A ducted aircraft and control method, apparatus, device

Abstract

This application discloses a ducted jet aircraft and its control method, apparatus, and equipment. The ducted jet aircraft has an arched fuselage, with the arch angle representing the fuselage tilt angle. A ducted jet flight system model is established using control force and torque parameters of the ducted jet with the tilt angle under different flight attitudes. The state vector of the target flight attitude to be achieved by the ducted jet aircraft is processed to obtain a control input vector, which is then input to the flight control system of the aircraft, enabling the controller to achieve the target flight attitude. This control input vector includes a high-channel command, roll control torque, pitch control torque, and yaw control torque. The yaw control torque includes an additional yaw torque generated based on the fuselage tilt angle. This application, by increasing the yaw torque through the fuselage tilt angle, improves the stability of the yaw channel of the four-ducted jet aircraft in disturbance environments such as gusts.

Description

Technical Field

[0001] This application relates to the field of aircraft technology, and more specifically to a method and system for determining the fuselage tilt angle of a four-ducted aircraft. Background Technology

[0002] In recent years, unmanned aerial vehicles (UAVs) have been considered among the most efficient automated systems, especially highly integrated and miniaturized UAV systems, which have gradually demonstrated significant value in scientific, military, and civilian fields. As a current research hotspot, small UAVs possess high maneuverability, thus offering unique advantages in disaster reconnaissance, material delivery, and military reconnaissance.

[0003] Considering the practical application scenarios of unmanned aerial vehicles (UAVs), conventional open rotors often cannot meet the safety requirements for interactions with the environment, humans, and buildings. To cope with complex operating environments, ducted rotor systems are currently commonly used. However, in practical applications facing complex operating environments such as gusts of wind, the yaw channel of ducted rotor systems is quite sensitive to actuator saturation, instability, and performance degradation. Therefore, enhancing the yaw performance of ducted rotor systems is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] In view of the above, this application provides the following technical solution:

[0005] A ducted jet aircraft, comprising:

[0006] The aircraft has a fuselage body with ducted openings. Ducted propellers are installed in the ducted openings. Each ducted propeller is equipped with a propeller motor. The aircraft fuselage is domed, and the dome angle ranges from 7.9° to 13.1°.

[0007] A ducted jet aircraft control method, applied to the ducted jet aircraft, the method comprising:

[0008] Based on the range of the ducted jet's dome angle, the fuselage tilt angle of the ducted jet is determined;

[0009] Obtain a ducted flight system model corresponding to the fuselage tilt angle, wherein the ducted flight system model is a model that optimizes the control force and control torque of the ducted aircraft based on the fuselage tilt angle;

[0010] Determine the state vector of the target flight attitude corresponding to the ducted jet;

[0011] The state vector is processed based on the ducted flight system model to obtain the control input vector, which includes high-channel command, roll control torque, pitch control torque and yaw control torque, wherein the yaw control torque includes an additional yaw torque generated based on the fuselage tilt angle;

[0012] Based on the control input vector, the ducted jet is controlled to achieve the target flight attitude.

[0013] Optionally, the method further includes:

[0014] Based on the physical quantities of the attitude of the ducted aircraft set in the Earth coordinate system, determine the rotation matrix from the body coordinate system to the Earth coordinate system.

[0015] Obtain the calculation equations for the total control force and control torque generated by the power units of each pre-created ducted propeller corresponding to the rotation matrix, and calculate the force and torque generated by the power unit of each ducted propeller based on the calculation equations using the duct inflow model.

[0016] The external disturbance force and torque are calculated based on the turbulent wind parameters, the rotation matrix, and the force and torque generated by the power unit of each ducted propeller.

[0017] Based on the external disturbance force and torque, the force and torque generated by the power unit of each ducted propeller and the current state matrix of the ducted aircraft, a state space equation is established.

[0018] Based on the state-space equations, a ducted flight system model is generated.

[0019] Optionally, the calculation of the force and torque generated by the power unit of each ducted propeller based on the calculation equation using the duct inflow model includes:

[0020] Based on the aforementioned inflow model, the velocity vectors located upstream of the rotor, at the rotor, and far downstream of the rotor were calculated respectively.

[0021] The air mass flow rate through the duct is calculated based on the velocity vector at the rotor.

[0022] Based on the airflow angle and the velocity vector, the rotor thrust is calculated, and the vertical and tangential rotational speeds of the rotor are determined.

[0023] The total thrust for a single rotation is calculated based on the vertical and tangential rotational speeds of the rotor.

[0024] Based on the fuselage tilt angle and the total thrust, the force and torque generated by the power unit of each ducted propeller are calculated respectively.

[0025] Optionally, determining the fuselage tilt angle of the ducted aircraft based on the range of the ducted aircraft's dome angle includes:

[0026] Obtain a set of candidate parameters for the ducted vehicle, wherein each subset of candidate parameters in the set includes the mass of the ducted vehicle, the wheelbase between adjacent propeller motors, and the number of apex angles within the apex angle range;

[0027] Based on the ducted flight system model, each of the candidate parameter subsets is processed to obtain response data corresponding to each candidate parameter subset;

[0028] Based on the response data, a target parameter subset is determined from each candidate parameter subset;

[0029] The dome angles in the target parameter subset are determined as the fuselage tilt angle of the ducted aircraft.

[0030] Optionally, determining the target parameter subset from the various candidate parameter subsets based on the response data includes:

[0031] Determine the cost function corresponding to each response data;

[0032] Each of the cost functions is processed to obtain the average value and standard deviation of each cost function;

[0033] Based on the mean and the standard deviation, the sensitivity coefficient of the cost function for each set of candidate parameters with respect to the corresponding response data is determined;

[0034] Based on the sensitivity coefficient, a target parameter subset is determined from each candidate parameter subset.

[0035] Optionally, it also includes:

[0036] Based on each of the candidate parameter subsets, frequency domain analysis is performed on the flight system of the ducted vehicle to determine the robust stability margin corresponding to each of the candidate parameter subsets.

[0037] The robust stability margin is compared with the target robust stability margin parameter to obtain the comparison result;

[0038] Based on the comparison results and the sensitivity coefficients, a target parameter subset is determined from each candidate parameter subset.

[0039] A ducted jet aircraft control device, applied to the ducted jet aircraft, the device comprising:

[0040] The first determining module is used to determine the fuselage tilt angle of the ducted aircraft based on the range of the apex angle of the ducted aircraft;

[0041] The first acquisition module is used to acquire a ducted flight system model corresponding to the fuselage tilt angle. The ducted flight system model is a model that optimizes the control force and control torque of the ducted aircraft based on the fuselage tilt angle.

[0042] The second determining module is used to determine the state vector of the target flight attitude corresponding to the ducted jet;

[0043] The processing module is used to process the state vector based on the ducted flight system model to obtain a control input vector. The control input vector includes a high-channel command, a roll control torque, a pitch control torque, and a yaw control torque. The yaw control torque includes an additional yaw torque generated based on the fuselage tilt angle.

[0044] The control module is used to control the ducted jet to achieve the target flight attitude based on the control input vector.

[0045] A storage medium storing a computer program that, when executed by a processor, implements the ducted vehicle control method as described in any of the preceding claims.

[0046] A control device, comprising:

[0047] Memory, used to store applications and the data generated by the running of the applications;

[0048] A processor for executing the application program to implement the ducted vehicle control method as described in any of the preceding embodiments.

[0049] As can be seen from the above technical solution, this application discloses a ducted jet aircraft and its control method, device, and equipment. The fuselage of the ducted jet aircraft is domed, and the corresponding dome angle is the fuselage tilt angle of the ducted jet aircraft. A ducted jet flight system model is established using the control force and torque parameters of the ducted jet aircraft with the fuselage tilt angle under different flight attitudes. The state vector of the target flight attitude to be achieved by the ducted jet aircraft is processed to obtain a control input vector, which is then input to the flight control system of the aircraft, enabling the controller to achieve the target flight attitude. The control input vector includes a high-channel command, roll control torque, pitch control torque, and yaw control torque. The yaw control torque includes an additional yaw torque generated based on the fuselage tilt angle. This application increases the yaw torque in principle by adjusting the fuselage tilt angle, thereby improving the stability of the yaw channel of the four-ducted jet aircraft in gust and other disturbance environments. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0051] Figure 1 An overall configuration diagram of a four-ducted aircraft provided in this application embodiment;

[0052] Figure 2 A schematic diagram illustrating the principle of increasing yaw moment of a tilting fuselage provided in this application embodiment;

[0053] Figure 3 A flowchart illustrating a ducted jet control method provided in this application embodiment;

[0054] Figure 4 A duct inflow model diagram provided for an embodiment of this application;

[0055] Figure 5 A schematic diagram illustrating a sensitivity analysis result provided in an embodiment of this application;

[0056] Figure 6 A schematic diagram of robust stability margin provided for an embodiment of this application;

[0057] Figure 7 This is a schematic diagram of the structure of a ducted aircraft control device provided in an embodiment of this application. Detailed Implementation

[0058] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0059] This application provides a ducted jet aircraft. In order to improve the adaptability of the ducted jet aircraft in complex operating environments, the ducted jet aircraft has a certain fuselage tilt angle, which in principle increases the yaw moment and improves the stability of the ducted jet aircraft's yaw channel under disturbances such as gusts.

[0060] See Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the overall structure of a ducted jet aircraft provided in an embodiment of this application. Figure 2A schematic diagram illustrating the principle of increasing the yaw moment for tilting the fuselage. Figure 1 As shown in the example, the ducted jet aircraft includes a fuselage body 10, on which a ducted port 11 is formed. A ducted propeller 12 is installed inside the ducted port 11, and each ducted propeller is equipped with a propeller motor (due to...). Figure 1 (This is an overall schematic diagram and the propeller motor is not shown.) The aircraft fuselage is domed, which generates a certain dome angle. This dome angle can be used as the fuselage tilt angle. Analysis and verification show that the ducted jet aircraft performs optimally when this dome angle is set between 7.9° and 13.1°. See details... Figure 2 , Figure 2 The angle α shown is the dome angle.

[0061] In addition, it should be noted that, Figure 1 and Figure 2 The ducted aircraft shown is a four-ducted aircraft, which is only an example of a ducted aircraft provided in this application embodiment. Specifically, the corresponding number of ducts can be determined according to actual design requirements. For ease of description, subsequent embodiments in this application will also use the same designation. Figure 1 and Figure 2 The quadruple-ducted aircraft shown is explained below.

[0062] Furthermore, the ducted jet aircraft may also include a flight control system. This system processes the current state parameters of the aircraft (such as attitude, position, and velocity) to generate control commands that enable the ducted jet aircraft to enter the corresponding flight attitude. Correspondingly, the ducted jet aircraft may also include a force-generating unit consisting of four ducted propeller power systems. The force difference between the two sets of ducted propeller power units located at the front and rear is used for pitch control; the force difference between the two sets of ducted propeller power units located at the left and right is used for roll control; the yaw control torque consists of two parts:

[0063] Two ducted propeller power units located on the same diagonal with the same direction of rotation generate the same counter-torque (such as clockwise), while two sets of power units on the other diagonal generate the counter-torque in the opposite direction (such as counterclockwise). The difference between the two sets of counter-torques with different directions is the yaw torque.

[0064] When the left and right fuselages rotate a certain angle around the forward direction (x-axis), the thrust vector generated by the ducted propeller power unit no longer strictly follows the direction of gravity lines, but has a component in the horizontal direction, such as... Figure 2 As shown. Therefore, in addition to the original counter-torque, the power unit located on the diagonal will also generate a corresponding additional torque, the difference of which is a certain amount of additional yaw torque.

[0065] exist Figure 1The diagram shows two coordinate systems: the Earth coordinate system and the body coordinate system. The corresponding Earth coordinate system is... That is, O e With x as the center, e y e , z e The coordinate system is defined by the axes; the body coordinate system is defined by... That is, O b With x as the center, b y b , z b A coordinate system with coordinate axes.

[0066] Figure 1 In the diagram, F1, F2, F3, and F4 represent the thrust generated by a single ducted propeller unit, and T1, T2, T3, and T4 represent the torque generated by the same single ducted propeller unit. (In Earth coordinate system) In this context, the real-time position of a four-ducted aircraft is defined as p = [x, y, z]. T and posture The physical quantity in the body coordinate system In this context, linear velocity V is defined as [u, v, w]. T And the rotational angular velocity ω=[p,q,r] T The physical quantity that characterizes attitude. In the physical quantities The elements represent the roll angle, pitch angle, and yaw angle, respectively. The rotational angular velocity ω = [p, q, r] characterizes this. T Each element r in the equation represents the angular velocity of the aircraft rotating along the x, y, and z axes in the body coordinate system, namely the roll angular velocity, pitch angular velocity, and yaw angular velocity.

[0067] To accurately output control data for the ducted jet aircraft at different flight attitudes, this application also provides a ducted jet aircraft control method. This method is applied to the ducted jet aircraft with fuselage tilt angle provided in this application. See [link to relevant documentation]. Figure 3 The method may include the following steps:

[0068] S101. Determine the fuselage tilt angle of the ducted aircraft based on the range of the apex angle of the ducted aircraft.

[0069] Typically, the dome angle of a ducted aircraft is fixed, meaning there is a fixed dome angle used as the fuselage tilt angle. However, for ducted aircraft where the dome angle is adjustable, a currently used dome angle can be determined as the fuselage tilt angle based on the current application scenario (such as environmental parameters, mission characteristics, etc.).

[0070] S102. Obtain the ducted flight system model corresponding to the fuselage tilt angle.

[0071] S103. Determine the state vector of the target flight attitude corresponding to the ducted jet.

[0072] S104. Based on the ducted flight system model, the state vector is processed to obtain the control input vector.

[0073] S105. Based on the control input vector, control the ducted jet to achieve the target flight attitude.

[0074] In order to quickly and accurately control the ducted jet with a fuselage tilt angle, a ducted jet flight system model capable of analyzing the current state vector of the ducted jet is pre-established in this embodiment. This ducted jet flight system model is a model that optimizes the control force and control torque of the ducted jet based on the fuselage tilt angle.

[0075] This ducted-aircraft flight system model is developed by collecting the state vectors and control input vectors of a ducted-aircraft with a fuselage tilt angle during stable flight under different attitude states. The state matrix and control matrix are determined through fitting analysis of the state vectors and control input vectors. Furthermore, the disturbance matrix is ​​determined using current external disturbance parameters, thus establishing a state-space equation, which serves as the ducted-aircraft flight system model. Subsequently, the real-time state vectors can be used as input to this model to obtain the output control input vector. This control input vector can then be input to the flight control system of the corresponding ducted-aircraft, thereby controlling the output thrust and torque of each power unit to achieve the corresponding target flight attitude.

[0076] Correspondingly, this application also provides a method for generating a ducted jet flight system model, including:

[0077] Based on the physical quantities of the attitude of the ducted aircraft set in the Earth coordinate system, determine the rotation matrix from the body coordinate system to the Earth coordinate system.

[0078] Obtain the calculation equations for the total control force and control torque generated by the power units of each pre-created ducted propeller corresponding to the rotation matrix, and calculate the force and torque generated by the power unit of each ducted propeller based on the calculation equations using the duct inflow model.

[0079] The external disturbance force and torque are calculated based on the turbulent wind parameters, the rotation matrix, and the force and torque generated by the power unit of each ducted propeller.

[0080] Based on the external disturbance force and torque, the force and torque generated by the power unit of each ducted propeller and the current state matrix of the ducted aircraft, a state space equation is established.

[0081] Based on the state-space equations, a ducted flight system model is generated.

[0082] Furthermore, the calculation of the force and torque generated by the power unit of each ducted propeller based on the duct inflow model and the calculation equation includes:

[0083] Based on the aforementioned inflow model, the velocity vectors located upstream of the rotor, at the rotor, and far downstream of the rotor were calculated respectively.

[0084] The air mass flow rate through the duct is calculated based on the velocity vector at the rotor.

[0085] Based on the airflow angle and the velocity vector, the rotor thrust is calculated, and the vertical and tangential rotational speeds of the rotor are determined.

[0086] The total thrust for a single rotation is calculated based on the vertical and tangential rotational speeds of the rotor.

[0087] Based on the fuselage tilt angle and the total thrust, the force and torque generated by the power unit of each ducted propeller are calculated respectively.

[0088] The specific process of generating a ducted flight system model is explained below.

[0089] First, in the Earth coordinate system In this context, the real-time position of a four-ducted aircraft is defined as p = [x, y, z]. T and posture The physical quantity in the body coordinate system In this context, linear velocity V is defined as [u, v, w]. T and rotational angular velocity ω =[p,q,r] T For the physical quantity, the rotation matrix from the body coordinate system to the Earth coordinate system is:

[0090]

[0091] Here, position p refers to the real-time position of the quadrupedal ducted aircraft in the Earth coordinate system. The aircraft's position changes in real time as it moves; therefore, p = [x, y, z]. T Indicates. Represents posture. In the physical quantities The elements represent the roll angle, pitch angle, and yaw angle, respectively.

[0092] Based on the Newton-Euler equations, the equations for force and moment are as follows:

[0093]

[0094] Where m is the mass of the quadrupedal ducted aircraft, J is the moment of inertia, g is the acceleration due to gravity, and e3 = [0, 0, 1]. T F is the direction vector. d and M d F represents the external disturbance force and torque, respectively. t and M t Let F represent the force and torque generated by the ducted propeller power unit, respectively. Therefore, the force and torque generated by the ducted propeller power unit are calculated as follows:

[0095]

[0096] In equation (3), p i =[x i ,y i ,z i ] T F is the position of the center of mass of each motor in the machine coordinate system. i and T i The force and torque generated by a single power unit are obtained from the following duct inflow model.

[0097] See Figure 4 This illustrates the inflow model for a single duct. During rotor rotation, the air velocities flowing into and out of the duct change in real time, and the following relationship holds:

[0098]

[0099] Where, γ R and γ ∞ The airflow angle k in the corresponding inflow area χR and k χ∞ This is the airflow deflection factor. Based on the above conditions, the velocity vector of the inflow model can be divided into three positions: upstream of the rotor, at the rotor, and downstream far from the rotor. That is, the velocity upstream of the rotor is... V 0, the speed at the rotor is V R The downstream velocity away from the rotor is V ∞ And given by the following formula:

[0100]

[0101] The control mass flow rate through the duct is:

[0102]

[0103] Where ρ is the air density, A D This is the cross-sectional area of ​​the duct at the rotor. The total thrust includes the rotor thrust and the duct thrust, expressed as:

[0104] F = F R +F D =(1+k) aug )F R (7)

[0105] Where, k aug This represents the lift increase factor. Based on the principles of conservation of mass, momentum, and energy, the modified thrust equation is derived as the induced velocity v. i The function is used to calculate the rotor thrust:

[0106]

[0107] Based on the blade element momentum theory, the vertical rotational velocity of the rotor can be expressed as:

[0108] V p =-V R sinγ R -2v i +(psinψ+qcosψ)dr (9)

[0109] The rotational tangential velocity of the rotor is:

[0110]

[0111] Where Π represents the blade rotation radians, and r e It is the distance ψ from the infinitesimal element on the blade to the motor shaft. w It is the azimuth angle relative to the wind. Therefore, the force of the blade element can be expressed as:

[0112]

[0113] Among them, C l and C d , respectively, are the lift and drag coefficients, and c is the chord length of a single blade. Integrating equation (11), the total thrust in a single rotation can be calculated:

[0114]

[0115] Where n is the number of blades and R is the rotor radius. Therefore, based on the fuselage tilt angle structure design, the thrust and torque generated by a single ducted propeller power unit are:

[0116]

[0117] Where α is the fuselage tilt angle, and c q It is the torque factor, dxy It is the wheelbase between adjacent motors, Fd xy sinα is the additional yaw moment resulting from structural optimization.

[0118] According to the simplified Dryden gust model, the external disturbance force and torque can be expressed as:

[0119]

[0120] Among them, V wind =[u wind ,v wind ,w wind ] T It indicates turbulent wind.

[0121] Based on the nominal hovering condition, the dynamic equation in equation (2) can be simplified to:

[0122]

[0123] The perturbation model can be further linearized using the small-angle approximation theory as follows:

[0124]

[0125] Among them, [F dx ,F dy ,F dz ] T and [M] dx M dy M dz ] T This represents the force and torque along each axis.

[0126] Considering the perturbation model and modeling errors, the linearized dynamic equation at the balancing point can be expressed as the following state-space equation:

[0127]

[0128] Where A represents the state matrix, B is the control matrix, and δ is a diagonal matrix representing the unknown modeling error in each channel. Furthermore, d and E are the perturbation input vectors and matrices, which can be represented as:

[0129]

[0130] The state vector x is:

[0131]

[0132] The control input vector u is:

[0133] u = [u hei u rol upit u yaw ] T (20)

[0134] Among them, u hei Indicates the height channel command, u rol It is the roll control torque, u pit It is the pitch control torque, u yaw It is the yaw control torque.

[0135] Based on the above conditions, the model can be linearized to obtain the system state matrix A, and a dynamic model can be further built to obtain the ducted flight system model.

[0136] After obtaining the range of the apex angle of the ducted jet, an optimal apex angle can usually be selected as the final fuselage tilt angle. In order to accurately obtain this angle value, the final fuselage tilt angle is determined through sensitivity analysis and robustness margin analysis in this embodiment of the application.

[0137] In one embodiment of this application, determining the fuselage tilt angle of the ducted jet based on the range of the ducted jet's dome angle includes:

[0138] Obtain a set of candidate parameters for the ducted vehicle, wherein each subset of candidate parameters in the set includes the mass of the ducted vehicle, the wheelbase between adjacent propeller motors, and the number of apex angles within the apex angle range;

[0139] Based on the ducted flight system model, each of the candidate parameter subsets is processed to obtain response data corresponding to each candidate parameter subset;

[0140] Based on the response data, a target parameter subset is determined from each candidate parameter subset;

[0141] The dome angles in the target parameter subset are determined as the fuselage tilt angle of the ducted aircraft.

[0142] Furthermore, determining the target parameter subset from each candidate parameter subset based on the response data includes:

[0143] Determine the cost function corresponding to each response data;

[0144] Each of the cost functions is processed to obtain the average value and standard deviation of each cost function;

[0145] Based on the mean and the standard deviation, the sensitivity coefficient of the cost function for each set of candidate parameters with respect to the corresponding response data is determined;

[0146] Based on the sensitivity coefficient, a target parameter subset is determined from each candidate parameter subset.

[0147] Sensitivity analysis reflects the impact of different candidate parameters on the uncertainties of a platform with a complex dynamic model, and is an essential step in structural optimization. Among various sensitivity analysis algorithms, the Monte Carlo algorithm has become one of the most widely used probability, statistics, and numerical methods due to its simplicity and high computational efficiency.

[0148] First, the first step is to determine candidate parameters and system responses to quantify the impact of inherent physical parameters on flight performance. Refer to Table 1 for the candidate parameters of the flight system, which represents the set of candidate parameters in the embodiments. Each subset of candidate parameters includes mass, wheelbase, and roll angle parameters. Table 1 lists the candidate parameters including mass, wheelbase, and roll angle. In addition to the candidate parameters, the relevant system responses are shown in Table 2. Considering the uncertainty of external wind interference and modeling errors caused by inter-channel coupling, the position tracking responses in all three directions are considered when considering yaw performance.

[0149] Secondly, the candidate parameters and system response are processed. The candidate parameters are defined as random variables within a range and distributed using the Sobol sampling method to form a fine, uniform partition among the parameter samples. The system response is set as a cost function with minimum signal variance, which can be expressed as:

[0150] y j =f j (x1,x2,x3),j=1,2,3,4 (22)

[0151] Where x1, x2, x3 represent candidate parameter random variables, and their normalized average is μ. xj The standard deviation is σ xj .

[0152] y j The Taylor expansion of the mean of each random variable is expressed as:

[0153]

[0154] y j The mean and standard deviation are:

[0155]

[0156] According to the Pearson correlation coefficient formula, the candidate parameter x i For the cost function y j The sensitivity coefficient is:

[0157]

[0158] Where k is the total number of tests, x in and y jn These are the values ​​of the candidate parameters and tracking error in each test.

[0159] Table 1 Candidate parameters for the flight system

[0160] Serial Number Candidate parameters nominal value Range of variation unit 1 m 3 2–4 kg 2 <![CDATA[d xy ]]> 0.2 0.15–0.25 m 3 α 0 0–20 degree

[0161] Table 2 Flight System Response

[0162]

[0163] Please refer to the sensitivity analysis results. Figure 5 The yaw tracking error analysis results show that, as the tilt angle has the greatest impact on yaw performance, the yaw tracking error decreases as the fuselage tilt angle increases.

[0164] Furthermore, frequency domain analysis methods are used to analyze the robustness of the flight system to determine an appropriate fuselage tilt angle. Correspondingly, the embodiments of this application also include:

[0165] Based on each of the candidate parameter subsets, frequency domain analysis is performed on the flight system of the ducted vehicle to determine the robust stability margin corresponding to each of the candidate parameter subsets.

[0166] The robust stability margin is compared with the target robust stability margin parameter to obtain the comparison result;

[0167] Based on the comparison results and the sensitivity coefficients, a target parameter subset is determined from each candidate parameter subset.

[0168] Due to external wind disturbances and parameter perturbations of the uncertain system, the robust stability margin of the system under different fuselage tilt angles was calculated using analysis tools (such as MATLAB). After applying the system uncertainty boundary, the expected peak gain of the closed-loop system was selected as 3. The calculated robust stability margin of the system is as follows. Figure 6 As shown.

[0169] Figure 6The robust stability of the system decreases as the fuselage tilt angle increases. When the tilt angle is greater than 13.1°, the robust stability margin is less than 1 (this "1" can be the target robust stability margin parameter), indicating that the system is unstable within certain uncertain amplitude ranges. Therefore, for the ducted jet with a tilted fuselage proposed in this application, the fuselage tilt angle should be less than 13.1°. Simultaneously, to ensure the increased yaw moment effect caused by the tilt angle, the fuselage tilt angle is selected to be above 7.9° in the design and analysis. In summary, the fuselage tilt angle range for the proposed ducted jet with a tilted fuselage in this embodiment is determined to be 7.9° to 13.1°.

[0170] Therefore, the fuselage tilt angle corresponding to the determined fuselage tilt angle range can be applied to the ducted aircraft provided in the embodiments of this application, thereby increasing the additional yaw moment and improving the stability of the proposed ducted aircraft yaw channel in disturbance environments such as gusts.

[0171] In another embodiment of this application, a ducted jet aircraft control device is provided, which is applied to the ducted jet aircraft, specifically to the ducted jet aircraft with fuselage tilt provided in this embodiment. For example, this control device can be applied to the flight control system of the ducted jet aircraft. See also... Figure 7 The ducted jet control system may include:

[0172] The first determining module 701 is used to determine the fuselage tilt angle of the ducted aircraft based on the range of the dome angle of the ducted aircraft;

[0173] The first acquisition module 702 is used to acquire a ducted flight system model corresponding to the fuselage tilt angle, wherein the ducted flight system model is a model that optimizes the control force and control torque of the ducted aircraft based on the fuselage tilt angle.

[0174] The second determining module 703 is used to determine the state vector of the target flight attitude corresponding to the ducted jet;

[0175] The processing module 704 is used to process the state vector based on the ducted flight system model to obtain a control input vector. The control input vector includes a high-channel command, a roll control torque, a pitch control torque, and a yaw control torque. The yaw control torque includes an additional yaw torque generated based on the fuselage tilt angle.

[0176] The control module 705 is used to control the ducted jet to achieve the target flight attitude based on the control input vector.

[0177] Furthermore, the device also includes a model generation module, which comprises:

[0178] The first determining submodule is used to determine the rotation matrix from the body coordinate system to the Earth coordinate system based on the physical quantities of the attitude of the ducted aircraft set in the Earth coordinate system.

[0179] The first acquisition submodule is used to acquire the calculation equations of the total control force and control torque generated by the power units of each pre-created ducted propeller corresponding to the rotation matrix, and to calculate the force and torque generated by the power unit of each ducted propeller based on the calculation equations using the duct inflow model.

[0180] The first calculation submodule is used to calculate the external disturbance force and torque based on the turbulent wind parameters, the rotation matrix, and the force and torque generated by the power unit of each ducted propeller.

[0181] A submodule is established to establish state-space equations based on the external disturbance forces and torques, the forces and torques generated by the power units of each ducted propeller, and the current state matrix of the ducted aircraft.

[0182] A generation submodule is used to generate a ducted flight system model based on the state-space equations.

[0183] Furthermore, the first acquisition submodule is specifically used for:

[0184] Based on the aforementioned inflow model, the velocity vectors located upstream of the rotor, at the rotor, and far downstream of the rotor were calculated respectively.

[0185] The air mass flow rate through the duct is calculated based on the velocity vector at the rotor.

[0186] Based on the airflow angle and the velocity vector, the rotor thrust is calculated, and the vertical and tangential rotational speeds of the rotor are determined.

[0187] The total thrust for a single rotation is calculated based on the vertical and tangential rotational speeds of the rotor.

[0188] Based on the fuselage tilt angle and the total thrust, the force and torque generated by the power unit of each ducted propeller are calculated respectively.

[0189] In one implementation, the first determining module includes:

[0190] The second acquisition submodule is used to acquire a set of candidate parameters for the ducted vehicle, wherein each subset of candidate parameters in the set includes the mass of the ducted vehicle, the wheelbase between adjacent propeller motors, and the number of apex angles within the apex angle range;

[0191] The processing submodule is used to process each of the candidate parameter subsets based on the ducted flight system model to obtain response data corresponding to each candidate parameter subset;

[0192] The second determining submodule is used to determine the target parameter subset from the various candidate parameter subsets based on the response data;

[0193] The third determining submodule is used to determine the dome angle in the target parameter subset as the fuselage tilt angle of the ducted aircraft.

[0194] Optionally, the second determining submodule is specifically used for:

[0195] Determine the cost function corresponding to each response data;

[0196] Each of the cost functions is processed to obtain the average value and standard deviation of each cost function;

[0197] Based on the mean and the standard deviation, the sensitivity coefficient of the cost function for each set of candidate parameters with respect to the corresponding response data is determined;

[0198] Based on the sensitivity coefficient, a target parameter subset is determined from each candidate parameter subset.

[0199] Furthermore, it also includes: a fourth determination submodule, used for:

[0200] Based on each of the candidate parameter subsets, frequency domain analysis is performed on the flight system of the ducted vehicle to determine the robust stability margin corresponding to each of the candidate parameter subsets.

[0201] The robust stability margin is compared with the target robust stability margin parameter to obtain the comparison result;

[0202] Based on the comparison results and the sensitivity coefficients, a target parameter subset is determined from each candidate parameter subset.

[0203] It should be noted that the specific implementation of each module and sub-module in this embodiment can be referred to the corresponding content above, and will not be described in detail here.

[0204] In another embodiment of this application, a storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the various steps of ducted aircraft control as described in any of the preceding claims.

[0205] In another embodiment of this application, a control device is also provided, which may include:

[0206] Memory, used to store applications and the data generated by the running of the applications;

[0207] A processor for executing the application program to implement the ducted vehicle control method as described in any of the above.

[0208] It should be noted that the specific implementation of the processor in this embodiment can be referred to the corresponding content above, and will not be described in detail here.

[0209] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0210] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0211] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0212] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A control method for a ducted jet aircraft, characterized in that, Applied to ducted jet aircraft with a fuselage tilt angle, the method includes: Based on the range of the ducted jet's dome angle, the fuselage tilt angle of the ducted jet is determined; Obtain a ducted flight system model corresponding to the fuselage tilt angle, wherein the ducted flight system model is a model that optimizes the control force and control torque of the ducted aircraft based on the fuselage tilt angle; Determine the state vector of the target flight attitude corresponding to the ducted jet; The state vector is processed based on the ducted flight system model to obtain the control input vector, which includes high-channel command, roll control torque, pitch control torque and yaw control torque, wherein the yaw control torque includes an additional yaw torque generated based on the fuselage tilt angle; Based on the control input vector, the ducted jet is controlled to achieve the target flight attitude.

2. The method according to claim 1, characterized in that, The method further includes: Based on the physical quantities of the attitude of the ducted aircraft set in the Earth coordinate system, determine the rotation matrix from the body coordinate system to the Earth coordinate system. Obtain the calculation equations for the total control force and control torque generated by the power units of each pre-created ducted propeller corresponding to the rotation matrix, and calculate the force and torque generated by the power unit of each ducted propeller based on the calculation equations using the duct inflow model. The external disturbance force and torque are calculated based on the turbulent wind parameters, the rotation matrix, and the force and torque generated by the power unit of each ducted propeller. Based on the external disturbance force and torque, the force and torque generated by the power unit of each ducted propeller and the current state matrix of the ducted aircraft, a state space equation is established. Based on the state-space equations, a ducted flight system model is generated.

3. The method according to claim 2, characterized in that, The calculation equations based on the ducted inflow model are used to calculate the force and torque generated by the power unit of each ducted propeller, including: Based on the aforementioned inflow model, the velocity vectors located upstream of the rotor, at the rotor, and far downstream of the rotor were calculated respectively. The air mass flow rate through the duct is calculated based on the velocity vector at the rotor. Based on the airflow angle and the velocity vector, the rotor thrust is calculated, and the vertical and tangential rotational speeds of the rotor are determined. The total thrust for a single rotation is calculated based on the vertical and tangential rotational speeds of the rotor. Based on the fuselage tilt angle and the total thrust, the force and torque generated by the power unit of each ducted propeller are calculated respectively.

4. The method according to claim 1, characterized in that, Determining the fuselage tilt angle of the ducted aircraft based on the range of its dome angle includes: Obtain a set of candidate parameters for the ducted jet, wherein each subset of candidate parameters in the set includes the mass of the ducted jet, the wheelbase between adjacent propeller motors, and the number of apex angles within the apex angle range; Based on the ducted flight system model, each of the candidate parameter subsets is processed to obtain response data corresponding to each candidate parameter subset; Based on the response data, a target parameter subset is determined from each candidate parameter subset; The dome angles in the target parameter subset are determined as the fuselage tilt angle of the ducted aircraft.

5. The method according to claim 4, characterized in that, The step of determining the target parameter subset from the various candidate parameter subsets based on the response data includes: Determine the cost function corresponding to each response data; Each of the cost functions is processed to obtain the average value and standard deviation of each cost function; Based on the mean and the standard deviation, the sensitivity coefficient of the cost function for each set of candidate parameters with respect to the corresponding response data is determined; Based on the sensitivity coefficient, a target parameter subset is determined from each candidate parameter subset.

6. The method according to claim 5, characterized in that, Also includes: Based on each of the candidate parameter subsets, frequency domain analysis is performed on the flight system of the ducted vehicle to determine the robust stability margin corresponding to each of the candidate parameter subsets. The robust stability margin is compared with the target robust stability margin parameter to obtain the comparison result; Based on the comparison results and the sensitivity coefficients, a target parameter subset is determined from each candidate parameter subset.

7. A ducted jet aircraft, characterized in that, include: The aircraft has a fuselage body with ducted openings. Ducted propellers are installed in the ducted openings. Each ducted propeller is equipped with a propeller motor. The aircraft fuselage is domed, and the dome angle ranges from 7.9° to 13.1°. The ducted jet aircraft is controlled using the ducted jet aircraft control method according to any one of claims 1 to 6.

8. A ducted jet aircraft control device, characterized in that, Applied to the ducted jet aircraft as described in claim 7, the device comprises: The first determining module is used to determine the fuselage tilt angle of the ducted aircraft based on the range of the apex angle of the ducted aircraft; The first acquisition module is used to acquire a ducted flight system model corresponding to the fuselage tilt angle. The ducted flight system model is a model that optimizes the control force and control torque of the ducted aircraft based on the fuselage tilt angle. The second determining module is used to determine the state vector of the target flight attitude corresponding to the ducted jet; The processing module is used to process the state vector based on the ducted flight system model to obtain a control input vector. The control input vector includes a high-channel command, a roll control torque, a pitch control torque, and a yaw control torque. The yaw control torque includes an additional yaw torque generated based on the fuselage tilt angle. The control module is used to control the ducted jet to achieve the target flight attitude based on the control input vector.

9. A storage medium, characterized in that, The storage medium stores a computer program, which, when executed by a processor, implements the ducted jet control method as described in any one of claims 1 to 6.

10. A control device, characterized in that, include: Memory, used to store applications and the data generated by the running of the applications; A processor for executing the application to implement the ducted vehicle control method as described in any one of claims 1 to 6.

Images