Radio altimeter testing method and testing device

Abstract

The present application relates to the field of avionics component testing. More particularly, the present application relates to a radio altimeter testing method and testing device. The method first acquires aviation characteristic data output by the radio altimeter under test; extracts fields from the aviation characteristic data to obtain characteristic fields, and determines whether the characteristic fields contain fault warning information; if the determination result is fault warning information, a fault warning instruction is issued; in response to the issuance of the fault warning instruction, a buzzer device is driven to issue a fault warning reminder. Distinguished from the prior art, the present application solves the problems of passive presentation of fault information, easy omission of transient faults, and false triggering of multi-path lightning signal crosstalk in traditional testing by real-time acquisition and analysis of the LABEL field and SSM field in the aviation characteristic data of the radio altimeter under test, and by the cooperative processing mechanism of active buzzer alarm and lightning strike test unique enable logic, thereby improving the timeliness of fault response, the safety of the testing process, and the maintenance efficiency.

Description

Technical Field

[0001] This invention relates to the field of avionics component testing. More specifically, this invention relates to a method and apparatus for testing radio altimeters. Background Technology

[0002] The ALA-52B radio altimeter is a lightweight solid-state digital airborne altimeter manufactured by Honeywell, widely used for terrain altitude measurement during aircraft landing and climb phases. This altimeter integrates two independent microprocessors: one for primary altitude calculation and the other for verifying the calculation results through independent comparison, thereby improving system reliability and safety. In current maintenance and testing practices, testing of the ALA-52B radio altimeter typically relies on general-purpose test instruments, such as discrete functional units (DFUs) (e.g., the T1201). These DFUs can display the airborne altitude and system status information output by the unit under test (UUT) in real time. However, existing testing methods have the following significant drawbacks:

[0003] Relying entirely on visual monitoring and lacking active alerts such as sound or other forms of notification makes it easy for maintenance personnel to overlook transient or intermittent fault information during multitasking or long-term testing. Fault response exhibits significant lag, severely impacting maintenance efficiency and testing reliability. Furthermore, the inability to effectively monitor changes in the status of the tested component while performing other operations results in poor work flexibility, easily leading to wasted manpower and the risk of misjudgment.

[0004] Meanwhile, operators need to manually set multiple switches to select pin type, lightning polarity, and enable channel. The system cannot automatically identify and block misoperations such as multiple enable switches being effective at the same time or mismatch between enable switches and pin types, which can easily lead to the false application of lightning strike signals, thereby damaging the tested component or the internal circuitry of the test equipment.

[0005] The existing ALA-52B radio altimeter testing method has significant shortcomings in terms of fault information identification, response timeliness, and user-friendly human-machine interaction. Summary of the Invention

[0006] To address the aforementioned technical problems related to fault information identification and timely response, this invention provides solutions in the following aspects.

[0007] In a first aspect, the present invention discloses a method for testing a radio altimeter, comprising: Step S10: Acquire the aeronautical feature data output by the radio altimeter under test; Step S20: Extract fields from the aviation feature data to obtain feature fields, and determine whether the feature fields contain fault warning information; Step S30: If the determination result is a fault warning message, then issue a fault alarm command; Step S40: In response to the issuance of the fault alarm command, drive the buzzer device to issue a fault warning reminder.

[0008] Preferably, field extraction from aviation feature data includes: Parse the data frame of aeronautical feature data according to the ARINC 429 protocol standard and extract the binary encoding of the LABEL and SSM fields; The value of the feature field is compared with a preset fault code table. If they match, it is determined to be a fault warning message.

[0009] Preferably, it also includes a lightning strike test, comprising the following steps: Select the type of pin to be tested; Determine the polarity of the lightning strike signal based on the pin type; Set the enable switch associated with the selected pin type to the ENABLE bit; The software monitors the status of all enable switches and performs interlock logic judgment. When there is one and only one enable switch in the ENABLE position and the pin type corresponding to the enable switch is consistent with the selected pin type, a lightning strike signal is generated and output to the device under test; otherwise, the generation of the lightning strike signal is prohibited and the fault indicator light is lit.

[0010] Preferably, the interlock logic judgment includes: Implemented by firmware interlock logic within the lightning strike signal control module, it ensures that at most one enable channel is in an effective state at any given time, forming a unique constraint on multiple enable switches; The interlocking mapping relationship between pins of the same type ensures that only one pin of the same type can be active at any given time, thus forming a hardware-level interlock.

[0011] Preferably, when the interlock condition is not met due to multiple enable switches being simultaneously in the ENABLE position, the fault mask corresponds to the first encoding value, and the fault indicator light illuminates at the first flashing frequency; when the interlock condition is not met due to the enable switch being inconsistent with the selected pin type, the fault mask corresponds to the second encoding value, and the fault indicator light illuminates at the second flashing frequency.

[0012] Preferably, in the electrical isolation channel, the lightning strike signal output channel is electrically isolated from other test signal channels using an optocoupler or similar device.

[0013] Preferably, the fault self-locking circuit maintains the state of prohibiting the output of lightning strike signals after detecting that the interlocking conditions are not met, until a manual reset signal or a system power failure restart signal is received, to prevent the accidental output of lightning strike signals without correcting the switch configuration.

[0014] Compared to existing technologies, this method solves the problem that traditional testing methods require maintenance personnel to passively judge the fault status of the tested component by continuously observing the display interface, making it difficult to capture transient or intermittent fault warning information. Furthermore, all fault alarm information can automatically trigger a buzzer alert and simultaneously record the timestamp of the fault occurrence and the corresponding ARINC 429 data frame. This means that the testing equipment itself possesses the dual functions of proactive alarm and fault log storage.

[0015] Furthermore, this invention employs an interlocking mechanism in lightning strike testing, combining the uniqueness judgment logic of the enable switch with the pin type consistency verification, to output a lightning strike signal only when a single enable is available and the type matches. It also uses a fault indicator light to provide differentiated flashing alarms for different abnormal causes (multiple enable conflicts, type mismatches), while employing a fault self-locking circuit to prevent erroneous output. This effectively avoids crosstalk and false triggering risks from multiple lightning strike signals, significantly improving the safety and reliability of the testing process.

[0016] In a second aspect, the present invention discloses a radio altimeter testing device, comprising: The ARINC 429 transceiver is used to receive aeronautical signature data output from the radio altimeter being measured. The controller, connected to the ARINC 429 transceiver, is used to acquire the aeronautical characteristic data output by the radio altimeter under test and issue fault alarm commands. A buzzer, connected to the controller, is used to trigger the buzzer device to receive fault alarm commands and issue fault warning reminders.

[0017] Preferred options also include: A discrete state judgment circuit, integrated within the lightning strike signal control circuit, is used to detect the state of multiple enable switches and the type of the tested pin. The fault indicator light, as the output of the lightning strike signal control circuit, is triggered by the discrete state judgment circuit to light up when multiple enable switches are simultaneously in the ENABLE position, or when the enable switch is inconsistent with the selected pin type being tested.

[0018] Preferably, the ARINC 429 transceiver includes: The timing control module, equipped with an FPGA chip and connected to the controller, is used to generate a serial data transmission timing sequence conforming to the ARINC 429 standard according to the controller's scheduling instructions, and simultaneously parse the serial data stream of the receiving channel in parallel. The level conversion module is connected between the FPGA chip and the relay module. It is used to convert the TTL / CMOS level signal output by the FPGA into a signal conforming to the ARINC 429 specification, and to convert the received signal into a logic level that the FPGA can recognize.

[0019] The beneficial effects of this invention are as follows: By acquiring the aviation characteristic data output by the tested radio altimeter in real time and parsing the LABEL and SSM fields, combined with a buzzer device to actively trigger fault warnings, this solves the problem in traditional testing methods where maintenance personnel can only continuously observe the display interface, easily missing transient or intermittent fault information, thus improving the timeliness of fault response and the reliability of testing. The lightning strike signal control module is configured with enable switch uniqueness judgment logic and pin type consistency verification, outputting a lightning strike signal only when a single enable is available and the type matches, and illuminating the fault indicator light in case of operational conflicts, avoiding the risk of multi-channel signal crosstalk and false triggering, and ensuring the safety of the tested component and testing equipment. Based on the ARINC429 protocol, fault data frames are parsed and timestamps are associated to generate fault logs. All alarm events can be traced back to specific data frames, providing a structured record basis for fault analysis and maintenance closed-loop. Attached Figure Description

[0020] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, and like or corresponding reference numerals denote like or corresponding parts, wherein: Figure 1 This is a flowchart of the active fault alarm steps in the radio altimeter testing method in Example 1; Figure 2 This is a flowchart of the lightning strike test steps in the radio altimeter test method of Example 1; Figure 3 This is a diagram showing the test system composition of the radio altimeter test method in Example 1; Figure 4 This is a schematic diagram of the radio altimeter testing equipment in Example 2. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] Example 1 like Figure 1 As shown, this embodiment discloses a method for testing a radio altimeter, including a fault active alarm step: Step S10: Acquire the aeronautical feature data output by the radio altimeter under test.

[0024] In this embodiment, the ALA-52B radio altimeter under test outputs a pair of differential signals according to the ARINC 429 aviation data bus standard. These signals are connected to the J1 interface input on the front panel of the test equipment via a dedicated test cable. The level conversion circuit inside the test equipment converts the differential signals to a 3.3V LVTTL logic level that the FPGA chip can recognize, while simultaneously achieving signal isolation and impedance matching to ensure data integrity during transmission. The FPGA chip is internally programmed with a timing control program that strictly follows the ARINC 429 protocol specification to parallelize the serial data stream and uploads the received data to the main control module via the parallel bus interface. ARINC 429 data words are in 32-bit format, where bit 32 is the parity bit, bits 31-30 are SSM, bits 29-11 are data, bits 10-9 are SDI, and bits 8-1 are LABEL.

[0025] It should be noted that in the normal ARINC 429 protocol, the least significant bit is usually transmitted first, which is common knowledge in this technical field and will not be explained in this article.

[0026] The main control module receives the ARINC429 data uploaded by the FPGA, extracts the LABEL, SDI, data field, and SSM field sequentially, and performs parity checking. At this point, the main control module's cache contains structured aeronautical feature data after protocol alignment and field separation, including the original data words and the parsed SSM field values.

[0027] Step S20: Extract fields from the aviation feature data to obtain feature fields, and determine whether the feature fields contain fault warning information.

[0028] Preferably, field extraction from aviation feature data includes: Parse the data frame of aeronautical feature data according to the ARINC 429 protocol standard and extract the binary encoding of the LABEL and SSM fields; The value of the feature field is compared with the preset fault code table. If they match, it is determined to be a fault warning message.

[0029] In this embodiment, after the main control module (i.e., the STM32 microcontroller) obtains the complete 32-bit ARINC 429 data word from its internal cache, the software program parses the data word bit by bit according to the ARINC 429 protocol standard. First, bits 1 to 8 are located as the LABEL field, and bits 30 to 31 are the binary encoding of the SSM field. The program extracts the binary values ​​of the LABEL and SSM fields through bitmasking operations and determines whether the encoding corresponds to a fault state.

[0030] It should be noted that this fault code table is pre-built according to the standard definitions of the LABEL and SSM fields in the ARINC 429 protocol and the maintenance manual of the ALA-52B radio altimeter, and is stored in the internal memory of the main control module.

[0031] For ease of subsequent description, the two main control programs involved in this invention are defined as follows: The controller (STM32 microcontroller) runs a first control program, which is responsible for parsing the received ARINC 429 data frames, extracting the LABEL and SSM fields, comparing fault codes, and generating and outputting fault alarm commands; at the same time, it acquires the status of the test equipment toggle switch (except for the lightning strike test part) and the discrete status information of the tested radio altimeter, and sends the status parsing information to the relay matrix module, the discrete configuration module, and the status display module.

[0032] The lightning strike signal control module has a second control program (hereinafter referred to as the second program) that runs independently. This program is specifically responsible for scanning the status of the enable switch, scanning the status of the pin type, verifying the pin type matching, controlling the generation of the lightning strike signal, and illuminating the fault indicator during the lightning strike test process.

[0033] The first control program and the second control program run independently of each other, each completing a different test task.

[0034] Step S30: If the determination result is a fault warning message, then issue a fault alarm command.

[0035] In this embodiment, after the first control program of the main control module, i.e., the STM32 microcontroller, completes the comparison of the binary encoding of the LABEL and SSM fields with the preset fault code table and confirms that it is a fault warning message, the program immediately executes the alarm instruction generation and output process. First, the first control program sets a fault warning flag bit in the internal memory, which is used to record the currently unprocessed fault state. Subsequently, the program performs level operation on the control pin connected to the buzzer device by calling the underlying hardware driver interface.

[0036] Specifically, the main control module has a dedicated output pin for enabling the buzzer among its general purpose input / output (GPIO) pins. The program pulls this pin from low to high; this high-level signal serves as the fault alarm command. This high-level signal is transmitted directly to the input of the buzzer driver circuit via the internal control bus of the test equipment. Only when subsequent received data frames are determined to no longer contain fault warning information will the first control program restore the GPIO pin to low, thus issuing a stop alarm command.

[0037] It should be noted that the buzzer driver circuit is common knowledge to those skilled in the art, and will not be described in detail in this embodiment.

[0038] Step S40: In response to the issuance of the fault alarm command, drive the buzzer device to issue a fault warning reminder.

[0039] In this embodiment, when the GPIO pin of the main control module outputs a high-level fault alarm command, the high-level signal is directly transmitted to the input terminal of the buzzer driver circuit via the control traces on the PCB board.

[0040] In the initial idle state, the GPIO pin outputs a low level, the transistor is in the cutoff region, the buzzer power supply circuit is disconnected, and the buzzer is silent. When a fault alarm command arrives, i.e., the GPIO pin goes high, the base of the transistor receives a forward bias current, the transistor conducts, and the voltage drop between its collector and emitter approaches zero, thereby pulling the negative terminal of the buzzer down to ground potential. The buzzer receives its rated operating voltage, the internal piezoelectric ceramic plate or electromagnetic coil begins to oscillate, driving the diaphragm to generate audio vibration and emit a continuous buzzing sound.

[0041] During the buzzer's sound, the main control module's first control program continuously monitors the LABEL and SSM fields of subsequently received ARINC429 data frames. Once the fault warning message is detected to have disappeared (i.e., the LABEL and SSM fields no longer match the fault code in the fault code table), the program restores the GPIO pin to a low level, turns off the transistor, interrupts the buzzer's power supply, and stops the sound.

[0042] like Figure 2 As shown, this embodiment discloses a method for testing a radio altimeter, which also includes a lightning strike test step: Select the type of pin to be tested; Determine the polarity of the lightning strike signal based on the pin type; Set the enable switch associated with the selected pin type to the ENABLE bit; The software monitors the status of all enable switches and performs interlock logic judgment. When there is one and only one enable switch in the ENABLE position and the pin type corresponding to the enable switch is consistent with the selected pin type, a lightning strike signal is generated and output to the device under test; otherwise, the generation of the lightning strike signal is prohibited and the fault indicator light is lit.

[0043] In this embodiment, the pin types of the radio altimeter under test that require lightning strike testing are divided into three main categories: unidirectional diode pins, bidirectional diode pins, and power supply pins. The bidirectional diode pins are further subdivided into ARINC 429 receive signal pins (429RX), ARINC 429 transmit signal pins (429TX), discrete output signal pins, and discrete input signal pins; the power supply pins mainly refer to the BP-9 pins.

[0044] The type of lightning strike signal and the test connection method provided by the testing equipment vary depending on the type of pin. For example, for a unidirectional diode pin, the multimeter needs to be set to diode mode and the forward voltage drop across the pin needs to be read. For a bidirectional diode pin, an oscilloscope needs to be used to observe the positive and negative pulse waveforms simultaneously to verify whether the diode's clamping characteristics are normal under forward and reverse voltages. For the power supply pin BP-9, an external DC power supply needs to be connected and reversed.

[0045] The front panel of the test equipment has multiple enable switches, corresponding to different pin types such as discrete output (DISC_OUT), discrete input (DISC_IN), ARINC 429 transmit (429TX), ARINC 429 receive (429RX), and power pin BP-9. Each enable switch is directly connected to the input port of the lightning strike signal control module. This lightning strike signal control module has a built-in independent second control program (hereinafter referred to as the second program), which is specifically responsible for the enable logic judgment, signal generation, and safety interlocking of the lightning strike test.

[0046] The second program reads the physical level status of all enable switches every few milliseconds using a cyclic scanning method. When a switch is set to the ENABLE position, its corresponding input port is at a low level; when set to the DISABLE position, it is at a high level. Simultaneously, the second program also reads the position codes of multiple rotary switches on the front panel to determine the specific pin type under test (e.g., selecting DISC_IN via the DIODE knob) and the polarity of the lightning strike signal (POS or NEG). Furthermore, the second program monitors other rotary switches and toggle switches in the "LIGHTNING TEST" area.

[0047] After acquiring all switch states, the second procedure first counts the number of enable switches that are low. If the number is not 1, it is determined to be an operational abnormality. The fault indicator light on the front panel is immediately illuminated via the fault indicator light driver circuit, and no trigger command is output to the lightning strike signal generation circuit, thus preventing the generation of a lightning strike signal. Simultaneously, the fault indicator light remains illuminated until the operator switches the excess enable switches back to the DISABLE position. This design mandates that only one pin type can be tested for lightning strikes at a time.

[0048] If the quantity is exactly 1, the second program further determines whether the pin type corresponding to the unique enable switch is consistent with the pin type selected by the rotary switch. For example, if the enable switch is "DISC_OUT" and the rotary switch "DIODE" is also in the "DISC_OUT" position, then the type is considered to match; if the enable switch is "DISC_OUT" but the rotary switch "DIODE" is not in the "DISC_OUT" position, then the type does not match. When the types match, the second program generates the corresponding control signal according to the polarity selection bit of the rotary switch: if the POS bit is selected, the lightning strike signal generating circuit is controlled to output a positive pulse waveform; if the NEG bit is selected, a negative pulse waveform is output. For pin types that do not require polarity selection (such as unidirectional diode testing), the second program directly outputs the default test signal.

[0049] The lightning strike signal control circuit performs pulse shaping to ensure the pulse signal width and rise time meet requirements, guaranteeing compliance with the lightning withstand test requirements of both ARINC 429 and discrete interfaces. The output of the lightning strike signal control circuit is connected to an isolation circuit using optocouplers to completely isolate the high-voltage lightning strike portion from the low-voltage control circuit of the test equipment. This prevents the lightning pulse from back-currently entering the controller or FPGA chip, thus protecting both the test equipment and the component under test. The isolated lightning strike signal is then applied to the corresponding pin of the radio altimeter under test via a test cable.

[0050] The entire judgment and enabling process is completed independently by the second program of the lightning strike signal control module, without relying on the main control module. Even if the main control module malfunctions or crashes, the second program can still execute the safety interlock logic based on the physical state of the front panel switch to ensure that no false lightning strike signal is issued.

[0051] Preferably, the interlock logic judgment includes: Implemented by firmware interlock logic within the lightning strike signal control module, it ensures that at most one enable channel is in an effective state at any given time, forming a unique constraint on multiple enable switches; The interlocking mapping relationship between pins of the same type ensures that only one pin of the same type can be active at any given time, thus forming a hardware-level interlock.

[0052] In this embodiment, the front panel of the test equipment is equipped with multiple sets of enable toggle switches, corresponding to discrete output, discrete input, ARINC 429 transmit, ARINC 429 receive, and power pin BP-9, respectively. The output of each enable switch is directly connected to the input port of the lightning strike signal control module. The lightning strike signal control module is equipped with an independent microcontroller, which contains a dedicated interlocking logic program. The program reads the level status of the general-purpose input / output pins corresponding to all enable switches every few milliseconds in a cyclic scanning manner. When the switch is set to the ENABLE position, the pin is at a low level; when it is set to the DISABLE position, it is at a high level. After acquiring all switch states, the program counts the number of enable switches at a high level. If the number is greater than 1, it is determined that the interlocking condition is not met. The front panel fault indicator is immediately illuminated through the drive circuit, and no trigger command is output to the lightning strike signal generation circuit, thereby ensuring that at most one enable channel is in an effective state at any given time. If the quantity is exactly 1, the program further determines whether the pin type corresponding to the unique enable switch is consistent with the pin type selected by the rotary switch. Only when the types are consistent will an enable signal be output.

[0053] For cases where there are multiple specific pins within the same pin type, such as a total of 12 discrete input pins (corresponding to positions 1 to 12 of the DISC_IN knob), and the ARINC 429 transmit pins divided into four pins: 1A, 1B, 2A, and 2B, the test equipment selects the specific pin number through a multi-position rotary switch on the front panel.

[0054] Preferably, when the interlock condition is not met due to multiple enable switches being simultaneously in the ENABLE position, the fault mask corresponds to the first encoding value, and the fault indicator light illuminates at the first flashing frequency; when the interlock condition is not met due to the enable switch being inconsistent with the selected pin type, the fault mask corresponds to the second encoding value, and the fault indicator light illuminates at the second flashing frequency.

[0055] In this embodiment, after completing the interlock logic judgment, the independent microcontroller inside the lightning strike signal control module generates different fault mask values ​​based on the specific reasons for the non-compliance if it determines that the interlock conditions are not met. The microcontroller internally presets two fault masks: the first encoding value corresponds to the fault type of "multiple enable switches simultaneously in the ENABLE position," and the second encoding value corresponds to the fault type of "a single enable switch in the ENABLE position, but its corresponding pin type is inconsistent with the pin type selected by the rotary switch." Based on the different fault masks, the microcontroller outputs pulse width modulation signals of different frequencies through its general-purpose input / output pins. These signals are connected to the drive circuit of the fault indicator light. When the pulse signal corresponding to the first encoding value is output, the drive circuit controls the fault indicator light to illuminate at a first flashing frequency (e.g., rapid flashing, approximately 5 times per second); when the pulse signal corresponding to the second encoding value is output, the fault indicator light illuminates at a second flashing frequency (e.g., slow flashing, approximately 1 time per second).

[0056] Preferably, in the electrical isolation channel, the lightning strike signal output channel is electrically isolated from other test signal channels using an optocoupler or similar device.

[0057] In this embodiment, an optocoupler is connected in series between the output of the lightning strike signal control module and the test cable. The input side of the optocoupler is connected to the lightning strike signal control circuit, and the output side is connected to the corresponding pin of the lightning strike signal generator and the radio altimeter under test. The lightning strike signal control circuit achieves electrical isolation between the input and output by controlling the optocoupler. Meanwhile, other test signal channels within the test equipment (such as ARINC 429 communication signals, discrete input / output signals, power supply lines, etc.) use independent wiring from the lightning strike signal test channel and have no direct electrical connection to each other.

[0058] Preferably, the fault self-locking circuit maintains the state of prohibiting the output of lightning strike signals after detecting that the interlocking conditions are not met, until a manual reset signal or a system power failure restart signal is received, to prevent the accidental output of lightning strike signals without correcting the switch configuration.

[0059] In this embodiment, when the independent microcontroller inside the lightning strike signal control module detects for the first time that the interlocking condition is not met (e.g., multiple enable switches are simultaneously in the ENABLE position, or the only enable switch is inconsistent with the selected pin type), it immediately sets a "fault lockout flag" in its internal register. Once this flag is set, the microcontroller will no longer respond to any subsequent enable switch operations or lightning strike signal generation commands, and the output of the lightning strike signal generation circuit will be forcibly cut off, prohibiting any lightning strike signal output to the device under test. The fault lockout flag will not be automatically cleared with subsequent changes in switch states. Even if the user subsequently switches the remaining enable switches back to the DISABLE position or adjusts the rotary switch to the correct position, the lightning strike signal output will remain disabled. Only when the user performs a manual reset operation (e.g., pressing the dedicated reset button on the front panel of the test equipment, or switching all fault-related enable switches to the DISABLE position and then toggling them again in a specific order) or power-offs and restarts the test equipment will the microcontroller clear the fault lockout flag and restart the normal lightning strike test interlocking judgment process. This self-locking mechanism ensures that the test equipment will not output a lightning strike signal due to accidental changes in the switch state until the reason for the failure to meet the interlocking conditions is actively confirmed and corrected by the user, effectively avoiding safety risks caused by operational negligence.

[0060] like Figure 3 As shown, the test system of this invention comprises two main parts: the ALA-52B radio altimeter under test and the test equipment. The radio altimeter under test provides a J1 interface and a maintenance interface. The J1 interface is used for receiving and transmitting aviation characteristic data and discrete signals, while the maintenance interface is used to connect to a host computer for operations such as fault memory clearing and BITE testing. The test equipment includes dedicated test equipment (radio altimeter test equipment) and general test equipment (multimeter, oscilloscope, DC power supply, discrete functional components, etc.). The radio altimeter test equipment connects to the J1 interface of the component under test via a dedicated test cable. Simultaneously, the radio altimeter under test communicates with the PC host, which contains host computer software. The radio altimeter test equipment also provides external instrument interfaces such as DMM, SCOP, PS, and T1201A, used to connect digital multimeters, oscilloscopes, DC power supplies, and discrete functional components, respectively. Furthermore, a power analyzer and a spectrum analyzer can be directly connected to the P1 interface of the component under test for measuring transmit power and spectral characteristics.

[0061] Example 2 This embodiment discloses a radio altimeter testing device, which includes: The ARINC 429 transceiver is used to receive aeronautical signature data output from the radio altimeter being measured. The controller, connected to the ARINC 429 transceiver, is used to acquire the aeronautical characteristic data output by the radio altimeter under test and to issue fault alarm commands. A buzzer, connected to the controller, is used to trigger the buzzer device to receive fault alarm commands and issue fault warning reminders.

[0062] Preferably, the testing equipment also includes: The lightning strike signal control circuit is used to monitor the status of the front panel enable switch and rotary switch, and control the generation of a lightning strike signal. Discrete state judgment circuit, integrated into the lightning strike signal control circuit, is used to detect the state of multiple enable switches and the type of the tested pin; The fault indicator light, as the output of the lightning strike signal control circuit, illuminates when multiple enable switches are simultaneously in the ENABLE position, or when the enable switch is inconsistent with the selected pin type being tested, triggering the discrete state judgment circuit to illuminate the fault indicator light.

[0063] Preferred options also include: The timing control module, equipped with an FPGA chip and connected to the controller, is used to generate a serial data transmission timing sequence conforming to the ARINC 429 standard according to the controller's scheduling instructions, and simultaneously parse the serial data stream of the receiving channel in parallel. The level conversion module is connected between the FPGA chip and the relay module. It is used to convert the TTL / CMOS level signal output by the FPGA into a signal conforming to the ARINC 429 specification, and to convert the received signal into a logic level that the FPGA can recognize.

[0064] Most importantly, it also includes: The power supply module is connected to the controller, ARINC 429 transceiver, buzzer and lightning strike signal control module respectively, and is used to provide working power; The relay matrix module is connected to the controller, ARINC 429 transceiver, buzzer, discrete configuration module and lightning strike signal control module, and is used to receive instructions from the controller and / or lightning strike signal control module to switch test channels. A discrete configuration module, connected to the controller, is used to receive instructions from the controller to configure discrete quantities; The status indication module, connected to the controller, is used to display the status of the discrete output of the radio altimeter under test and the operating status of the test equipment.

[0065] It should be added that the lightning strike signal control circuit and the controller are independent hardware modules. The lightning strike signal control circuit contains an independent microcontroller or logic circuit, which can complete the enable switch state scanning, interlock judgment and lightning strike signal generation without relying on the controller's instructions.

[0066] like Figure 4 As shown, in this embodiment, the controller is implemented as a controller, the FPGA chip is integrated into the timing control module, the level conversion circuit is the level conversion module, the lightning strike signal control circuit is the lightning strike signal control module, the power supply circuit is the power supply module, the relay matrix is ​​the relay module, the discrete configuration circuit is the discrete configuration module, and the status indicator group is the status display module.

[0067] The principle block diagram of the radio altimeter test equipment in this embodiment includes a controller, a timing control module, a level conversion module, a power supply module, a lightning strike signal control module, a relay module, a discrete configuration module, a status display module, and a test cable. The controller, as the core control unit, connects to each module; the timing control module and the level conversion module work together to transmit and receive ARINC 429 data and perform protocol parsing; the power supply module provides a stable operating voltage for the entire test equipment; the lightning strike signal control module independently handles the enable logic and signal generation for lightning strike testing; the relay module is responsible for switching test channels; the discrete configuration module and the status display module respectively complete the configuration and status indication of discrete quantities; the test cable connects the component under test to the internal circuitry of the test equipment. External input 1 and external input 2 represent user operation inputs such as front panel toggle switches and rotary switches, and measurement signal inputs from external instruments such as multimeters and oscilloscopes, respectively.

[0068] In this embodiment, the operating logic of the test equipment is as follows: The power supply circuit provides operating power to the controller, ARINC 429 transceiver, buzzer, and all other modules. After the test equipment starts up, the controller works in conjunction with the ARINC 429 transceiver through the FPGA chip and level conversion circuit: the level conversion circuit converts the differential signal received by the ARINC 429 transceiver into a logic level that the FPGA can recognize; the FPGA chip generates a serial data transmission timing sequence conforming to the ARINC 429 standard according to the controller's scheduling instructions, and simultaneously parses the serial data stream of the receiving channel in parallel, uploading the parsed aviation characteristic data to the controller. After acquiring this data, the controller analyzes it to determine whether it contains fault warning information. If a fault is detected, a fault alarm command is issued to drive the buzzer to emit an audible alert, and the fault status can be displayed through the status indicator group. When performing other tests, such as discrete quantity tests, the controller switches test channels through a relay matrix and configures the discrete input and output status through a discrete configuration circuit. The status indicator group displays the discrete output status of the tested radio altimeter and the status of the test equipment itself in real time. For lightning strike testing, the lightning strike signal control circuit independently monitors the status of the front panel enable switch and rotary switch. Its internal discrete state judgment circuit detects the status of multiple enable switches: if and only if one enable switch is in the ENABLE position and the type matches, the corresponding lightning strike signal is generated; if multiple enable switches are in the ENABLE position at the same time, or if the enable switch is inconsistent with the type of the selected pin under test, the fault indicator light is triggered and the generation of the lightning strike signal is prohibited.

[0069] The testing equipment also includes other components well known to those skilled in the art, such as communication interfaces. Their settings and functions are known in the art and will not be described in detail here.

[0070] In this invention, the aforementioned memory can be any tangible medium containing or storing a program that can be used or combined with an instruction execution system, apparatus, or device. For example, a computer-readable storage medium can be any suitable magnetic or magneto-optical storage medium, such as Resistive Random Access Memory (RRAM), Dynamic Random Access Memory (DRAM), Static Random Access Memory (SRAM), Enhanced Dynamic Random Access Memory (EDRAM), High-Bandwidth Memory (HBM), Hybrid Memory Cube (HMC), etc., or any other medium that can be used to store desired information and can be accessed by an application, module, or both. Any such computer storage medium can be part of, accessible to, or connected to a test device. Any application or module described in this invention can be implemented using computer-readable / executable instructions that can be stored or otherwise maintained by such a computer-readable medium.

[0071] In the description of this specification, "multiple" means at least two, such as two, three or more, etc., unless otherwise expressly and specifically defined.

[0072] While this specification has shown and described numerous embodiments of the invention, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Many modifications, alterations, and alternatives will occur to those skilled in the art without departing from the spirit and essence of the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in the practice of this invention.

Claims

1. A method for testing a radio altimeter, characterized in that, Including proactive fault alarm procedures: Step S10: Acquire the aeronautical feature data output by the radio altimeter under test; Step S20: Extract fields from the aviation feature data to obtain feature fields, and determine whether the feature fields contain fault warning information; Step S30: If the determination result is a fault warning message, then issue a fault alarm command; Step S40: In response to the issuance of the fault alarm command, drive the buzzer device to issue a fault warning reminder.

2. The radio altimeter testing method according to claim 1, characterized in that, Field extraction from aviation feature data includes: Parse the data frame of aeronautical feature data according to the ARINC 429 protocol standard and extract the binary encoding of the LABEL and SSM fields; The value of the feature field is compared with a preset fault code table. If they match, it is determined to be a fault warning message.

3. The radio altimeter testing method according to claim 1, characterized in that, It also includes lightning strike testing procedures, specifically: Select the type of pin to be tested; Determine the polarity of the lightning strike signal based on the pin type; Set the enable switch associated with the selected pin type to the ENABLE bit; The software monitors the status of all enable switches and performs interlock logic judgment. When there is one and only one enable switch in the ENABLE position and the pin type corresponding to the enable switch is consistent with the selected pin type, a lightning strike signal is generated and output to the device under test; otherwise, the generation of the lightning strike signal is prohibited and the fault indicator light is lit.

4. The radio altimeter testing method according to claim 3, characterized in that, In the lightning strike test procedure, the interlocking logic judgment includes: Implemented by firmware interlock logic within the lightning strike signal control module, it ensures that at most one enable channel is in an effective state at any given time, forming a unique constraint on multiple enable switches; The interlocking mapping relationship between pins of the same type ensures that only one pin of the same type can be active at any given time, thus forming a hardware-level interlock.

5. The radio altimeter testing method according to claim 4, characterized in that, During the lightning strike test, when the interlock condition is not met due to multiple enable switches being simultaneously in the ENABLE position, the fault mask corresponds to the first encoding value, and the fault indicator light illuminates at the first flashing frequency; when the interlock condition is not met due to the enable switch being inconsistent with the selected pin type, the fault mask corresponds to the second encoding value, and the fault indicator light illuminates at the second flashing frequency.

6. The radio altimeter testing method according to claim 3, characterized in that, In the lightning strike test procedure, an optocoupler is used to electrically isolate the lightning strike signal output channel from other test signal channels.

7. The radio altimeter testing method according to claim 3, characterized in that, In the lightning strike test procedure: The fault self-locking circuit maintains the state of prohibiting the output of lightning strike signals after detecting that the interlocking conditions are not met, until a manual reset signal or a system power failure restart signal is received, to prevent the accidental output of lightning strike signals without correcting the switch configuration.

8. A radio altimeter testing device, characterized in that, The test apparatus for the radio altimeter test method according to any one of claims 1-7 comprises: The ARINC 429 transceiver is used to receive aeronautical signature data output from the radio altimeter being measured. The controller, connected to the ARINC 429 transceiver, is used to acquire the aeronautical characteristic data output by the radio altimeter under test and issue fault alarm commands. A buzzer, connected to the controller, is used to trigger the buzzer device to receive fault alarm commands and issue fault warning reminders.

9. The radio altimeter testing device according to claim 8, characterized in that, The testing equipment also includes: The lightning strike signal control circuit is used to monitor the status of the front panel enable switch and rotary switch, and control the generation of a lightning strike signal. A discrete state judgment circuit, integrated within the lightning strike signal control circuit, is used to detect the state of multiple enable switches and the type of the tested pin. The fault indicator light, as the output of the lightning strike signal control circuit, is triggered by the discrete state judgment circuit to light up when multiple enable switches are simultaneously in the ENABLE position, or when the enable switch is inconsistent with the selected pin type being tested.

10. The radio altimeter testing device according to claim 8, characterized in that, The ARINC 429 transceiver includes: The timing control module, equipped with an FPGA chip and connected to the controller, is used to generate a serial data transmission timing sequence conforming to the ARINC 429 standard according to the controller's scheduling instructions, and simultaneously parse the serial data stream of the receiving channel in parallel. The level conversion module is connected between the FPGA chip and the relay module. It is used to convert the TTL / CMOS level signal output by the FPGA into a signal conforming to the ARINC 429 specification, and to convert the received signal into a logic level that the FPGA can recognize.

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