the difference ΔX 43 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A8; A8, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 and the difference ΔX 43 Both exceed the threshold value, and the difference ΔX 32 and the difference ΔX 21 If both values ​​do not exceed the threshold, the atmospheric parameter voting value V X =X2, otherwise, Go to step A9; A9, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 and the difference ΔX 21 Both exceed the threshold value, and the difference ΔX 32 and the difference ΔX 43 If both values ​​do not exceed the threshold, the atmospheric parameter voting value V X =X3, otherwise, go to step A10; A10, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 21 and the difference ΔX 43 Both exceed the threshold value, and the difference ΔX 32 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A11; A11, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 and the difference ΔX 32 Both exceed the threshold value, and the difference ΔX 21 and the difference ΔX 43 If both do not exceed the threshold value, the voting fails and the atmospheric parameter voting value V X = voting value of atmospheric parameters in the previous period, otherwise, go to step A12; A12, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 and the difference ΔX 43 Both exceed the threshold value, and the difference ΔX 21 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A13; A13, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 and the difference ΔX 21 Both exceed the threshold value, and the difference ΔX 43 If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step A14; A14, if the difference ΔX 41 , difference ΔX 31 , difference ΔX 42 , difference ΔX 32 , difference ΔX 21 and the difference ΔX 43 If both exceed the threshold value, the voting fails and the atmospheric parameter voting value V X = Voting value of atmospheric parameters in the previous period.

6. The successive approximation type four-redundancy atmospheric parameter voting method according to claim 4, characterized in that: The specific steps of the three-redundancy atmospheric parameter voting in step S32 are: B1. Sort the three atmospheric data parameters in ascending order, including the minimum value X1', the middle value X2' and Maximum value X3'; B2. Calculate the difference between the minimum value X1', the middle value X2' and the maximum value X3', and get the difference ΔX 31 ', difference ΔX 32 ' and the difference ΔX 21 ', and make logical judgments; B3, if the difference ΔX 31 'If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, proceed to step B4, where SUM() represents a summation function; B4, if the difference ΔX 31 'Exceeds the threshold value, and the difference ΔX 32 ' and the difference ΔX 21 'Does not exceed the threshold value, then the atmospheric parameter voting value V X =X2, otherwise, go to step B5; B5, if the difference ΔX 31 ' and the difference ΔX 21 'All exceed the threshold value, and the difference ΔX 32 'If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step B6; B6, if the difference ΔX 31 ' and the difference ΔX 32 'All exceed the threshold value, and the difference ΔX 21 'If the threshold value is not exceeded, the atmospheric parameter voting value Otherwise, go to step B7; B7, if the difference ΔX 31 ', difference ΔX 32 ' and the difference ΔX 21 ' exceeds the threshold value, the vote fails, and the atmospheric parameter voting value V X = Voting value of atmospheric parameters in the previous period.

7. The successive approximation type four-redundancy atmospheric parameter voting method according to claim 4, characterized in that: The specific steps of dual-redundancy atmospheric parameter voting in step S33 are: C1. Sort the two atmospheric data parameters in ascending order, including the minimum value X1” and the maximum value X2”; C2, calculate the difference between the minimum value X1" and the maximum value X2", and get the difference ΔX 21 ", and make logical judgments; C3, if the difference ΔX 21 "Does not exceed the threshold value, then the atmospheric parameter voting value Otherwise, go to step C4, where SUM() represents a summation function; C4, if the difference ΔX 21 If the threshold value is exceeded, the voting fails and the atmospheric parameter voting value V X = Previous cycle Voting values ​​of atmospheric parameters.

8. The successive approximation type four-redundancy atmospheric parameter voting method according to claim 3 is characterized in that: The fault tree bottom events in step S4 include sensor drift X1, clock drift X2, common circuit failure X3, self-test circuit failure X4, power supply failure X5, frequency signal processing failure X6, sensor performance degradation X7, bus transmission failure X8, FPGA performance degradation X9, clock drift X10, common circuit failure X11, self-test circuit failure X12, FPGA performance degradation X13, CPU performance degradation X14, 429 communication failure X15 and power supply failure X16.

9. The successive approximation type four-redundant atmospheric parameter voting method according to claim 8, characterized in that: The probability of the pressure altitude / airspeed outputting erroneous data in step S6 The calculation formula is: in, Indicates that the pressure altitude / airspeed output is correct or lost. Indicates a redundancy in pressure altitude / airspeed output, correct data or loss. It indicates a redundant pressure altitude / airspeed output error data, and Xi indicates the bottom event of the fault tree.

Images