Undercarriage folding and unfolding turning control system analog circuit and debugging method

Abstract

The invention provides an undercarriage folding and unfolding turning control system simulation circuit, which comprises an upper computer, a folding and unfolding turning controller and a test circuit, and is characterized in that the test circuit comprises a proximity sensor simulation unit, a load simulation unit and a test control module. The folding and unfolding turning controller is a detected object, the upper computer is used for sending instructions and receiving feedback information, the proximity sensor simulation unit is used for simulating the approaching / leaving state of a real proximity sensor, and the load simulation unit is used for simulating the discrete quantity driving function of an enabling valve and an electromagnetic valve and the analog quantity driving function of a servo valve. The test control module communicates with the upper computer through a second serial port, communicates with the proximity sensor simulation unit through a third serial port, and communicates with the load simulation unit through a fourth serial port; the upper computer communicates with the folding and unfolding turning controller through a first serial port; the analog circuit is simple in structure, functions are easy to realize, and each unit module can work independently. The invention further provides a debugging method.

Description

Technical Field

[0001] The invention relates to a landing gear retraction and extension turning control system simulation circuit and a debugging method, and belongs to the field of engineering system simulation circuits. Background Art

[0002] The landing gear retraction and turning control system is a complex control system involving multiple systems (retraction and turning systems) and multiple devices (retraction and turning controllers, solenoid valves, enabling valves, servo valves, and position proximity sensors). Before conducting system integration testing, it is necessary to ensure that each device in each system has been debugged and verified. Debugging other systems or devices solely based on the actual system or device is time-consuming, labor-intensive, and prone to problems. Therefore, it is urgent to design a simulation circuit for the retraction and turning control system to replace the actual system or device as a debugging tool. Summary of the Invention

[0003] The present invention aims to provide a landing gear retraction and turning control system simulation circuit, which can effectively complete the single-machine function debugging and system joint debugging verification of the retraction and turning control system, saving time and labor and shortening the verification cycle.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is: a landing gear retraction and turning control system simulation circuit, the simulation circuit comprising a host computer, a retraction and turning controller, and a test circuit; the host computer is connected to the retraction and turning controller via a first serial port; the retraction and turning controller is the detected object of the landing gear retraction and turning control system; the test circuit comprises a proximity sensor simulation unit, a load simulation unit, and a test control module; the proximity sensor simulation unit is used to simulate the approach / disappearance state of a real proximity sensor; the load comprises a solenoid valve, an enabling valve, and a servo valve; the load simulation unit is used to simulate the discrete quantity drive function of the enabling valve and the solenoid valve, and simulate the analog quantity drive function of the servo valve; the test control module is connected to the host computer via a second serial port, connected to the proximity sensor simulation unit via a third serial port, and connected to the load simulation unit via a fourth serial port; the retraction and turning controller is connected to the proximity sensor simulation unit and the load simulation unit, respectively.

[0005] In the present invention, a logical relationship exists between the proximity sensor simulation unit and the load simulation unit. To ensure that both can operate independently during debugging, separate bus interfaces are provided for each simulation unit. The test control module integrates the different serial ports of the two simulation units into a single serial port, resolving the issue of the host computer having only a single serial port and being unable to communicate with both simulation units simultaneously. The same host computer simultaneously transmits commands and receives related feedback signals, ensuring the logical order of the two simulation units.

[0006] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization:

[0007] In one preferred embodiment, the proximity sensor simulation unit includes a first inductor and a second inductor; the first inductor and the second inductor are connected in series between the first port and the second port of the retractable and turning controller, and the second inductor is connected in parallel with the switch control module.

[0008] The proximity sensor simulation unit uses two inductive components connected in series to simulate the proximity sensor's approach / remote state. When the switch control module is disconnected, the simulated proximity sensor is in the approach state, and when the switch control module is closed, the simulated proximity sensor is in the remote state. The switch control module can simulate the approach / remote state function of a real proximity sensor through manual or automatic control.

[0009] In one preferred embodiment, the switch control module is a third relay; the common end of the third relay is connected between the first inductor and the second inductor, and the normally open end of the third relay is connected between the second inductor and the first port of the retraction and turning controller; the proximity sensor simulation unit also includes a first microprocessor; the first output end of the first microprocessor is connected to the input end of the first drive unit, the output end of the first drive unit is connected to the negative power supply electrode of the third relay, the positive power supply electrode of the third relay is connected to the power supply, the negative power supply electrode of the first drive unit is grounded, and the positive power supply electrode of the first drive unit is connected to the power supply; the second output end of the first microprocessor is connected to the normally closed end of the third relay; the first microprocessor is also connected to the test control module.

[0010] The switch control module can control the normal and open circuit operation of the second inductor in manual mode to realize the approach / disappearance state of the simulated proximity sensor. When there are multiple simulated proximity sensors in the test circuit, manual control alone is time-consuming and labor-intensive and cannot fully simulate the simultaneous approach / disappearance of multiple proximity sensors, which is detrimental to the overall test. Therefore, an automatic control method is required to realize the approach / disappearance state of the simulated proximity switch.

[0011] In one preferred embodiment, a manual self-locking button is connected in parallel to the second inductor. Considering the problem of relay failure in the analog proximity sensor, the manual self-locking button is connected in parallel to the second inductor to ensure that the inductor can be freely switched to the close / distance position by manual control when the automatic control relay fails.

[0012] In one preferred embodiment, the load simulation unit includes a second microprocessor; the first output end of the second microprocessor is connected to the first input end of the second drive unit, the first output end of the second drive unit is connected to the negative power supply of the first relay, the negative power supply of the second drive unit is grounded, and the positive power supply of the second drive unit is connected to the power supply; the positive power supply of the first relay is connected to the power supply, the common end of the first relay is grounded, the normally open end of the first relay is connected to one end of the first resistor, and the other end of the first resistor is connected to the retractable and turning controller; the first resistor is used to simulate the solenoid valve and the enabling valve; the second microprocessor is connected to the first resistor and the first resistor through a first branch. between the retractable and extending turning controllers; the second output end of the second microprocessor is connected to the second input end of the second drive unit, and the second output end of the second drive unit is connected to the negative power supply electrode of the second relay; the positive power supply electrode of the second relay is connected to the power supply, the normally closed end of the second relay is connected to the retractable and extending turning controller, the common end of the second relay is connected to one end of the second resistor, and the other end of the second resistor is grounded; the second resistor is used to simulate the servo valve; the load simulation unit also includes an analog-to-digital converter, one end of which is connected between the common end of the second relay and the second resistor, and the other end is connected to the second microprocessor through a second branch; the second microprocessor is also connected to the test control module.

[0013] The first circuit is used to feed back the current signal of the normal operation of the enabling valve and solenoid valve simulated by the load simulation unit to the second microprocessor through a voltage feedback detection method; the second circuit is used to feed back the current signal of the normal operation of the servo valve simulated by the load simulation unit to the second microprocessor through a voltage feedback detection method.

[0014] In one preferred embodiment, the second microprocessor is further connected between the first resistor and the retraction and turning controller through a third branch.

[0015] In the present invention, the load simulation unit can be debugged separately. When the first resistor is connected to the second microprocessor through the third branch, the load simulation unit is in a separate debugging mode for simulating the enabling valve and the solenoid valve;

[0016] In one preferred embodiment, the load simulation unit also includes a sub-simulation circuit; the sub-simulation circuit includes a digital-to-analog converter, a reference voltage module, a driving operational amplifier module and an amplifier; the second microprocessor is connected to the input end of the digital-to-analog converter through a fourth branch circuit, the output end of the digital-to-analog converter and the output end of the reference voltage module are both connected to the input end of the driving operational amplifier module, the output end of the driving operational amplifier module is connected to the input end of the amplifier, and the output end of the amplifier is connected to the normally open end of the second relay.

[0017] In the present invention, when the load simulation unit is debugged separately, a sub-simulation circuit is required to generate the current required for the normal operation of the servo valve. The sub-simulation circuit determines the reference voltage value based on the reference voltage module, controls the digital-to-analog converter to output a voltage of a specified magnitude through the second microprocessor, and performs current control through the drive op amp module and the amplifier to realize the analog drive function of the servo valve. The normal operation current signal of the servo valve is fed back to the host computer through the analog-to-digital converter in the form of a voltage signal through the second resistor. The second relay is used to determine the source of the servo valve control signal. When the common terminal of the second relay is connected to the normally closed terminal, the retraction and extension turning controller provides the servo valve control signal; when the common terminal of the second relay is connected to the normally open terminal, the second microprocessor provides the servo valve control signal.

[0018] In one preferred embodiment, the test control module includes a third microprocessor, which communicates with the host computer through the second RS422 serial port, communicates with the proximity sensor simulation unit through the third RS422 serial port, and communicates with the load simulation unit through the fourth RS422 serial port.

[0019] Based on the same concept, the present invention also provides a debugging method for an analog circuit of a landing gear retraction and turning control system. The debugging method is based on the above-mentioned landing gear retraction and turning control system and includes a debugging mode for a simulated enabling valve and a solenoid valve alone, a debugging mode for a simulated servo valve alone, and a system debugging mode.

[0020] Simulate the enabling valve and solenoid valve separate debugging mode:

[0021] When the first resistor is connected to the second microprocessor through the third branch, the load simulation unit is in a separate debugging mode for simulating the enabling valve and the solenoid valve, and the second microprocessor is connected to a debugging host computer, which is used to simulate the functions of the host computer during separate debugging. The debugging host computer sends an unlocking / locking instruction signal through the second microprocessor through the third branch to control the operation of the first resistor, and feeds back the load current of the simulated enabling valve and the solenoid valve to the debugging host computer in the form of voltage through the first branch.

[0022] Simulated servo valve separate debugging mode:

[0023] When the common terminal of the second relay is connected to the normally open terminal, the load simulation unit is in a separate debugging mode for simulating the servo valve, and the second microprocessor is connected to the debugging host computer, which is used to simulate the functions of the host computer during separate debugging; the debugging host computer sends an unlocking instruction signal through the fourth branch via the second microprocessor, controls the operation of the second resistor through the sub-simulation circuit, and feeds back the load current of the simulated servo valve to the debugging host computer in the form of voltage through the second branch;

[0024] System debugging mode:

[0025] When the second microprocessor is connected to the test control module, the third branch is not working and the first resistor is connected to the retraction and extension turning controller, and the common end of the second relay is connected to the normally closed end, the load simulation unit is in system debugging mode.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a landing gear retraction and turning control system simulation circuit, which realizes the debugging and verification function of the retraction and turning control system by simulating the approach / disappearance function of the proximity sensor, simulating the driving function of the load, and adding a test control module to realize the communication function between the load, the proximity sensor, the retraction and turning controller and the host computer. The simulation circuit has a simple structure, easy functions to realize, and each module can work independently, effectively solving the problem that the debugging and verification cycle of a single device or system relying on other devices and systems is long, labor-intensive, and has many problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a diagram of the analog circuit architecture of a retractable turning control system according to one embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of a proximity sensor simulation unit according to another embodiment of the present invention;

[0029] Figure 3 is a schematic diagram of a load simulation unit according to another embodiment of the present invention;

[0030] Figure 4 It is a schematic diagram of a test control module according to another embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention may be combined with each other.

[0032] Example 1

[0033] This embodiment 1 provides a landing gear retraction and turning control system simulation circuit, such as Figure 1 The diagram shows the simulation circuit architecture of the landing gear retraction and turning control system. The retraction and turning control system in Example 1 includes a host computer, a retraction and turning controller, and a test circuit. The test circuit includes a proximity sensor simulation unit, a load simulation unit, and a test control module. The retraction and turning controller is the object to be tested; the host computer is used to send instructions and receive feedback information; the proximity sensor simulation unit in the test circuit primarily uses two inductive components to simulate the approach / disappearance state functions of a real proximity sensor through manual and automatic control methods; the load includes the landing gear and door retraction solenoid valve, the turning enable valve, and the turning servo valve. The load simulation unit uses resistor components to simulate the discrete drive function of the enable valve and solenoid valve for normal operation, and uses components such as a DAC, a driver op amp, and resistors to simulate the analog drive function of the servo valve. The test control module uses the SCIA and SCIB serial ports of the DSP chip to communicate with the proximity sensor simulation unit and the load simulation unit, respectively, and uses the SCIC serial port to communicate with the host computer. The retraction and turning controller receives approach / disappearance status signals from multiple sensors in the proximity sensor simulation unit, and simultaneously controls the unlocking / locking / unlocking of various valves in the load simulation unit, thereby controlling the landing gear mechanism to perform the corresponding retraction / deployment / turning actions. Since the test circuit in the system primarily simulates the related functions of the proximity sensor and the load, and there is a certain logical relationship between the two, separate bus interfaces are set up for the two simulation units to ensure that both can work independently during debugging. Therefore, using a test control module, on the one hand, the different serial ports of the two different units can be integrated into a single serial port through this module, solving the problem of the host computer having only a single serial port to communicate with the two simulation units separately. On the other hand, the same host computer can be used to send commands and receive related feedback signals, ensuring logical sequence.

[0034] The operating principle of the landing gear retraction and turning control system simulation circuit provided in this embodiment 1 is as follows:

[0035] During debugging of the retraction / steering control system, the retraction / steering controller receives the approach / proximity status signals from multiple sensors in the proximity sensor simulation unit and transmits them to the host computer. The host computer determines the current retraction / extending position of the landing gear and decides whether to execute the retraction / extending / steering action. If the landing gear position meets the retraction / extending position requirements, the host computer sends the corresponding landing gear retraction / extending / steering command via the first RS422 serial port. The retraction / steering controller processes this command and drives the solenoid valve, enabling valve, and servo valve in the load simulation unit to unlock / lock / control the unlocking level accordingly, thereby controlling the landing gear mechanism to execute the corresponding retraction / extending / steering action. The load simulation unit feeds back the current signal of the normal operation of the simulated valve to the test control module via the fourth RS422 serial port in the form of voltage feedback, and finally to the host computer via the second RS422 serial port.

[0036] The test control module receives and processes the proximity sensor status command signal sent by the host computer through the second RS422 serial port, and controls the two inductors in the proximity sensor simulation unit to work in series (simulating the proximity sensor approach state) or one of the inductors to work (simulating the proximity sensor distance state) through the third RS422 serial port; when the proximity sensor state is automatically controlled, the DSP end can detect whether the proximity sensor is currently in the approach / distance state by checking whether the signal at the normally closed end of the relay is 0.

[0037] The test control module receives the opening / locking / unlocking size command signal of the solenoid valve / enabling valve / servo valve sent by the host computer through the second RS422 serial port, which is processed by the test control module and transmitted to the load simulation unit main chip DSP through the fourth RS422 serial port. The DSP controls the opening / locking / unlocking size of the three valves; and feeds back the feedback current signal of the solenoid valve / enabling valve / servo valve in the load simulation unit. The current signal is fed back to the test control module in the form of voltage through the fourth RS422 serial port, and is processed by the test control module and the feedback voltage is transmitted to the host computer through the second RS422 serial port.

[0038] Example 2

[0039] According to actual usage requirements, the critical values ​​of the proximity sensor in the approach / distance state are 5.25mH / 4.95mH respectively.

[0040] Figure 2The schematic diagram of the proximity sensor simulation unit in the test circuit is shown below. The proximity sensor simulation unit simulates the proximity sensor state by connecting inductor 1 (4.7mH) and inductor 2 (1mH) in series. At this point, the simulated proximity sensor state can be measured from the first and second ports of the retraction and extension controller. If a self-locking pushbutton switch SW (7*7) is connected in parallel with inductor 2, when switch SW is open, the simulated proximity sensor remains in the approach state, and when switch SW is closed, the simulated proximity sensor is in the distance state. This self-locking pushbutton switch SW must be manually opened and closed to simulate the proximity sensor's approach / distance state. Because the test circuit contains multiple simulated proximity sensors, manual control alone is time-consuming and labor-intensive, and cannot fully simulate the simultaneous approach / distance of multiple proximity sensors, which is detrimental to the overall test. Therefore, an automated control method is required to simulate the proximity switch's approach / distance state. If relay 3 (G6K-2G-Y) is connected in parallel with inductor 2, the normally open end of relay 3 is connected to the common end by powering on relay 3 (using the proximity sensor simulation unit main chip DSP (TMS320F28335PGFA) to output a high level to control the first driver chip (ULN2803A) to output a low level to drive the relay to work normally), thereby controlling the distance state of the simulated proximity sensor. At the same time, the normally closed end signal of relay 3 can be 0, and the proximity sensor can be detected in the distance state at the proximity sensor simulation unit main chip DSP end; the low level output of relay 3 when it is powered off controls the first driver chip to output a high level, driving the relay. (Electrical device 3 is not operating) by connecting the normally closed terminal of control relay 3 to the common terminal, thereby controlling the proximity state of the analog proximity sensor. Simultaneously, by detecting that the proximity sensor is in the proximity state on the DSP side when the normally closed terminal signal of relay 3 is non-zero, the DSP side can automatically control the simultaneous approach / removal of multiple proximity sensors. To account for relay failure in the analog proximity sensor, a self-locking pushbutton switch SW can be connected in parallel with inductor 2, and a relay (G6K-2G-Y) can be connected in parallel between inductor 2 and the parallel self-locking pushbutton switch SW. This ensures that if the automatic control relay fails, the self-locking pushbutton SW can be manually controlled to freely switch the inductor approach / removal. The choice of manual or automatic operation depends on the specific environment. The debugging host computer is used when the proximity sensor simulation unit is operating independently or debugging separately.

[0041] Figure 3The figure shows the schematic diagram of the load simulation unit in the test circuit. The load simulation unit simulates the enabling valve / solenoid valve itself through resistor 1 (94Ω) based on the normal operating voltage (28V) and current (0.3A) of the solenoid valve and the enabling valve. The load simulation board main chip DSP (TMS320F28335PGFA) controls the driver chip (ULN2803A) to drive relay 1 (G3VM-61QV2H) to turn on / off power (when the DSP outputs a high level, the driver chip outputs a low level, at which point the common terminal and the normally open terminal are connected, and the relay is powered on; when the DSP outputs a low level, the driver chip outputs a high level, at which point the common terminal and the normally open terminal are disconnected, and the relay is powered off). The control circuit is turned on / off to achieve the operating / non-operating state of the enabling valve / solenoid valve, and the current signal during the circuit connection process is fed back to the host computer in the form of voltage. According to the normal working current of the servo valve (±8mA), the actual turning controller has built a circuit to generate this current. By controlling the size of the current signal, the resistor 2 (320Ω) of the simulated servo valve can be controlled to work normally. The normal working current signal of the servo valve is fed back to the main chip DSP of the load simulation board through ADC (ADS8668) in the form of a voltage signal. When the load simulation unit is debugged alone, there is no circuit to generate the normal working current (±8mA) of the servo valve. The load simulation unit needs to generate it by building its own circuit, so it is added. Figure 3 The circuit within the solid-line box (DAC module (MCP4725A0T-E / CH), reference voltage module (REF5025), driver op amp (GS8052), and amplifier (OP07) modules) determines the reference voltage value based on the reference voltage chip. The main control chip, DSP (TMS320F28335PGFA), controls the DAC to output a specified voltage. Current control is achieved through the driver op amp and amplifier, enabling the normal operation of the servo valve with a ±8mA current variation, thus realizing the servo valve's analog drive function. The normal operating current signal of the servo valve is fed back as a voltage signal via resistor 2 (320Ω) and ADC (ADS8668) to the load simulation board's main chip, DSP. Relay 2 (G6K-2G-Y) determines the source of the servo valve's control signal. When the common terminal of relay 2 is connected to the normally closed terminal, the retraction and extension steering controller provides the servo valve control signal. When the common terminal of relay 2 is connected to the normally open terminal, the load simulation unit's main chip, DSP, provides the servo valve control signal. Among them, the debugging host computer and thick line are both used when the load simulation unit works independently / is debugged separately.

[0042] Figure 4The figure shows the schematic diagram of the test control module. The test control module uses the SCIA and SCIB ports of the DSP (TMS320F28335PGFA) to communicate with the proximity sensor simulation unit and the load simulation unit respectively through the RS422 serial port, and uses the SCIC port to communicate with the test host computer through the RS422 serial port. It transmits the host computer's instructions to the two simulation units and transmits the feedback signals of the two simulation units to the host computer.

[0043] The contents described in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A landing gear retraction and extension turning control system simulation circuit, characterized in that: The simulation circuit includes a host computer, a retractable and extending turning controller and a test circuit; the host computer is connected to the retractable and extending turning controller through a first serial port; the retractable and extending turning controller is a detected object of the landing gear retractable and extending turning control system; the test circuit includes a proximity sensor simulation unit, a load simulation unit and a test control module; the proximity sensor simulation unit is used to simulate the approach / distance state of a real proximity sensor; the load includes a solenoid valve, an enabling valve and a servo valve; the load simulation unit is used to simulate the discrete quantity driving function of the enabling valve and the solenoid valve, and simulate the analog quantity driving function of the servo valve; the test control module is connected to the host computer through a second serial port, connected to the proximity sensor simulation unit through a third serial port, and connected to the load simulation unit through a fourth serial port; the retractable and extending turning controller is connected to the proximity sensor simulation unit and the load simulation unit respectively.

2. The landing gear retraction and turning control system according to claim 1, characterized in that: The proximity sensor simulation unit includes a first inductor and a second inductor; the first inductor and the second inductor are connected in series between a first port and a second port of the retractable and extending turning controller, and the second inductor is connected in parallel to a switch control module.

3. The landing gear retraction and turning control system according to claim 2, characterized in that: The switch control module is a third relay; The common end of the third relay is connected between the first inductor and the second inductor, and the normally open end of the third relay is connected between the second inductor and the first port of the retractable and extending turning controller; The proximity sensor simulation unit also includes a first microprocessor; The first output terminal of the first microprocessor is connected to the input terminal of the first drive unit, the output terminal of the first drive unit is connected to the negative power supply electrode of the third relay, the positive power supply electrode of the third relay is connected to the power supply, the negative power supply electrode of the first drive unit is grounded, and the positive power supply electrode of the first drive unit is connected to the power supply; The second output terminal of the first microprocessor is connected to the normally closed terminal of the third relay; The first microprocessor is also connected to the test control module.

4. The landing gear retraction and turning control system according to claim 3, characterized in that: The second inductor is also connected in parallel with a manual self-locking button.

5. The landing gear retraction and turning control system according to claim 1, characterized in that: The load simulation unit includes a second microprocessor; The first output terminal of the second microprocessor is connected to the first input terminal of the second drive unit, the first output terminal of the second drive unit is connected to the negative power supply electrode of the first relay, the negative power supply electrode of the second drive unit is grounded, and the positive power supply electrode of the second drive unit is connected to the power supply; The positive power supply electrode of the first relay is connected to the power supply, the common end of the first relay is grounded, the normally open end of the first relay is connected to one end of a first resistor, and the other end of the first resistor is connected to the retractable and extending turning controller; the first resistor is used to simulate the solenoid valve and the enabling valve; The second microprocessor is connected between the first resistor and the retracting and extending turning controller through a first branch; The second output terminal of the second microprocessor is connected to the second input terminal of the second driving unit, and the second output terminal of the second driving unit is connected to the negative power supply terminal of the second relay; The positive pole of the second relay is connected to the power supply, the normally closed end of the second relay is connected to the retractable and extending turning controller, the common end of the second relay is connected to one end of the second resistor, and the other end of the second resistor is grounded; the second resistor is used to simulate the servo valve; The load simulation unit further comprises an analog-to-digital converter, one end of which is connected between the common end of the second relay and the second resistor, and the other end of which is connected to the second microprocessor via a second branch; The second microprocessor is also connected to the test control module.

6. The landing gear retraction and extension turning control system according to claim 5, characterized in that: The second microprocessor is also connected between the first resistor and the retracting and extending turning controller through a third branch.

7. The landing gear retraction and extension turning control system according to claim 6, characterized in that: The load simulation unit further includes a sub-simulation circuit; the sub-simulation circuit includes a digital-to-analog converter, a reference voltage module, a driving operational amplifier module and an amplifier; The second microprocessor is connected to the input end of the digital-to-analog converter through a fourth branch, the output end of the digital-to-analog converter and the output end of the reference voltage module are both connected to the input end of the driving operational amplifier module, the output end of the driving operational amplifier module is connected to the input end of the amplifier, and the output end of the amplifier is connected to the normally open end of the second relay.

8. The landing gear retraction and turning control system according to claim 1, characterized in that: The test control module includes a third microprocessor, which is communicatively connected to the host computer via the second RS422 serial port, is communicatively connected to the proximity sensor simulation unit via the third RS422 serial port, and is communicatively connected to the load simulation unit via the fourth RS422 serial port.

9. A method for debugging a simulation circuit of a landing gear retraction and extension turning control system, characterized in that: The debugging method is based on the landing gear retraction and extension turning control system according to claim 7, and the debugging method includes a simulation enabling valve and solenoid valve separate debugging mode, a simulation servo valve separate debugging mode and a system debugging mode; Simulate the enabling valve and solenoid valve separate debugging mode: When the first resistor is connected to the second microprocessor through the third branch, the load simulation unit is in a separate debugging mode of the simulation enabling valve and the solenoid valve, the second microprocessor is connected to the debugging host computer, and the debugging host computer is used for functional simulation of the host computer during separate debugging; the debugging host computer sends an unlocking / locking instruction signal through the second microprocessor through the third branch to control the operation of the first resistor, and feeds back the load current of the simulation enabling valve and the solenoid valve to the debugging host computer in the form of voltage through the first branch; Simulate servo valve single debugging mode: When the common end of the second relay is connected to the normally open end, the load simulation unit is in the simulated servo valve separate debugging mode, the second microprocessor is connected to the debugging host computer, and the debugging host computer is used for the function simulation of the host computer during separate debugging; the debugging host computer sends the unlocking size instruction signal through the second microprocessor through the fourth branch, controls the second resistor to work through the sub-simulation circuit, and feeds back the load current of the simulated servo valve to the debugging host computer in the form of voltage through the second branch; System debugging mode: When the second microprocessor is connected to the test control module, the third branch is not working and the first resistor is connected to the retractable and extending turning controller, and the common end of the second relay is connected to the normally closed end, the load simulation unit is in system debugging mode.

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