Aircraft control parameter design method and device, equipment and storage medium

Abstract

The invention provides an aircraft control parameter design method, device and equipment and a storage medium, and belongs to the field of unmanned aircraft control system.The method comprises the steps that kinematics and dynamics equations are established; establishing a transfer function of the unmanned aerial vehicle; determining a subsystem transfer function; constructing a control system of control parameters of the unmanned aerial vehicle; the retrograde control parameters are adjusted, and the stability of the adjusted control system is determined; and adjusting the control system according to a judgment result of the stability of the control system, and further determining control parameters of the unmanned aerial vehicle according to the adjusted control system. Therefore, the unmanned aerial vehicle can be accurately controlled, the maneuverability of the unmanned aerial vehicle is improved under the condition that the system performance of the unmanned aerial vehicle is fully played, the control parameters are adjusted in multiple directions, the stability of the control system is ensured, and the maneuverability of the unmanned aerial vehicle can be further improved.

Description

Technical Field

[0001] The present invention belongs to the field of unmanned aerial vehicle control system design, and in particular relates to a design method, device, equipment and storage medium for aircraft control parameters. Background Art

[0002] Taking into account the complexity of design, most UAVs are currently designed with axisymmetric structures. For UAVs with special mission objectives, their maneuverability is one of the important parameters to test their performance indicators. However, in the existing UAV design process, considering the complexity of control system design, a statically stable aerodynamic layout design is adopted at the beginning of the UAV design. This ensures the simplicity and reliability of the control system design to a certain extent, but greatly increases the difficulty of the structural design of the UAV, and at the same time results in the UAV's weak maneuverability and a limited range of mission objectives that can be accomplished. Therefore, in recent years, there has been more and more design research on statically unstable aircraft control systems.

[0003] In recent years, the design of control parameters for statically unstable unmanned aerial vehicles mainly includes the following categories:

[0004] One is to fully consider the complexity of static instability control system design, and select parameter feature points by designing the flight trajectory, so that the UAV can better avoid static instability flight conditions during flight, thereby realizing control system design. This type of design method avoids the difficulty of aircraft structure design to a certain extent, but does not fully reflect the advantages of aircraft maneuverability under this structure, limiting the scope of application of the aircraft;

[0005] The other type is based on the traditional PID design method, but this type of control system design still belongs to the traditional single-input single-output control system design method. It has obvious advantages in the design of statically stable aircraft control systems, but it is difficult to adapt to the design of statically unstable control systems, and it has high requirements on the performance indicators of the actuators of unmanned aerial vehicles, which greatly increases the design cost of the product.

[0006] Therefore, the control parameters designed according to the existing design method of control parameters of unmanned aerial vehicles still cannot meet the requirements for the maneuverability of unmanned aerial vehicles. Summary of the invention

[0007] In order to solve the problem that the control parameters of an unmanned aerial vehicle cannot meet the maneuverability requirements, the present invention provides a design method, device, equipment and storage medium for the control parameters of an aircraft.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] First, a method for designing aircraft control parameters is provided, the method comprising:

[0010] Establish kinematic and dynamic equations based on the power parameters, aerodynamic parameters and structural parameters of the UAV;

[0011] Establishing a dynamic transfer function of the unmanned aerial vehicle based on kinematic and dynamic equations; determining a subsystem transfer function based on the performance of each subsystem of the unmanned aerial vehicle, wherein the subsystem of the unmanned aerial vehicle includes a navigation system and an actuator;

[0012] Solving the dynamic transfer function to determine a control path transfer function of the unmanned aerial vehicle;

[0013] A control system for control parameters of the unmanned aerial vehicle is constructed through subsystem transfer functions and control path transfer functions, and retrograde control parameters corresponding to the navigation system, the actuator and the control path are respectively set to adjust the stability of the control system;

[0014] When the stability of the control system meets the preset judgment conditions, the control parameters of the unmanned aerial vehicle are determined according to the adjusted control system.

[0015] Optionally, establishing kinematic and dynamic equations according to power parameters, aerodynamic parameters and structural parameters of the unmanned aerial vehicle includes:

[0016] Establish ground coordinate system and missile body coordinate system;

[0017] Based on the ground coordinate system, determining the global position of the unmanned aerial vehicle according to the power parameters of the unmanned aerial vehicle;

[0018] Based on the body coordinate system, determining the posture and motion state of the unmanned aerial vehicle itself according to the power parameters, aerodynamic parameters and structural parameters of the unmanned aerial vehicle;

[0019] The kinematic and dynamic equations of the unmanned aerial vehicle are determined according to the global position of the unmanned aerial vehicle and the posture and motion state of the unmanned aerial vehicle itself.

[0020] Optionally, the preset judgment condition includes a preset stability condition and a preset overshoot condition; and adjusting the stability of the control system by using a plurality of retrograde control parameters includes:

[0021] Initializing the retrograde control parameters;

[0022] Determining an open-loop transfer function and a closed-loop transfer function of the control system based on the retrograde control parameter;

[0023] Determining the open-loop stability of the control system according to a preset stability condition, and determining the closed-loop stability of the control system according to a preset overshoot condition;

[0024] When the open-loop stability does not meet the preset stability condition, or the closed-loop stability does not meet the preset overshoot condition, the reverse control parameter is adjusted until the control system meets the preset judgment condition.

[0025] Optionally, the open-loop transfer function G3(s) is:

[0026]

[0027] Among them, K ω , K θ and K P is the retrograde control parameter, G1(s) and G2(s) are the navigation system transfer function and the actuator transfer function respectively, n y (s) is the control quantity, is the pitch angular velocity, δ z (s) is the pitch channel rudder command, s is the reference area;

[0028] The closed-loop transfer function is:

[0029]

[0030] Optionally, when the open-loop stability does not meet a preset stability condition, adjusting the retrograde control parameter includes:

[0031] reducing the value of the first retrograde control parameter, and updating the second retrograde control parameter and the third retrograde control parameter based on the adjusted first retrograde control parameter and the control system;

[0032] Determining an amplitude margin and a phase margin of the open-loop transfer function, and determining an open-loop stability of the control system according to the amplitude margin, the phase margin, and preset stability judgment conditions for the amplitude margin and the phase margin;

[0033] The reverse control parameter is adjusted cyclically until the open-loop transfer function satisfies the open-loop stability.

[0034] Optionally, when the closed-loop stability does not satisfy a preset overshoot condition, adjusting the retrograde control parameter includes:

[0035] Increasing the value of the first retrograde control parameter, and updating the second retrograde control parameter and the third retrograde control parameter based on the adjusted first retrograde control parameter and the control system;

[0036] Determining an overshoot of the closed-loop transfer function, and determining the closed-loop stability of the control system according to the overshoot and a preset overshoot condition;

[0037] The reverse control parameter is adjusted cyclically until the closed-loop transfer function satisfies the closed-loop stability.

[0038] Secondly, a design device for aircraft control parameters is provided, the device comprising:

[0039] Establishing a module, for establishing kinematic and dynamic equations according to power parameters, aerodynamic parameters and structural parameters of the unmanned aerial vehicle; establishing a dynamic transfer function of the unmanned aerial vehicle according to the kinematic and dynamic equations; determining a subsystem transfer function according to the performance of each subsystem of the unmanned aerial vehicle, wherein the subsystem of the unmanned aerial vehicle includes a navigation system and an actuator; solving the dynamic transfer function to determine a control path transfer function of the unmanned aerial vehicle;

[0040] An adjustment module, used to construct a control system for control parameters of the unmanned aerial vehicle through a subsystem transfer function and a control path transfer function, and respectively set retrograde control parameters corresponding to the navigation system, the actuator and the control path to adjust the stability of the control system;

[0041] The determination module is used to determine the control parameters of the unmanned aerial vehicle according to the adjusted control system when the stability of the control system meets the preset judgment conditions.

[0042] In addition, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned method for designing aircraft control parameters is implemented.

[0043] Finally, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for designing aircraft control parameters when executing the program.

[0044] The design method of aircraft control parameters provided by the present invention has the following beneficial effects:

[0045] The transfer function is constructed through the kinematic and dynamic equations of the unmanned aerial vehicle, and the subsystem transfer function is determined according to the performance of each subsystem. Then, the control system is constructed through the transfer function and the subsystem transfer function. The kinematic and dynamic information of the unmanned aerial vehicle and the performance of each subsystem are fully considered, and the current state of the unmanned aerial vehicle can be accurately grasped, which is beneficial to the maneuverability of the unmanned aerial vehicle. The control system of the unmanned aerial vehicle is constructed based on the current state of the unmanned aerial vehicle and the system performance. It can accurately control the unmanned aerial vehicle, give full play to the system performance of the unmanned aerial vehicle while ensuring the stability of the current state of the control system, make multi-directional adjustments to the control parameters, and improve the maneuverability of the unmanned aerial vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiment of the present invention and its design scheme, the following briefly introduces the drawings required for this embodiment. The drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0047] Figure 1 The present invention is a flowchart of a method for designing aircraft control parameters according to an exemplary embodiment of the present invention.

[0048] Figure 2 The present invention is a schematic diagram of a control system according to an exemplary embodiment.

[0049] Figure 3 The present invention is a schematic flow chart of a method for designing aircraft control parameters according to another exemplary embodiment of the present invention.

[0050] Figure 4 A block diagram of a device for designing aircraft control parameters according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the technical solution of the present invention and implement it, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the scope of protection of the present invention.

[0052] The present invention proposes a control parameter design method for statically unstable unmanned aerial vehicles. The method adopts an adaptive optimization design method based on modern control principles to design control system parameters under different actuator deflection angles. Under the premise of ensuring the stability of the control system, the optimal rapidity of the control system response is designed. A smooth transition method is adopted according to the control parameters under different rudder deflection conditions to minimize the impact of system nonlinearity. Therefore, without changing the original aircraft structure and shape, the demand for actuator performance indicators is greatly reduced, and the stability and rapidity of the control system are improved.

[0053] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0054] First, the present invention provides a method for designing aircraft control parameters, specifically, Figure 1 As shown, the following steps are included:

[0055] S101. Establish kinematic and dynamic equations according to power parameters, aerodynamic parameters and structural parameters of the unmanned aerial vehicle.

[0056] Specifically, firstly, a ground coordinate system and a projectile coordinate system are established; secondly, based on the ground coordinate system, the global position of the unmanned aerial vehicle is determined according to the power parameters of the unmanned aerial vehicle; and based on the projectile coordinate system, the posture and motion state of the unmanned aerial vehicle itself are determined according to the power parameters, aerodynamic parameters and structural parameters of the unmanned aerial vehicle; finally, the kinematic and dynamic equations of the unmanned aerial vehicle are determined according to the global position of the unmanned aerial vehicle and the posture and motion state of the unmanned aerial vehicle itself.

[0057] For example, the ground coordinate system O d -xyz: origin of coordinate system O d is the projection of the center of mass of the missile on the earth’s surface at the time of launch, O d The x-axis is in the horizontal plane and points to the target direction. d The y-axis is perpendicular to the horizontal plane and points upward. d z and xO d y forms a right-handed rectangular coordinate system.

[0058] Projectile body coordinate system O-xyz: The coordinate origin O is taken at the center of mass of the missile, the axis Ox1 points to the head of the missile along the missile axis, Oy1 is located in the longitudinal symmetry plane of the missile, perpendicular to Ox1 and pointing upward is positive, Oz1 and x1Oy1 form a right-handed rectangular coordinate system.

[0059] The conversion angles between the ground coordinate system and the missile body coordinate system are: pitch angle θ, yaw angle ψ and roll angle γ.

[0060] Perform force analysis based on the overall parameters of the UAV:

[0061] The total aerodynamic force is decomposed into the axial force F along the elastic system. x1 , normal force F y1 , and the lateral force F z1 :

[0062]

[0063] Where: Q is the dynamic pressure of the UAV, S is the reference area, C is the A , C N , C Z are the aerodynamic axial force coefficient, normal force coefficient and lateral force coefficient respectively; α, β are the angle of attack and sideslip angle, Ma is the Mach number, δ x ,δ y ,δ Z They are roll rudder deflection angle, yaw rudder deflection angle and pitch rudder deflection angle respectively.

[0064] The component of gravity in the missile body coordinate system is G x1 , G y1 , G z1 for:

[0065]

[0066] Where: m is the mass of the aircraft, g is the acceleration due to gravity.

[0067] The engine thrust is P.

[0068] The kinematic equation of the center of mass is established as follows:

[0069] The velocity component of the missile in the missile body coordinate system is calculated as follows:

[0070]

[0071] Where: V x1 、V y1 、V z1 are the velocity components of each axis in the projectile system;

[0072] Calculation of ballistic inclination and ballistic deviation:

[0073]

[0074] Among them, V x 、V y 、V z are the velocity components of each axis in the ground coordinate system.

[0075] During the flight of the UAV, in order to achieve the mission purpose, the flight speed V needs to be changed. y1 、V z1 The change in its velocity value depends largely on the aerodynamic force F y1 、F z1 Considering that Ma changes little, its aerodynamic force comes from α and δ z or β, δ y , so the rotational dynamics equation of the unmanned aerial vehicle needs to be established as follows:

[0076]

[0077] Where: m x 、m y 、m z are the aerodynamic rolling moment coefficient, yaw moment coefficient and pitch moment coefficient; ω x ,ω y ,ω z is the three-axis angular velocity output; J x , J y , J z is the three-axis moment of inertia of the UAV, and L is the length of the UAV.

[0078] The dynamics calculation equation of the unmanned aerial vehicle is as follows:

[0079]

[0080] After completing the kinematic and dynamic modeling of the UAV, a simulation verification model is built according to the mission target characteristics. At this time, the control system is simplified to a first-order transfer function, and the trajectory simulation of the UAV is performed to determine the control system indicators, as shown in the following formula:

[0081]

[0082] Among them, F yc 、F zc is the control force command, F yc 、F zc is the first-order time constant in response to the control force command.

[0083] S102, establishing a dynamic transfer function of the unmanned aerial vehicle according to kinematic and dynamic equations; determining a subsystem transfer function according to the performance of each subsystem of the unmanned aerial vehicle; solving the dynamic transfer function to determine a control path transfer function of the unmanned aerial vehicle.

[0084] Among them, the subsystems of the unmanned aerial vehicle include a navigation system and an actuator.

[0085] Specifically, in order to construct the dynamic transfer function, the kinematic and dynamic equations are first linearized to establish a state space model. This is usually done by performing a small perturbation analysis near a certain equilibrium point of the UAV to obtain approximate linear system parameters. Secondly, based on the state space model, the dynamic transfer function of the UAV can be established.

[0086] Considering the axisymmetric properties of the UAV, the dynamic transfer function can be designed only for the longitudinal channel in the control path of the UAV. The control system is designed based on the above kinematic and dynamic equations. The nonlinear system is solved by "small disturbance linearization" and "parameter solidification" to solve the longitudinal motion transfer function of the UAV. The solution method of the longitudinal motion transfer function is as follows:

[0087] Calculation method of longitudinal motion control system equations:

[0088]

[0089] in:

[0090] is the aerodynamic moment coefficient m z Yes z The reciprocal of .

[0091] is the aerodynamic moment coefficient m z The reciprocal of α.

[0092] is the aerodynamic moment coefficient m z δ z The reciprocal of .

[0093] is the reciprocal of the aerodynamic coefficient with respect to α.

[0094] is the aerodynamic coefficient of δ z The reciprocal of .

[0095] The transfer function calculation method of the longitudinal channel of the unmanned aerial vehicle is:

[0096]

[0097] Confirm the transfer function of each component performance and build the control system block diagram. The transfer function of each subsystem is as follows:

[0098] Navigation system transfer function:

[0099] Where: T Navi is the equivalent second-order time constant of the navigation system.

[0100] Actuator transfer function:

[0101] Where: T Act is the equivalent second-order time constant of the actuator system.

[0102] S103, constructing a control system for control parameters of the unmanned aerial vehicle through subsystem transfer functions and control path transfer functions, and respectively setting retrograde control parameters corresponding to the navigation system, actuators and control paths to adjust the stability of the control system.

[0103] The control system represents the change process of the control parameters of the unmanned aerial vehicle.

[0104] Specifically, according to the influence of the control path transfer function, the subsystem transfer function and the corresponding three retrograde control parameters on the control parameters of the unmanned aerial vehicle, a control system is constructed. The control system is specifically as follows: Figure 2 shown.

[0105] After the control system is constructed, the stability of the control system also needs to be adjusted.

[0106] Specifically, the control system is firstly judged for stability, and then adjusted based on the judgment result. The judgment on the stability of the control system is based on the stability of its open-loop transfer function and closed-loop transfer function, so the preset judgment condition includes a preset stability condition corresponding to the open-loop transfer function and a preset overshoot condition corresponding to the closed-loop transfer function. The specific steps are as follows: initialize the retrograde control parameter; determine the open-loop transfer function and closed-loop transfer function of the control system based on the retrograde control parameter; determine the open-loop stability of the control system according to the preset stability condition, and determine the closed-loop stability of the control system according to the preset overshoot condition; when the open-loop stability does not meet the preset stability condition, or the closed-loop stability does not meet the preset overshoot condition, adjust the retrograde control parameter until the control system meets the preset judgment condition.

[0107] In this step, the control parameters are initialized. According to the characteristics of statically unstable unmanned aerial vehicles, the transfer function It is an unstable system, so the single parameter K ω The inner loop formed is an unstable system, and K ω , K θ For the overall design, consider K P When choosing the appropriate situation, it will not affect the stability of the control system design. The parameters are designed as follows when initializing:

[0108]

[0109] where ω c is the design parameter.

[0110] In one embodiment, the value of a first retrograde control parameter is reduced, and a second retrograde control parameter and a third retrograde control parameter are updated based on the adjusted first retrograde control parameter and the control system; after the retrograde control parameter is updated, an open-loop transfer equation of the control system is determined; an amplitude margin and a phase margin of the open-loop transfer equation are determined, and the open-loop stability of the control system is determined based on the amplitude margin, the phase margin, and preset stability judgment conditions for the amplitude margin and the phase margin; and the retrograde control parameter is cyclically adjusted until the open-loop transfer function satisfies the open-loop stability.

[0111] For example, considering that the actuator is the last step and the most relevant part of the dynamics and kinematics model, the stability of its output command determines the stability of the system's control system. Therefore, it is necessary to solve the open-loop control margin at the actuator disconnection point under the updated control parameters. The solution method is as follows:

[0112] The open-loop transfer equation at the actuator disconnection point is:

[0113]

[0114] The margin function in MATLAB software programming is used to solve the amplitude margin and phase margin of the G3(s) transfer function. The solution is as follows:

[0115] [Gm1,Pm,~,~]=margin(G3(s))

[0116] Gm=20*log10(Gm1).

[0117] Where: Pm is the phase margin of the open-loop control system, and Gm is the amplitude margin of the open-loop control system.

[0118] The stability of the open-loop control system at the disconnection of the actuator is compared, and the stability threshold range judgment conditions are set as follows: the amplitude margin of the open-loop control system is less than 8dB; the phase margin is less than 55°.

[0119] If the stability calculation results meet the above conditions at the same time, the control parameter K is completed. ω , K θ Otherwise, update the design parameter ω c =ω c After +0.1, re-perform K ω , K θ Design and repeat the above steps.

[0120] In another embodiment, the value of the first retrograde control parameter is increased, and the second retrograde control parameter and the third retrograde control parameter are updated based on the adjusted first retrograde control parameter and the control system; after the retrograde control parameter is updated, the closed-loop control system transfer function is determined; the overshoot of the time domain performance indicator of the closed-loop control system transfer function is determined, and the closed-loop stability of the control system is determined based on the overshoot and a preset overshoot condition; and the retrograde control parameter is cyclically adjusted until the closed-loop transfer function satisfies the closed-loop stability.

[0121] Control parameter K P When designing a closed-loop control system, it is necessary to perform time domain performance analysis of the closed-loop control system. The analysis method is as follows:

[0122] Calculate the transfer function of the closed-loop control system:

[0123]

[0124] Use the step function in matlab software programming to calculate the transfer function G of the closed-loop control system n (s) The overshoot of the time domain performance index is calculated as follows:

[0125]

[0126] in is the overshoot of the closed-loop control system, y BC is the output value under the step signal.

[0127] In this step, the closed-loop control system is set to meet the overshoot threshold of 8%. If the overshoot calculation result is not greater than 8%, the optimal parameter design of the control system is completed. Otherwise, the closed-loop stability judgment in the above steps is repeated until the overshoot threshold setting requirements are met.

[0128] S104: When the stability of the control system meets the preset judgment conditions, determine the control parameters of the unmanned aerial vehicle according to the adjusted control system.

[0129] In this step, if the stability calculation results meet the preset judgment conditions at the same time, the control parameter K is completed. ω , The optimization process is then used to determine the control parameters of the unmanned aerial vehicle based on the control system constructed according to the optimized retrograde control parameters; otherwise, the design parameters ω are updated. c =ω c After +0.1, re-perform K ω , K θ Design and repeat the open-loop stability judgment process in the above step S103.

[0130] By adopting the above method, a transfer function is constructed through the kinematic and dynamic equations of the unmanned aerial vehicle, and the subsystem transfer function is determined according to the performance of each subsystem, and then a control system is constructed through the transfer function and the subsystem transfer function. The kinematic and dynamic information of the unmanned aerial vehicle and the performance of each subsystem are fully considered, and the current state of the unmanned aerial vehicle can be accurately grasped, which is beneficial to the maneuverability of the unmanned aerial vehicle. Based on the current state of the unmanned aerial vehicle and the system performance, the control system of the unmanned aerial vehicle can be constructed, and the unmanned aerial vehicle can be accurately controlled. While ensuring the stability of the current state of the control system, the system performance of the unmanned aerial vehicle can be fully utilized, and the control parameters can be adjusted in all directions to improve the maneuverability of the unmanned aerial vehicle.

[0131] Based on the above steps, the present invention also provides an embodiment, specifically as follows Figure 3 shown.

[0132] Step S1: Determine the basic coordinate system for control system design and its transformation relationship, as shown below:

[0133] Ground coordinate system O d -xyz: origin of coordinate system O d is the projection of the center of mass of the missile on the earth’s surface at the time of launch, O d The x-axis is in the horizontal plane and points to the target direction. dThe y-axis is perpendicular to the horizontal plane and points upward. d z and xO d y forms a right-handed rectangular coordinate system.

[0134] Projectile body coordinate system O-xyz: The coordinate origin O is taken at the center of mass of the missile, the axis Ox1 points to the head of the missile along the missile axis, Oy1 is located in the longitudinal symmetry plane of the missile, perpendicular to Ox1 and pointing upward is positive, Oz1 and x1Oy1 form a right-handed rectangular coordinate system.

[0135] The conversion angles between the ground coordinate system and the missile body coordinate system are: pitch angle θ, yaw angle ψ and roll angle γ; secondly, the parameters of the unmanned aerial vehicle required for the design of the control system are determined, as shown in Table 1:

[0136] Table 1 Overall parameters of unmanned aerial vehicle

[0137] Serial number parameter symbol 1 Axial force coefficient <![CDATA[C A ]]> 2 Normal force coefficient <![CDATA[C N ]]> 3 Lateral force coefficient <![CDATA[C Z ]]> 4 Pitch moment coefficient <![CDATA[m z ]]> 5 Yaw moment coefficient <![CDATA[m y ]]> 6 Rolling moment coefficient <![CDATA[m x ]]> 7 Thrust data <![CDATA[P t ]]> 8 UAV moment of inertia JxJ 9 Aerodynamic reference area of ​​unmanned aerial vehicle S 10 Aerodynamic reference length of unmanned aerial vehicle L

[0138] Then the input data parameters of the unmanned aerial vehicle are used to build the dynamic model, as shown in the following formula:

[0139]

[0140] in:

[0141] ω x ,ω y ,ω z It is the three-axis angular velocity output;

[0142] Establish the kinematic equations of the UAV:

[0143]

[0144] Q=0.5*ρ*V 2

[0145] Where: ρ is the atmospheric density.

[0146] At the same time, a simplified first-order transfer function model of the control system is established to control the normal and lateral forces. The simplified equation is as follows

[0147]

[0148] Finally, according to the mission objectives, the trajectory model is established in combination with the above equations to determine the control system design indicators. Generally speaking, the following requirements must be met:

[0149] Control system frequency domain amplitude margin: ≮6dB;

[0150] Control system frequency domain phase margin: ≮50°;

[0151] Control system step response overshoot: ≯5%;

[0152] Control system step response rise time: ≯0.8s.

[0153] Step S2: Calculate and determine the transfer function of the UAV, and build a transfer function model of the UAV. Considering the axisymmetric properties of the UAV, control parameters can be designed only for the longitudinal channel during control system design. The transfer function of the UAV is solved by “small disturbance linearization” and “parameter solidification” for the nonlinear system. For the specific solution process, see the corresponding steps of the previous embodiment.

[0154] In the example of the present invention, the parameter values ​​in the transfer function are shown in Table 2.

[0155] Table 2 Coefficient values ​​in the transfer function of unmanned aerial vehicle

[0156] Serial number parameter Parameter Value 1 <![CDATA[a1]]> 2.5 2 <![CDATA[a2]]> -60 3 <![CDATA[a3]]> 50 4 <![CDATA[a4]]> 0.4 5 <![CDATA[a5]]> 0.02

[0157] Step S3: According to the performance of each subsystem on the unmanned aerial vehicle, the transfer function of each component performance is confirmed and the control system block diagram is constructed, where the structural design block diagram of the control system is shown in Figure 2, and the performance indicators of each subsystem are shown in Table 3. The transfer functions of each subsystem are as follows:

[0158] Navigation system transfer function:

[0159] Where: T Navi is the equivalent second-order time constant of the navigation system.

[0160] Actuator transfer function:

[0161] Where: T Act is the equivalent second-order time constant of the actuator system.

[0162] Table 3 Coefficients in the transfer function of unmanned aerial vehicles

[0163] Serial number parameter Parameter Value 1 Equivalent second-order time constant of navigation system 0.004s 2 Equivalent second-order time constant of actuator 0.01s

[0164] Step S4: According to Figure 2 The control structure block diagram shown in the figure and the initialization of the reverse control parameters are as follows:

[0165]

[0166] Where: c The initial value is designed to be 5 in the example of the present invention.

[0167] Step S5: According to Figure 2The control structure design block diagram in is used to solve the control system stability at the actuator disconnection point. The solution method is as follows:

[0168] The open-loop transfer equation at the actuator disconnection point is:

[0169]

[0170] The margin function in MATLAB software programming is used to solve the amplitude margin and phase margin of the G3(s) transfer function. The solution is as follows:

[0171] [Gm1,Pm,~,~]=margin(G3(s))

[0172] Gm=20*log10(Gm1).

[0173] Where: Pm is the phase margin of the open-loop control system, Gm is the amplitude margin of the open-loop control system;

[0174] Step S6: judging the control system stability result calculated in step 5, and setting the stability threshold range judgment condition as follows:

[0175] The amplitude margin of the open-loop control system is <8dB; the phase margin of the open-loop control system is <55°.

[0176] If the stability calculation results meet the above conditions at the same time, the control parameter K is completed. ω , K θ Otherwise, update the design parameter ω c =ω c After +0.1, re-perform K ω , K θ Design and repeat steps 5 and 6.

[0177] For example, K can be reduced P Value one order of magnitude, K ω , K θ Updates.

[0178] Step S7: Execute the control parameter K in the present invention example P Design, the time domain performance analysis of the closed-loop control system is required during design. The analysis method is as follows:

[0179] Calculate the transfer function of the closed-loop control system:

[0180]

[0181] Use the step function in matlab software programming to calculate the transfer function G of the closed-loop control system n(s) The overshoot of the time domain performance index is solved in the following way:

[0182] y BC =step(G n )

[0183]

[0184] in is the overshoot of the closed-loop control system.

[0185] Step S8: In step 8 of the present invention, the overshoot threshold of the closed-loop control system is set to 8%. If the overshoot calculation result in step 7 is not greater than 8%, the optimal parameter design of the control system is completed. Otherwise, steps 7 and 8 are repeated until the overshoot threshold setting requirements are met.

[0186] For example, when repeating steps 7 and 8, you can increase K P The value improves the system speed and solves the time domain performance of the control system.

[0187] The control parameters are calculated according to the method of the present invention, and the calculation results of the control parameters are as follows:

[0188]

[0189] According to the control parameter design results, the stability analysis of the unmanned aerial vehicle control system is carried out, and it is found that its frequency domain amplitude margin is 12dB and the phase margin is 59.8°; at the same time, the time domain indicators of the control system are analyzed, and it can be seen that the overshoot of the control system is 2% and the rise time is 0.665s.

[0190] Secondly, the present invention also provides a design device for aircraft control parameters, such as Figure 4 As shown, including:

[0191] Establishing module 401, used to establish kinematic and dynamic equations according to power parameters, aerodynamic parameters and structural parameters of the unmanned aerial vehicle; establish a longitudinal motion transfer function of the unmanned aerial vehicle according to the kinematic and dynamic equations; determine a subsystem transfer function according to the performance of each subsystem of the unmanned aerial vehicle, wherein the subsystem of the unmanned aerial vehicle includes a navigation system and an actuator; solve the longitudinal motion transfer function to determine a control path transfer function of the unmanned aerial vehicle;

[0192] An adjustment module 402 is used to construct a control system for control parameters of the unmanned aerial vehicle through a subsystem transfer function and a control path transfer function, and respectively set retrograde control parameters corresponding to the navigation system, the actuator and the control path to adjust the stability of the control system;

[0193] The determination module 403 is used to determine the control parameters of the unmanned aerial vehicle according to the adjusted control system when the stability of the control system meets the preset judgment conditions.

[0194] By adopting the above-mentioned device, a transfer function is constructed through the kinematic and dynamic equations of the unmanned aerial vehicle, and the subsystem transfer function is determined according to the performance of each subsystem, and then a control system is constructed through the transfer function and the subsystem transfer function, which fully considers the kinematic and dynamic information of the unmanned aerial vehicle and the performance of each subsystem, can accurately grasp the current state of the unmanned aerial vehicle, is conducive to the maneuverability of the unmanned aerial vehicle, and builds a control system for the unmanned aerial vehicle based on the current state of the unmanned aerial vehicle and the system performance, which can accurately control the unmanned aerial vehicle, give full play to the system performance of the unmanned aerial vehicle while ensuring the stability of the current state of the control system, make multi-directional adjustments to the control parameters, and improve the maneuverability of the unmanned aerial vehicle.

[0195] The present invention also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 1 The steps of a method for designing aircraft control parameters are provided.

[0196] The present invention also provides a computer device. At the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 The steps of a method for designing aircraft control parameters are provided.

[0197] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0198] The present invention is described with reference to flowcharts and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as a combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0199] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0200] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0201] It should be noted that the above specific implementation method can enable those skilled in the art to understand the invention more comprehensively, but does not limit the invention in any way. Therefore, although the present invention has been described in detail in this specification, those skilled in the art should understand that the invention can still be modified or replaced by equivalents; and all technical solutions and improvements that do not deviate from the spirit and scope of the invention are included in the protection scope of the patent for the invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

Claims

1. A method for designing aircraft control parameters, characterized in that: The method comprises: Establish kinematic and dynamic equations based on the power parameters, aerodynamic parameters and structural parameters of the UAV; Establishing a dynamic transfer function of the unmanned aerial vehicle based on kinematic and dynamic equations; determining a subsystem transfer function based on the performance of each subsystem of the unmanned aerial vehicle, wherein the subsystem of the unmanned aerial vehicle includes a navigation system and an actuator; Solving the dynamic transfer function to determine a control path transfer function of the unmanned aerial vehicle; A control system for control parameters of the unmanned aerial vehicle is constructed through subsystem transfer functions and control path transfer functions, and retrograde control parameters corresponding to the navigation system, the actuator and the control path are respectively set to adjust the stability of the control system; When the stability of the control system meets the preset judgment conditions, the control parameters of the unmanned aerial vehicle are determined according to the adjusted control system.

2. The method for designing aircraft control parameters according to claim 1, characterized in that: The kinematic and dynamic equations established according to the power parameters, aerodynamic parameters and structural parameters of the unmanned aerial vehicle include: Establish ground coordinate system and missile body coordinate system; Based on the ground coordinate system, determining the global position of the unmanned aerial vehicle according to the power parameters of the unmanned aerial vehicle; Based on the body coordinate system, determining the posture and motion state of the unmanned aerial vehicle itself according to the power parameters, aerodynamic parameters and structural parameters of the unmanned aerial vehicle; The kinematic and dynamic equations of the unmanned aerial vehicle are determined according to the global position of the unmanned aerial vehicle and the posture and motion state of the unmanned aerial vehicle itself.

3. The method for designing aircraft control parameters according to claim 1, characterized in that: The preset judgment conditions include preset stability conditions and preset overshoot conditions; The stability adjustment of the control system by using a plurality of retrograde control parameters includes: Initializing the retrograde control parameters; Determining an open-loop transfer function and a closed-loop transfer function of the control system based on the retrograde control parameter; Determining the open-loop stability of the control system according to a preset stability condition, and determining the closed-loop stability of the control system according to a preset overshoot condition; When the open-loop stability does not meet the preset stability condition, or the closed-loop stability does not meet the preset overshoot condition, the reverse control parameter is adjusted until the control system meets the preset judgment condition.

4. The method for designing aircraft control parameters according to claim 3, characterized in that: The open-loop transfer function G3(s) is: Among them, K ω , K θ and K P is the retrograde control parameter, G1(s) and G2(s) are the navigation system transfer function and the actuator transfer function respectively, n y (s) is the control quantity, is the pitch angular velocity, δ z (s) is the pitch channel rudder command, s is the reference area; The closed-loop transfer function is:

5. A method for designing aircraft control parameters according to claim 4, characterized in that: When the open-loop stability does not meet the preset stability condition, adjusting the reverse control parameter includes: reducing the value of the first retrograde control parameter, and updating the second retrograde control parameter and the third retrograde control parameter based on the adjusted first retrograde control parameter and the control system; Determining an amplitude margin and a phase margin of the open-loop transfer function, and determining an open-loop stability of the control system according to the amplitude margin, the phase margin, and preset stability judgment conditions for the amplitude margin and the phase margin; The reverse control parameter is adjusted cyclically until the open-loop transfer function satisfies the open-loop stability.

6. The method for designing aircraft control parameters according to claim 4, characterized in that: When the closed-loop stability does not meet the preset overshoot condition, adjusting the reverse control parameter includes: Increasing the value of the first retrograde control parameter, and updating the second retrograde control parameter and the third retrograde control parameter based on the adjusted first retrograde control parameter and the control system; Determining an overshoot of the closed-loop transfer function, and determining the closed-loop stability of the control system according to the overshoot and a preset overshoot condition; The reverse control parameter is adjusted cyclically until the closed-loop transfer function satisfies the closed-loop stability.

7. A design device for aircraft control parameters, characterized in that: The device comprises: Establishing a module, for establishing kinematic and dynamic equations according to power parameters, aerodynamic parameters and structural parameters of the unmanned aerial vehicle; establishing a dynamic transfer function of the unmanned aerial vehicle according to the kinematic and dynamic equations; determining a subsystem transfer function according to the performance of each subsystem of the unmanned aerial vehicle, wherein the subsystem of the unmanned aerial vehicle includes a navigation system and an actuator; solving the dynamic transfer function to determine a control path transfer function of the unmanned aerial vehicle; An adjustment module, used to construct a control system for control parameters of the unmanned aerial vehicle through a subsystem transfer function and a control path transfer function, and respectively set retrograde control parameters corresponding to the navigation system, the actuator and the control path to adjust the stability of the control system; The determination module is used to determine the control parameters of the unmanned aerial vehicle according to the adjusted control system when the stability of the control system meets the preset judgment conditions.

8. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

9. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method according to any one of claims 1 to 6 is implemented.

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