Stable flight control method for combined helicopter

Abstract

The invention discloses a composite helicopter stable flight control method, which relates to the technical field of aviation flight control, and comprises the following steps: S100, synchronously acquiring a blade vibration trace, a helicopter body pitching swing trace and a tail section acceleration trace under a high-speed cruise steering working condition, pressing into a coupling time sequence band by using a unified time reference, and obtaining a coupling time sequence band; and continuously traceable resonance candidate segments are marked in the coupling time sequence band. According to the method, a multi-control-chain peak shifting admission mechanism is established by triggering an anchor point cable, time layering coordination of propeller pitch adjustment, pitching balancing and propelling thrust is achieved, modal energy superposition of rotors and an aircraft body is avoided, and the flight attitude is kept stable; and through breathing type phase turn-back gate control driven by the damping bill chain, dynamic circulation of energy absorption and recovery is realized, vibration accumulation is inhibited, flight immunity and structural stability are improved, and stable flight is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of aviation flight control technology, specifically to a composite helicopter stable flight control method. Background Technology

[0002] Composite helicopter stable flight control refers to the technical process of dynamically and stably regulating the attitude, speed, and heading of a composite helicopter, which combines the lift characteristics of both rotor and fixed-wing aircraft, during different flight phases such as vertical takeoff and landing, hovering, transition, and level flight. This is achieved through the comprehensive coordination of rotor thrust, tail rotor yaw moment, fixed-wing lift, and propulsion thrust. Its core lies in the real-time perception of the aircraft's flight status parameters, such as pitch angle, roll angle, sideslip angle, airflow disturbance, and load changes, under complex aerodynamic environments and multi-source interference conditions. A multi-input coupled control strategy is used for feedback and feedforward adjustments to maintain a dynamic balance between lift distribution, thrust vector, and flight attitude, thereby ensuring smooth transitions and precise control during different mode transitions. This control method emphasizes the synergy of composite power and multi-dimensional attitude steady-state coupling, representing a comprehensive control system integrating aerodynamics, flight control engineering, and intelligent adaptive control technologies.

[0003] The existing technology has the following shortcomings: In existing technologies, compound helicopters typically rely on the coordinated operation of rotor attitude adjustment and fuselage pitch control to maintain flight stability during high-speed cruise and turn maneuvers. However, when the rotor system operates under high speed and high aerodynamic load conditions, the rotor structure exhibits inherent high-frequency vibration modes, while the fuselage generates low-frequency pitch oscillation modes during turn maneuvers. When the frequencies of these two modes converge under specific flight conditions, they enter a resonance zone, creating a self-excited coupling effect between the rotor vibration modes and the fuselage pitch modes. This self-excited coupling causes vibration energy to be continuously transferred and amplified between the rotor and the fuselage, resulting in unpredictable periodic vibrations in the tail section structure, manifested as abnormally increased local amplitudes in the tail boom, tail fin, and tail rotor assembly. Because existing technologies have failed to establish real-time detection and suppression mechanisms for this cross-modal resonance coupling, when the resonance zone is unexpectedly triggered, the stability of the fuselage tail section is easily lost control. In severe cases, this can lead to accelerated propagation of structural fatigue cracks, abrupt changes in flight attitude, or even overall instability, becoming a potentially high-risk problem affecting the stable flight of compound helicopters.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a composite helicopter stable flight control method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a composite helicopter stable flight control method, comprising the following steps: S100 synchronously acquires blade vibration traces, airframe pitch yaw traces, and tail acceleration traces during high-speed cruise and turning conditions, and presses them into the coupling timing band with a unified time reference, marking continuously traceable resonance candidate segments within the coupling timing band. S200 extracts the close segments of the blade vibration peak group that approach the pitch peak group of the aircraft based on the resonance candidate segment, generates a phase close list, and solidifies the end of the phase close list as a trigger anchor cable, which is used as the starting reference for subsequent control chain adjustment. S300 performs micro-time difference splitting and arrangement around the trigger anchor cable to the pitch adjustment chain, pitch trim chain and propulsion thrust chain to form a staggered entry sequence of the three control chains, and generates a staggered traction sequence to be written into the tail control section. S400 establishes an anti-resonance shadow channel based on the staggered traction sequence, introduces the high-frequency jitter energy of the tail section into the shadow channel, maps the introduced energy into damped injection notes, and writes them back to form a damped note chain. The S500 implements breathing-style phase reversal braking according to the damping note chain rhythm. During the peak of the steering rhythm, it tightens the pitch change port and increases the damping injection density. During the trough of the steering rhythm, it relaxes the pitch trim port and recovers the propulsion thrust pulsation. Through the periodic reversal of the phase reversal braking, it achieves cross-modal self-excited coupling dynamic suppression, thereby maintaining the stable flight state of the compound helicopter.

[0007] Preferably, step S100 includes: A multi-point flight status data acquisition chain is established around the rotor system, the airframe pitch axis and the tail boom structure. By deploying flight status sensing units at the blade root, the center of the airframe longitudinal axis and the key nodes of the tail boom, the blade vibration trajectory, the airframe pitch oscillation trajectory and the tail section acceleration trajectory are obtained respectively. Using the flight control center time as a unified time reference, time remapping and continuous interpolation are performed on the three types of tracks to achieve a smooth correspondence between the high-frequency changes of the blade vibration track and the low-frequency changes of the airframe pitch sway track on the same time axis. Based on the time synchronization results, a coupled time series is established, and the three types of traces are pressed in at equal steps to form an uplink trajectory, a midlink trajectory, and a downlink trajectory, thus constructing a continuous and traceable dynamic coupling relationship; Using the vibration peaks of the blade vibration trajectory as a reference in the coupled time series, the response trends of the pitch and roll trajectory and the tail acceleration trajectory of the aircraft are retrieved, and the time intervals in which the changes of the three trajectories converge are marked as candidate resonance segments.

[0008] Preferably, after establishing the coupling time series, the blade vibration trajectory is arranged in layers as the upward trajectory, the airframe pitch oscillation trajectory as the mid-course trajectory, and the tail acceleration trajectory as the downward trajectory through time series indexing, and they are kept synchronously deployed on the time axis. This allows the rotor system, airframe pitch system, and tail response system to form a dynamic mapping relationship under the same time reference, thereby improving the continuous traceability and timing correlation accuracy of the resonance candidate segment.

[0009] Preferably, step S200 includes: Within the coupling time band, the synchronous change trajectory of the blade vibration trajectory and the airframe pitch oscillation trajectory is obtained. Based on the principle of time consistency, the peak group correspondence is established, and the blade vibration peak group sequence and the airframe pitch peak group sequence are formed. Using the time points of the blade vibration peak groups as a reference, the time points of adjacent pitch peak groups of the aircraft are retrieved, and the time intervals that are close to each other are extracted as phase close segments, and the continuous close time periods are included in the close segment range. A phase proximity list is generated based on the temporal sequence and amplitude characteristics of the proximity segments. Multiple proximity segments are arranged in temporal sequence to form a time chain, which is used to describe the dynamic approximation trend between the rotor mode and the airframe mode. The time index of the phase close to the end of the list is fixed as the trigger anchor line, and the trigger anchor line is used as the time reference for subsequent control chain adjustment and staggered scheduling.

[0010] Preferably, the solidification of the trigger anchor cable is based on the time index of the phase close to the end of the list. Solidification is completed when the phase of the blade vibration peak group and the pitch peak group of the airframe are closest. The trigger anchor cable is used as the time reference for the actions of multiple control chains, so that the pitch adjustment chain, pitch trim chain and propulsion thrust chain intervene in the time domain in sequence, so as to achieve consistent rhythm and continuous dynamic response of the control chain actions.

[0011] Preferably, step S300 includes: Using the trigger anchor cable as the core time reference, the time intervention windows of the pitch adjustment chain, pitch trim chain and thrust chain are established, and the time displacement relative to the trigger anchor cable is determined according to the function of each control chain, so that the pitch adjustment chain intervenes first, the pitch trim chain intervenes in sequence, and the thrust chain intervenes last. Using the trigger anchor cable as the base point, micro-time difference splitting is performed on the three control chains, causing the pitch adjustment chain time window to be slightly advanced, the pitch trim chain time window to be slightly delayed, and the propulsion thrust chain time window to be extended accordingly. Based on the splitting results, a staggered entry sequence of three control chains is constructed so that the control actions unfold sequentially to form a rhythmically coordinated dynamic response; A staggered traction sequence is generated based on the staggered entry order and written into the tail control section to ensure that the control signal distribution and energy traction are executed continuously in time sequence.

[0012] Preferably, after the staggered traction sequence is written into the tail control segment, the tail control segment triggers the control actions of the pitch adjustment chain, pitch trim chain and thrust chain in sequence according to the time order of the staggered traction sequence, so that the rotor lift adjustment, airframe attitude correction and thrust compensation are continuously connected in time, thereby maintaining a balanced torque distribution and stable attitude during flight.

[0013] Preferably, step S400 includes: A time structure framework for the anti-resonance shadow channel is established based on the staggered traction sequence, so that the time axis of the shadow channel is consistent with the staggered traction sequence, and an energy migration path is formed in the tail response region. Energy import operations are performed around the high-frequency jitter response of the tail section. The energy absorption process is initiated at the high-frequency nodes of the staggered traction sequence, so that the high-frequency energy migrates along the shadow channel and avoids being concentrated on the main structure of the tail beam. The high-frequency energy imported into the shadow channel is mapped as damped injection tickets, and a ticket chain is generated according to the time sequence to record the energy absorption behavior. The damping injection notes are written back to the end of the staggered traction sequence in chronological order to form a continuous damping note chain to maintain the dynamic energy balance at the end.

[0014] Preferably, during the high-frequency jitter energy introduction process in the tail section, the anti-resonance shadow channel dynamically adjusts the energy absorption window according to the time rhythm of the staggered traction sequence, so that the energy absorption zone is synchronized with the rhythm of the pitch adjustment chain, pitch trim chain and propulsion thrust chain, thereby achieving a periodic balance between energy absorption and release during energy migration, and ensuring that the tail section structure maintains a stable response under high load conditions.

[0015] Preferably, step S500 includes: Based on the time rhythm of the damped ticket chain, a rhythmic framework for breathing-type phase return gate control is established, enabling the flight control system to perform tightening control during the energy release phase and relaxing control during the energy recovery phase. During the peak of the steering rhythm, tighten the pitch change port and increase the damping injection density to introduce high-frequency vibration energy into the shadow channel in time to prevent energy superposition. During the low point of the steering rhythm, the pitch trim is relaxed and the propulsion thrust pulsation is recovered, so that the tail section structure can achieve aerodynamic balance during the energy recovery phase. Based on the time rhythm of the damping note chain, the phase reversal gate periodic commutation is performed, so that energy circulates between the rotor system, the airframe pitch system and the tail section structure, achieving dynamic suppression of cross-modal self-excited coupling.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: This invention establishes a multi-control chain staggered entry mechanism centered on trigger anchor cables, enabling the pitch adjustment chain, pitch trim chain, and propulsion thrust chain to form an orderly, layered intervention relationship in the time domain. This effectively avoids the energy superposition of high-frequency rotor vibration modes and low-frequency airframe pitch modes over time. Through micro-time-difference splitting and rhythmic staggered traction, the flight attitude control and aerodynamic thrust response maintain phase separation during dynamic changes, ensuring continuous connection between rotor load distribution, airframe attitude adjustment, and tail thrust compensation in the time dimension. This significantly improves the coupling response balance during flight, achieving a smooth transition of flight state and stable attitude maintenance.

[0017] This invention achieves dynamic absorption and cyclic recovery of high-frequency jitter energy in the tail section through a breathing-style phase-reversal gate control based on a damped ticket chain, enabling energy release and absorption to form a breathing-like cycle over time. By increasing the damping injection density during the peak of the steering rhythm and recovering propulsion pulsations during the trough, the energy transfer between the rotor system and the airframe structure is kept in dynamic balance. This effectively suppresses vibration energy accumulation in the cross-modal self-excited coupling region, significantly improving the flight control system's anti-disturbance capability and structural stability, and ensuring the stable flight performance of the compound helicopter in complex aerodynamic environments. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a flowchart of a composite helicopter stable flight control method according to the present invention. Detailed Implementation

[0020] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the description of this disclosure will be more complete and fully convey the concept of the exemplary embodiments to those skilled in the art.

[0021] This invention provides, for example Figure 1 The method for stable flight control of a helicopter, as shown, includes the following steps: S100 synchronously acquires blade vibration traces, airframe pitch yaw traces, and tail acceleration traces during high-speed cruise and turning conditions, and presses them into the coupling timing band with a unified time reference, marking continuously traceable resonance candidate segments within the coupling timing band. To address the potential coupling between blade vibration modes and fuselage pitch modes in compound helicopters during high-speed cruise and turning, a time-unified multi-source flight state information acquisition and processing workflow was established. This enabled the synchronous capture and coupled analysis of blade vibration trajectories, fuselage pitch oscillation trajectories, and tail acceleration trajectories, providing fundamental support for subsequent resonance candidate segment identification and dynamic control. The specific steps are as follows: When a compound helicopter enters the high-speed cruise and turn phase, a multi-point flight status data acquisition chain is established around the rotor system, fuselage pitch axis, and tail boom structure. Multiple types of flight status sensing units are deployed at the blade roots, the center of the fuselage longitudinal axis, and key nodes of the tail boom to capture blade vibration tracks, fuselage pitch yaw tracks, and tail acceleration tracks, respectively. The blade vibration tracks record the minute elastic vibration changes of the rotor under different blade pitch angles and aerodynamic loads; the fuselage pitch yaw tracks reflect the dynamic deviation of the aircraft's pitch attitude during high-speed turns; and the tail acceleration tracks reflect the inertial response and force distribution of the tail boom and tail rotor. The three track signals are continuously recorded during acquisition and updated in real-time within fixed time windows, ensuring a unified basis for sampling frequency and timing marking, thereby guaranteeing a direct temporal correspondence between the dynamic information of different physical parts.

[0022] After simultaneously acquiring three types of tracks, the propeller vibration track, airframe pitch yaw track, and tail acceleration track were aligned to a unified time reference based on the principle of time consistency. Using the flight control center time as the core time axis, the timestamps of each track signal were remapped onto this unified time axis, ensuring that each propeller vibration signal point, airframe pitch attitude signal point, and tail acceleration signal point corresponded on the same time scale. During this process, continuous interpolation and time alignment were used to ensure a smooth transition between the high-frequency changes of the propeller vibration track and the low-frequency changes of the airframe pitch yaw track within the same time domain, thus avoiding time drift caused by differences in the update rates of different signals. This processing enabled the three track signals to form a continuous and comparable time sequence under the same time reference, providing data consistency assurance for the subsequent insertion of the coupling time band.

[0023] After unifying the time reference, a coupled time series is established based on the time synchronization results of the blade vibration trajectory, the fuselage pitch yaw trajectory, and the tail acceleration trajectory. The three types of signals are then indented into this time series with equal steps. The coupled time series is a channel combining tracks over a continuous time period, used to centrally reflect the dynamic correspondence between the rotor system, the fuselage structure, and the tail response. During the indentation process, the blade vibration trajectory is used as the upward trajectory, the fuselage pitch yaw trajectory as the mid-course trajectory, and the tail acceleration trajectory as the downward trajectory. These three trajectories unfold side-by-side along a unified time axis, with the time series as the core index, forming an integrated dynamic coupled distribution structure. This indentation method visually reflects whether the change in blade vibration intensity at a specific flight moment has a synchronous tendency with the change in fuselage pitch angle and the tail inertial response, thus constructing a dynamic correspondence framework between the three in the time dimension. The establishment of the coupled time series enables a unified mapping relationship between the dynamic responses of different parts, providing a continuously trackable time-domain basis for the subsequent identification of resonance candidate segments.

[0024] After the coupled time series is constructed, continuously trackable resonance candidate segments are identified and marked based on the continuous time data within this time series. During the analysis, using the vibration peaks of the blade vibration trajectory as a reference, the response trends of the aircraft pitch yaw trajectory and the tail acceleration trajectory are gradually retrieved within the same time period. Special attention is paid to whether the blade vibration amplitude increase region and the aircraft pitch angle offset region exhibit characteristics of frequency proximity, phase convergence, or response delay contraction. When the three trajectories show a convergent trend within a certain time interval, that time period is designated as a resonance candidate segment. Within the resonance candidate segment, the peak correspondence between the vibration trajectory and the pitch yaw trajectory is continuously tracked to ensure the resonance candidate segment remains continuously extendable on the time axis, and it is marked when the tail acceleration trajectory shows an abnormal increase in amplitude. In this way, not only can resonance risk regions be located in real time during flight, but a traceable time link can also be formed within the coupled time series, providing a basic reference for subsequent phase proximity list generation and trigger anchor cable solidification.

[0025] S200 extracts the close segments of the blade vibration peak group that approach the pitch peak group of the aircraft based on the resonance candidate segment, generates a phase close list, and solidifies the end of the phase close list as a trigger anchor cable, which is used as the starting reference for subsequent control chain adjustment. After constructing the coupling time series and obtaining candidate resonance segments, in order to analyze the dynamic relationship between the blade vibration mode and the airframe pitch mode, the close proximity process between the blade vibration peak group and the airframe pitch peak group in time is identified. Close proximity segments reflecting the convergence characteristics of modes are extracted, and a phase proximity list is established to depict the temporal correlation of potential resonance trends. Then, the time index at the end of the phase proximity list is solidified as a trigger anchor cable, which serves as the time reference for subsequent control chain adjustment and peak staggering. The specific steps are as follows: Within the coupled time series, the synchronous change trajectories of the blade vibration trajectory and the airframe pitch oscillation trajectory in the resonance candidate segment are obtained, and a peak group correspondence is established based on the principle of time consistency. By arranging the continuous peak points of the blade vibration trajectory over time, a blade vibration peak group sequence is formed; then, the peak change points of the airframe pitch oscillation trajectory are extracted using the same time window, forming an airframe pitch peak group sequence. In this process, the time axis of the coupled time series is used as a reference, allowing both types of peak groups to unfold at the same time scale, ensuring the continuity and traceability of the correspondence between each peak group. Through this parallel unfolding in the time domain, the temporal convergence trend between the blade vibration intensity change and the airframe pitch response can be clearly identified in the resonance candidate segment, providing a foundation for the subsequent extraction of phase-close segments.

[0026] Based on the established peak group correspondence, phase-close segments are gradually extracted by considering the relative temporal distribution of the blade vibration peak group and the airframe pitch peak group. Specifically, using the time point of the blade vibration peak group as a reference, the time points of adjacent airframe pitch peak groups are retrieved, and the intervals in which they approach each other in time are identified and defined as phase-close segments. This extraction process is characterized by a continuous decrease in time distance, focusing on the continuous trend of the blade vibration peak group approaching the time point of the airframe pitch peak group, rather than a single intersection point. When multiple adjacent peak groups show a gradual approaching trend, this continuous time period is included in the phase-close segment range. In this way, dynamic segments that truly reflect the convergence of modes can be extracted from the coupled time series, providing a temporal basis for the early identification of resonance risk zones.

[0027] After generating phase-close segments, a phase-close list is created based on the temporal sequence and amplitude characteristics of these segments. Using the start and end times, peak values ​​of the blade vibration peaks, and peak values ​​of the airframe pitch peaks as fundamental information, multiple phase-close segments are arranged and numbered chronologically to form the phase-close list. This list records the entire process of the blade vibration peaks gradually approaching the airframe pitch peaks in a progressively advancing manner, reflecting the dynamic interaction trend between the rotor's high-frequency modes and the airframe's low-frequency modes at different flight moments. During generation, the temporal continuity and amplitude matching consistency of the phase-close segments are maintained, ensuring that the phase-close list not only reflects the proximity state at a single point in time but also demonstrates the proximity evolution across time intervals. In this way, the phase-close list becomes a time chain describing the resonance formation trend, providing a direct quantitative reference for the subsequent solidification of the trigger anchor cable.

[0028] After generating the phase proximity list, the time index at the end of the list is fixed as a trigger anchor line, serving as the starting reference for subsequent control chain adjustments. The time position corresponding to the trigger anchor line represents the moment when the blade vibration peaks and the airframe pitch peaks are closest in phase, and it is also the critical range where cross-modal resonance effects may be triggered. By fixing this time position as the trigger anchor line, the pitch trim chain, propulsion thrust chain, and other control chains can be synchronized and staggered in subsequent control stages, using this anchor point as a reference. The trigger anchor line serves not only as a time marker but also as a guiding index for dynamic control, establishing the entry sequence and response rhythm of each control chain action. In this process, the phase proximity list provides continuous time evolution data for the trigger anchor line, while the fixing of the trigger anchor line provides a clear starting point for subsequent control, ensuring time traceability and dynamic response consistency throughout the entire flight control process.

[0029] S300 performs micro-time difference splitting and arrangement around the trigger anchor cable to the pitch adjustment chain, pitch trim chain and propulsion thrust chain to form a staggered entry sequence of the three control chains, and generates a staggered traction sequence to be written into the tail control section. After generating the phase proximity list and solidifying the trigger anchor cable, to achieve temporal decoupling and energy distribution coordination among multiple control chains, micro-time-difference splitting and staging are performed around the trigger anchor cable for the pitch adjustment chain, pitch trim chain, and thrust chain. By establishing a staggered entry sequence, the three control chains intervene in the flight control process in a layered manner within the phase critical region, and a staggered traction sequence is further generated and written into the tail control segment. This process uses the trigger anchor cable as the central reference and time-domain micro-displacement as the main control means to construct the sequential intervention order and action rhythm of the control chains, thereby forming a distributed energy response path in the flight control execution phase. The entire process includes the following steps: Using the trigger anchor cable as the core time reference, time intervention windows are established for the pitch control chain, pitch trim chain, and thrust chain. The trigger anchor cable is defined as the zero-phase moment on the time axis, serving as a synchronization reference point for the actions of multiple control chains. Based on this, the response time intervals of the pitch control chain, pitch trim chain, and thrust chain are quantified and divided. According to the functional characteristics of each control chain in flight control, its time displacement relative to the trigger anchor cable is determined. The pitch control chain, as the control path directly affecting rotor lift and load distribution, has its time window set to open first, allowing rotor lift adjustment to intervene in the early stages of phase approach. The pitch trim chain, as the airframe attitude correction path, has its intervention time window set after the pitch control chain, ensuring that pitch correction can accommodate changes in rotor lift. The thrust chain, as the speed and forward force control path, has its time window set to intervene last, allowing thrust adjustment to compensate after the attitude has stabilized. This hierarchical setting makes the trigger anchor cable the origin of the three control chains' time entry, establishing a control rhythm based on time sequence.

[0030] After establishing the time intervention window, micro-time difference splitting is performed based on the time distribution characteristics of the three control chains. Using the trigger anchor cable as a base point, the entry times of the pitch control chain, pitch trim chain, and thrust chain are slightly staggered along the time axis, creating distinct time difference layers between the three control chains. The pitch control chain's time window is slightly advanced before the trigger anchor cable to allow rotor lift adjustment to intervene first; the pitch trim chain's time window is slightly delayed after the trigger anchor cable to ensure its pitch attitude correction unfolds smoothly after rotor lift is generated; the thrust chain's time window is further extended to allow thrust response to smoothly intervene during the attitude stabilization phase. This micro-time difference splitting avoids the energy superposition effect caused by the three control chains simultaneously initiating control commands at the same time point, preventing new dynamic instability caused by excessive concentration of instantaneous control energy in the flight attitude. The core of this splitting process lies in achieving the phased unfolding of control actions through extremely small time displacement differences, so that each control chain forms a progressive and interconnected logical sequence in the time domain, thereby achieving dynamic decoupling and operational balance during flight.

[0031] After establishing a micro-time-difference split structure, a staggered entry sequence for the three control chains is constructed based on the split time order. The sequence of actions of the pitch trim chain, pitch trim chain, and thrust chain on the time axis is used as the basis to solidify the action sequence of the three control chains into a set of temporal arrangements. This staggered entry sequence not only defines the intervention order of the control chains but also determines the priority of each control chain in flight control. The pitch trim chain intervenes first, pre-correcting rotor lift distribution during the phase close phase; the pitch trim chain intervenes in the mid-phase to adjust the airframe pitch angle and maintain attitude balance; and the thrust chain intervenes in the final phase to fine-tune forward velocity and attitude coordination, thus forming a continuous control link from lift to attitude to thrust. During the staggered entry process, the time difference between the three control chains is kept constant, and each control chain is ensured to complete its respective control objective within its intervention phase. This sequential time allocation ensures that the energy output of different control paths does not overlap in time, but unfolds sequentially in the time dimension, forming a rhythmically coordinated dynamic response process, thus creating conditions for the compound helicopter to achieve smooth control in complex flight phases.

[0032] After determining the staggered entry sequence, a staggered traction sequence is generated based on this temporal arrangement and written into the tail control segment. The staggered traction sequence uses time as an index and the entry sequence of the three control chains as its core content, encoding the intervention rhythms of the pitch adjustment chain, pitch trim chain, and thrust chain along the time axis. Upon receiving this staggered traction sequence, the tail control segment can execute control signal distribution and energy traction in a predetermined order, ensuring that control actions strictly adhere to the preset sequence in time, guaranteeing the sequential execution of rotor lift adjustment, airframe attitude correction, and thrust compensation. Through this writing method, the staggered traction sequence forms a continuously executable time command chain in the tail control segment, giving the control process continuity and time constraints. After receiving the staggered traction sequence, the tail control segment can gradually trigger the action rhythms of the control chains according to the temporal sequence, achieving a complete dynamic transition from lift adjustment to attitude stabilization to thrust compensation, thereby effectively preventing the concentrated superposition of control energy in the time domain and maintaining a balanced torque distribution and stable attitude during flight.

[0033] S400 establishes an anti-resonance shadow channel based on the staggered traction sequence, introduces the high-frequency jitter energy of the tail section into the shadow channel, maps the introduced energy into damped injection notes, and writes them back to form a damped note chain. After determining the staggered entry sequence of the three control chains and generating the staggered traction sequence, to further weaken the high-frequency vibration transmission effect caused by rotor-airframe coupling, an anti-resonance shadow channel is established around the staggered traction sequence. By guiding the high-frequency jitter energy in the tail section to migrate into this shadow channel, the energy distribution changes from concentrated transmission to layered absorption, thus forming a virtual damping path at the structural level. Subsequently, the high-frequency jitter energy introduced into the shadow channel is mapped as damping injection tickets, and these tickets are gradually written back to the tail of the staggered traction sequence, forming a continuously updatable chain of damping tickets. The entire process uses the staggered traction sequence as the time guide and tail section energy migration and damping mapping as the core technical means to construct a closed-loop path of energy introduction, mapping, and feedback, specifically including the following steps: Based on the generated staggered traction sequence, a temporal structure framework for the anti-resonance shadow channel is established. Guided by the time rhythms of the pitch adjustment chain, pitch trim chain, and thrust chain in the staggered traction sequence, a virtual energy transfer channel is opened in the tail-end response region, maintaining strict consistency between the time axis of this channel and the staggered traction sequence. The anti-resonance shadow channel is not a physical channel, but a response path based on time and energy stratification. Its function is to provide a transfer trajectory for high-frequency vibration energy in the tail end, allowing it to avoid the resonance response frequency band of the main structure in time. In this step, the time nodes of the shadow channel correspond one-to-one with the time rhythm of the staggered traction sequence. When the pitch adjustment chain action causes changes in rotor lift, the shadow channel reserves an energy transfer window; when the pitch trim chain performs attitude correction, the shadow channel expands the energy absorption zone accordingly; when the thrust chain intervenes in thrust compensation, the shadow channel further extends the energy dissipation zone. Through this time-level correspondence, the anti-resonance shadow channel forms a mapping synchronization with the three control chains on the time axis, providing a bearable energy diversion path for subsequent energy introduction.

[0034] After the anti-resonance shadow channel is established, high-frequency energy is introduced around the high-frequency jitter response in the tail section region. The high-frequency jitter energy in the tail section mainly originates from the inertial disturbance generated by the coupling between blade vibration and the airframe pitch mode. Through time allocation in the staggered traction sequence, the shadow channel initiates the energy absorption process at the corresponding moments. Specifically, when the local acceleration peak of the tail section structure appears at the high-frequency node of the staggered traction sequence, the shadow channel immediately receives the energy peak and extends the energy absorption window on the time axis, causing the high-frequency energy to migrate along the direction of the shadow channel and no longer concentrate on the main tail boom structure. During this process, the rhythmic changes of the pitch adjustment chain, pitch trim chain, and propulsion thrust chain have a chain effect on the energy guidance of the shadow channel, resulting in a time-dispersed energy transfer between the rotor system and the tail section structure. In this way, the high-frequency vibration energy of the tail section is no longer directly fed back to the main structure path, but forms a controllable energy dissipation trajectory through the shadow channel, avoiding the formation of a periodic amplification effect at the structural level.

[0035] After high-frequency energy import is completed, an energy mapping operation is performed around the energy distribution within the shadow channel, mapping the high-frequency energy imported into the shadow channel into damping injection tickets. A damping injection ticket is a time-recording unit used to describe the correspondence between energy absorption and damping compensation; its function is to correlate the energy absorption amount with the staggered traction sequence in chronological order. The mapping process is based on the temporal distribution of energy in the shadow channel, converting the energy intensity corresponding to each energy absorption moment into a damping injection record, and generating a ticket chain in chronological order. Each damping injection ticket contains three pieces of information: energy import moment, absorption duration, and energy density, reflecting the energy absorption behavior of the shadow channel within that time period. Through this energy mapping mechanism, the energy absorption process of the shadow channel is quantified into a time series, ensuring that the damping effect is consistent with the rhythm of the control chain in the time dimension. The generation of damping injection tickets not only provides a reference for subsequent energy feedback but also establishes a mapping relationship between energy absorption and time control at the structural level, thereby achieving synergy between energy distribution and attitude control in the control logic.

[0036] After the damping injection notes are generated, they are written back to the tail of the staggered traction sequence in chronological order, forming a continuous damping note chain. The formation of this chain endows the staggered traction sequence with energy feedback capabilities, transforming the control chain from a mere time-sequential control chain into a dynamic feedback structure with energy circulation capabilities. During the writing process, the damping note chain maintains a one-to-one correspondence with the staggered traction sequence in time, ensuring that each control chain action is linked to the corresponding damping record at its completion stage. This allows for energy redistribution in the next cycle of control actions based on the rhythm of the damping note chain. The continuous writing of the damping note chain gives the staggered traction sequence dynamic evolution characteristics, enabling it to automatically extend or contract the energy transmission window of the shadow channel based on energy absorption during flight, maintaining dynamic energy balance in the tail section. In this way, the anti-resonance shadow channel, energy mapping mechanism, and damping note chain together form a closed energy circulation path, allowing the tail structure to maintain energy dissipation capacity and dynamic stability under sustained high load conditions.

[0037] The S500 implements breathing-style phase reversal brake control according to the damping note chain rhythm. During the peak of the steering rhythm, it tightens the pitch change port and increases the damping injection density. During the trough of the steering rhythm, it relaxes the pitch trim port and recovers the propulsion thrust pulsation. Through the periodic reversal of the phase reversal brake control, it achieves cross-modal self-excited coupling dynamic suppression, thereby maintaining the stable flight state of the compound helicopter. After generating and rewriting the damping note chain, to achieve periodic balance in energy exchange between the tail section structure and the rotor system over time, a breathing-style phase reversal control is implemented based on the rhythmic changes of the damping note chain. By alternately adjusting the pitch change, pitch trim, and thrust pulsation during the peak and trough phases of the steering rhythm, the periodic breathing-style expansion and contraction of the flight control chain is achieved, creating a regular reciprocating rhythm in the energy release and absorption process. This process is time-driven by the damping note chain, with phase reversal as the core of rhythmic control. Through a synergistic mechanism of energy density adjustment and thrust response reversal, a dynamic suppression closed loop with cross-modal self-excited coupling is formed. The specific steps are as follows: Based on the temporal rhythm of the damping note chain, a rhythmic framework for breathing-style phase-reversal gate control is established. The damping note chain records the energy absorption intensity and damping injection density of the anti-resonance shadow channel in various time periods, and its rhythmic changes reflect the dynamic distribution of energy release and absorption in the tail phase. Guided by the periodic changes of the damping note chain, the breathing rhythm of the flight control system is determined, i.e., tightening control is performed during the energy release phase, and relaxing control is performed during the energy recovery phase. In this way, breathing-style phase-reversal gate control can maintain a correspondence with energy flow on the time axis, enabling rotor lift adjustment, airframe attitude correction, and thrust pulsation control to coordinate rhythmically. The establishment of the breathing-style rhythmic framework provides a time scale for the subsequent alternating regulation of pitch change, pitch trim, and propulsion thrust pulsation, and enables the entire control process to operate synchronously with the damping note chain rhythm, thereby forming an alternating response of energy release and absorption in the time domain.

[0038] After the breathing rhythm framework is determined, tightening control is performed around the peak phase of the steering rhythm. During this peak phase, the rotor system of the compound helicopter experiences significant lift loads, the rate of change of the airframe pitch angle accelerates, and the tail section structure is in a high-energy response state. At this time, based on the high-density segment of the damping chain, tightening control is applied to the pitch angle, limiting the rapid fluctuation amplitude of the pitch angle and suppressing the instantaneous rate of change of rotor lift. Simultaneously, the damping injection density is increased, enhancing the energy absorption capacity of the anti-resonance shadow channel, causing more high-frequency vibration energy to be introduced into the shadow channel in time, thereby reducing the instantaneous energy transmitted to the tail section structure. By implementing this dual control during the peak phase—tightening the pitch angle and increasing the damping injection density—the system can achieve controlled release in the energy peak region, preventing the superposition of vibration energy within the structure and avoiding synchronous excitation of the pitch and rotor modes in time. This step enables the flight control system to form an active contraction breathing process during the high-energy phase, creating conditions for energy recovery in the next stage.

[0039] After tightening control during the peak phase, a relaxation control operation is performed during the trough phase of the steering rhythm. During the trough phase, the lift changes in the rotor system become smoother, the pitch angle changes decrease, and the tail section energy response enters a relatively stable range. At this time, based on the low-density section of the damping chain, the pitch trim is gradually relaxed, increasing the amplitude of the aircraft attitude correction and releasing some of the stress accumulated during the peak phase. Simultaneously, thrust pulsations are recovered, causing slight fluctuations in thrust over time. These thrust pulsations recover the energy absorbed by the tail section structure in the previous phase, redistributing energy to the propulsion chain and promoting overall aerodynamic balance. Through this relaxation and recovery process, the breathing-style phase-returning brake achieves a rhythmic transformation from energy absorption to energy recovery, creating a breathing-like energy cycle in the flight control process: absorbing energy during peak phases and releasing energy during trough phases. The combined effect of the relaxation of the pitch trim and the recovery of thrust pulsations restores the aircraft's attitude balance, rematches rotor lift and thrust, and ensures stable recovery of flight attitude during the trough phase.

[0040] After completing the alternating control of peak and trough phases, the phase reversal control continuously executes periodic reversal operations based on the time rhythm of the damping note chain. The core of phase reversal control lies in achieving the alternation of energy flow direction through periodic reversals in time, allowing energy to continuously circulate between the rotor system, the airframe pitch system, and the tail section structure. Each rhythmic reversal is marked by a time node in the damping note chain. When the damping injection density reaches its maximum value, the phase reversal control executes a reversal, changing the energy flow direction from absorption to release; when the damping injection density drops to its minimum, the phase reversal control reverses again, changing the energy flow direction from release to absorption. Through this periodic reversal, energy is kept in dynamic balance among different structural parts, avoiding any part from bearing concentrated stress for a long time. The continuous execution of phase reversal control enables the entire flight control system to form an adaptive breathing rhythm, exhibiting regular expansion and contraction in time and dynamic flow and absorption in energy distribution. Ultimately, dynamic suppression of cross-modal self-excited coupling is achieved, ensuring that the high-frequency vibration modes of the rotor and the low-frequency pitch modes of the airframe are always in a staggered state in the time domain, preventing the formation of stable standing waves in the resonance zone, thereby maintaining the stable flight state of the compound helicopter under high-speed turning and complex flight conditions.

[0041] This invention establishes a multi-control chain staggered entry mechanism centered on trigger anchor cables, enabling the pitch adjustment chain, pitch trim chain, and propulsion thrust chain to form an orderly, layered intervention relationship in the time domain. This effectively avoids the energy superposition of high-frequency rotor vibration modes and low-frequency airframe pitch modes over time. Through micro-time-difference splitting and rhythmic staggered traction, the flight attitude control and aerodynamic thrust response maintain phase separation during dynamic changes, ensuring continuous connection between rotor load distribution, airframe attitude adjustment, and tail thrust compensation in the time dimension. This significantly improves the coupling response balance during flight, achieving a smooth transition of flight state and stable attitude maintenance.

[0042] This invention achieves dynamic absorption and cyclic recovery of high-frequency jitter energy in the tail section through a breathing-style phase-reversal gate control based on a damped ticket chain, enabling energy release and absorption to form a breathing-like cycle over time. By increasing the damping injection density during the peak of the steering rhythm and recovering propulsion pulsations during the trough, the energy transfer between the rotor system and the airframe structure is kept in dynamic balance. This effectively suppresses vibration energy accumulation in the cross-modal self-excited coupling region, significantly improving the flight control system's anti-disturbance capability and structural stability, and ensuring the stable flight performance of the compound helicopter in complex aerodynamic environments.

[0043] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A compound helicopter hover control method, characterized by, Includes the following steps: S100 synchronously acquires blade vibration traces, airframe pitch yaw traces, and tail acceleration traces during high-speed cruise and turning conditions, and presses them into the coupling timing band with a unified time reference, marking continuously traceable resonance candidate segments within the coupling timing band. S200 extracts the close segments of the blade vibration peak group that approach the pitch peak group of the aircraft based on the resonance candidate segment, generates a phase close list, and solidifies the end of the phase close list as a trigger anchor cable, which is used as the starting reference for subsequent control chain adjustment. S300 performs micro-time difference splitting and arrangement around the trigger anchor cable to the pitch adjustment chain, pitch trim chain and propulsion thrust chain to form a staggered entry sequence of the three control chains, and generates a staggered traction sequence to be written into the tail control section. S400 establishes an anti-resonance shadow channel based on the staggered traction sequence, introduces the high-frequency jitter energy of the tail section into the shadow channel, maps the introduced energy into damped injection notes, and writes them back to form a damped note chain. The S500 implements breathing-style phase reversal braking according to the damping note chain rhythm. During the peak of the steering rhythm, it tightens the pitch change port and increases the damping injection density. During the trough of the steering rhythm, it relaxes the pitch trim port and recovers the propulsion thrust pulsation. Through the periodic reversal of the phase reversal braking, it achieves cross-modal self-excited coupling dynamic suppression, thereby maintaining the stable flight state of the compound helicopter.

2. The method of claim 1, wherein, Step S100 includes: A multi-point flight status data acquisition chain is established around the rotor system, the airframe pitch axis and the tail boom structure. By deploying flight status sensing units at the blade root, the center of the airframe longitudinal axis and the key nodes of the tail boom, the blade vibration trajectory, the airframe pitch oscillation trajectory and the tail section acceleration trajectory are obtained respectively. Using the flight control center time as a unified time reference, time remapping and continuous interpolation are performed on the three types of tracks to achieve a smooth correspondence between the high-frequency changes of the blade vibration track and the low-frequency changes of the airframe pitch sway track on the same time axis. Based on the time synchronization results, a coupled time series is established, and the three types of traces are pressed in at equal steps to form an uplink trajectory, a midlink trajectory, and a downlink trajectory, thus constructing a continuous and traceable dynamic coupling relationship; Using the vibration peaks of the blade vibration trajectory as a reference in the coupled time series, the response trends of the pitch and roll trajectory and the tail acceleration trajectory of the aircraft are retrieved, and the time intervals in which the changes of the three trajectories converge are marked as candidate resonance segments.

3. The composite helicopter stable flight control method according to claim 2, characterized in that, After establishing the coupling time series, the blade vibration trajectory is arranged in layers as the upward trajectory, the airframe pitch oscillation trajectory as the mid-course trajectory, and the tail acceleration trajectory as the downward trajectory through time series indexing, and they are kept synchronously deployed on the time axis. This enables the rotor system, airframe pitch system and tail response system to form a dynamic mapping relationship under the same time reference, so as to improve the continuous traceability of resonance candidate segments and the accuracy of time series correlation.

4. The compound helicopter steady flight control method of claim 2, wherein Step S200 includes: Within the coupling time band, the synchronous change trajectory of the blade vibration trajectory and the airframe pitch oscillation trajectory is obtained. Based on the principle of time consistency, the peak group correspondence is established, and the blade vibration peak group sequence and the airframe pitch peak group sequence are formed. Using the time points of the blade vibration peak groups as a reference, the time points of adjacent pitch peak groups of the aircraft are retrieved, and the time intervals that are close to each other are extracted as phase close segments, and the continuous close time periods are included in the close segment range. A phase proximity list is generated based on the temporal sequence and amplitude characteristics of the proximity segments. Multiple proximity segments are arranged in temporal order to form a time chain, which is used to describe the dynamic approximation trend between the rotor mode and the airframe mode. The time index of the phase close to the end of the list is fixed as the trigger anchor line, and the trigger anchor line is used as the time reference for subsequent control chain adjustment and staggered scheduling.

5. A compound helicopter hover control method according to claim 4, characterized in that, The solidification of the trigger anchor cable is based on the time index of the phase close to the end of the list. Solidification is completed when the phase of the blade vibration peak group and the pitch peak group of the airframe are closest. The trigger anchor cable is used as the time reference for the action of multiple control chains, so that the pitch adjustment chain, pitch trim chain and propulsion thrust chain are engaged in sequence in the time domain.

6. The compound helicopter steady flight control method of claim 4, wherein Step S300 includes: Using the trigger anchor cable as the core time reference, the time intervention windows of the pitch adjustment chain, pitch trim chain and thrust chain are established, and the time displacement relative to the trigger anchor cable is determined according to the function of each control chain, so that the pitch adjustment chain intervenes first, the pitch trim chain intervenes in sequence, and the thrust chain intervenes last. Using the trigger anchor cable as the base point, micro-time difference splitting is performed on the three control chains, causing the pitch adjustment chain time window to be slightly advanced, the pitch trim chain time window to be slightly delayed, and the propulsion thrust chain time window to be extended accordingly. Based on the splitting results, a staggered entry sequence of three control chains is constructed so that the control actions unfold sequentially to form a rhythmically coordinated dynamic response; A staggered traction sequence is generated based on the staggered entry order and written into the tail control section to ensure that the control signal distribution and energy traction are executed continuously in time sequence.

7. The compound helicopter steady flight control method of claim 6, wherein After the staggered traction sequence is written into the tail control segment, the tail control segment triggers the control actions of the pitch adjustment chain, pitch trim chain and thrust chain in sequence according to the time order of the staggered traction sequence. This ensures that the rotor lift adjustment, airframe attitude correction and thrust compensation are connected in time, thereby maintaining a balanced torque distribution and stable attitude during flight.

8. The compound helicopter steady flight control method of claim 6, wherein, Step S400 includes: A time structure framework for the anti-resonance shadow channel is established based on the staggered traction sequence, so that the time axis of the shadow channel is consistent with the staggered traction sequence, and an energy migration path is formed in the tail response region. Energy import operations are performed around the high-frequency jitter response of the tail section. The energy absorption process is initiated at the high-frequency nodes of the staggered traction sequence, so that the high-frequency energy migrates along the shadow channel and avoids being concentrated on the main structure of the tail beam. The high-frequency energy imported into the shadow channel is mapped as damped injection tickets, and a ticket chain is generated according to the time sequence to record the energy absorption behavior. The damping injection notes are written back to the tail of the staggered traction sequence in chronological order to form a continuous damping note chain to maintain the dynamic energy balance at the tail end.

9. The compound helicopter steady flight control method of claim 8, wherein, During the high-frequency vibration energy introduction process in the tail section, the anti-resonance shadow channel dynamically adjusts the energy absorption window according to the time rhythm of the staggered traction sequence, so that the energy absorption zone is synchronized with the rhythm of the pitch adjustment chain, pitch trim chain and propulsion thrust chain, thereby achieving a periodic balance between energy absorption and release during energy migration, and ensuring that the tail section structure maintains a stable response under high load conditions.

10. The compound helicopter steady flight control method of claim 9, wherein, Step S500 includes: Based on the time rhythm of the damped ticket chain, a rhythmic framework for breathing-type phase return gate control is established, enabling the flight control system to perform tightening control during the energy release phase and relaxing control during the energy recovery phase. During the peak of the steering rhythm, tighten the pitch change port and increase the damping injection density to introduce high-frequency vibration energy into the shadow channel in time to prevent energy superposition. During the low point of the steering rhythm, the pitch trim is relaxed and the propulsion thrust pulsation is recovered, so that the tail section structure can achieve aerodynamic balance during the energy recovery phase. The phase reversal control periodically reverses according to the time rhythm of the damping ticket chain, so that energy circulates between the rotor system, the airframe pitch system and the tail section structure.

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