An aircraft automatic command pitch control method, system, device and storage medium

Abstract

The application relates to the technical field of aircraft power control, and discloses an aircraft automatic instruction variable-pitch control method, system, equipment and a storage medium, wherein the method comprises the following steps: after the aircraft is powered on, performing propeller pitch self-checking, allowing the engine to start after the self-checking is passed, setting the starting throttle opening degree and the starting target rotating speed according to the flight height and the ambient temperature, and performing a flight task after the starting is completed; in the flight process, the current during propeller variable-pitch is monitored, if the current is not abnormal, the automatic constant-speed mode is maintained; if the current is abnormal, the automatic instruction variable-pitch mode is switched to, a propeller pitch increasing instruction or a propeller pitch decreasing instruction is sent according to the difference between the actual rotating speed of the propeller and the target rotating speed; if the current is further increased to exceed an overcurrent threshold, the manual instruction variable-pitch mode is switched to; when the difference between the actual rotating speed of the propeller and the target rotating speed is within a preset range or a switching instruction is received, the automatic instruction variable-pitch mode is exited and the automatic constant-speed mode is restored.

Description

Technical Field

[0001] This invention relates to the field of aircraft power control technology, and in particular to an automatic command pitch control method, system, device and storage medium for aircraft. Background Technology

[0002] Currently, aircraft are mainly used as a new type of information acquisition carrier, injecting new vitality into the low-altitude economy. They have advantages such as high maneuverability, operability, and adaptability to the operating environment, and are increasingly being used in various industries.

[0003] As a core component of aircraft, propulsion limits their use in many ways. Currently, large aircraft primarily use piston engines combined with propellers. Electric variable-pitch propellers are widely used because they can automatically adjust pitch to ensure the power system operates within a high-efficiency range. However, their application has gradually revealed various problems, such as inability to adjust pitch, overcurrent faults, and abnormal pitch adjustments. Avoiding these problems during operation is directly related to the aircraft's mission execution and safe flight.

[0004] Currently, most electric variable-pitch propeller-powered aircraft use fixed-pitch propellers, which cannot efficiently utilize the power generated by the engine, resulting in power loss that affects the aircraft's takeoff weight and flight performance. Even some variable-pitch propellers frequently experience pitch anomalies, and there are no effective measures to avoid these anomalies, or the mechanisms to resolve them promptly after they occur. This significantly reduces the safety margin of the power system, thereby affecting the aircraft's operational safety.

[0005] CN102923299A discloses a constant-speed propeller torque-variable PID control system, including a control circuit, a drive circuit, a current detection circuit, a speed detection circuit, and a position detection circuit. The control circuit receives a propeller speed setting signal from the flight control system and determines the theoretical engine value based on the proportional relationship between the propeller and the engine. The speed detection circuit and the current detection circuit input the real-time detected current speed and current of the torque motor to the control circuit, respectively. The position detection circuit inputs the real-time detected current position of the propeller to the control circuit. The control circuit judges the current current of the torque motor. If an overcurrent occurs, it issues a control signal to shut down the drive circuit; otherwise, it reads the current engine speed detected by the engine detection circuit, selects the value of the proportional element based on the difference between the current speed and the theoretical engine value, and outputs a PWM signal to the drive circuit using a PID algorithm based on the selected proportional element value, the current propeller speed, the current propeller position, and the current speed and position of the torque motor. The drive circuit then controls the speed and direction of the torque motor according to the PWM signal. However, the system has a relatively simple control objective and relies on the deviation of the rotation speed. When there are sudden changes in the flight state, there is a lag problem. The PID parameters are fixed, and the pitch will stop if an overcurrent occurs, resulting in poor adaptability to operating conditions.

[0006] CN108791819A discloses an automatic variable-pitch propeller device and its control method, as well as an aircraft. The variable-pitch drive device is connected to the propeller via a variable-pitch structure, and the propeller pitch is adjusted by manipulating the variable-pitch structure. A thrust measurement module is connected to the propulsion system to measure the dynamic thrust of the propulsion system. The variable-pitch controller determines real-time propeller efficiency information based on the dynamic thrust and input power, determines the target pitch range based on propeller speed and airspeed information, and provides a pitch value within the target pitch range using an automatic optimization method based on the propeller efficiency data, allowing the propeller to perform variable-pitch operation. However, this scheme is disconnected from the aircraft's control commands, has a narrow applicability, and the automatic optimization used is an iterative process. When the flight state changes rapidly, there may be calculation delays, reducing the efficiency of the power system. Summary of the Invention

[0007] To address the aforementioned issues, this invention proposes an automatic command pitch control method, system, device, and storage medium for aircraft, which allows the power system to always operate within a high efficiency range, effectively avoids current overload, and has a wide range of applications.

[0008] The technical solution adopted in this invention is as follows: An automatic command pitch control method for an aircraft includes: After the aircraft is powered on, it performs a propeller pitch self-check. Once the self-check is passed, the engine is allowed to start. The starting throttle opening and target starting speed are set according to the flight altitude and ambient temperature. After starting, the flight mission is executed. During flight, the current during propeller pitch changes is monitored. If the current is normal, the automatic constant speed mode is maintained. If the current is abnormal, the automatic command pitch mode is switched to. Based on the difference between the actual propeller speed and the target speed, the pitch increase command or pitch decrease command is sent. If the current further increases to exceed the overcurrent threshold, the manual command pitch mode is switched to. When the difference between the actual propeller speed and the target speed is within a preset range or when a switching command is received, the automatic command pitch change mode is exited and the automatic constant speed mode is restored.

[0009] Furthermore, after the aircraft is powered on, it performs a propeller pitch self-check, including: Check if the propeller is at its minimum blade angle position to confirm that the propeller blades can perform increased pitch operation based on the minimum blade angle; Check if the propeller working mode switching function is working properly to confirm that the propeller can switch normally between different working modes; If any of the above checks fails, a self-test fault is identified and the self-test process is terminated, and the engine is prohibited from starting.

[0010] Furthermore, the step of setting the starting throttle opening and target starting speed based on flight altitude and ambient temperature includes: Obtain the ambient air pressure and static temperature at the current altitude of the aircraft; The corresponding altitude is determined based on the ambient air pressure. As the altitude increases, the starting throttle opening is increased accordingly, and the starting target speed is increased. Based on the aforementioned static atmospheric temperature, as the static atmospheric temperature decreases, the starting throttle opening is increased accordingly, and the target starting speed is increased.

[0011] Furthermore, after the start-up is completed, the flight mission is executed, including: After the engine start-up procedure is completed, a pre-flight condition check is performed on the engine to confirm that the engine's operating parameters are normal under each operating condition. The engine was checked under rapid acceleration and deceleration conditions, simulating a scenario of rapid throttle changes during flight, to confirm that the engine was working normally during the transient response process; The aircraft is permitted to take off and perform its flight mission only after all the above checks have been passed. If any abnormality in the engine's operating condition is found during any of the above checks and affects the engine's continued operation, the flight mission will be terminated.

[0012] Furthermore, the monitoring of the propeller current during pitch change, and maintaining the automatic constant speed mode if no abnormality is found in the current, includes: The pitch controller continuously collects the operating parameters of the propeller during the pitch change process in automatic constant speed mode. The operating parameters include at least the pitch change drive current and the pitch change operation frequency. The collected variable pitch drive current is compared with the preset normal operating current range, and the variable pitch operating frequency is compared with the preset normal frequency range. When the variable pitch drive current and variable pitch operation frequency are both within their respective normal ranges, the propeller system is determined to be operating normally and the current automatic constant speed mode is maintained. When the variable pitch drive current exceeds the normal operating current range or the variable pitch operation frequency exceeds the normal frequency range, the current is determined to be abnormal.

[0013] Furthermore, the step of switching to automatic command pitch mode if an abnormal current occurs includes: During the cruise or approach positioning phase, if the pitch controller detects an abnormal current in automatic constant speed mode and meets the allowable conditions for automatic command pitch, it will switch to automatic command pitch mode. During the descent phase, if the pitch controller has experienced a current anomaly once in automatic constant speed mode and has performed a reset operation, and then experiences another current anomaly, it will switch to automatic command pitch mode. After entering the automatic command pitch control mode, the current actual speed and the target speed are obtained at predetermined time intervals, and the deviation between the two is calculated. If the deviation exceeds the preset allowable range and the current actual speed is higher than the target speed, then send an increase pitch command once. If the deviation still exceeds the preset allowable range after sending a preset number of increase pitch commands, then it is determined that the command pitch is abnormal and the increase pitch command is stopped. If the deviation exceeds the preset allowable range and the current actual speed is lower than the target speed, a pitch reduction command is sent once. If the deviation still exceeds the preset allowable range after sending a preset number of pitch reduction commands, it is determined that the command pitch is abnormal and the pitch reduction command is stopped. If the deviation is within the preset allowable range, no pitch change command will be sent.

[0014] Furthermore, the step of exiting the automatic command pitch mode and resuming the automatic constant speed mode when the difference between the actual propeller speed and the target speed is within a preset range or when a switching command is received includes: After entering the automatic command pitch control mode, if the deviation between the current actual speed and the target speed has recovered to the preset allowable range after a predetermined time, the automatic command pitch control mode will be automatically exited and switched back to the automatic constant speed mode. At the same time, the delay and speed limit links of the speed command will be re-initialized and reassigned according to the current actual speed. During automatic variable pitch mode operation, if an external input switching command is received, the automatic variable pitch mode will be immediately exited and switched back to automatic constant speed mode. At the same time, the delay and speed limiting links of the speed command will be re-initialized and reassigned according to the current actual speed.

[0015] An automatic command pitch control system for an aircraft, comprising: The power-on self-test and start-up parameter setting module is configured to perform a propeller pitch self-test after the aircraft is powered on. After the self-test passes, the engine is allowed to start. The starting throttle opening and target starting speed are set according to the flight altitude and ambient temperature. After starting, the flight mission is executed. The control mode switching module is configured to monitor the current during propeller pitch changes during flight. If the current is normal, it maintains the automatic constant speed mode. If the current is abnormal, it switches to the automatic command pitch mode and sends an increase or decrease pitch command based on the difference between the actual propeller speed and the target speed. If the current further increases to exceed the overcurrent threshold, it switches to the manual command pitch mode. When the difference between the actual propeller speed and the target speed is within a preset range or a switching command is received, it exits the automatic command pitch mode and resumes the automatic constant speed mode.

[0016] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the automatic command pitch control method for an aircraft.

[0017] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the automatic command pitch control method for an aircraft.

[0018] The beneficial effects of this invention are as follows: 1. This invention, by performing a propeller pitch self-check after power-on and allowing engine start only after the self-check passes, and by differentially setting the starting throttle opening and target starting speed based on flight altitude and ambient temperature, effectively ensures smooth engine start and safe initial operation under various environmental conditions. During flight, by continuously monitoring the propeller pitch current, it promptly switches from automatic constant speed mode to automatic command pitch mode when the current is abnormal. The flight control computer actively sends commands to increase or decrease the pitch based on the difference between the actual speed and the target speed for precise adjustment, keeping the propeller speed within the desired range and avoiding control failures that may result from relying on automatic adjustment with fixed parameters under abnormal conditions. When the current further increases to exceed the overcurrent threshold, it switches to manual command pitch mode, providing a final safety guarantee for extreme situations. At the same time, it automatically exits automatic command pitch mode and resumes automatic constant speed mode when the deviation between the actual speed and the target speed returns to the preset range or when an external switching command is received, thus maintaining the system's efficient autonomous operation capability while ensuring safety. Through the aforementioned multi-level progressive mode switching logic, this invention effectively avoids the problems of speed runaway and overcurrent damage caused by abnormal pitch in traditional solutions, ensuring that the power system maintains high operating efficiency within a wide operating envelope, while also improving the power system's adaptability to complex and variable flight conditions.

[0019] 2. This invention sets differentiated automatic command pitch control mode entry conditions for different flight phases such as cruise, approach positioning, and glide, making mode switching decisions more closely aligned with actual flight scenarios and avoiding erroneous or missed switching due to a single trigger condition. In automatic command pitch control mode, a control method employing fixed-period sampling of speed deviation and sequentially sending single-step pitch control commands based on the deviation direction ensures both the determinism and controllability of pitch adjustment while avoiding overshoot and oscillation problems that may arise from continuous control. Simultaneously, by setting an upper limit on the number of consecutive transmissions and automatically stopping transmissions and providing an anomaly warning upon reaching the limit, this effectively prevents increased electrical load or motor overheating damage caused by continuous command transmission in cases where mechanical jamming or other faults have occurred in the pitch control mechanism, thus protecting the physical safety of the pitch control actuator. This method, through the aforementioned refined control strategy, proactively intervenes to replace conventional control when anomalies occur, reducing additional wear on moving components such as the pitch motor and reduction gear transmission mechanism under abnormal operating conditions, and contributing to extending the overall service life of the propeller pitch control system.

[0020] 3. In this invention, when exiting the automatic command pitch control mode and resuming the automatic constant speed mode, the delay and speed limiting components of the speed control command are reinitialized based on the current actual speed. This approach effectively avoids sudden command changes or speed jumps caused by the mismatch between the control state and the current speed during mode switching, ensuring a smooth transition and continuous flight quality. Furthermore, the direct takeover of pitch control by the flight control computer tightly links the pitch adjustment command with the overall control law of the aircraft, avoiding the disconnect between pitch control and flight management in traditional solutions, and improving the level of integrated flight-engine-propeller control. This invention does not rely on a specific hardware architecture and is applicable to the modification and upgrading of the power control systems of various electric variable-pitch propeller aircraft, possessing good platform versatility and promising prospects for widespread application. Attached Figure Description

[0021] Figure 1 This is an overall flowchart of an automatic command pitch control method for an aircraft according to Embodiment 2 of the present invention.

[0022] Figure 2 This is a detailed flowchart of an automatic command pitch control method for an aircraft according to Embodiment 2 of the present invention. Detailed Implementation

[0023] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments are now described. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention; that is, the described embodiments are only a part of the embodiments of the invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0024] Example 1 This embodiment provides an automatic command pitch control method for an aircraft, including: After the aircraft is powered on, it performs a propeller pitch self-check. Once the self-check is passed, the engine is allowed to start. The starting throttle opening and target starting speed are set according to the flight altitude and ambient temperature. After starting, the flight mission is executed. During flight, the current during propeller pitch changes is monitored. If the current is normal, the automatic constant speed mode is maintained. If the current is abnormal, the automatic command pitch mode is switched to. Based on the difference between the actual propeller speed and the target speed, the pitch increase command or pitch decrease command is sent. If the current further increases to exceed the overcurrent threshold, the manual command pitch mode is switched to. When the difference between the actual propeller speed and the target speed is within a preset range or when a switching command is received, the automatic command pitch change mode is exited and the automatic constant speed mode is restored.

[0025] Preferably, after the aircraft is powered on, it performs a propeller pitch self-check, including: checking whether the propeller is at the minimum blade angle position to confirm that the propeller blades can perform the pitch increase operation based on the minimum blade angle; checking whether the propeller working mode switching function is normal to confirm that the propeller can switch normally between different working modes; if any of the above checks fails, a self-check fault is determined and the self-check process is terminated, and the engine is prohibited from starting.

[0026] Specifically, after the aircraft is powered on and enters the self-test process, the flight control computer first sends a query command to the pitch controller to obtain the current actual blade angle position signal of the propeller. This signal is then compared with the pre-stored minimum blade angle position calibration value to confirm whether the propeller has fully retracted to the minimum blade angle position. Only when the propeller is indeed at the minimum blade angle position can the blade angle adjust from the minimum position to an increasing position during subsequent engine startup, thus ensuring that the propeller's load torque is at its minimum during startup, which is beneficial for a smooth engine start. Simultaneously, the flight control computer also verifies whether the pitch controller can reliably switch between automatic constant speed mode and command control mode by sending a mode switching test command to the pitch controller. Specifically, the flight control computer sends a set of mode switching request signals and monitors the mode status confirmation signal returned by the pitch controller to confirm that its mode switching logic and communication link are intact. If the pitch controller fails to respond correctly to the mode switching request or the returned status signal is inconsistent with expectations, it indicates that there is an anomaly in the operating mode switching function. If any of the above checks fails, the flight control computer will immediately determine that the self-test has failed, terminate the subsequent self-test process, and not send an enable signal to allow the engine to start. The aircraft will remain on the ground until the fault is resolved.

[0027] It should be noted that using the minimum blade angle check as a precondition for starting ensures that the blade load is minimized during engine start-up, which helps reduce the engine's starting torque requirement and improves the start-up success rate. Simultaneously, the pre-verification of the mode switching function ensures that the pitch controller can reliably respond to the flight control computer's switching commands when the propeller control mode needs to be changed during flight. This avoids the inability to respond promptly to pitch anomalies due to mode switching function failure, thereby improving the reliable transmission and execution capability of power system control commands.

[0028] Preferably, the step of setting the starting throttle opening and starting target speed based on flight altitude and ambient temperature includes: acquiring the ambient air pressure and atmospheric static temperature at the current altitude of the aircraft; determining the corresponding altitude based on the ambient air pressure, and increasing the starting throttle opening and starting target speed accordingly as the altitude increases; and increasing the starting throttle opening and starting target speed accordingly as the atmospheric static temperature decreases.

[0029] Specifically, before engine start-up, the flight control computer obtains the ambient air pressure and static temperature data of the aircraft's current location through the onboard air data system. Ambient air pressure data is used to calculate the current altitude. Higher altitudes result in lower air density and a corresponding decrease in oxygen content per unit volume. To ensure the fuel-air ratio in the combustion chamber maintains normal ignition and stable combustion during start-up, the opening of the starting throttle needs to be appropriately increased to increase the airflow into the cylinders. Simultaneously, to improve the initial energy of turbine start-up, the target engine speed needs to be increased accordingly. Static temperature data directly reflects the ambient thermodynamic state. Lower temperatures result in higher air density but also increase engine lubricant viscosity and starting resistance. Therefore, in low-temperature environments, it is also necessary to increase the starting throttle opening and the target engine speed to overcome the increased mechanical resistance and ensure reliable ignition. The flight control computer stores control tables or correction algorithms that match the relationship between altitude, atmospheric static temperature and starting parameters. Based on the real-time acquired altitude and atmospheric static temperature, the corresponding throttle opening correction and target speed correction are retrieved from the table or calculated by the algorithm and superimposed on the reference starting parameters to form the final starting control command.

[0030] It should be noted that by introducing altitude and atmospheric static temperature to jointly correct the starting parameters, the engine can obtain the appropriate starting fuel supply and target speed under extreme environmental conditions such as high altitude, cold, or high temperature. This avoids the starting difficulties or overheating problems that may occur when fixed starting parameters are used in low-density air or low temperature conditions, significantly expands the range of usable take-off and landing environments for the aircraft, and improves the reliability and consistency of engine starting.

[0031] Preferably, the execution of the flight mission after the start-up is completed includes: after the engine start-up process is completed, performing a pre-takeoff condition check on the engine to confirm that the engine's operating parameters are normal under each operating condition; performing a rapid acceleration and deceleration condition check on the engine to simulate a rapid throttle change scenario during flight and confirm that the engine is working normally during the transient response process; and allowing the aircraft to take off and execute the flight mission only after all the above checks have passed. If any abnormal engine operating condition is found during any of the above checks and affects the engine's continued operation, the flight mission is terminated.

[0032] Specifically, after the engine successfully starts and stabilizes at idle, the aircraft does not take off immediately but enters the pre-takeoff ground test procedure. In this procedure, the flight control computer sends commands to the engine control system according to a preset detection sequence, causing the engine to operate sequentially to different power states, such as idle, cruise power, and takeoff power. In each state, the flight control computer collects key operating parameters such as engine speed, exhaust temperature, lubricating oil pressure, and fuel flow through onboard sensors and compares these parameters with the normal range thresholds for the corresponding state to determine whether the engine is performing normally at different steady-state operating points. Subsequently, the flight control computer performs a rapid acceleration / deceleration test, simulating a situation where thrust needs to be rapidly changed during flight. This involves rapidly increasing the throttle opening to quickly climb the engine speed to a higher power state, and then rapidly decreasing the throttle opening to quickly drop the engine speed back to idle. During this transient process, the engine speed overshoot, recovery time, and peak exhaust temperature are continuously monitored to assess whether the engine's transient response characteristics and acceleration / deceleration performance meet flight safety requirements. If any of the monitoring parameters under any of the above steady-state or transient operating conditions exceed the allowable range and indicate that the engine has a fault trend that affects continuous safe operation, the flight control computer will determine that the engine is in an abnormal operating state, terminate the flight mission, and troubleshoot on the ground.

[0033] It should be noted that completing comprehensive steady-state and transient condition checks before takeoff can detect potential problems on the ground, such as sluggish response of the engine's fuel supply system, rotor bearing wear, or sensor drift, which are not easily exposed under idling conditions. This prevents potential faults from being carried into the flight phase and significantly reduces the probability of in-flight engine failure. The rapid acceleration and deceleration condition check simulates frequent throttle operations in actual flight, ensuring that the engine has good dynamic following capability throughout the entire available power range, providing preliminary verification of the aircraft's power response reliability during maneuvering flight.

[0034] Preferably, the monitoring of the propeller current during pitch change, and maintaining the automatic constant speed mode if the current is not abnormal, includes: continuously collecting operating parameters of the propeller during pitch change by the pitch controller in automatic constant speed mode, the operating parameters including at least the pitch drive current and the pitch operation frequency; comparing the collected pitch drive current with a preset normal operating current range, and comparing the pitch operation frequency with a preset normal frequency range; when both the pitch drive current and the pitch operation frequency are within their respective normal ranges, the propeller system is determined to be operating normally, and the current automatic constant speed mode is maintained; when the pitch drive current exceeds the normal operating current range or the pitch operation frequency exceeds the normal frequency range, the current is determined to be abnormal.

[0035] Specifically, during flight, when the pitch controller operates in automatic constant speed mode, its internal monitoring circuit collects the current value in the variable pitch motor drive circuit in real time at a fixed sampling period, and records the number of times the variable pitch action is triggered per unit time as the variable pitch action frequency. The pitch controller internally stores the normal operating current range threshold and the normal variable pitch frequency range threshold, which are obtained through ground bench testing and calibration. For each sampled current value, the pitch controller compares it with the upper and lower limits of the normal operating current range; for the variable pitch action frequency, it compares it with the upper and lower limits of the normal frequency range. Only when the current sample value is always within the normal operating current range and the variable pitch action frequency is always within the normal frequency range, does the pitch controller determine that the electrical load and action rhythm of the current propeller variable pitch system are in a normal state, and that there is no abnormal resistance or electrical fault in the system. Therefore, it continues to maintain the automatic constant speed mode, and the pitch controller continues to adjust the pitch automatically according to the speed deviation. Conversely, if the current sampling value exceeds the upper or lower limit of the normal operating current range, or if the pitch control frequency increases or decreases abnormally, the pitch controller will determine that the pitch control system is abnormal and report the abnormality to the flight control computer via the communication bus, triggering the subsequent mode switching logic.

[0036] It should be noted that using both the variable pitch drive current and the variable pitch operating frequency as anomaly criteria allows for a comprehensive assessment of the health status of the variable pitch system from both electrical load and mechanical operation perspectives. The drive current directly reflects the load torque borne by the variable pitch motor; an abnormally high current usually indicates mechanical jamming or poor lubrication in the variable pitch mechanism. An abnormal variable pitch operating frequency, on the other hand, may reflect oscillations in the control loop or jitter in sensor signals. Combining these two criteria provides higher fault detection sensitivity and accuracy than relying solely on current thresholds, enabling earlier detection of degradation trends in the variable pitch system and providing a more reliable trigger for active mode switching.

[0037] Preferably, the step of switching to automatic commanded pitch mode if an abnormal current occurs includes: during the cruise or approach positioning phase, if the pitch controller detects an abnormal current in automatic constant speed mode and meets the allowable conditions for automatic commanded pitch, then switching to automatic commanded pitch mode; during the descent phase, if the pitch controller has already experienced one abnormal current and performed a reset operation in automatic constant speed mode, and then experiences another abnormal current, then switching to automatic commanded pitch mode; after entering automatic commanded pitch mode, the current actual speed and target speed are acquired at predetermined time intervals, and the deviation between the two is calculated; if the deviation exceeds a predetermined value... If the deviation still exceeds the preset allowable range and the current actual speed is higher than the target speed, then an increase pitch command is sent. If the deviation still exceeds the preset allowable range after sending a preset number of increase pitch commands, then the command pitch change is determined to be abnormal and the transmission of increase pitch commands is stopped. If the deviation exceeds the preset allowable range and the current actual speed is lower than the target speed, then a decrease pitch command is sent. If the deviation still exceeds the preset allowable range after sending a preset number of decrease pitch commands, then the command pitch change is determined to be abnormal and the transmission of decrease pitch commands is stopped. If the deviation is within the preset allowable range, then no pitch change command is sent.

[0038] Specifically, the flight control computer (FDC) sets differentiated entry conditions for the automatic commanded pitch mode triggered by current anomalies, depending on the flight phase. During the cruise and approach positioning phases, the flight attitude and airspeed are relatively stable, and the pitch change demand is relatively gentle. When the pitch controller reports a current anomaly and the automatic commanded pitch permission flag inside the FDC is valid, the FDC issues a mode switching command, causing the pitch controller to exit the automatic constant speed mode and enter the automatic commanded pitch mode. During the descent phase, as the aircraft is descending and landing, the altitude decreases and the airspeed changes significantly, resulting in relatively frequent pitch changes. If a current anomaly occurs for the first time during this phase, the FDC first sends a pitch controller reset command to attempt recovery. If the pitch change function is normal after the reset, the original mode continues. If a current anomaly reappears after the reset, indicating that the anomaly is repetitive and persistent, the FDC directly switches to the automatic commanded pitch mode.

[0039] Regardless of the method used to enter automatic command pitch control mode, the flight control computer reads the current actual rotational speed of the propeller at fixed time intervals, and simultaneously reads the target rotational speed value calculated by the control law, calculating the difference between the two. If the absolute value of this difference is within the preset allowable deviation range, it indicates that the current rotational speed meets the requirements, and the flight control computer does not send any pitch control commands; the pitch remains in its current state. If the difference exceeds the allowable deviation range and the actual rotational speed is higher than the target rotational speed, it indicates that the propeller speed is too high and the pitch needs to be increased to increase the load torque and reduce the rotational speed. The flight control computer sends an increase pitch command to the pitch controller via the communication bus. After sending, it reads the actual rotational speed again and recalculates the deviation in the next judgment cycle. If the deviation still exceeds the allowable range, it sends another increase pitch command. If the number of consecutive increase pitch commands sent reaches the preset limit and the deviation still has not returned to the allowable range, it indicates that the pitch control mechanism may be stuck in a certain position and unable to respond to commands or responding insufficiently. At this time, the flight control computer generates a command pitch error message and stops sending more increase pitch commands to prevent invalid commands from continuously occupying bus resources. If the difference exceeds the allowable deviation range and the actual speed is lower than the target speed, then symmetrical pitch reduction logic is executed, continuously sending pitch reduction commands until the deviation is recovered or the maximum number of consecutive sending times is reached, at which point the error is stopped and an error is indicated.

[0040] It should be noted that the entry conditions for the automatic command pitch control mode are differentiated according to the flight phase. This ensures that the mode will not easily intervene due to a single, occasional anomaly during the cruise phase, where current anomalies are relatively easy to recover from. During the descent phase, where pitch changes are frequent, a reset-then-judgment mechanism reduces unnecessary mode switching and improves the rationality of the mode switching logic. Once in automatic command pitch control mode, the mode samples the speed deviation at a fixed period and sends single-step pitch control commands sequentially. This avoids the excessive commands and overshoot problems that may occur in traditional continuous control, making the pitch change process smoother and more controllable. Simultaneously, by setting an upper limit on the number of consecutive transmissions and stopping transmissions and indicating an anomaly after reaching the limit, it effectively prevents the motor from overheating or burning out if mechanical jamming has occurred in the pitch control mechanism. It also provides operators with clear fault indications for timely intervention.

[0041] Preferably, the step of exiting the automatic command pitch change mode and resuming the automatic constant speed mode when the difference between the actual propeller speed and the target speed is within a preset range or when a switching command is received includes: after entering the automatic command pitch change mode for a predetermined period of time, if the deviation between the current actual speed and the target speed has recovered to a preset allowable range, then the automatic command pitch change mode is automatically exited and the automatic constant speed mode is switched back, and the delay and speed limiting components of the speed command are re-initialized based on the current actual speed; during the operation of the automatic command pitch change mode, if an externally input switching command is received, the automatic command pitch change mode is immediately exited and the automatic constant speed mode is switched back, and the delay and speed limiting components of the speed command are re-initialized based on the current actual speed.

[0042] Specifically, upon entering the automatic commanded pitch mode, the flight control computer (FDC) starts a timer. After operating in this mode for a predetermined duration, the FDC determines whether the deviation between the current actual rotational speed and the target rotational speed has returned to within the preset allowable range. If the deviation has narrowed to the allowable range, it indicates that the propeller speed has been successfully adjusted to near the target value through the aforementioned sequential sending of increase or decrease pitch commands, and the abnormal pitch state has been eliminated. At this point, the FDC automatically sends a command to the pitch controller to exit the commanded pitch mode, causing the pitch controller to return to the automatic constant speed mode. Simultaneously with switching back to the automatic constant speed mode, the FDC acquires the current actual rotational speed value, uses this value as the initial value for the rotational speed command delay stage in the automatic constant speed mode, and resets the upper and lower boundary constraints of the speed limiting stage based on this actual rotational speed value. This ensures that both the delay stage and the speed limiting stage restart operation based on the current actual state, avoiding sudden changes due to mismatch between the stage state and the current rotational speed. On the other hand, at any time during the operation of the automatic command pitch mode, if the flight control computer receives a switching command sent by the ground remote control equipment, it will immediately perform an exit operation regardless of whether the current speed deviation has been recovered, forcibly switching the pitch controller back to the automatic constant speed mode. At the same time, the speed command delay and speed limiting links will be re-initialized and assigned values ​​according to the current actual speed to ensure the continuity of control parameters at the moment of switching.

[0043] It should be noted that by setting an automatic exit condition based on a predetermined duration, the automatic command pitch mode can promptly hand over control to the automatic constant speed mode after completing its adjustment mission. This avoids prolonged operation in command pitch mode after the anomaly is resolved, which would increase the control burden on the flight control computer. It also allows the propeller system to quickly return to autonomous constant speed adjustment, improving system operating efficiency. The design of unconditionally exiting and immediately resuming automatic constant speed mode upon receiving an external switching command preserves the highest priority intervention authority for ground operators. This allows operators to manually restore the system to the normal control mode when special changes occur in flight status or when the flight control computer's automatic judgment deviates. The reinitialization of the delay and speed limiting components based on the current actual speed during exit effectively suppresses control quantity jumps that may be caused by inconsistent component states during switching, ensuring a smooth mode switching process and flight quality.

[0044] Accordingly, this embodiment also provides an automatic command pitch control system for an aircraft, including: The power-on self-test and start-up parameter setting module is configured to perform a propeller pitch self-test after the aircraft is powered on. After the self-test passes, the engine is allowed to start. The starting throttle opening and target starting speed are set according to the flight altitude and ambient temperature. After starting, the flight mission is executed. The control mode switching module is configured to monitor the current during propeller pitch changes during flight. If the current is normal, it maintains the automatic constant speed mode. If the current is abnormal, it switches to the automatic command pitch mode and sends an increase or decrease pitch command based on the difference between the actual propeller speed and the target speed. If the current further increases to exceed the overcurrent threshold, it switches to the manual command pitch mode. When the difference between the actual propeller speed and the target speed is within a preset range or a switching command is received, it exits the automatic command pitch mode and resumes the automatic constant speed mode.

[0045] Specifically, the power-on self-test and start-up parameter setting module is deployed inside the flight control computer and runs as an embedded software functional module. After the aircraft is powered on, this module first activates the self-test subroutine, sending a query command to the pitch controller via the communication interface to obtain feedback on the minimum blade angle position and the mode switching self-test response. Based on the returned results, it determines whether the self-test has passed. After the self-test passes, the module obtains the ambient air pressure and static temperature provided by the atmospheric data system, calculates the matching start-up throttle opening and target start-up speed through internal algorithms, and sends these parameters to the engine controller via the control bus to execute the start-up. After the engine starts and the ground test passes, this module maintains background monitoring of the engine status until the flight mission ends.

[0046] The control mode switching module is also deployed in the flight control computer and runs continuously throughout the flight. This module receives current monitoring data and speed data reported by the pitch controller in real time via a high-speed communication bus. Internally, it includes current threshold comparison logic, flight phase identification logic, and mode switching decision logic. When the module determines that the current is abnormal and meets the switching conditions for the corresponding flight phase, it sends a mode switching command to the pitch controller, causing it to switch to automatic commanded pitch mode. In this mode, the module performs speed deviation calculations at fixed intervals and sends corresponding single-step pitch commands to the pitch controller based on the direction of the deviation. The module also monitors the continuous trend of current changes. If the current value exceeds the overcurrent protection threshold, it immediately sends a manual mode switching command to the pitch controller and simultaneously sends an alarm message to the ground station via data link. When the module detects that the speed deviation has recovered or receives a ground remote control switching command, it performs a recovery switchback operation to automatic constant speed mode.

[0047] It should be noted that integrating the above control methods into the flight control computer in a modular form fully utilizes the existing communication interfaces and computing resources of the flight control computer, eliminating the need for additional dedicated pitch control hardware and reducing system complexity and hardware costs. The power-on self-test and start-up parameter setting module ensures that all pre-start preparations are executed systematically under the unified scheduling of the flight control computer, avoiding potential oversights that might occur with manual item-by-item checks. The control mode switching module integrates current monitoring, flight phase judgment, speed deviation calculation, and command transmission into a single control loop, enabling the entire pitch mode switching process to be completed within milliseconds, meeting the real-time requirements of pitch control during flight. Simultaneously, the redundant judgment logic within the module ensures the reliability of the mode switching decision.

[0048] Example 2 See Figure 1 This embodiment provides an automatic command pitch control method for aircraft, applied to an electric variable pitch propeller-powered aircraft. The method includes the following steps: S1: Power-on self-test. A power-on self-test is performed before engine start-up, checking the minimum propeller blade angle and the propeller operating mode switching.

[0049] S2: Starting parameter setting. After entering the starting process, the flight control computer automatically controls different starting throttle openings and target starting speeds according to different altitudes and atmospheric static temperatures.

[0050] S3: Start and execute flight. After start-up, complete pre-flight condition checks, rapid acceleration / deceleration condition checks, and pre-flight engine condition checks, and then execute the flight mission.

[0051] S4: Automatic constant speed mode. During flight, the propeller controller monitors the current and frequency of the propeller during pitch changes. If no significant abnormalities are found in any of the parameters, the current operating mode is maintained.

[0052] S5: Command Pitch Control Mode (i.e., Command Control Mode). There are two types of command control modes: automatic command control mode and manual command control mode. If a sudden pitch change or abnormal current fluctuation occurs during mission flight, the operating mode will be switched accordingly. The two operating modes will be adjusted based on the magnitude of the current change.

[0053] S6: Mission accomplished. Command control mode does not affect mission execution during flight, and flight performance is not significantly affected, greatly improving the mission completion rate.

[0054] The propeller used in this embodiment has a pitch-changing function. The propeller pitch change commands come from the flight control computer and a manual control switch. The pitch controller operates in three modes: automatic constant speed mode, command control mode, and manual control mode. Upon power-up, the pitch controller defaults to "automatic constant speed mode," with the default "target speed" being the "target speed" before power-off. When the pitch controller receives a command from the flight control computer to enter "command control mode," it enters command control mode. In this mode, propeller pitch changes are controlled by commands from the flight control computer to "increase pitch" and "decrease pitch." When the pitch controller receives a signal from the manual control switch, it performs the corresponding increase / decrease pitch control, at which point it is in manual control mode. The control priority of the pitch controller is: manual control > automatic constant speed = command control (commands are mutually exclusive). If the pitch controller was in "command control mode" before power-off, the default "target speed" when it enters "automatic constant speed mode" upon the next power-up is the "target speed" when the pitch controller was in "automatic constant speed mode" last time.

[0055] The purpose of the automatic command pitch mode is to prevent "overcurrent" in the pitch controller to some extent. (See also...) Figure 2 After the power system of an electrically variable pitch propeller-powered aircraft is powered on, a propeller pitch check is performed first. If the check passes, the engine is started. During propeller operation, if an overcurrent alarm occurs, the flight control computer automatically sends a reset signal to the pitch controller. Once the alarm disappears, the automatic constant speed mode is restored. If the alarm persists, the automatic command pitch program is entered. The flight control computer, based on the control law, issues speed commands and automatically sends "pitch + / -" commands to control the propeller speed. This prevents excessively high engine speeds due to a small propeller pitch, which could damage the engine, or even cause engine overspeed, loss of control, engine shutdown, and ultimately, a loss of power and a safety hazard.

[0056] Preferably, if any fault occurs in step S1, including minimum blade angle or propeller working mode switching, the pre-start self-test process will terminate.

[0057] Preferably, in step S2, the starting parameters are set such that the throttle opening and target speed are increased accordingly to match the increase in altitude (0-6km) and the decrease in atmospheric static temperature (-50-55℃).

[0058] Preferably, in step S3, the engine's operating status is checked after the start-up process is completed. If an abnormality occurs that affects the engine's operation, the flight mission is terminated, thereby improving the aircraft's ease of use, safety, and timeliness.

[0059] Preferably, in the automatic constant speed mode in step S4, the propeller controller monitors the current and frequency when the propeller pitch changes, and if no obvious abnormality is found in any of the parameters, the current working mode is maintained.

[0060] Preferably, if an abnormality occurs in step S5, such as a rapid pitch change or abnormal current change during mission flight, the operating mode is switched in a timely manner. The two operating modes are adjusted according to the magnitude of the current change. During normal pitch change, the current is ≤I0. If the current is >I0 during pitch change, the system switches to automatic command pitch change. If the current continues to increase to the level of an "overcurrent" fault, exceeding the overcurrent threshold I1, the system enters manual command pitch change mode.

[0061] Preferably, the conditions for entering automatic command pitch control are as follows, wherein the following conditions are or: a) During the "cruise" and "approach positioning" phases, when the pitch controller is in "automatic constant speed mode" and automatic command pitch change is allowed, the pitch controller monitors and judges "overcurrent". b) During the glide phase, the pitch controller is in automatic constant speed mode and automatic command pitch is enabled. During the glide phase, a pitch controller overcurrent fault has occurred once and an automatic "pitch controller reset" command has been sent. After the flight control computer judges the "overcurrent" condition, it enters "automatic command pitch" mode.

[0062] Preferably, after entering the automatic command pitch control mode, the flight control computer controls the pitch controller to enter the "command control mode," and automatically determines whether to perform pitch control at regular intervals, as follows: a) When the current voting speed is greater than the preset value of the target speed given by the control law, the flight control computer sends a command to the pitch controller to increase the pitch. If the preset value "increase pitch" command is sent continuously, and the actual speed still does not meet the target speed, a "command pitch error" prompt is issued, and the "increase pitch" command is no longer sent. b) When the current voting speed is less than the preset value of the target speed given by the control law, the flight control computer sends a command to the pitch controller to reduce the pitch. If the preset value "reduce pitch" command is sent continuously, and the actual speed still does not meet the target speed, a "command pitch error" prompt is issued, and the "reduce pitch" command is no longer sent. c) When the current voting speed and the target speed are within a reasonable range, no more pitch control commands will be sent.

[0063] Preferably, the conditions for exiting automatic command pitch control are as follows, wherein the following conditions are either: a) After entering the "automatic command pitch mode" for a certain period of time, if the deviation between the actual voting speed and the target speed is within the preset range, it will automatically enter the "automatic constant speed mode" and at the same time re-initialize the speed command delay link and the speed limiting link according to the actual speed. b) If the "pitch autonomous" command is sent manually, the system will switch to "automatic constant speed mode" and the speed command delay and speed limiting circuits will be reinitialized according to the actual speed.

[0064] It should be noted that the automatic command control mode does not affect mission execution during flight missions, and flight performance is not significantly affected. It reduces the failure rate while greatly improving the mission completion rate.

[0065] Example 3 This embodiment is based on embodiment 1: This embodiment provides a computer device, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the automatic command pitch control method for aircraft of Embodiment 1. The computer program can be in the form of source code, object code, executable file, or some intermediate form.

[0066] Specifically, this computer device can be an airborne flight control computer or other dedicated electronic control unit. Its memory stores pre-written and compiled control programs containing all the logical steps for implementing the aforementioned automatic command pitch control method. The processor executes this program, reads program instructions and data from memory, performs arithmetic and logical operations and control operations, sends control commands to peripheral devices such as the pitch controller and engine controller, and receives feedback signals, thereby fully realizing the entire control process, including self-testing, starting parameter setting, current monitoring, mode switching decisions, speed deviation calculation, and command transmission. This computer device is also equipped with a communication interface for data exchange with the atmospheric data system, pitch controller, engine controller, and ground data link system, ensuring real-time transmission of various sensor signals and control commands.

[0067] It should be noted that by running the above control method as a computer program on general-purpose computer equipment, the method does not depend on specific hardware circuits, making it easy to port and deploy on control computers of different aircraft models. The programmatic implementation also facilitates online upgrades and optimizations of time parameters, frequency thresholds, and deviation ranges in the control logic based on actual usage experience, improving the system's maintainability and upgradeability.

[0068] Example 4 This embodiment is based on embodiment 1: This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the automatic command-based variable-range control method for aircraft described in Embodiment 1. The computer program can be in the form of source code, object code, executable file, or some intermediate form. The storage medium includes any entity or device capable of carrying computer program code, a recording medium, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0069] Specifically, the computer program stored in the computer-readable storage medium exists in the form of binary code or an executable file. When the medium is installed or loaded onto the aircraft control computer, the computer's processor can read the program code stored in the medium and execute it line by line, thereby implementing all the control steps described in the above method embodiments. This storage medium can be pre-installed in the flight control computer before the aircraft leaves the factory, or it can be used as a separate software upgrade carrier to update the control software of aircraft already in service on-site.

[0070] It should be noted that providing the above control program in the form of a computer-readable storage medium allows the control method to be propagated and distributed independently of hardware devices, facilitating the sharing and reuse of control logic across different aircraft platforms. The program code permanently stored in the storage medium is unaffected by environmental factors such as electromagnetic interference during use, ensuring the integrity and stability of the control logic. This has significant engineering implications for the security and reliability requirements of aircraft control software.

[0071] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

[0072] It should be noted that, for the sake of simplicity, the foregoing method embodiments are described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

Claims

1. A method for automatic command pitch control of an aircraft, characterized in that, include: After the aircraft is powered on, it performs a propeller pitch self-check. Once the self-check is passed, the engine is allowed to start. The starting throttle opening and target starting speed are set according to the flight altitude and ambient temperature. After starting, the flight mission is executed. During flight, monitor the current when the propeller pitch changes. If the current is not abnormal, maintain the automatic constant speed mode. If an abnormal current occurs, the system switches to automatic command pitch control mode and sends a command to increase or decrease the pitch based on the difference between the actual propeller speed and the target speed. If the current increases further to exceed the overcurrent threshold, the system switches to manual command pitch control mode. When the difference between the actual propeller speed and the target speed is within a preset range or when a switching command is received, the automatic command pitch change mode is exited and the automatic constant speed mode is restored.

2. The automatic command pitch control method for aircraft according to claim 1, characterized in that, After the aircraft is powered on, it performs a propeller pitch self-check, including: Check if the propeller is at its minimum blade angle position to confirm that the propeller blades can perform increased pitch operation based on the minimum blade angle; Check if the propeller working mode switching function is working properly to confirm that the propeller can switch normally between different working modes; If any of the above checks fails, a self-test fault is identified and the self-test process is terminated, and the engine is prohibited from starting.

3. The automatic command pitch control method for an aircraft according to claim 1, characterized in that, The setting of the starting throttle opening and target starting speed based on flight altitude and ambient temperature includes: Obtain the ambient air pressure and static temperature at the current altitude of the aircraft; The corresponding altitude is determined based on the ambient air pressure. As the altitude increases, the starting throttle opening is increased accordingly, and the starting target speed is increased. Based on the aforementioned static atmospheric temperature, as the static atmospheric temperature decreases, the starting throttle opening is increased accordingly, and the target starting speed is increased.

4. The automatic command pitch control method for an aircraft according to claim 1, characterized in that, The execution of the flight mission after startup includes: After the engine start-up procedure is completed, a pre-flight condition check is performed on the engine to confirm that the engine's operating parameters are normal under each operating condition. The engine was checked under rapid acceleration and deceleration conditions, simulating a scenario of rapid throttle changes during flight, to confirm that the engine was working normally during the transient response process; The aircraft is permitted to take off and perform its flight mission only after all the above checks have been passed. If any abnormality in the engine's operating condition is found during any of the above checks and affects the engine's continued operation, the flight mission will be terminated.

5. The automatic command pitch control method for an aircraft according to claim 1, characterized in that, The monitoring of propeller pitch current, if no abnormality is found, maintains automatic constant speed mode, including: The pitch controller continuously collects the operating parameters of the propeller during the pitch change process in automatic constant speed mode. The operating parameters include at least the pitch change drive current and the pitch change operation frequency. The collected variable pitch drive current is compared with the preset normal operating current range, and the variable pitch operating frequency is compared with the preset normal frequency range. When the variable pitch drive current and variable pitch operation frequency are both within their respective normal ranges, the propeller system is determined to be operating normally and the current automatic constant speed mode is maintained. When the variable pitch drive current exceeds the normal operating current range or the variable pitch operation frequency exceeds the normal frequency range, the current is determined to be abnormal.

6. The automatic command pitch control method for an aircraft according to claim 1, characterized in that, If an abnormal current occurs, the system will switch to automatic command pitch control mode, including: During the cruise or approach positioning phase, if the pitch controller detects an abnormal current in automatic constant speed mode and meets the allowable conditions for automatic command pitch, it will switch to automatic command pitch mode. During the descent phase, if the pitch controller has experienced a current anomaly once in automatic constant speed mode and has performed a reset operation, and then experiences another current anomaly, it will switch to automatic command pitch mode. After entering the automatic command pitch control mode, the current actual speed and the target speed are obtained at predetermined time intervals, and the deviation between the two is calculated. If the deviation exceeds the preset allowable range and the current actual speed is higher than the target speed, then send an increase pitch command once. If the deviation still exceeds the preset allowable range after sending a preset number of increase pitch commands, then it is determined that the command pitch is abnormal and the increase pitch command is stopped. If the deviation exceeds the preset allowable range and the current actual speed is lower than the target speed, a pitch reduction command is sent once. If the deviation still exceeds the preset allowable range after sending a preset number of pitch reduction commands, it is determined that the command pitch is abnormal and the pitch reduction command is stopped. If the deviation is within the preset allowable range, no pitch change command will be sent.

7. The automatic command pitch control method for an aircraft according to claim 6, characterized in that, The step of exiting the automatic command pitch mode and resuming the automatic constant speed mode when the difference between the actual propeller speed and the target speed is within a preset range or when a switching command is received includes: After entering the automatic command pitch control mode, if the deviation between the current actual speed and the target speed has recovered to the preset allowable range after a predetermined time, the automatic command pitch control mode will be automatically exited and switched back to the automatic constant speed mode. At the same time, the delay and speed limit links of the speed command will be re-initialized and reassigned according to the current actual speed. During automatic variable pitch mode operation, if an external input switching command is received, the automatic variable pitch mode will be immediately exited and switched back to automatic constant speed mode. At the same time, the delay and speed limiting links of the speed command will be re-initialized and reassigned according to the current actual speed.

8. An automatic command pitch control system for an aircraft, characterized in that, include: The power-on self-test and start-up parameter setting module is configured to perform a propeller pitch self-test after the aircraft is powered on. After the self-test passes, the engine is allowed to start. The starting throttle opening and target starting speed are set according to the flight altitude and ambient temperature. After starting, the flight mission is executed. The control mode switching module is configured to monitor the current during propeller pitch change during flight. If the current is not abnormal, the automatic constant speed mode is maintained. If an abnormal current occurs, the system switches to automatic command pitch control mode and sends a command to increase or decrease the pitch based on the difference between the actual propeller speed and the target speed. If the current further increases to exceed the overcurrent threshold, the system switches to manual command pitch control mode. When the difference between the actual propeller speed and the target speed is within a preset range or a switching command is received, the system exits the automatic command pitch control mode and resumes the automatic constant speed mode.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the automatic command pitch control method for an aircraft as described in any one of claims 1-7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the automatic command pitch control method for aircraft as described in any one of claims 1-7.

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