40 results about "Variable pitch propeller" patented technology

The invention provides a composite feedforward cooperative control method and system for propulsion of a controllable-pitch propeller of a ship. The method comprises the following steps: establishing a propulsion composite model comprising a ship load inquiry function model and a controllable-pitch propeller propulsion cooperative control model; identifying ship resistance characteristics in real time through a load inquiry model, predicting main engine power and propeller rotating speed requirements at different navigational speeds, and calculating a main engine power margin; setting a host security threshold based on the maximum persistent power margin; within the allowable range of the safety threshold value, three cooperative control modes are selected and executed in a self-adaptive mode according to the navigation working condition, wherein the three cooperative control modes include the pitch-accelerator joint control mode under the constant rotating speed of a main engine, the main engine rotating speed-accelerator joint control mode under the fixed pitch of a controllable-pitch propeller and the controllable-pitch propeller rotating speed-pitch joint control mode under the constant power of the main engine. According to the invention, through feedforward prediction and multivariable cooperation, navigational speed closed-loop stable control is realized, the problems of host overload, black smoke emission, high exhaust temperature and large control fluctuation are fundamentally avoided, and fuel economy and all-condition navigation safety are improved.

The invention relates to the field of unmanned aerial vehicles, and discloses a tilting type composite thrust system of a small fixed-wing aircraft, comprising: a physical bearing and power unit module comprising wings and six groups of tilting thrust units on the wings, each group of unit being composed of a turboprop engine and a variable pitch propeller and generating thrust; the thrust vector adjusting module comprises six sets of electric tilting joints and drives the tilting thrust unit to rotate so as to adjust the thrust direction. The state sensing and feedback module is provided with an angle sensor for monitoring the tilting angle in real time; the cooperation and synchronization control module comprises a synchronization controller which is connected with the angle sensor and the electric tilting joints and controls the six sets of electric tilting joints to be converted in batches according to the monitored angle. According to the invention, the integrated electric tilting joint is arranged, and the joint contains a main tilting shaft for wide-angle mode switching and an auxiliary fine tuning shaft for small-range active compensation, so that two adjusting mechanisms with different functions are integrated in a single structure.

Variable pitch propeller, comprising at least two blades and a rotor with a hub, the hub comprising a blade support for each blade of the propeller, each blade comprising a blade foot designed to cooperate with one of said blade supports in order to maintain the blade in position in the rotor while allowing the pitch to be changed, comprising: - a blade foot comprising a composite core (11), disposed in an outer sleeve (13) of the blade support resting on it by means of an elastomer buffer (12), - a blade support (4) having an upper bearing (2) and a lower bearing (3) in contact with the outer sleeve (13), the blade support (4) also comprising at least two half-jaws (14) cooperating with the composite core (11) in order to prevent the blade foot from moving in a radial direction relative to the blade support (4). Figure for the abridged version: Fig 8

The utility model discloses an aerial variable pitch propeller variable pitch mechanism stability augmentation structure and a propeller, the stability augmentation structure comprises a variable pitch disc, the variable pitch disc is provided with at least two axial through limiting guide holes, and guide columns are arranged in the limiting guide holes in a sliding mode. The propeller comprises the stability augmentation structure. According to the utility model, the guide post is arranged, so that the variable-pitch disc does not rotate and does not shake, the planeness of the variable-pitch disc in the variable-pitch movement process is improved, and the variable-pitch precision is improved; the resistance of up-down movement of the variable-pitch disc is reduced by arranging the linear bearing, the service life is prolonged, and the mechanical transmission efficiency is improved.

The utility model discloses a variable pitch propeller structure of an unmanned aerial vehicle, which relates to the field of unmanned aerial vehicle structures and comprises a propeller mounting seat, the bottom end of the propeller mounting seat is connected with a telescopic propeller shaft structure, and propeller blades are arranged on the periphery of the propeller mounting seat; the ends, close to the propeller mounting base, of the propeller blades are connected with propeller blade adjusting shafts, the ends, close to the propeller mounting base, of the propeller blade adjusting shafts are connected with the propeller mounting base, and the propeller blade adjusting shafts are further connected with limiting clamping rings. The outer wall of the limiting clamping ring is connected with an upper limiting clamp and a lower limiting clamp through bolts, and the lower limiting clamp is used for being connected with a propeller mounting base. According to the propeller structure, the included angle (pitch) between the rotating plane of the propeller blades of the propeller structure and airflow can be adjusted according to needs, so that the propeller system optimizes thrust and efficiency in different flight states, and the unmanned aerial vehicle can adapt to different environments.

The invention relates to an assembly comprising a propeller blade (10) and a pitch adjustment system (34) for setting the pitch of the blade (10), wherein the root (14) of the blade (10) has a bulb (32) and the pitch adjustment system (34) for setting the pitch of the blade (10) comprises: - a cup (58) having an upper opening (58c); - a retaining ring (82) extending around the bulb (32), the retaining ring being at least limited in axial movement relative to the cup (58) towards the opening (58c) and having a bearing face (84) to hinder axial movement of the root (14) towards the opening (58c); the pitch adjustment system (34) being characterized in that it further comprises a lower seat (88) by which the root (14) is engaged with the cup (58), the seat (88) and / or the retaining ring (82) being mounted so as to be axially translatable relative to the cup (58) by at least one clamping mechanism (90).

The utility model provides a variable pitch blade device, which relates to the technical field of unmanned aerial vehicle engines, and comprises a fixed seat fixedly arranged at an air inlet of a supercharger, a plurality of mounting holes are arranged around the fixed seat perpendicular to the air inlet direction, blades of the supercharger are rotatably mounted in the mounting holes, and a guide groove is arranged on the fixed seat along the air inlet direction. The sliding block is arranged in the guide groove in a sliding mode and moves back and forth along the guide groove under the action of the lead screw, a mounting cavity is formed between the sliding block and the fixing base in a surrounding mode, the paddles penetrate through the mounting holes, an eccentric wheel is arranged in the mounting cavity, the outer edge of the eccentric wheel is pushed when the sliding block moves, the paddles are made to rotate, and then the screw pitch between the adjacent paddles is changed. The continuous power output capacity of the unmanned aerial vehicle engine under the dynamic load change is improved, the reliability of the unmanned aerial vehicle engine in complex tasks is enhanced, and the unmanned aerial vehicle engine system is compact in structure, simple in design and suitable for being used in space-limited and large-height-span unmanned aerial vehicle engine systems.

A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

The propulsion system is a propulsion system for a hybrid propulsion ship having a variable pitch propeller, an engine for controlling the rotational speed in accordance with a rotational speed command value, a motor generator, a power converter, and a controller for controlling the power converter, the controller including a processing circuit that acquires blade angle data of the variable pitch propeller and transmits the acquired blade angle data to the variable pitch propeller. When the rate of change in the blade angle of the variable pitch propeller is equal to or greater than a predetermined threshold value, a command value for adjusting the power received by the power converter from the motor generator or the power supplied from the power converter to the motor generator is generated, and the command value is output to the power converter.

A system (34) for controlling the pitch of a propeller blade (10) of a turboprop engine of an aircraft is disclosed, characterized in that it comprises a cup (58) comprising an annular wall (58a) extending around an axis (A) serving as an axis of pitch setting of the blade, and a bottom wall (58b) configured to cooperate in a shape-matched manner with a free end (28) of said root (14), so as to prevent the cup (58) from rotating with respect to the root (14) around the axis (A), and a fixing ring (52, 52') configured to be mounted inside the cup (58) and to cooperate with the root (14) and with the annular wall (58a) of the cup (58), respectively, so as to ensure the axial retention of the root (14) in the cup (58).

The utility model belongs to aerospace equipment technical field, concretely relates to a variable pitch propeller. The utility model discloses variable pitch propeller includes a plurality of blades, hub assembly and a plurality of locating plate, and the blade includes blade main part and locating protruding, and locating protruding sets up at the root of blade main part, and hub assembly includes detachably connected first hub and second hub, and first hub includes first hub main part and a plurality of first connecting part, and second hub includes second hub main part and a plurality of second connecting part, and first connecting part and the second connecting part of direct setting form the slot, and the slot is used for and the root of blade main part inserts, and first hub main part and second hub main part splice and form a plurality of open slot, and open slot and the slot correspond and communicate with the slot, and locating plate inserts in open slot, and locating plate is provided with locating insertion hole, and locating insertion hole is used for and locating protruding inserts. The variable pitch propeller in this technical scheme can realize quick variable pitch and improve variable pitch accuracy.

The invention discloses a fixed-wing unmanned aerial vehicle self-adaptive flight control method based on a variable-pitch propeller and the self-adaptive variable-pitch propeller. The method comprises the steps that multi-sensor data such as the air speed, the height, the vertical speed, the accelerator and the rotating speed are collected in real time; based on a predefined comprehensive scoring model, scores of all flight stages are calculated through piecewise scoring functions of five dimensions of height, air speed, vertical speed, accelerator and time, and a strict conversion logic and hysteresis mechanism is combined to intelligently judge that the aircraft is in a take-off, climbing, cruising or descending stage at present; according to the judged stages and the real-time state, the pitch angle of the variable pitch propeller and the position of an engine throttle are dynamically calculated, control parameters are adjusted according to the stages, and height and rotating speed compensation is introduced; meanwhile, three-level safety protection including warning, active intervention and emergency response is implemented, and thrust and system efficiency are calculated online to optimize energy efficiency. According to the invention, self-adaptive, high-safety and high-efficiency control in the whole flight process is realized.

The application discloses a pitch feedback adjusting circuit based on frequency signal transmission of a pitch control propeller, and relates to the technical field of electrical control.The circuit comprises a pitch signal acquisition circuit, a voltage-to-frequency signal transmission circuit and a frequency-to-voltage signal adjusting circuit.The pitch signal acquisition circuit is connected with a pitch potentiometer, used for acquiring and processing a pitch feedback signal and transmitting the signal to the voltage-to-frequency signal transmission circuit to be converted into a frequency signal for long-distance transmission.The frequency-to-voltage signal adjusting circuit converts the long-distance transmitted frequency signal into a voltage signal, and outputs a pitch feedback signal meeting the use requirements of a pitch control propeller ship after signal adjustment.The pitch signal acquisition circuit comprises a signal acquisition circuit, a filter following circuit and a zero point and range adjusting circuit.The voltage-to-frequency signal transmission circuit comprises a voltage / frequency conversion chip and a peripheral circuit thereof.The frequency-to-voltage signal adjusting circuit comprises a frequency / voltage conversion chip and a peripheral circuit thereof.

The rigid-flexible composite propeller hub connecting device for the variable pitch propeller comprises a propeller hub and a propeller root assembly, and is characterized in that a flexible connecting assembly is arranged at the connecting interface of the propeller hub and the propeller root assembly. The assembly is composed of rigid inner and outer ring bushings and a rubber elastomer embedded between the rigid inner and outer ring bushings. The inner ring lining is in close contact with the propeller root, and the outer ring lining is in interference fit with the propeller hub. By means of the rigid-flexible composite structure, reliable and accurate transmission of torque and centrifugal force is ensured, meanwhile, vibration energy generated by working of the propeller is effectively absorbed and dissipated through the high-damping rubber material, and therefore a vibration transmission path is remarkably blocked, the excellent vibration and noise reduction effect is achieved, and the working stability and reliability of a system are improved; and the service life of the propeller is prolonged. The variable-pitch propeller is compact in structure, convenient to assemble and maintain and easy to integrate into an existing variable-pitch propeller structure.

The application discloses a pitch signal adjusting circuit and a three-way feedback redundancy control method for a variable pitch propeller, comprising a power supply circuit, a pitch signal collecting and adjusting circuit and a three-way feedback redundancy control module; the three-way feedback redundancy control module receives three-way pitch feedback current signals respectively and is configured to execute a three-way feedback redundancy control method; the method comprises safety threshold judgment, weighted voting, consistency detection, majority voting, dynamic selection, stability judgment, recursive average filtering and median filtering algorithms executed in a preset rule sequence, and according to the deviation, change rate and fluctuation state of the three-way signals, effective signals are dynamically selected to participate in the closed-loop control of the variable pitch propeller, or the pitch is locked and an alarm is given when all the signals are abnormal. The three-way pitch feedback signals of the variable pitch propeller are independent of each other and do not interfere with each other, the three-way pitch signals are processed through the method, the reliability of the variable pitch propeller system is improved, and the method is suitable for popularization and use in a pitch control system of the variable pitch propeller.

Disclosed is a variable pitch propeller blade for an aircraft turbine engine. The blade includes an airfoil connected to a root, the root having a body housed in an annular barrel that extends around a pitch axis of the blade, the body including a free end opposite the airfoil; a shoulder towards the airfoil; and a bulb located between the free end and the shoulder. The bulb can have a cross-section, referred to as the middle section, that has a maximum value Sm, and the barrel can be affixed to the body and covers and matches at least a portion of the bulb and the shoulder.

The invention relates to the technical field of mechanical structure optimization, in particular to an ejector rod mechanism for variable pitch propeller pitch measurement, which comprises a self-lubricating roller bearing, a displacement rod, a support, a reset mechanism and a dustproof limiting assembly. Through rolling contact between the self-lubricating roller bearing and the cam, angular displacement is accurately converted into axial linear displacement of the displacement rod, through cooperation with double-point radial constraint of the linear motion bearing and the category limiting assembly, it is ensured that the motion trail is stable, and the propeller pitch measurement precision is improved, and through interference fit between a dustproof ring in the dustproof limiting assembly and the displacement rod, the propeller pitch measurement precision is improved. Foreign matters such as dust and carbon powder are effectively prevented from entering the cavity, clamping stagnation caused by movement is avoided, the reliability of the mechanism in a severe environment is guaranteed, a reset spring in the reset mechanism provides reset elastic force, a displacement rod can rapidly and reversely move when the pitch of a propeller is decreased by adopting a piano steel wire material, real-time dynamic response is achieved, and the reliability of the mechanism is improved. And the real-time measurement requirement of the blade angle is met.

A method of operating a variable pitch propeller system for an aircraft. The method includes: receiving aircraft flight information; performing a virtual pitch calculation to determine a virtual propeller pitch or virtual blade angle from the aircraft flight information; and performing a pitch protection process in response to low virtual propeller pitch or virtual blade angle being determined.

The invention relates to a variable-pitch propeller assembly and an aircraft. The variable-pitch propeller assembly comprises a propeller hub, a propeller blade mechanism and a variable-pitch mechanism. A containing space is formed around the rotation axis of the propeller hub. The paddle mechanism comprises a paddle, a switching assembly and a rocker arm. Each paddle comprises a paddle shaft and a paddle wing which are integrally connected and are made of different materials, and the paddle shaft is made of a metal material. A first limiting part and an external thread part are arranged on the circumferential surface of the paddle shaft, and are arranged at an interval in the axial direction of the paddle shaft. The switching assembly comprises a bearing part and a locking end cover, and the propeller shaft is rotatably mounted in the mounting hole of the propeller hub through the bearing part. The locking end cover is in threaded connection with the external thread part; and the bearing part is limited and propped between the first limiting part and the locking end cover along the axial direction of the propeller shaft. The rocker arm is located in the containing space and fixedly connected to the propeller shaft in a sleeving mode, and the locking end cover is located between the rocker arm and the first limiting part in the axial direction of the propeller shaft. The pitch changing mechanism is connected with the rocker arm and used for driving the rocker arm to drive the propeller shaft to rotate axially. The flight reliability of the aircraft can be improved.

The utility model relates to the field of variable pitch propellers, and provides a propeller hub structure for an electric variable pitch propeller, which comprises an upper propeller hub, a lower propeller hub, a variable pitch mechanism, a first guide rod, a paddle mechanism and a power motor, the power motor comprises a rotor and a stator, the rotor is fixedly connected with the lower propeller hub, and the lower propeller hub is fixedly connected with the upper propeller hub through a fixing piece; the first guide rod is connected with the upper propeller hub and the lower propeller hub in an inserted mode. The variable-pitch mechanism comprises a variable-pitch motor, a center shaft, a moving part and a variable-pitch sliding block, the variable-pitch motor is fixedly connected with the stator, the center shaft is fixedly arranged at the upper end of the variable-pitch motor, the lower end of the moving part is fixedly connected with the output end of the variable-pitch motor, the upper end of the moving part is fixedly connected with the variable-pitch sliding block, and the moving part is in sliding fit with the center shaft; the variable-pitch sliding block is in sliding fit with the first guide rod; the blade mechanism comprises blades and an eccentric pin cover plate, and the variable-pitch sliding block is rotatably connected with the blades, so that the accurate adjustment of the pitch is realized, and the working efficiency of the propeller is improved.

The utility model provides a blade hoisting tool for a controllable-pitch propeller. The blade hoisting tool comprises a vertical frame, a first transverse frame and a second transverse frame, the first transverse frame and the second transverse frame are mounted in parallel in parallel in the perpendicular bisector direction of the vertical frame, and the horizontal length of the first transverse frame is larger than that of the second transverse frame; an inner space formed by the vertical frame, the first transverse frame and the second transverse frame can realize positioning of propeller blades; the roots of the propeller blades are placed below the second transverse frame, the first transverse frame is placed on the lower middle portion of the propeller blades, and the top of the vertical frame is higher than the tops of the propeller blades. The novel paddle hoisting tool can improve the safety of constructors, is high in adaptability, reduces the cost and saves the ship maintenance time.

The invention discloses a model-based shaft fan variable cycle engine paddle performance matching optimization method, which comprises the following steps of: based on a component-level modeling method, introducing a key geometric adjustable component and an area-adjustable convergent nozzle, and constructing a shaft fan variable cycle engine component-level model with a turboshaft and turbofan dual working mode; establishing a high-precision propeller performance calculation model based on a propeller strip theory and airfoil profile data; and constructing an axial fan variable cycle engine-propeller comprehensive performance model, proposing a comprehensive matching performance evaluation index, and seeking an optimal index through an optimization algorithm. The method is suitable for the axial fan variable cycle engine with double working modes, the problems of low efficiency, poor dynamic response, unstable mode switching and the like in the traditional matching process are effectively solved through optimization design of comprehensive matching performance indexes, the integrated comprehensive matching performance is remarkably improved, and the method is suitable for popularization and application. Technical support is provided for demonstration of power system schemes of advanced rotor aircrafts such as high-speed helicopters.

A method of performing health monitoring for an aircraft having a variable pitch propeller system. The method includes: receiving aircraft flight information; performing a virtual pitch calculation to determine a virtual propeller pitch or virtual blade angle from the aircraft flight information; receiving a measured propeller pitch or blade angle from at least one physical sensor associated with the propeller; and using the virtual propeller pitch or virtual blade angle and the measured propeller pitch or blade angle to perform a health monitoring process to determine a health condition of at least one component of the aircraft, wherein the at least one component is distinct from the blades.

The application provides a kind of ship variable pitch propeller propulsion composite feedforward collaborative control method and system, comprising: the establishment of containing ship load inquiry function model and variable pitch propeller propulsion collaborative control model propulsion composite model;Through load inquiry model, the ship resistance characteristics are identified in real time, the main engine power and propeller speed demand under different sailing speed are predicted, and the main engine power margin is calculated;Set the main engine safety threshold based on maximum continuous power margin;Within the allowable range of safety threshold, three kinds of collaborative control modes are adaptively selected and executed according to sailing conditions: pitch-throttle joint control under constant speed of main engine, main engine speed-throttle joint control under constant pitch of variable pitch propeller, variable pitch propeller speed-pitch joint control mode under constant power of main engine.The application realizes closed loop stable control of sailing speed through feedforward prediction and multivariable collaboration, fundamentally avoids the problem of main engine overload, black smoke, high exhaust temperature and large control fluctuation, and improves fuel economy and full working condition sailing safety.

The invention discloses a variable pitch propeller ship shaft belt electric excitation synchronous motor and a starting method thereof, and relates to the technical field of reversible ship shaft belt motors. The system comprises a motor starting structure arranged on an electro-magnetic synchronous generator, and the motor starting structure comprises a brush lifting device, an automatic voltage regulator, an excitation frequency converter and a ship power station power supply and is used for providing power support for the whole motor starting structure. A stator winding and a rotor winding are arranged on a motor base of the electro-magnetic synchronous generator, and the stator winding is electrically connected with a stator three-phase terminal. The starting method comprises the following steps that S1, the excitation frequency converter sends an instruction to control the brush lifting device to execute brush pressing action; s2, starting is started, an excitation frequency converter sends out a pulse instruction to enable a three-phase terminal of a stator winding to be connected, and the excitation frequency converter sends out a pulse instruction to enable a direct-current excitation terminal to be connected; and S3, accelerated operation: the excitation frequency converter controls the electrically excited synchronous generator to gradually accelerate to a rated voltage and a rated rotating speed.

A propeller blade includes a first material and a second material. The first material includes fibers. The second material is different from the first material. The fibers are interspersed through the second material and the fibers are oriented in a same direction within the second material. The propeller blade is anisotropic and includes sections of the fibers.

The application discloses a motor-driven variable-pitch propeller, wherein a forward-reverse motor is fixed at the front end of a propeller shell; screw rods are rotatably installed in the inner wall grooves of the front and rear end faces of the propeller shell; the driving shaft of the forward-reverse motor is connected with the screw rods through a key groove; a thread nut with a circle of rectangular grooves on the peripheral wall is connected with the screw rods, and eccentric pins of each propeller blade are arranged in the rectangular grooves; the forward-reverse motor stops running at the moment when the thread nut leaves the contact of a feathering stroke control lever; when the thread nut moves towards the motor direction against the contact of the feathering stroke control lever, the thread nut can stop at a position between the positions of the thread nut on the screw rods when the propeller blades are in the feathering and reverse directions according to the propeller blade angle selected by a propeller blade angle control panel; the forward-reverse motor stops running at the moment when the thread nut contacts the reverse stroke control lever. The application realizes the functions of variable-pitch, feathering and reverse, and has no oil leakage problem; the variable-pitch speed and precision are greatly improved; the mass of the propeller is reduced; and the quality and safety of the propeller are improved.

The present invention relates to a controllable pitch propeller capable of changing the pitch of the blade according to the navigation conditions of the ship, and particularly, to a controllable pitch propeller having an optimum hub to tip diameter ratio, which is capable of reducing the size of the hub in order to have a high efficiency close to the propulsive efficiency of a fixed pitch propeller (FPP). In order to achieve the above-mentioned object, the present invention relates to a controllable pitch propeller comprising a hub mounted at the propulsion shaft of the ship and a blade mounted at the circumference of the hub and having a variable pitch, and is technically characterized by an H / D ratio of the diameter (H) of the propeller to the diameter (D) of the hub of 0.170-0.2.

The application relates to the technical field of engine performance calculation technology, in particular to a power optimization control method of a variable-pitch propeller. The power optimization control method of the variable-pitch propeller can obtain a power optimization working relationship of the propeller. Based on the power optimization working relationship of the propeller, a power coefficient can be determined on the preset power optimization working relationship of the propeller according to the working condition and the thrust demand, and the minimum power is obtained. That is, under the premise of the same flight working condition and the same thrust demand, there is only one set of speed or pitch angle combination of the variable-pitch propeller propulsion system, so that the power consumed by the propulsion system is minimum, and the variable-pitch propeller propulsion system is in the optimal propulsion efficiency at any time, thereby achieving the technical effect of aviation low carbon and environmental protection.

The invention relates to a variable-pitch propeller assembly and an aircraft. The variable-pitch propeller assembly comprises a propeller hub, a propeller blade mechanism and a variable-pitch mechanism. A containing space is formed around the rotating axis of the propeller hub, and the propeller hub comprises a mounting hole formed in a penetrating mode in the direction intersecting with the rotating axis. The paddle mechanism comprises a paddle and a switching assembly. Each paddle comprises a paddle shaft and a paddle wing which are integrally connected and are made of different materials, and the paddle shaft is made of a metal material. The adapter assembly comprises a bearing part and a locking part, the bearing part is arranged on the propeller shaft in a sleeving manner, the propeller shaft is rotatably mounted in the mounting hole through the bearing part, the locking part is arranged on the propeller shaft in a sleeving manner, and the position of the bearing part is limited in the axial direction of the propeller shaft. The pitch changing mechanism comprises a rocker arm and a driving assembly, the rocker arm is located in the containing space and fixedly connected with the propeller shaft, and the driving assembly is connected with the rocker arm and can drive the rocker arm to drive the propeller shaft to rotate in the axial direction. According to the scheme, the flight reliability of the aircraft can be improved.