A fixed-time control method for coaxial dual rotors considering ground effect and gyroscope cross-linking

Abstract

This invention relates to the field of unmanned aerial vehicle (UAV) control technology, specifically to a fixed-time control method for a coaxial dual-rotor UAV that considers ground effect and gyro cross-linking. The method includes: establishing a multi-input multi-output state-space equation incorporating time-varying downwash delay and gyro cross-linking torque; estimating the transmission delay and loss coefficient that vary exponentially with altitude through real-time altitude feedback; designing two power-law fixed-time sliding surfaces to achieve rapid convergence of attitude tracking errors; and employing a hyperbolic tangent continuous reaching law, combined with a decoupled feedforward matrix for ground effect and gyro, to inversely reconstruct the total control torque command and drive the coaxial actuator. This invention achieves complete decoupling of multi-channel cross-interference at the physical level, resulting in high near-ground control accuracy and effectively eliminating high-frequency chattering of the actuator, thus extending hardware lifespan.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle control technology, specifically to a fixed-time control method for coaxial dual rotors that takes into account ground effect and gyroscope cross-linking. Background Technology

[0002] Coaxial multirotor aircraft, due to their unique double-rotor overlapping and counter-rotating structure, have advantages such as high payload, compact structure, and strong wind resistance. However, during their vertical descent landing or near-ground hovering phases, the control system faces extremely severe and complex composite physical interference: Ground effect-induced time-varying distortion of the flow field: The high-speed downwash slipstream generated by the upper rotor has a physical transmission time delay during its downward transmission to impact the lower rotor. As the aircraft approaches the ground or landing platform, the ground effect obstructs the airflow, creating a non-linear "air cushion" between the rotors and beneath the fuselage. This causes a sharp decrease in the downward velocity of the downwash flow, resulting in a transmission delay. It exhibits an exponential elongation; simultaneously, the airflow overflows laterally in all directions, reducing the aerodynamic loss coefficient of the rotor directly impacting it. Nonlinear decay occurs. Conventional control algorithms treat aerodynamic disturbances as steady or instantaneous mappings, leading to feedforward phase misalignment near the ground, making the system state highly susceptible to instability.

[0003] Strong cross-coupling of counter-rotating dual-drive gyro precession torque: To offset the nonlinear aerodynamic losses in the pitch or roll channels, the real-time operating speeds of the upper and lower counter-rotating propellers are often unequal. When the airframe generates dynamic pitch or roll angular velocities, due to the asymmetry of the counter-rotating speeds, the system spontaneously generates extremely strong, cross-channel cross-linked residual gyro precession torque. This causes the multirotor to yaw violently laterally at the moment of pitching up or down, exhibiting strong multiple-input multiple-output (MIMO) nonlinear coupling characteristics.

[0004] Traditional control algorithms (such as conventional linear sliding mode control or conventional PID control) have several drawbacks: First, due to a lack of understanding of the mechanism of the time-delayed flow field and gyro precession characteristics unique to coaxial rotors, the algorithms lack prior information on time delay and coupling, leading to feedforward phase mismatch and severe steady-state dynamic-static error and peak miss. Second, in order to resist noise, traditional sliding mode often requires extremely high switching gain or hard commutation using sign functions, which can induce extremely severe high-frequency mechanical chattering in actual operation, easily burning out the actuator motor.

[0005] Therefore, designing an advanced multivariable control method that can sense the height variation of ground effect online, decouple and cancel cross-channel gyro inertia, and has high continuity and no jitter is the core bottleneck for coaxial multirotor aircraft to achieve high-precision near-ground landing. Summary of the Invention

[0006] To address the aforementioned technical shortcomings, this invention provides a fixed-time control method for coaxial dual-rotor aircraft that considers ground effect and gyro cross-linking. By introducing a height-adaptive mechanism feedforward matrix and a multidimensional nonlinear fixed-time sliding mode algorithm, this method aims to jointly eliminate cross-linking instability, position divergence, and mechanical chattering problems in the vertical landing phase of coaxial multi-rotor aircraft from both the physical source and the control level.

[0007] This invention is achieved through the following technical solution: A fixed-time control method for a coaxial dual-rotor rotor considering ground effect and gyro interaction is provided, the method comprising the following steps: Step S10: Construct the attitude-anti-torque multidimensional physically coupled state space equation and establish the coaxial dual rotor multi-input multi-output MIMO state equation, which includes actuator dynamics inertia, ground effect time-varying downwash delay, and reverse gyroscope cross-linking torque. Step S20: Based on the MIMO state equation, design an adaptive time-series slip reconstruction mechanism for ground effect flow field parameters. Obtain the current relative altitude of the multi-rotor in real time through an altimeter, establish a topological dynamic model of time-varying aerodynamic downwash transmission delay and loss coefficient that varies with altitude, and input the historical rotational speed time-series term containing the time-varying aerodynamic downwash transmission delay as a state feedforward compensation variable into the controller. Step S30: Based on the results of the adaptive temporal sliding reconstruction mechanism of the flow field parameters, design a matrix-type asymmetric two-segment power fixed-time sliding surface, extract the multidimensional attitude tracking error vector and its first derivative, and construct a fixed-time sliding function vector with infinite adsorption stiffness at the hyperspace origin. Step S40: Based on the fixed-time sliding mode function vector, construct a high-order continuous anti-jitter reaching law matrix and a fully physical channel decoupled feedforward control law, introduce a high-steep hyperbolic tangent function to construct a multidimensional continuous anti-jitter reaching law function, perform physical inverse mapping reconstruction based on the MIMO state equation, calculate the composite total control torque command, and drive the dual-drive reverse actuator of the coaxial dual-rotor aircraft in real time according to the command.

[0008] Preferably, the vector of the reverse gyroscope crosslinking torque in step S10 is... The explicit expression matrix is:

[0009] The MIMO state equation is as follows:

[0010] in, The gyroscope cross-linking torque is the pitch angle. The cross-linking torque of the gyroscope for the roll angle, The moment of inertia of a single propeller blade assembly is its rotation. For nominal moment of inertia, This refers to the real-time operating speed of the upper rotor. This refers to the real-time operating speed of the lower rotor. and These are the corresponding pitch and roll angular velocity components, respectively. Let be the body attitude angle vector. Let be the second derivative of the body attitude angle vector. The pitch angle, For roll angle, The multidimensional total control torque vector output by the controller, where This is the pitch angle control torque vector. This is the roll angle control torque vector. The downwash flow disturbance torque vector varies with height and time delay. This represents the external random gust interference vector.

[0011] Preferably, in step S20, the current relative altitude of the multirotor is obtained in real time using an altimeter, and a time-varying aerodynamic downwash transport delay and loss coefficient topological dynamics model is established, with the calculation formula as follows:

[0012]

[0013] Where h is the height, Let be the nominal basis of the propagation delay constant of the aircraft in free atmosphere, with a value of 0.005s. The loss coefficient, The nominal basic flow field aerodynamic loss coefficient in free atmosphere is 0.00012.

[0014] Preferably, the construction of a fixed-time sliding mode function vector with infinite adsorption stiffness at the hyperspace origin in step S30 specifically includes: Based on the desired attitude vector Extracting the multidimensional attitude tracking error vector and its first derivative Construct a fixed-time sliding mode function vector with infinite adsorption stiffness at the origin of hyperspace. The calculation formula is:

[0015] in, For multidimensional attitude tracking error vector The first derivative, and Design gain hyperparameters for positive definiteness. and Let p and q be small positive real numbers, and let p and q be asymmetric two-segment fractional power exponents. For standard mathematical symbol functions; Fixed-time sliding mode function vector Align the internal hyperparameter boundary constraints to design gain. The introduced minimal constant Used to completely eliminate the origin singularity, and to strictly limit the two segments of nonlinear fractional power exponents. It is 0.0005, and the range is This ensures that the tracking error has a superlinear recovery slope when it is far from the equilibrium point, and has a super strong origin adsorption stiffness when it is close to the origin equilibrium point.

[0016] Preferably, in step S40, a high-steep hyperbolic tangent function is introduced to construct a multidimensional continuous anti-jitter reaching law function. Based on the MIMO state equation, a physical inverse mapping reconstruction is performed to calculate the composite total control torque command. The dual-drive reverse actuator of the coaxial dual-rotor aircraft is then driven in real time according to the command. Specifically, this includes: Introducing a steep hyperbolic tangent function Constructing a multidimensional continuous debouncing reaching law function :

[0017] in, and To approximate the hyperparameters of the gain matrix, For a fixed-time sliding mode function vector, Where m and n are the boundary layer scaling factors, and m and n are the debouncing power exponents; Based on the aforementioned MIMO state equations, a physical inverse mapping reconstruction is performed to calculate the equivalent control term. Switching items And a fixed integrated feedforward term that includes gyroscope feedforward and flow field feedforward. Cascaded composite total control torque command :

[0018] Through the total control torque command A dual-drive reverse actuator that drives a coaxial multi-rotor aircraft in real time, enabling precise near-ground landing; Among them, the multidimensional continuous dejitter reaching law function The internal parameter alignment satisfies the condition that the gain approaches the target value. Boundary layer scaling factor The debouncing approach is subject to strict power-law constraints. This is used to ensure that the control trajectory remains completely smooth and continuous in a high order when crossing the sliding surface hyperplane, eliminating the mechanical high-frequency commutation chattering of traditional conventional sliding mode control input.

[0019] Preferably, the defense components at each level within the composite total control torque command in step S40 are specifically expanded into the following matrix calculation formula:

[0020]

[0021]

[0022] in, For equivalent control items, For toggle items, This is a fixed-state integrated feedforward term that includes gyroscope feedforward and flow field feedforward. For nominal moment of inertia, For the multidimensional continuous debouncing reaching law function, Let be the second derivative of the body attitude angle vector. and Design gain hyperparameters for positive definiteness. and Let p and q be small positive real numbers, and let p and q be asymmetric two-segment fractional power exponents. For multidimensional attitude tracking error vector The first derivative of the gyroscope feedforward component With the flow field feedforward component The physical cancellation matrix is ​​analytically expressed as:

[0023]

[0024] in, The moment of inertia of a single propeller blade assembly is its rotation. For nominal moment of inertia, and These are the corresponding pitch and roll angular velocity components, respectively. This refers to the real-time operating speed of the upper rotor. To introduce a nominal hovering constant, for abbreviation, The estimated rotational speed term of the lower blade constructed later:

[0025] By connecting a first-order low-pass transmission inertial element and a first-order storage delay module to the controller output, the computational deadlock is broken, and the total torque command is obtained. Real-time drive of coaxial actuators.

[0026] Preferably, the total control torque command in step S40 In the closed-loop circuit from the output end to the multi-rotor physical object, a set of single-step time storage delay modules (Memory) or first-order transmission inertia low-pass circuits are mounted to cut off the algebraic gap between control quantity calculation and state feedback, and resolve the deadlock algebraic loop of the underlying topology calculation.

[0027] Furthermore, this invention also proposes a coaxial dual-rotor fixed-time control system that considers ground effect and gyroscope cross-linking, comprising: Coupled Modeling Module: Used to construct attitude-inverse torque multidimensional physically coupled state space equations, and establish coaxial dual-rotor multi-input multi-output MIMO state equations that include actuator dynamics inertia, ground effect time-varying downwash delay, and reverse gyroscope cross-linking torque; Ground effect parameter adaptive module: Based on the MIMO state equation, it designs an adaptive time-series slip reconstruction mechanism for ground effect flow field parameters. It obtains the current relative altitude of the multi-rotor in real time through an altimeter, establishes a topological dynamic model of time-varying aerodynamic downwash transmission delay and loss coefficient that varies with altitude, and inputs the historical rotational speed time series term containing the time-varying aerodynamic downwash transmission delay as a state feedforward compensation variable into the controller. Sliding surface design module: Based on the results of the adaptive temporal sliding reconstruction mechanism of the flow field parameters, design a matrix-type asymmetric two-segment power fixed-time sliding surface, extract the multidimensional attitude tracking error vector and its first derivative, and construct a fixed-time sliding function vector with infinite adsorption stiffness at the hyperspace origin. The decoupled control law generation and actuator driving module is used to construct a high-order continuous anti-jitter reaching law matrix and a full physical channel decoupled feedforward control law based on the fixed-time sliding mode function vector. It introduces a high-steep hyperbolic tangent function to construct a multidimensional continuous anti-jitter reaching law function, performs physical inverse mapping reconstruction based on the MIMO state equation, calculates the composite total control torque command, and drives the dual-drive reverse actuator of the coaxial dual-rotor aircraft in real time according to the command.

[0028] Furthermore, to achieve the above objectives, the present invention also proposes a coaxial dual-rotor fixed-time control device that considers ground effect and gyro cross-linking. The device includes: a memory, a processor, and a program for coaxial dual-rotor fixed-time control that considers ground effect and gyro cross-linking, stored in the memory and executable on the processor. The program for coaxial dual-rotor fixed-time control that considers ground effect and gyro cross-linking comprises the steps for implementing the coaxial dual-rotor fixed-time control method that considers ground effect and gyro cross-linking as described above.

[0029] Furthermore, to achieve the above objectives, the present invention also provides a computer program product, which includes a program for fixed-time control of a coaxial dual rotor considering ground effect and gyroscope cross-linking, etc. When the program for fixed-time control of a coaxial dual rotor considering ground effect and gyroscope cross-linking is executed by a processor, it implements the fixed-time control method for a coaxial dual rotor considering ground effect and gyroscope cross-linking as described above.

[0030] The advantages and effects of this invention are: This invention proposes a fixed-time control method for coaxial dual rotors that considers ground effect and gyroscope cross-interference, achieving complete physical-level decoupling of multi-dimensional channel cross-interference. This invention achieves this by introducing [a specific method] into the overall control law. and The decoupled feedforward matrix cancels out the reverse gyroscope precession torque and the time-varying flow field loss of ground effect online before the control input is issued, which makes the multi-rotor exhibit excellent servo performance throughout the descent period and overcomes the technical defects of conventional methods that are prone to instability and divergence in the face of complex aerodynamic disturbances. High-precision orbit control under extreme near-ground conditions was achieved. Thanks to the design of two fractional-order power sliding surfaces, the multi-dimensional attitude tracking error was tightly locked under the impact of sudden white noise, strong winds, and sudden ground effect airflow. Within the microscopic neighborhood, the control accuracy and convergence speed are significantly improved compared to traditional algorithms; This invention perfectly eliminates the high-frequency commutation heat and wear of the actuator. It adopts a continuous hyperbolic tangent approaching matrix to completely eliminate the dense burrs and high-frequency chattering of mechanical commutation that are common in traditional sliding mode control input torque curves. The control torque curve is smooth and continuous with no obvious high-frequency pulsation, which greatly extends the mechanical service life of the UAV hardware system. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a flowchart of a fixed-time control method for a coaxial dual-rotor considering the cross-linking of ground effect and gyroscope according to the present invention.

[0033] Figure 2 This is a comparison diagram of pitch and roll channel attitude tracking response in one embodiment of the present invention and the traditional sliding mode method.

[0034] Figure 3This is a comprehensive analysis diagram of the attitude tracking, error convergence, and control torque of the roll channel under combined interference in one embodiment of the present invention.

[0035] Figure 4 This is a comparison diagram of the input control torque of a dual-channel actuator in one embodiment of the present invention and the traditional sliding mode method.

[0036] Figure 5 A diagram illustrating the nonlinear evolution of ground effect flow field parameters during the vertical descent phase in one embodiment of the present invention.

[0037] Figure 6 A comparison diagram of the convergence behavior of dual-channel sliding mode switching surface variables in one embodiment of the present invention.

[0038] Figure 7 A comparison diagram of the geometric phase plane motion trajectory of the dual-channel state error space in one embodiment of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] like Figure 1 As shown, in one embodiment of the present invention, a fixed-time control method for a coaxial dual-rotor considering ground effect and gyroscope cross-linking includes the following steps: Step S10: Construct attitude-inverse torque multidimensional physically coupled state-space equations and establish coaxial dual-rotor multi-input multi-output MIMO state equations that include actuator dynamics inertia, ground effect time-varying downwash delay, and reverse gyroscope crosslinking torque.

[0041] Specifically, the vector of the reverse gyroscope crosslinking torque in step S10 The explicit expression matrix is:

[0042] The MIMO state equation is as follows:

[0043] in, The gyroscope cross-linking torque is the pitch angle. The cross-linking torque of the gyroscope for the roll angle, The moment of inertia of a single propeller blade assembly is its rotation. For nominal moment of inertia, This refers to the real-time operating speed of the upper rotor. This refers to the real-time operating speed of the lower rotor. and These are the corresponding pitch and roll angular velocity components, respectively. Let be the body attitude angle vector. Let be the second derivative of the body attitude angle vector. The pitch angle, For roll angle, The multidimensional total control torque vector output by the controller, where This is the pitch angle control torque vector. This is the roll angle control torque vector. The downwash flow disturbance torque vector varies with height and time delay. This represents the external random gust interference vector.

[0044] Step S20: Based on the MIMO state equation, design an adaptive time-series slip reconstruction mechanism for ground effect flow field parameters. Obtain the current relative altitude of the multi-rotor in real time through an altimeter, establish a topological dynamic model of time-varying aerodynamic downwash transmission delay and loss coefficient that varies with altitude, and input the historical rotational speed time series term containing the time-varying aerodynamic downwash transmission delay as a state feedforward compensation variable into the controller.

[0045] Specifically, in step S20, the current relative altitude of the multirotor is obtained in real time using an altimeter, and a topological dynamic model of the time-varying aerodynamic downwash transport delay and loss coefficient that varies with altitude is established. The calculation formula is as follows:

[0046]

[0047] Where h is the height, Let be the nominal basis of the propagation delay constant of the aircraft in free atmosphere, with a value of 0.005s. The loss coefficient, The nominal basic flow field aerodynamic loss coefficient in free atmosphere is 0.00012.

[0048] Step S30: Based on the results of the adaptive temporal sliding reconstruction mechanism of the flow field parameters, design a matrix-type asymmetric two-segment power fixed-time sliding mode surface, extract the multidimensional attitude tracking error vector and its first derivative, and construct a fixed-time sliding mode function vector with infinite adsorption stiffness at the hyperspace origin.

[0049] Specifically, step S30 involves constructing a fixed-time sliding mode function vector with infinite adsorption stiffness at the hyperspace origin, which includes: Based on the desired attitude vector Extracting the multidimensional attitude tracking error vector and its first derivative Construct a fixed-time sliding mode function vector with infinite adsorption stiffness at the origin of hyperspace. The calculation formula is:

[0050] in, For multidimensional attitude tracking error vector The first derivative, and Design gain hyperparameters for positive definiteness. and Let p and q be small positive real numbers, and let p and q be asymmetric two-segment fractional power exponents. For standard mathematical symbol functions; Fixed-time sliding mode function vector Align the internal hyperparameter boundary constraints to design gain. The introduced minimal constant Used to completely eliminate the origin singularity. The value is 0.0005, which strictly limits the range of the two nonlinear fractional power exponents. This ensures that the tracking error has a superlinear recovery slope when it is far from the equilibrium point, and has a super strong origin adsorption stiffness when it is close to the origin equilibrium point.

[0051] Step S40: Based on the fixed-time sliding mode function vector, construct a high-order continuous anti-jitter reaching law matrix and a fully physical channel decoupled feedforward control law, introduce a high-steep hyperbolic tangent function to construct a multidimensional continuous anti-jitter reaching law function, perform physical inverse mapping reconstruction based on the MIMO state equation, calculate the composite total control torque command, and drive the dual-drive reverse actuator of the coaxial dual-rotor aircraft in real time according to the command.

[0052] Specifically, in step S40, a high-steep hyperbolic tangent function is introduced to construct a multidimensional continuous anti-jitter reaching law function. Based on the MIMO state equation, a physical inverse mapping reconstruction is performed to calculate the composite total control torque command. According to the command, the dual-drive reverse actuator of the coaxial dual-rotor aircraft is driven in real time, specifically including: Introducing a steep hyperbolic tangent function Constructing a multidimensional continuous debouncing reaching law function :

[0053] in, and To approximate the hyperparameters of the gain matrix, For a fixed-time sliding mode function vector, Where m and n are the boundary layer scaling factors, and m and n are the debouncing power exponents; Based on the aforementioned MIMO state equations, a physical inverse mapping reconstruction is performed to calculate the equivalent control term. Switching items And a fixed integrated feedforward term that includes gyroscope feedforward and flow field feedforward. Cascaded composite total control torque command :

[0054] Through the total control torque command A dual-drive reverse actuator that drives a coaxial multi-rotor aircraft in real time, enabling precise near-ground landing; Among them, the multidimensional continuous dejitter reaching law function The internal parameter alignment satisfies the condition that the gain approaches the target value. Boundary layer scaling factor The debouncing approach is subject to strict power-law constraints. This is used to ensure that the control trajectory remains completely smooth and continuous in a high order when crossing the sliding surface hyperplane, eliminating the mechanical high-frequency commutation chattering of traditional conventional sliding mode control input.

[0055] Specifically, the defense components at each level within the composite total control torque command in step S40 are expanded into the following matrix solution formula:

[0056]

[0057]

[0058] in, For equivalent control items, For toggle items, This is a fixed-state integrated feedforward term that includes gyroscope feedforward and flow field feedforward. For nominal moment of inertia, For the multidimensional continuous debouncing reaching law function, Let be the second derivative of the body attitude angle vector. and Design gain hyperparameters for positive definiteness. and Let p and q be small positive real numbers, and let p and q be asymmetric two-segment fractional power exponents. For multidimensional attitude tracking error vector The first derivative of the gyroscope feedforward component With the flow field feedforward component The physical cancellation matrix is ​​analytically expressed as:

[0059]

[0060] in, The moment of inertia of a single propeller blade assembly is its rotation. For nominal moment of inertia, and These are the corresponding pitch and roll angular velocity components, respectively. This refers to the real-time operating speed of the upper rotor. To introduce a nominal hovering constant, for abbreviation, The estimated rotational speed term of the lower blade constructed later:

[0061] By connecting a first-order low-pass transmission inertial element and a first-order storage delay module to the controller output, the computational deadlock is broken, and the total torque command is obtained. Real-time drive of coaxial actuators.

[0062] Specifically, the total control torque command in step S40 In the closed-loop circuit from the output end to the multi-rotor physical object, a set of single-step time storage delay modules (Memory) or first-order transmission inertia low-pass circuits are mounted to cut off the algebraic gap between control quantity calculation and state feedback, and resolve the deadlock algebraic loop of the underlying topology calculation.

[0063] This invention is implemented in a dual-track parallel topology canvas model comprising an upper part (the adaptive track of this invention) and a lower part (the conventional sliding mode control track). The nominal inertia of the multi-rotor is set. single propeller inertia The main signal source input is configured with dual-channel asymmetric expectation. The pitch channel is a standard sine wave, and the roll channel is a standard cosine wave with Phase=pi / 2, which is used to drive the multi-rotor to perform spatial circular motion.

[0064] The altitude source was configured as a Ramp module, with an initial altitude of 4m and an inclination of -0.4, simulating a uniform and safe descent to a 0m landing platform within 10 seconds. The ode4 (Runge-Kutta) fixed-step runtime environment was selected, with the step size strictly limited to 0.001s.

[0065] The comparative quantitative analysis of the experiments is as follows: like Figure 2 The image shown is a comparison of the pitch and roll channel attitude tracking response in one embodiment of the present invention with that of the traditional sliding mode method. (See also...) Figure 2(a) and (b) show a large initial deviation at t=0 due to the sine and cosine initial differences. Traditional sliding mode control (red dashed line) cannot achieve rapid acquisition due to the unique reverse gyro coupling and downwash delay of coaxial rotors, resulting in significant follow-up hysteresis (taking more than 1.2s); while the method of this invention (blue solid line) exhibits superior large-range recovery stiffness, achieving rapid return to orbit within 0.4s.

[0066] See Figure 2 (c) Microscopic error evolution and embedded magnification window. During the most intense ground impact phase from 5s to 8s, traditional sliding mode exhibits fluctuations due to aerodynamic transmission phase misalignment, while the blue solid line consistently maintains the error center firmly within... Inside.

[0067] like Figure 3 The diagram shown is a comprehensive analysis of the attitude tracking, error convergence, and control torque of the roll channel under combined disturbances in one embodiment of the present invention. (See also...) Figure 3 Based on the comprehensive analysis of the roll channel, in the face of initial yaw and complex disturbances, the method of this invention achieves rapid track control convergence while exhibiting smaller fluctuations in the control output torque, demonstrating superior control energy scheduling capabilities.

[0068] like Figure 4 The figure shown is a comparison of the input control torque of the dual-channel actuator in one embodiment of the present invention with that of the traditional sliding mode method. See also... Figure 4 Both traditional sliding mode and the method of this invention output smooth control torque. It should be noted that the torque smoothness of traditional sliding mode (red dashed line) is a passive compromise at the cost of feedback stiffness and switching gain, which directly leads to its performance in the attached... Figure 2 This resulted in an unavoidable steady-state error. The method of this invention (blue solid line), while maintaining the same torque smoothness, utilizes adaptive feedforward decoupling of the flow field to counteract ground effect interference and simultaneously achieves sensitive compensation for minute errors through high-order nonlinear power terms, thus realizing… Figure 2 Zero static error precise follow-up.

[0069] like Figure 5 The diagram shown illustrates the nonlinear evolution of ground-effect flow field parameters during the vertical descent phase in one embodiment of the present invention. (See also...) Figure 5 This reflects the evolution of ground effect parameters. As the relative height decreases uniformly to 0 meters, the downwash loss coefficient exhibits a nonlinear exponential decay near the ground. This evolution trend provides the physical basis for introducing a ground effect feedforward compensation matrix in this invention.

[0070] like Figure 6 The image shown is a comparison of the convergence behavior of dual-channel sliding mode switching surface variables in one embodiment of the present invention. See also... Figure 6Regarding the convergence behavior of sliding mode variables, traditional linear sliding mode variables have a long adjustment period when disturbed; the fixed-time sliding mode variables designed in this invention can converge to zero quickly and remain stable in a very short time under nonlinear stiffness constraints.

[0071] like Figure 7 The image shown is a comparison diagram of the geometric phase plane motion trajectory in the dual-channel state error space according to one embodiment of the present invention. See also... Figure 7 The phase plane motion trajectory is shown, with the horizontal axis representing position error and the vertical axis representing velocity error. Compared to the limiting cycle oscillations near the equilibrium point in traditional sliding mode, the phase trajectory of the method in this invention exhibits a centripetal spiral shape, rapidly converging to the origin equilibrium point along a smooth parabolic path, verifying that the closed-loop system possesses good global asymptotic stability.

[0072] Furthermore, in one embodiment of the present invention, a coaxial dual-rotor fixed-time control system considering ground effect and gyro interconnection is proposed, wherein the coaxial dual-rotor fixed-time control system considering ground effect and gyro interconnection includes: Coupled Modeling Module: Used to construct attitude-inverse torque multidimensional physically coupled state space equations, and establish coaxial dual-rotor multi-input multi-output MIMO state equations that include actuator dynamics inertia, ground effect time-varying downwash delay, and reverse gyroscope cross-linking torque; Ground effect parameter adaptive module: Based on the MIMO state equation, it designs an adaptive time-series slip reconstruction mechanism for ground effect flow field parameters. It obtains the current relative altitude of the multi-rotor in real time through an altimeter, establishes a topological dynamic model of time-varying aerodynamic downwash transmission delay and loss coefficient that varies with altitude, and inputs the historical rotational speed time series term containing the time-varying aerodynamic downwash transmission delay as a state feedforward compensation variable into the controller. Sliding surface design module: Based on the results of the adaptive temporal sliding reconstruction mechanism of the flow field parameters, design a matrix-type asymmetric two-segment power fixed-time sliding surface, extract the multidimensional attitude tracking error vector and its first derivative, and construct a fixed-time sliding function vector with infinite adsorption stiffness at the hyperspace origin. The decoupled control law generation and actuator driving module is used to construct a high-order continuous anti-jitter reaching law matrix and a full physical channel decoupled feedforward control law based on the fixed-time sliding mode function vector. It introduces a high-steep hyperbolic tangent function to construct a multidimensional continuous anti-jitter reaching law function, performs physical inverse mapping reconstruction based on the MIMO state equation, calculates the composite total control torque command, and drives the dual-drive reverse actuator of the coaxial dual-rotor aircraft in real time according to the command.

[0073] This application provides a coaxial dual-rotor fixed-time control system that considers ground effect and gyroscopic cross-linking. Employing a coaxial dual-rotor fixed-time control method considering ground effect and gyroscopic cross-linking as described in the above embodiments, it solves the technical problems of cross-linking instability, position divergence, and mechanical chattering in the vertical landing phase of existing coaxial multi-rotor systems. Compared with the prior art, the beneficial effects of the coaxial dual-rotor fixed-time control system considering ground effect and gyroscopic cross-linking provided in this application are the same as those of the coaxial dual-rotor fixed-time control method considering ground effect and gyroscopic cross-linking provided in the above embodiments. Furthermore, other technical features of the coaxial dual-rotor fixed-time control system considering ground effect and gyroscopic cross-linking are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0074] This application provides a coaxial dual-rotor fixed-time control device that considers ground effect and gyroscope cross-linking. The coaxial dual-rotor fixed-time control device that considers ground effect and gyroscope cross-linking includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the coaxial dual-rotor fixed-time control method considering ground effect and gyroscope cross-linking as described in Embodiment 1 above.

[0075] In one embodiment of the present invention, a coaxial dual-rotor fixed-time control device considering ground effect and gyroscope interconnection can include, but is not limited to, mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Description), PMPs (Portable Media Players), etc., and fixed terminals such as digital TVs, desktop computers, etc. The described coaxial dual-rotor fixed-time control device considering ground effect and gyroscope interconnection is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0076] A coaxial dual-rotor fixed-time control device considering ground effect and gyroscope interconnection may include a processor (e.g., a central processing unit, graphics processing unit, etc.) that can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) or a program loaded from a storage device into a machine-readable storage medium (RAM). The RAM also stores various programs and data required for the operation of the coaxial dual-rotor fixed-time control device considering ground effect and gyroscope interconnection. The processor, ROM, and RAM are interconnected via a bus. Input / output (I / O) interfaces are also connected to the bus. Typically, the following systems can be connected to the I / O interface: input devices including, for example, touchscreens, touchpads, keyboards, mice, image sensors, microphones, accelerometers, gyroscopes, etc.; output devices including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; storage devices including, for example, magnetic tapes, hard disks, etc.; and a communication unit. The communication unit allows the coaxial dual-rotor fixed-time control device considering ground effect and gyroscope interconnection to exchange data with other devices wirelessly or via wired communication. It should be understood that it is not required to implement or have all of the systems shown. Alternatively, more or fewer systems may be implemented or have.

[0077] Specifically, according to the embodiments disclosed in this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments disclosed in this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication unit, or installed from a storage device, or installed from a read-only memory. When the computer program is executed by a processor, it performs the functions defined in the methods of the embodiments disclosed in this application.

[0078] This application provides a coaxial dual-rotor fixed-time control device that considers ground effect and gyro cross-linking. Employing a coaxial dual-rotor fixed-time control method considering ground effect and gyro cross-linking as described in the above embodiments, it solves the technical problems of cross-linking instability, position divergence, and mechanical chattering during the vertical landing phase of existing coaxial multi-rotor systems. Compared with the prior art, the beneficial effects of the coaxial dual-rotor fixed-time control device considering ground effect and gyro cross-linking provided in this application are the same as those of the coaxial dual-rotor fixed-time control method considering ground effect and gyro cross-linking provided in the above embodiments. Furthermore, other technical features of this coaxial dual-rotor fixed-time control device considering ground effect and gyro cross-linking are the same as those disclosed in the previous embodiment method, and will not be repeated here.

[0079] The various parts disclosed in this application can be implemented using hardware, software, firmware, or a combination thereof. In the description of the above embodiments, specific features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0080] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the above-described coaxial dual-rotor fixed-time control method considering ground effect and gyroscope cross-linking.

[0081] The computer program product provided in this application can solve the technical problems of crosslink instability, position divergence, and mechanical chattering in the vertical landing phase of coaxial multi-rotor systems in the prior art. Compared with the prior art, the beneficial effects of the computer program product provided in this application are the same as those of the fixed-time control method for coaxial dual-rotor systems considering ground effect and gyro crosslinking provided in the above embodiments, and will not be repeated here.

[0082] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A fixed-time control method for a coaxial dual-rotor considering the interaction between ground effect and gyroscope, characterized in that, Includes the following steps: Step S10: Construct the attitude-anti-torque multidimensional physically coupled state space equation and establish the coaxial dual rotor multi-input multi-output MIMO state equation, which includes actuator dynamics inertia, ground effect time-varying downwash delay, and reverse gyroscope cross-linking torque. Step S20: Based on the MIMO state equation, design an adaptive time-series slip reconstruction mechanism for ground effect flow field parameters. Obtain the current relative altitude of the multi-rotor in real time through an altimeter, establish a topological dynamic model of time-varying aerodynamic downwash transmission delay and loss coefficient that varies with altitude, and input the historical rotational speed time-series term containing the time-varying aerodynamic downwash transmission delay as a state feedforward compensation variable into the controller. Step S30: Based on the results of the adaptive temporal sliding reconstruction mechanism of the flow field parameters, design a matrix-type asymmetric two-segment power fixed-time sliding surface, extract the multidimensional attitude tracking error vector and its first derivative, and construct a fixed-time sliding function vector with infinite adsorption stiffness at the hyperspace origin. Step S40: Based on the fixed-time sliding mode function vector, construct a high-order continuous anti-jitter reaching law matrix and a fully physical channel decoupled feedforward control law, introduce a high-steep hyperbolic tangent function to construct a multidimensional continuous anti-jitter reaching law function, perform physical inverse mapping reconstruction based on the MIMO state equation, calculate the composite total control torque command, and drive the dual-drive reverse actuator of the coaxial dual-rotor aircraft in real time according to the command.

2. The coaxial dual-rotor fixed-time control considering ground effect and gyroscope cross-linking as described in claim 1, characterized in that, The vector of the reverse gyroscope crosslinking torque in step S10 The explicit expression matrix is: The MIMO state equation is as follows: in, The gyroscope cross-linking torque is the pitch angle. The cross-linking torque of the gyroscope for the roll angle, The moment of inertia of a single propeller blade assembly is its rotation. For nominal moment of inertia, This refers to the real-time operating speed of the upper rotor. This refers to the real-time operating speed of the lower rotor. and These are the corresponding pitch and roll angular velocity components, respectively. Let be the body attitude angle vector. Let be the second derivative of the body attitude angle vector. The pitch angle, For roll angle, The multidimensional total control torque vector output by the controller, where This is the pitch angle control torque vector. This is the roll angle control torque vector. The downwash flow disturbance torque vector varies with height and time delay. This represents the external random gust interference vector.

3. The coaxial dual-rotor fixed-time control considering ground effect and gyroscope cross-linking as described in claim 1, characterized in that, In step S20, the current relative altitude of the multirotor is obtained in real time using an altimeter, and a topological dynamic model of the time-varying aerodynamic downwash transport delay and loss coefficient that varies with altitude is established. The calculation formula is as follows: Where h is the height, Let $\fraction \ ... The loss coefficient, is the nominal basic flow field aerodynamic loss coefficient in the free atmosphere.

4. The coaxial dual-rotor fixed-time control considering ground effect and gyroscope cross-linking as described in claim 1, characterized in that, The construction of a fixed-time sliding mode function vector with infinite adsorption stiffness at the hyperspace origin in step S30 specifically includes: Based on the desired attitude vector Extract the multidimensional attitude tracking error vector and its first derivative Let X be the attitude vector, and construct a fixed-time sliding mode function vector with infinite adsorption stiffness at the origin of hyperspace. The calculation formula is: in, For multidimensional attitude tracking error vector The first derivative, and Design gain hyperparameters for positive definiteness. and Let p and q be small positive real numbers, and let p and q be asymmetric two-segment fractional power exponents. For standard mathematical symbol functions; Fixed-time sliding mode function vector Align the internal hyperparameter boundary constraints to design gain. The introduction of tiny positive real numbers Used to completely eliminate the origin singularity, and to strictly limit the two segments of nonlinear fractional power exponents. It is 0.0005.

5. The coaxial dual-rotor fixed-time control considering ground effect and gyroscope cross-linking according to claim 1, characterized in that, In step S40, a high-steep hyperbolic tangent function is introduced to construct a multidimensional continuous anti-jitter reaching law function. Based on the MIMO state equation, a physical inverse mapping reconstruction is performed to calculate the composite total control torque command. According to the command, the dual-drive reverse actuator of the coaxial dual-rotor aircraft is driven in real time, specifically including: Introducing a steep hyperbolic tangent function Constructing a multidimensional continuous debouncing reaching law function : in, and To approximate the hyperparameters of the gain matrix, For a fixed-time sliding mode function vector, Where m and n are the boundary layer scaling factors, and m and n are the debouncing power exponents; Based on the aforementioned MIMO state equations, a physical inverse mapping reconstruction is performed to calculate the equivalent control term. Switching items And a fixed integrated feedforward term that includes gyroscope feedforward and flow field feedforward. Cascaded composite total control torque command : Through the total control torque command A dual-drive reverse actuator that drives a coaxial multi-rotor aircraft in real time enables precise near-ground follow-up landing.

6. The fixed-time control of a coaxial dual-rotor considering ground effect and gyro cross-linking as described in claim 1, characterized in that, The defense components at each level within the composite total control torque command in step S40 are specifically expanded into the following matrix calculation formula: in, For equivalent control items, For toggle items, This is a fixed-state integrated feedforward term that includes gyroscope feedforward and flow field feedforward. For nominal moment of inertia, For the multidimensional continuous debouncing reaching law function, Let be the second derivative of the body attitude angle vector. and Design gain hyperparameters for positive definiteness. and Let p and q be small positive real numbers, and let p and q be asymmetric two-segment fractional power exponents. For multidimensional attitude tracking error vector First derivative, gyroscope feedforward component With the feedforward component of the flow field The physical cancellation matrix is ​​analytically expressed as: in, The moment of inertia of a single propeller blade assembly is its rotation. For nominal moment of inertia, and These are the corresponding pitch and roll angular velocity components, respectively. This refers to the real-time operating speed of the upper rotor. To introduce a nominal hovering constant, for abbreviation, The estimated rotational speed term of the lower blade constructed later: 。 7. A coaxial dual-rotor fixed-time control system considering ground effect and gyroscope cross-linking, characterized in that, The system executes the coaxial dual-rotor fixed-time control method of claim 1, which considers ground effect and gyro cross-linking, comprising: Coupled Modeling Module: Used to construct attitude-inverse torque multidimensional physically coupled state space equations, and establish coaxial dual-rotor multi-input multi-output MIMO state equations that include actuator dynamics inertia, ground effect time-varying downwash delay, and reverse gyroscope cross-linking torque; Ground effect parameter adaptive module: Based on the MIMO state equation, it designs an adaptive time-series slip reconstruction mechanism for ground effect flow field parameters. It obtains the current relative altitude of the multi-rotor in real time through an altimeter, establishes a topological dynamic model of time-varying aerodynamic downwash transmission delay and loss coefficient that varies with altitude, and inputs the historical rotational speed time series term containing the time-varying aerodynamic downwash transmission delay as a state feedforward compensation variable into the controller. Sliding surface design module: Based on the results of the adaptive temporal sliding reconstruction mechanism of the flow field parameters, design a matrix-type asymmetric two-segment power fixed-time sliding surface, extract the multidimensional attitude tracking error vector and its first derivative, and construct a fixed-time sliding function vector with infinite adsorption stiffness at the hyperspace origin. The decoupled control law generation and actuator driving module is used to construct a high-order continuous anti-jitter reaching law matrix and a full physical channel decoupled feedforward control law based on the fixed-time sliding mode function vector. It introduces a high-steep hyperbolic tangent function to construct a multidimensional continuous anti-jitter reaching law function, performs physical inverse mapping reconstruction based on the MIMO state equation, calculates the composite total control torque command, and drives the dual-drive reverse actuator of the coaxial dual-rotor aircraft in real time according to the command.

8. A coaxial dual-rotor fixed-time control device considering the cross-linking of ground effect and gyroscope, characterized in that, include: The system includes a memory, a processor, and a coaxial dual-rotor fixed-time control program that considers ground effect and gyroscopic cross-linking, stored in the memory and executable on the processor. When executed by the processor, the coaxial dual-rotor fixed-time control program that considers ground effect and gyroscopic cross-linking implements a coaxial dual-rotor fixed-time control method that considers ground effect and gyroscopic cross-linking as described in any one of claims 1 to 6.

9. A computer program product, characterized in that, The computer program product includes a coaxial dual-rotor fixed-time control program that considers ground effect and gyro cross-linking. When the coaxial dual-rotor fixed-time control program that considers ground effect and gyro cross-linking is executed by the processor, it implements a coaxial dual-rotor fixed-time control method that considers ground effect and gyro cross-linking as described in any one of claims 1 to 6.

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