Cabin pressure controller closed loop dynamic test system

Abstract

This invention relates to the field of aircraft cockpit pressurization system testing technology, specifically to a closed-loop dynamic testing system for aircraft cockpit pressure controllers. It solves the problem of incomplete simulation of the operating conditions of cockpit pressurization controllers, leading to unsatisfactory offline performance testing of aircraft cockpit pressurization systems and difficulty in accurately verifying cabin pressure rates during closed-loop equilibrium. The system includes: a power module providing operating power to the cockpit pressure controller under test; a test adapter interface box electrically connected to the cockpit pressure controller under test, providing signal conditioning, switching control, load simulation, and closed-loop control functions; and an industrial control computer with a built-in ARINC429 communication board, communicating with the test adapter interface box and a digital multimeter via RS232 / RS485 bus. This invention, through a two-stage integrating circuit and software configuration framework, completes the simulation of the full operating conditions of the cockpit pressure controller, achieving comprehensive offline performance testing of the aircraft cockpit pressurization system.

Description

Technical Field

[0001] This invention relates to the field of aircraft cabin pressurization system testing technology, specifically to a closed-loop dynamic testing system for aircraft cabin pressure controllers. Background Technology

[0002] The aircraft cabin pressurization system is used to control the cabin pressure. It can automatically adjust the cabin pressure according to the aircraft's altitude, climb rate, and other flight conditions to ensure that the cabin pressure changes according to a preset pattern. The system generally consists of three parts: a control panel, a cabin pressure controller, and an outflow valve. The control panel is used to set system control parameters such as the maximum rate of change of cabin pressure, landing airport altitude, and control mode. The cabin pressure controller is the core of the entire system. Based on real-time data collection of the aircraft's status, it adjusts the cabin pressure by controlling the action of the outflow valve. The outflow valve is the actuator of the cabin pressure control system. The opening and closing of the valve controls the rate of air overflow from inside and outside the cabin, i.e., the flow rate, which in turn affects the cabin pressure value. The cabin pressurization system of the B757 / 767 series aircraft was developed by Honeywell Corporation of the United States. The core control component, the cabin pressure controller, is a digital computer. The pressurization system is equipped with two controllers, which control one set of outflow valves to achieve dual-redundancy control. The working controller can be specified by the mode selection switch on the operation panel. When the controller fails during self-test, the system automatically switches to the other controller. The controller function test requires special testing equipment.

[0003] The simulation of the operating conditions of the cabin pressurization controller is incomplete, resulting in unsatisfactory offline performance testing of the aircraft cabin pressurization system and difficulty in accurately verifying the cabin pressure rate during closed-loop equilibrium. Therefore, it does not meet the existing requirements. To address this, we propose a closed-loop dynamic testing system for the aircraft cabin pressure controller. Summary of the Invention

[0004] The purpose of this invention is to provide a closed-loop dynamic testing system for aircraft cabin pressure controllers, in order to solve the problem mentioned in the background art that the simulation of the working conditions of the cabin pressurization controller is incomplete, resulting in unsatisfactory offline performance testing of the aircraft cabin pressurization system and difficulty in accurately verifying the cabin pressure rate during closed-loop equilibrium.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a closed-loop dynamic testing system for aircraft cabin pressure controllers, comprising: The power module is used to provide operating power to the pressure controller of the cabin under test. Test adapter interface box. The test adapter interface box is electrically connected to the pressure controller of the cabin under test and is used to provide signal conditioning, switching control, load simulation and closed-loop control functions. The industrial control computer has a built-in ARINC429 communication board, which communicates with the test adapter interface box and digital multimeter via RS232 / RS485 bus; Atmospheric data analyzer is used to provide a controllable air source for the pressure controller of the cabin under test and to simulate cabin pressure changes; A digital multimeter is used to measure the output signal of the cabin pressure controller under test. The industrial control computer operation and testing software automatically adjusts the analog input signal based on the collected output signal of the cabin pressure controller under test, thereby realizing closed-loop dynamic testing of the cabin pressure controller under test.

[0006] Preferably, the power module includes: The medium-frequency AC power supply outputs 115V and 400Hz, and is used to provide working power to the pressure controller of the cockpit under test. DC control power supply, outputting 28V, 24V and 5V, used to power the internal modules of the test adapter interface box.

[0007] Preferably, the test adapter interface box includes: Panel potentiometer module, used to simulate the landing altitude selection potentiometer and pressure rate selection potentiometer on the cabin pressure control panel; The switch control module is used to control the switch input, power supply on / off of the pressure controller under test cabin, and the selection of measurement signals by the multimeter. The signal conditioning module is used to condition and acquire the analog input / output signals and digital output signals of the cabin pressure controller under test. Speed ​​feedback generation module, used to generate simulated external flow valve speed feedback signal; The pressure-controlled closed-loop control module is used to generate simulated pressure signals and implement rate closed-loop control. The serial decoding module is used to decode the synchronous serial maintenance information output by the pressure controller of the test cabin into an RS232 signal. The load module is used to provide a switchable analog load to the valve drive output of the pressure controller of the cabin under test.

[0008] Preferably, the switch control module includes: The first relay board is an intelligent 32-channel relay DO board that receives instructions from the industrial control computer via RS485 bus to control switch inputs and power supply on / off. The second relay board is a 16-channel double-pole double-position relay cascade circuit, used to expand the number of contacts of the first relay board and realize the selection of multimeter measurement signals.

[0009] Preferably, the signal conditioning module includes: Analog input / output board: The analog input / output board communicates with the industrial computer via RS485 bus to acquire the conditioned valve drive signal and output analog control signal; Hall voltage sensor module: The Hall voltage sensor module is used to detect the AC drive signal of the valve of the pressure controller of the cabin under test and convert it into an isolated AC signal. The rectifier and filter circuit, which consists of an operational amplifier, diodes, and resistive and capacitive components, converts the AC signal output by the Hall voltage sensor module into a DC voltage and outputs it to the analog input / output board. The digital input acquisition module is used to acquire the digital output signal of the cabin pressure controller under test after optocoupler isolation and level conversion.

[0010] Preferably, the speed feedback generation module includes: The synchronous square wave generation circuit samples the 115V power supply, and after shaping and isolation by a comparator and optocoupler, generates a square wave signal with the same frequency as the power supply. The amplitude control circuit controls the amplitude of the output square wave according to the TACH DC control signal output by the industrial control computer. The phase control circuit controls the phase relationship between the output square wave signal and the 115V power supply based on the polarity of the TACH DC control signal.

[0011] Preferably, the chamber pressure closed-loop control module includes: The integral direction control circuit compares the conditioned gate drive signal with a preset threshold or limit to generate OPEN Ctrl and CLOSE Ctrl level signals to control the integral direction. A two-stage rate integrator circuit, comprising a first-stage integrator circuit and a second-stage integrator circuit, is cascaded to perform integration operations on the input signal; The reset control circuit controls the operating state of the two-stage rate integral circuit based on the reset signal output by the industrial control computer.

[0012] Preferably, the serial decoding module includes an 8051 microcontroller, which acquires and decodes the clock signal SCLK and data output signal SDATA in the synchronous serial signal output by the cockpit pressure controller under test, and transmits the data content to the industrial control computer through the RS232 interface.

[0013] Preferably, the load module includes a relay switching circuit that supports switching between three load states: no-load, rated load, and overload, to simulate the load characteristics of the outflow valve under different operating conditions.

[0014] Preferably, the industrial control computer operation test software is developed based on LabVIEW and includes: The ARINC429 output configuration module configures the flight altitude and pressure correction reference parameters according to the atmospheric data computer manual, and sends the maintenance mode memory read command word at a 200ms cycle. The speed tracking module periodically reads the valve drive signal status and automatically provides the TACH output channel voltage according to the OPEN and CLOSE drive output status to simulate the change process of valve motor speed from startup to stable operation. The closed-loop control module switches between open-loop and closed-loop modes based on the reset signal output by the industrial control computer. In closed-loop mode, it achieves precise closed-loop control of the pressure rate through a two-stage integral circuit. The fault injection module injects fault conditions into the pressure controller of the cabin under test through software configuration and detects the fault response of the controller.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention uses a two-stage integral circuit and software configuration combined framework structure to complete the simulation of the full working conditions of the cabin pressure controller, realize the full-coverage offline performance test of the aircraft cabin pressurization system, and at the same time, it sends ARINC429 information at different flight altitudes to the cabin pressure controller by configuring a simulated atmospheric data computer (ADC), and configures different landing altitudes and cabin climb / descendancy rates on the simulated cabin pressure control panel to check the output of the cabin pressure controller in each stage of taxiing, takeoff, cruise, landing, parking and ground testing, and obtain the complete cabin pressure control logic algorithm inside the controller; 2. This invention uses a bipolar square wave signal instead of a sine wave signal to simulate the speed feedback signal of the external flow valve, which reduces the difficulty of waveform generation caused by signal phase synchronization. It uses a comparison circuit to generate a synchronous square wave control signal, converts the adjustable DC signal into a bipolar square wave signal acceptable to the chamber pressure controller, and realizes the simulation of the equivalent speed sensor signal. 3. This invention utilizes a two-stage integrator circuit with a reset function to realize an adjustable chamber pressure simulation signal for chamber pressure rate and chamber pressure acceleration, achieving closed-loop and open-loop control functions for chamber pressure rate, and can accurately verify the chamber pressure rate when the closed loop is balanced. 4. The testing system of this invention has a software-controlled fault injection function, which can realize the fault status of various components of the aircraft pressurization system and detect whether the cabin pressure controller can identify system faults. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the test system architecture; Figure 2 This is a circuit diagram for a switch control system. Figure 3 This is a circuit diagram of a cascaded relay. Figure 4 This is a circuit diagram for signal conditioning and acquisition. Figure 5 This is a diagram of a rectifier and filter circuit. Figure 6 This is a circuit diagram for speed feedback control. Figure 7 This is the circuit diagram for the integral direction control. Figure 8 This is a two-stage rate integrator circuit diagram; Figure 9 This is a schematic diagram of a serial decoding circuit. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] The aircraft cabin pressure controller closed-loop dynamic testing system includes: The power module is used to provide operating power to the pressure controller of the cabin under test.

[0019] The power supply module includes a medium-frequency AC power supply and a DC control power supply.

[0020] The medium-frequency AC power supply outputs 115V and 400Hz, and is used to provide working power to the pressure controller of the cockpit under test. DC control power supply, outputting 28V, 24V and 5V, used to power the internal modules of the test adapter interface box.

[0021] Test adapter interface box. The test adapter interface box is electrically connected to the pressure controller of the cabin under test and is used to provide signal conditioning, switching control, load simulation and closed-loop control functions.

[0022] The test adapter interface box includes a panel potentiometer module, a switch control module, a signal conditioning module, a speed feedback generation module, a chamber pressure closed-loop control module, a serial decoding module, and a load module.

[0023] Panel potentiometer module: This module is used to simulate the landing altitude selection potentiometer and pressure rate selection potentiometer on the cabin pressure control panel.

[0024] The switch control module is used to control the switch input, power supply on / off of the pressure controller of the cabin under test, and the selection of measurement signals by the multimeter.

[0025] In the preferred embodiment, the switch control module includes a first relay board and a second relay board: The first relay board is an intelligent 32-channel relay DO board that receives commands from the industrial control computer via RS485 bus to control switch inputs and power supply on / off. The second relay board is a 16-channel double-pole double-position relay cascade circuit, used to expand the number of contacts on the first relay board and enable the selection of measurement signals by the multimeter.

[0026] The signal conditioning module is used to condition and acquire the analog input / output signals and digital output signals of the pressure controller under test.

[0027] In the preferred embodiment, the signal conditioning module includes an analog input / output board, a Hall voltage sensor module, and a rectifier and filter circuit. The analog input / output board communicates with the industrial computer via an RS485 bus to acquire the conditioned valve drive signal and output analog control signal. The Hall voltage sensor module is used to detect the AC drive signal of the valve of the pressure controller of the cabin under test and convert it into an isolated AC signal. The rectifier and filter circuit consists of an operational amplifier, diodes, and resistive and capacitive components. It converts the AC signal output by the Hall voltage sensor module into a DC voltage and outputs it to the analog input / output board. The digital input acquisition module is used to acquire the digital output signal of the cabin pressure controller under test after optocoupler isolation and level conversion.

[0028] The speed feedback generation module is used to generate a simulated external flow valve speed feedback signal.

[0029] In the preferred embodiment, the speed feedback generation module includes a synchronous square wave generation circuit, an amplitude control circuit, and a phase control circuit. The synchronous square wave generation circuit samples the 115V power supply, and after shaping and isolation by a comparator and optocoupler, generates a square wave signal with the same frequency as the power supply. The amplitude control circuit controls the amplitude of the output square wave according to the TACH DC control signal output by the industrial control computer; The phase control circuit controls the phase relationship between the output square wave signal and the 115V power supply based on the polarity of the TACH DC control signal.

[0030] The speed feedback generation module outputs a bipolar square wave signal. The speed feedback input terminal of the pressure controller in the cabin under test is connected to the speed feedback terminal. satisfy: ; In the formula, The power supply frequency is 115V. Depend on Signal polarity determines when When the signal is positive When it is negative ; Depend on The amplitude of the DC control signal is linearly determined.

[0031] The chamber pressure closed-loop control module is used to generate simulated chamber pressure signals and realize rate closed-loop control.

[0032] In the preferred embodiment, the chamber pressure closed-loop control module includes an integral direction control circuit, a two-stage rate integral circuit, and a reset control circuit. The integral direction control circuit compares the conditioned gate drive signal with a preset threshold or limit to generate OPENCtrl and CLOSECtrl level signals to control the integral direction. The two-stage rate integrator circuit includes a first-stage integrator circuit and a second-stage integrator circuit, which are cascaded together to perform integration operations on the input signal. In a two-stage rate integrator circuit, the first-stage integrator output voltage satisfy: ; Second-stage integral output voltage satisfy: ; Final simulated chamber pressure signal satisfy: ; in, The time constant for the first-order integral. The time constant for the second-order integral. The rate voltage signal output by the integral direction control circuit. The initial chamber pressure voltage set for the industrial control computer.

[0033] The reset control circuit controls the operating state of the two-stage rate integral circuit based on the reset signal output by the industrial control computer.

[0034] The serial decoding module is used to decode the synchronous serial maintenance information output by the pressure controller of the test cabin into an RS232 signal.

[0035] In the preferred embodiment, the serial decoding module includes an 8051 microcontroller, which acquires and decodes the clock signal SCLK and data output signal SDATA in the synchronous serial signal output by the pressure controller under test. After parsing the data content, it transmits it to the industrial control computer through the RS232 interface.

[0036] The load module is used to provide a switchable analog load to the valve drive output of the pressure controller of the cabin under test.

[0037] In the preferred embodiment, the load module includes a relay switching circuit that supports switching between three load states: no-load, rated load, and overload, to simulate the load characteristics of the outflow valve under different operating conditions.

[0038] The industrial control computer has a built-in ARINC429 communication board, which communicates with the test adapter interface box and digital multimeter via RS232 / RS485 bus.

[0039] An atmospheric data analyzer is used to provide a controllable air source for the pressure controller of the cabin under test, simulating cabin pressure changes.

[0040] A digital multimeter is used to measure the output signal of the cabin pressure controller under test.

[0041] The industrial control computer operation and testing software automatically adjusts the analog input signal based on the collected output signal of the cabin pressure controller under test, thereby realizing closed-loop dynamic testing of the cabin pressure controller under test.

[0042] The industrial control computer operation test software is developed based on LabVIEW and includes an ARINC429 output configuration module, a speed tracking module, a closed-loop control module, and a fault injection module. The ARINC429 output configuration module configures the flight altitude and pressure correction reference parameters according to the atmospheric data computer manual, and sends maintenance mode memory read command words at a 200ms cycle. The speed tracking module periodically reads the valve drive signal status and automatically assigns the TACH output channel voltage according to the OPEN and CLOSE drive output status to simulate the change process of the valve motor speed from startup to stable operation. The closed-loop control module controls the chamber pressure closed-loop control module to switch between open-loop mode and closed-loop mode according to the reset signal output by the industrial control computer. In closed-loop mode, the precise closed-loop control of the chamber pressure rate is achieved through a two-stage integral circuit. The fault injection module injects fault conditions into the pressure controller of the cabin under test through software configuration and detects the fault response of the controller.

[0043] Example 1: The device under test (DUT) is connected to the interface adapter box, which is powered by the cabinet power supply. The adapter box provides AC power, digital and analog I / O signals, and communication switching for the DUT, and is responsible for connecting the DUT's output signals to an external digital multimeter for measuring parameters such as voltage and current. An industrial computer controls the interface adapter box via RS232 and RS485 communication ports. The computer has a PCI-429 communication card installed, which can establish a communication connection with the DUT's ARINC429 channel. The industrial computer communicates with the digital multimeter via the RS232 port to read the measured values.

[0044] The interface box is responsible for functions such as power supply switching, signal conditioning, and I / O signal control of the device under test. Its internal module design includes functional modules such as panel potentiometer, switch control, signal conditioning, serial communication decoding, output load, and indicator lights.

[0045] The front panel of the interface box is equipped with an adjustable potentiometer, which is used to simulate the landing altitude and pressure rate settings on the pressure control panel. The potentiometer resistance value is configured according to the potentiometer settings on the pressure control panel.

[0046] The circuit principle is as follows: (This refers to the circuit diagram showing the control of the controller under test, including its digital input, power supply on / off, and multimeter measurement signal selection.) Figure 2 The main control module M1 of the circuit uses a domestic intelligent 32-channel relay DO board ZS-DO-R-5A-32-RS485, powered by 24V, with a rated contact current of 5A. The test system computer remotely controls the board's operation via RS485.

[0047] M2 is a self-made 16-channel double-pole double-position relay cascade circuit used for multimeter measurement signal selection. This board expands the number of switch contacts of M1.

[0048] The signal conditioning module is responsible for conditioning and acquiring the controller's analog input and output signals, as well as digital output signals. Its internal circuitry is as follows: Figure 4 .

[0049] The M3 module is a domestically produced intelligent analog input / output board ZQWL-DAM-5443D. The board's input / output channels provide ±10V voltage signals, and the communication interface is RS485. The analog input channels 1 and 2 acquire conditioned gate drive OPEN and CLOSE signals.

[0050] The analog output channel 1 simulates the chamber pressure input when the chamber pressure controller is not in closed-loop control. Channel 2 provides a 6.6V test mode input signal for the device under test. Channel 3 provides a speed conditioning control signal. Channel 4 controls the connection of the valve drive load resistor. Channel 5 is used to control the integral speed of the rate closed-loop module M12. Channel 6 controls the reset of the rate closed-loop module M12 circuit.

[0051] Modules M5 and M6 are Hall voltage sensors used for detecting AC drive signals of the valve. They convert the valve drive output signal into an isolated AC signal, which is then rectified and filtered by module M4 to become a DC signal. The DC signal is then output to analog input channels 1 and 2 of module M3 for acquisition. The CHV-25P / 200 sensor module from domestic Senshe Electronics Co., Ltd. is selected, with a rated range of 200Vrms, a rated output of 5Vrms, an accuracy of ±0.1%, and a response frequency of 0~20KHz.

[0052] M8 is a digital input acquisition module used to acquire the AUTOFAULT and LOWFLOW digital output signals after they have been conditioned by the M4 module.

[0053] The M4 module is responsible for providing ±15V power to the M5 and M6 Hall voltage sensor modules and rectifying and filtering the sensor output signals. In addition, the M4 module is equipped with an optocoupler circuit to isolate and perform level conversion on the AUTOFAULT and LOWFLOW signals output by the chamber pressure controller.

[0054] The rectifier and filter circuit is as follows: operational amplifier U3A, rectifier diodes D17 and D18 constitute the rectifier circuit, and U1, R1, R2, R3, C1, C2, C11, C5, and C13 are low-pass active filters that convert the AC signal output by the sensor into DC voltage.

[0055] Module M11 is responsible for generating the valve speed feedback signal TACHFEEDBACK and connecting the valve drive output load. The valve speed feedback signal comes from the speed sensor on the outflow valve. The signal frequency is the same as the AC power supply of the controller, i.e., 400Hz. The signal phase is configured to be in phase or out of phase according to the drive output OPEN or CLOSE state.

[0056] To achieve synchronization between the speed feedback signal and the 115V power supply, the speed feedback signal generation circuit samples the 115V power supply. After being shaped and isolated by comparator U6 and optocoupler U7, it is converted into a square wave signal of the same frequency. This square wave signal drives transistor Q1 to switch on and off. TACH is a DC control signal, the amplitude of which controls the amplitude of the speed feedback signal, i.e., the speed value. The polarity of the TACH signal controls the phase relationship between the output signal and the 115V power supply.

[0057] When Q1 is not conducting, the output TACHFEEDBACK signal is out of phase with the TACH input signal. When Q1 is conducting, the TACHFEEDBACK signal is in phase with the TACH input signal. The actual outflow valve speed feedback signal on the aircraft is a sine wave signal. The cabin pressure controller performs synchronous rectification and filtering on this signal. When the speed feedback signal is in phase with the 115V power supply, a positive voltage is output; otherwise, a negative voltage is output. The TACHFEEDBACK signal output by the test system is a bipolar square wave signal, which can be accepted by the cabin pressure controller, i.e., it is equivalent to a sine wave signal.

[0058] Module M12 is responsible for generating the simulated chamber pressure signal PCsim and performing rate closed-loop control based on the valve drive output signal. The main circuits include integral direction control and a two-stage rate integral circuit. The principle of the integral direction control circuit is as follows: the voltage sensor signal after conditioning as described above is compared with a preset threshold or limit, and the signal is converted into square wave level signals OPENCtrl and CLOSECtrl. The two signals control the conduction of transistors Q4 and Q5 respectively. When the controller has an OPEN or CLOSE drive output, one of the transistors in Q4 or Q5 will conduct, thereby configuring the circuit output signal RATEV to the set signal RATESV or the inverted signal of RATESV. The RATEV signal is the input signal of the subsequent two-stage rate integral circuit.

[0059] The principle of a two-stage rate integrator circuit is as follows: Figure 7 As shown, relays U15 and U16, MOSFETs Q6, Q7, and Q8, and optocoupler U17 constitute a reset control circuit. When the external input signal RESET is high, the output of optocoupler U17 is low, Q6 and Q7 are not conducting, relays U16 and U17 are not energized, the integrator circuit is in a reset state, and the output signal PC (SENSOR) is the same as the input PCSET signal. At this time, the circuit is in an open-loop control state, and the simulated cabin pressure signal is directly controlled by the test software. When the input signal RESET is low, relays U15 and U16 are energized. At this time, the output signal PC (SENSOR) is affected by two-stage integrator circuits. It changes with the PCSET signal as the starting voltage. U10A and U10B constitute the first-stage integrator circuit. The input voltage RATEV represents the rate of change of the chamber pressure. The rate of change of the output voltage of the first-stage integrator is determined by the input voltage RATEV and R74, R85, and C23. The output voltage is applied to the input terminal of the second-stage integrator. The second-stage integrator rate is affected by R94, R117, and C24. The integration result is subtracted from the PCSET signal to obtain the total output signal PC (SENSOR).

[0060] The serial decoding circuit is responsible for decoding the serial maintenance information output by the cabin pressure controller and converting it into RS232 communication for transmission to the control computer of the test system. The serial communication of the controller is a synchronous serial output, and the signals include clock SCLK and data output SDATA. The decoding circuit of the test system uses an 8051 microcontroller to acquire the two signals and parse the data content on the SDATA data line.

[0061] The OPEN and CLOSE valves of the pressure controller are configured to output loads in three states: no-load, rated load, and overload, and the load type is switched using relays.

[0062] Configure the flight altitude (ALTITUDE), pressure correction reference (BAROSET), data transmission rate, and update cycle according to the aircraft air data computer (ADC) manual. Configure the maintenance data read command word according to the CMM manual. The software sends the command word at a 200ms cycle.

[0063] The software periodically reads the valve drive signal status of the analog signal acquisition board and automatically assigns the TACH output channel voltage based on the OPEN and CLOSE drive output status to simulate the change in valve motor speed from startup to stable operation.

[0064] When the closed-loop control RESET switch of the test system is in the ON state, the reset signal of the software-controlled two-stage rate closed-loop circuit is high level, and the chamber pressure set voltage is directly given by PCSET on the software interface. At this time, it is in open-loop control mode.

[0065] When the RESET switch is in the OFF position, the system enters the closed-loop control mode, the integrator circuit starts working, and the first-stage integrator output voltage begins to gradually increase, meaning the chamber pressure change acceleration increases linearly and slowly. When the given chamber pressure rate balances with the set chamber pressure rate, the valve stops driving. At this time, the first-stage integrator output remains unchanged, meaning the chamber pressure rate remains stable. The input voltage of the first-stage integrator circuit is determined by the aforementioned feedback speed TACH. That is, the faster the valve motor speed, the faster the valve opens or closes, and the faster the chamber pressure change acceleration. The valve opening affects the chamber pressure change rate. By reasonably setting the TACH feedback voltage amplitude, it is ensured that the device under test can reach chamber pressure rate balance within 6~10 seconds, thereby allowing the detection of the controller's closed-loop control accuracy and response speed.

[0066] Through software configuration, various fault conditions can be injected into the cabin pressure controller under test to test whether the controller can identify and make the correct fault response. The types of faults that can be injected include ARINC429 information error, LGS wheel pressure switch status error, valve motor failure, selection panel failure, low flow failure, etc.

[0067] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A closed-loop dynamic testing system for aircraft cabin pressure controllers, characterized in that: include: The power module is used to provide operating power to the pressure controller of the cabin under test. Test adapter interface box. The test adapter interface box is electrically connected to the pressure controller of the cabin under test and is used to provide signal conditioning, switching control, load simulation and closed-loop control functions. The industrial computer has a built-in ARINC429 communication board, which communicates with the test adapter interface box and digital multimeter via RS232 / RS485 bus. Atmospheric data analyzer is used to provide a controllable air source for the pressure controller of the cabin under test and to simulate cabin pressure changes; A digital multimeter is used to measure the output signal of the cabin pressure controller under test. The industrial control computer operation and testing software automatically adjusts the analog input signal based on the collected output signal of the cabin pressure controller under test, thereby realizing closed-loop dynamic testing of the cabin pressure controller under test.

2. The closed-loop dynamic testing system for aircraft cabin pressure controller according to claim 1, characterized in that: The power module includes: The medium-frequency AC power supply outputs 115V and 400Hz, and is used to provide working power to the pressure controller of the cockpit under test. DC control power supply, outputting 28V, 24V and 5V, used to power the internal modules of the test adapter interface box.

3. The closed-loop dynamic testing system for aircraft cabin pressure controller according to claim 1, characterized in that: The test adapter interface box includes: Panel potentiometer module, used to simulate the landing altitude selection potentiometer and pressure rate selection potentiometer on the cabin pressure control panel; The switch control module is used to control the switch input, power supply on / off of the pressure controller under test cabin, and the selection of measurement signals by the multimeter. The signal conditioning module is used to condition and acquire the analog input / output signals and digital output signals of the cabin pressure controller under test. Speed ​​feedback generation module, used to generate simulated external flow valve speed feedback signal; The pressure-controlled closed-loop control module is used to generate simulated pressure signals and implement rate closed-loop control. The serial decoding module is used to decode the synchronous serial maintenance information output by the pressure controller of the test cabin into an RS232 signal. The load module is used to provide a switchable analog load to the valve drive output of the pressure controller of the cabin under test.

4. The closed-loop dynamic testing system for aircraft cabin pressure controller according to claim 3, characterized in that: The switch control module includes: The first relay board is an intelligent 32-channel relay DO board that receives instructions from the industrial control computer via RS485 bus to control switch inputs and power supply on / off. The second relay board is a 16-channel double-pole double-position relay cascade circuit used to expand the number of contacts on the first relay board and enable the selection of measurement signals by the multimeter.

5. The closed-loop dynamic testing system for aircraft cabin pressure controller according to claim 3, characterized in that: The signal conditioning module includes: Analog input / output board: The analog input / output board communicates with the industrial computer via RS485 bus to acquire the conditioned valve drive signal and output analog control signal; Hall voltage sensor module: The Hall voltage sensor module is used to detect the AC drive signal of the valve of the pressure controller of the cabin under test and convert it into an isolated AC signal. The rectifier and filter circuit, which consists of an operational amplifier, diodes, and resistive and capacitive components, converts the AC signal output by the Hall voltage sensor module into a DC voltage and outputs it to the analog input / output board. The digital input acquisition module is used to acquire the digital output signal of the cabin pressure controller under test after optocoupler isolation and level conversion.

6. The closed-loop dynamic testing system for aircraft cabin pressure controller according to claim 3, characterized in that: The speed feedback generation module includes: The synchronous square wave generation circuit samples the 115V power supply, and after shaping and isolation by a comparator and optocoupler, generates a square wave signal with the same frequency as the power supply. The amplitude control circuit controls the amplitude of the output square wave according to the TACH DC control signal output by the industrial control computer. The phase control circuit controls the phase relationship between the output square wave signal and the 115V power supply based on the polarity of the TACH DC control signal.

7. The closed-loop dynamic testing system for aircraft cabin pressure controller according to claim 3, characterized in that: The chamber pressure closed-loop control module includes: The integral direction control circuit compares the conditioned gate drive signal with a preset threshold or limit to generate OPEN Ctrl and CLOSE Ctrl level signals to control the integral direction. A two-stage rate integrator circuit, comprising a first-stage integrator circuit and a second-stage integrator circuit, is cascaded to perform integration operations on the input signal; The reset control circuit controls the operating state of the two-stage rate integral circuit based on the reset signal output by the industrial control computer.

8. The closed-loop dynamic testing system for aircraft cabin pressure controller according to claim 3, characterized in that: The serial decoding module includes an 8051 microcontroller, which collects and decodes the clock signal SCLK and data output signal SDATA in the synchronous serial signal output by the cockpit pressure controller under test. After parsing the data content, it transmits it to the industrial control computer through the RS232 interface.

9. The closed-loop dynamic testing system for aircraft cabin pressure controller according to claim 3, characterized in that: The load module includes a relay switching circuit that supports switching between three load states: no-load, rated load, and overload, to simulate the load characteristics of the outflow valve under different operating conditions.

10. The closed-loop dynamic testing system for aircraft cabin pressure controller according to claim 1, characterized in that: The industrial control computer operation test software is developed based on LabVIEW and includes: The ARINC429 output configuration module configures the flight altitude and pressure correction reference parameters according to the atmospheric data computer manual, and sends the maintenance mode memory read command word at a 200ms cycle. The speed tracking module periodically reads the valve drive signal status and automatically provides the TACH output channel voltage according to the OPEN and CLOSE drive output status to simulate the change process of valve motor speed from startup to stable operation. The closed-loop control module switches between open-loop and closed-loop modes based on the reset signal output by the industrial control computer. In closed-loop mode, it achieves precise closed-loop control of the pressure rate through a two-stage integral circuit. The fault injection module injects fault conditions into the pressure controller of the cabin under test through software configuration and detects the fault response of the controller.

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