Aircraft self-adaptive thrust steering control method based on attitude measurement
Technical Field
The invention belongs to the technical field of attitude control of aircrafts, and particularly relates to an aircraft self-adaptive thrust steering control method based on attitude measurement.
Background
Aircraft, particularly shaped aircraft, are paid attention to because of their unique aerodynamic profile, control is also more difficult than conventional aircraft, and particularly elliptical and disc-shaped aircraft are often controlled by redundant control arrangements, which on the one hand reduce the difficulty of control and on the other hand can remain stable when a single control is unstable.
The control concept of the existing aircraft is based on the consideration of two dimensions from rotation moment stabilization to vertical stress stabilization of a pitching channel, certain complexity exists, the traditional aircraft generally adopts composite control of a thrust steering system and a mass distance dual control system, one control system is responsible for stabilizing balance of force, the other control system is responsible for balancing mutual matching of moment, but under special conditions, such as the condition that the mass distance control system fails, the independent thrust steering control can also support basic stable flight of the aircraft. It is therefore necessary to propose an aircraft adaptive thrust steering control method based on attitude measurements.
Disclosure of Invention
Aiming at the problems existing in the prior art, the self-adaptive thrust steering control method of the aircraft based on attitude measurement is characterized in that the self-adaptive compensation is carried out on the speed pitching dip angle, the pitch angle rate and the uncertainty related to a pitch angle error hinge according to the pitch angle error and the pitch angle rate by measuring the speed pitching dip angle, the pitch angle and the pitch angle rate, and then an equivalent control item is constructed through an aerodynamic coefficient of a model, and the total thrust steering control quantity is formed by combining the pitch angle rate, the pitch angle error integral and the self-adaptive signal, so that the tracking and the regulation of the expected pitch angle of the aircraft are realized, and the control precision and the stability of the aircraft are improved.
The invention provides an aircraft self-adaptive thrust steering control method based on attitude measurement, which comprises the following steps:
S1, measuring pitch angle rate omega z and pitch angle of an aircraft And a speed pitch angle θ;
S2, mounting a thrust steering device at the axial tail part of the flying direction of the aircraft, wherein the thrust pitching swing angle of the thrust steering device is xi, and the expected pitch angle of the aircraft is set as Comparing with the pitch angle omega z of the aircraft to obtain a pitch angle error e, and integrating to obtain a pitch angle error integral s 1 of the aircraft, specifically:
s3, solving an error related item self-adaptive signal;
S4, solving an angular rate related term self-adaptive signal:
s5, solving a total control signal of thrust steering and pitching of the aircraft to realize steering control, wherein the substeps comprise the following steps:
S51, pitching the dip angle theta and the pitch angle according to the speed of the aircraft And aerodynamic parameters of the aircraft, designing a thrust steering equivalent control signal f e of the aircraft:
wherein a 24、az is the aerodynamic parameter of the aircraft and is constant;
The expression of the dynamics control model in the aircraft pitching channel control is as follows:
Δu=K1Δα+K1Δq
Wherein Deltau is a control input signal of the elevator, deltaalpha is pitch angle deviation, deltaq is pitch angle speed deviation, and K 1、K1 is control gain;
After receiving the pitch angle error e and the pitch angle rate omega z, the pitch angle theta and the pitch angle of the speed are adjusted The flight control parameters are compensated, and the aircraft is adapted to the environmental and aerodynamic parameter changes by adjusting the control gain parameters, so that the aircraft control system can dynamically compensate the interference factors in real time;
S52, superposing a pitch angle error e, a pitch angle error integral S 1, a pitch angle rate omega z, an error related item self-adaptive signal f c and an angular rate related item self-adaptive signal f d to form a thrust steering pitch total control signal of the aircraft, and transmitting the thrust steering pitch total control signal to a thrust steering device to control the thrust pitch swing angle of an engine to be equal to the thrust steering pitch total control signal of the aircraft, wherein the method specifically comprises the following steps of:
ξa=-l1ωz-l2e-l3s1+fc+fd-fe;
Wherein, xi a is the total control signal of thrust steering and pitching, l 1、l2、l3 is the control parameter, and both are constants;
And constructing an equivalent control item through the model aerodynamic coefficient, and combining a pitch angle rate, a pitch angle error integral and a self-adaptive signal to form a thrust steering total control signal so as to realize the regulation and control of the aircraft on the expected pitch angle.
Preferably, the step S3 includes the following substeps:
S31, solving an error and speed pitching inclination angle hinge factor self-adaptive growth rate c 1d according to a pitching angle error e and a speed pitching inclination angle theta, and integrating to obtain an error and speed pitching inclination angle hinge self-adaptive signal c 1;
c1(n+1)=c1(n)+c1dT
wherein k 1、k2 is a constant parameter used for adjusting the self-adaptive signal growth rate of the error and the speed, pitch and inclination angle hinge, epsilon 1 is a constant parameter used for softening the angle signal, and T is a constant integral parameter;
S32, according to the pitch angle error e and the pitch angle Solving the self-adaptive increase rate c 2d of the error and pitch angle hinge factor, and integrating to obtain an error and pitch angle hinge self-adaptive signal c 2:
c2(n+1)=c2(n)+c2dT
Wherein, k 3 and k 4 are constant parameters for adjusting the self-adaptive signal growth rate of the error and pitch angle hinge;
S33, solving the adaptive growth rate c 3d of the error and pitch rate hinge factor according to the pitch angle error e and the pitch rate omega z, and integrating to obtain an adaptive signal c 3 of the error and the pitch rate hinge:
c3(n+1)=c3(n)+c3dT
Wherein, k 5 and k 6 are constant parameters, which are used for adjusting the self-adaptive signal growth rate of the error and pitch angle rate hinge, and epsilon 2 is a constant parameter;
S34, according to the pitch angle error e, solving an error factor self-adaptive growth rate c 4d, and integrating to obtain an error factor self-adaptive signal c 4;
c4(n+1)=c4(n)+c4dT
wherein, k 7 and k 8 are constant parameters for adjusting the error factor adaptive signal growth rate;
S35, signal superposition and comprehensive summarization are carried out, and error related item self-adaptive signals f c are obtained:
Preferably, the step S4 includes the following substeps:
s41, solving the self-adaptive growth rate c 5d of the angle rate and the speed pitching inclination angle hinge factor according to the pitch angle rate omega z and the speed pitching inclination angle theta, and integrating to obtain an angle rate and speed pitching inclination angle hinge self-adaptive signal c 5:
c5(n+1)=c5(n)+c5dT
Wherein d 1 and d 2 are constant parameters for adjusting the rate of increase of the self-adaptive signals of the angular rate and the speed pitch tilt angle hinge;
s42, according to the pitch angle rate omega z and the pitch angle Solving the self-adaptive growth rate c 6d of the angle rate and pitch angle hinge factor, and integrating to obtain an angle rate and pitch angle hinge self-adaptive signal c 6:
c6(n+1)=c6(n)+c6dT;
Wherein d 3 and d 4 are constant parameters for adjusting the rate of increase of the self-adaptive signal of the angle rate and pitch angle hinge;
S43, solving an angular rate factor self-adaptive growth rate c 7d according to the pitch angle rate omega z, and integrating to obtain an angular rate factor self-adaptive signal c 7:
c7(n+1)=c7(n)+c7dT
Wherein d 5 and d 6 are constant parameters for adjusting the pitch rate adaptive signal growth rate;
S44, solving the self-adaptive growth rate c 8d of the angle rate and pitch angle error hinge according to the angle rate omega z and the pitch angle error c 1d, and integrating to obtain an angle rate and pitch angle error hinge self-adaptive signal c 8:
c8(n+1)=c8(n)+c8dT
wherein d 7 and d 8 are constant parameters for adjusting the rate of increase of the self-adaptive signal of the angle rate and pitch angle error hinge;
S45, signal superposition and comprehensive summarization are carried out, and an angular rate related item self-adaptive signal f d is obtained:
Preferably, the pitch angle θ and the pitch angle are measured by measuring the speed And the pitch angle rate omega z, then, the speed pitch inclination angle theta, the pitch angle rate omega z and the uncertainty related to a pitch angle error e hinge are respectively subjected to self-adaptive compensation according to the pitch angle error e and the pitch angle rate omega z, self-adaptive signals related to the angle and the angle rate are respectively obtained, then, an equivalent control item is constructed through a model aerodynamic coefficient, and then, the dynamic characteristics of the pitch angle rate omega z are subjected to inversion design, and the pitch angle rate omega z, the pitch angle error e, the pitch angle error integral s 1 and the self-adaptive signals f d are combined to form a thrust steering total control quantity, so that the aircraft tracks and regulates the expected pitch angle.
Preferably, the pitch angle is measured by measuring the pitch angle rate omega z of the aircraftAnd the speed pitching inclination angle theta realize the self-adaptive control of the thrust steering of the aircraft, and specifically comprises the following steps:
the error and speed pitch tilt hinge adaptation signal c 1 is:
c1=∫(k1 e+k2 e)dt
The error and pitch angle hinge adaptive signal c 2 is:
c2=∫(k3 e+k4θ)dt
the angular rate and velocity pitch angle hinge adaptation signal c 5 is:
c5=∫(k5θ+k6θv)dt
The thrust steering pitch total control signal ζ a is:
Xi a=k7e+k8∫edt+k9 e+ adaptive signal
Where k 1、k2、k3、k4、k5 and k 6 are tuning parameters and k 7、k8、k9 is a control gain parameter.
Compared with the prior art, the invention has the following advantages:
1. the invention relates to an aircraft self-adaptive thrust steering control method based on attitude measurement,
1. And carrying out self-adaptive compensation on the disturbance and uncertainty related to various hinges of the speed pitch inclination angle, the pitch angle rate and the pitch angle error according to the pitch angle error signal and the pitch angle rate signal, and respectively obtaining self-adaptive signals related to the angle and the angular rate, thereby enabling the whole control system to be capable of self-adapting to the change of the environment and the aerodynamic parameters.
2. According to the attitude measurement-based aircraft self-adaptive thrust steering control method, the equivalent control item is constructed through the model aerodynamic coefficient, the known structural information of the model is reasonably and effectively utilized, and the unknown part and the interference part can be self-adaptively compensated.
3. According to the attitude measurement-based self-adaptive thrust steering control method for the aircraft, disclosed by the invention, the mode of matching error integration, proportion and pitch angle rate is adopted, the assistance of quality distance control is not needed, and the stable flight of the aircraft can be independently ensured when a quality distance control system fails.
4. According to the attitude measurement-based aircraft self-adaptive thrust steering control method, the problems of dynamic compensation and stabilization of stress stabilization in the vertical direction of pitching and the pitching inclination angle of speed do not need to be considered, so that the analysis and control logic and the process of the whole system are simple and effective.
Drawings
FIG. 1 is a flow chart of an aircraft adaptive thrust steering control method based on attitude measurements of the present invention;
FIG. 2 is a schematic diagram of a thrust steering apparatus according to the thrust steering control method of the present invention;
FIG. 3 is a graph of an aircraft pitch rate signal for an embodiment of a thrust steering control method of the present invention;
FIG. 4 is a graph of aircraft pitch angle for an embodiment of a thrust steering control method of the present invention;
FIG. 5 is a graph of aircraft speed pitch angle for an embodiment of a thrust steering control method of the present invention;
FIG. 6 is a graph of an aircraft pitch angle error signal for an embodiment of a thrust steering control method of the present invention;
FIG. 7 is a graph of integrated signal of pitch angle error of an aircraft for an embodiment of a thrust steering control method of the present invention;
FIG. 8 is a graph of an aircraft thrust vectoring total control signal for an embodiment of a thrust vectoring control method of the present invention.
Detailed Description
The present invention is described in detail with reference to the drawings, wherein the invention is described in detail.
The invention relates to an aircraft self-adaptive thrust steering control method based on attitude measurement, which is shown in fig. 1 and comprises the following steps:
S1, measuring pitch angle rate omega z and pitch angle of an aircraft The change curve of the speed pitching angle theta is shown in fig. 3-5.
As shown in fig. 4, the pitch angle of the aircraftRise to the desired value of 10 deg. around 1 s.
As shown in fig. 5, the pitch angle error e converges to 0 at around 1 s;
S2, mounting a thrust steering device at the axial tail part of the flying direction of the aircraft, wherein as shown in FIG. 2, the embodiment takes a circular aircraft as an example, the method provided by the invention does not require that the shape of the aircraft is limited to a circular shape, a dish shape or an oval shape, the thrust pitching swing angle is xi, and the expected pitch angle of the aircraft is set as xi according to the flying task In this embodiment, the expected pitch angle signal of the aircraft is 10 °, and compared with the pitch angle ω z of the aircraft, a pitch angle error e is obtained, the pitch angle error e curve is shown in fig. 6, and the pitch angle error integral s 1 is obtained by integration, specifically:
S3, solving an error related term self-adaptive signal, which comprises the following substeps:
S31, solving an error and speed pitching inclination angle hinge factor self-adaptive growth rate c 1d according to a pitching angle error e and a speed pitching inclination angle theta, and integrating to obtain an error and speed pitching inclination angle hinge self-adaptive signal c 1;
c1(n+1)=c1(n)+c1dT
Wherein k 1、k2 is a constant parameter for adjusting the error and the rate of growth of the self-adaptive signal of the speed-pitching inclination angle hinge, k 1=0.1,k2=0.15,ε1 is a constant parameter for softening the angle signal, and T is a constant integral parameter;
S32, according to the pitch angle error e and the pitch angle Solving the self-adaptive increase rate c 2d of the error and pitch angle hinge factor, and integrating to obtain an error and pitch angle hinge self-adaptive signal c 2:
c2(n+1)=c2(n)+c2dT
Wherein k 3 and k 4 are constant parameters for adjusting the error and pitch angle hinge adaptive signal growth rate, k 3=0.18,k4 =0.25 in the present embodiment;
S33, solving the adaptive growth rate c 3d of the error and pitch rate hinge factor according to the pitch angle error e and the pitch rate omega z, and integrating to obtain an adaptive signal c 3 of the error and the pitch rate hinge:
c3(n+1)=c3(n)+c3dT
Wherein k 5 and k 6 are constant parameters for adjusting the rate of increase of the adaptive signal of the error and pitch rate hinge, and k 5=0.35,k6=0.05,ε2 is a constant parameter in the embodiment;
S34, according to the pitch angle error e, solving an error factor self-adaptive growth rate c 4d, and integrating to obtain an error factor self-adaptive signal c 4;
c4(n+1)=c4(n)+c4dT
where k 7 and k 8 are constant parameters for adjusting the rate of increase of the error factor adaptive signal, k 7=0.03,k8 =0.08 in this embodiment.
S35, signal superposition and comprehensive summarization are carried out, and error related item self-adaptive signals f c are obtained:
s4, solving an angular rate related term self-adaptive signal, which comprises the following substeps:
s41, solving the self-adaptive growth rate c 5d of the angle rate and the speed pitching inclination angle hinge factor according to the pitch angle rate omega z and the speed pitching inclination angle theta, and integrating to obtain an angle rate and speed pitching inclination angle hinge self-adaptive signal c 5:
c5(n+1)=c5(n)+c5dT
Wherein d 1 and d 2 are constant parameters for adjusting the rate of increase of the adaptive signal of the angular rate and the rate of pitch angle hinge, and d 1=0.25,d2 =0.13 in the present embodiment.
S42, according to the pitch angle rate omega z and the pitch angleSolving the self-adaptive growth rate c 6d of the angle rate and pitch angle hinge factor, and integrating to obtain an angle rate and pitch angle hinge self-adaptive signal c 6:
c6(n+1)=c6(n)+c6dT;
Wherein d 3 and d 4 are constant parameters for adjusting the rate of increase of the adaptive signal of the angular rate and the pitch angle hinge, and d 3=0.6,d4 =0.04 is selected in this embodiment.
S43, solving an angular rate factor self-adaptive growth rate c 7d according to the pitch angle rate omega z, and integrating to obtain an angular rate factor self-adaptive signal c 7:
c7(n+1)=c7(n)+c7dT
Where d 5 and d 6 are constant parameters for adjusting the pitch rate adaptive signal growth rate, d 5=0.33,d6 =0.02 in this embodiment.
S44, solving the self-adaptive growth rate c 8d of the angle rate and pitch angle error hinge according to the angle rate omega z and the pitch angle error c 1d, and integrating to obtain an angle rate and pitch angle error hinge self-adaptive signal c 8:
c8(n+1)=c8(n)+c8dT
Where d 7 and d 8 are constant parameters for adjusting the rate of increase of the adaptive signal of the angular rate and pitch angle error hinge, d 7=0.05,d8 =0.1 in this embodiment.
S45, signal superposition and comprehensive summarization are carried out, and an angular rate related item self-adaptive signal f d is obtained:
s5, solving a total control signal of thrust steering and pitching of the aircraft to realize steering control, wherein the substeps comprise the following steps:
S51, pitching the dip angle theta and the pitch angle according to the speed of the aircraft And aerodynamic parameters of the aircraft, designing a thrust steering equivalent control signal f e of the aircraft:
Where a 24、az is the aerodynamic parameter of the aircraft, and in this embodiment, a 24=829,az = -12.89 is obtained according to the wind tunnel test result of its external dimension.
The expression of the dynamics control model in the aircraft pitching channel control is as follows:
Δu=K1Δα+K1Δq
Where Δu is the elevator control input signal, Δα is the pitch angle deviation, Δq is the pitch angle rate deviation, and K 1、K1 is the control gain.
After receiving the pitch angle error e and the pitch angle rate omega z in the step S5, the pitch angle theta and the pitch angle of the speed are adjustedThe flight control parameters are compensated, and the aircraft is adapted to the environmental and aerodynamic parameter changes by adjusting the gain parameters, so that the aircraft control system can dynamically compensate the interference factors in real time.
S52, superposing a pitch angle error e, a pitch angle error integral S 1, a pitch angle rate omega z, an error related item self-adaptive signal f c and an angular rate related item self-adaptive signal f d to form a thrust steering pitch total control signal of the aircraft, and transmitting the thrust steering pitch total control signal to a thrust steering device to control the thrust pitch swing angle of an engine to be equal to the thrust steering pitch total control signal of the aircraft, wherein the method specifically comprises the following steps of:
ξa=-l1ωz-l2e-l3s1+fc+fd-fe;
Where ζ a is the total thrust steering pitch control signal, l 1、l2、l3 is the control parameter, which are both constants, and in this embodiment l 1=0.5,l1=1.5,l3 =0.1.
And obtaining a total control signal of thrust steering and pitching, realizing the tracking of the expected pitch angle by the aircraft, and completing the pitch channel control task.
By measuring pitch angle rate omega z, pitch angle of aircraftAnd the speed pitching inclination angle theta realize the self-adaptive control of the thrust steering of the aircraft, and specifically comprises the following steps:
the error and speed pitch tilt hinge adaptation signal c 1 is:
c1=∫(k1 e+k2 e)dt
The error and pitch angle hinge adaptive signal c 2 is:
c2=∫(k3e+k4θ)dt
the angular rate and velocity pitch angle hinge adaptation signal c 5 is:
c5=∫(k5θ+k6θv)dt
The thrust steering pitch total control signal ζ a is:
Xi a=k7e+k8∫edt+k9 e+ adaptive signal
Where k 1、k2、k3、k4、k5 and k 6 are tuning parameters and k 7、k8、k9 is a control gain parameter.
First, by measuring the speed pitch angle θ, pitch angleAnd the pitch angle rate omega z, then pitch the tilt angle theta and the pitch angle according to the pitch angle error e and the pitch angle rate omega z The method comprises the steps of adaptively compensating uncertainty related to a pitch angle rate omega z and a pitch angle error e hinge, respectively obtaining adaptive signals related to the angle and the angle rate, constructing an equivalent control item through an aerodynamic coefficient of a model, adopting inversion design through dynamic characteristics of the pitch angle rate omega z, combining the pitch angle rate omega z, the pitch angle error e, a pitch angle error integral s 1 and an adaptive signal f d to form a thrust steering total control quantity, tracking the expected pitch angle of the aircraft, and completing a pitch channel control task.
As shown in fig. 8, the total control signal of thrust steering pitch is smoothly stabilized at 0, the maximum value of the whole process is not more than 4, no obvious flutter and shake are generated, the control signal can meet engineering requirements, and the whole system response has very good stability and rapidity.
The invention discloses an aircraft self-adaptive thrust steering control method based on attitude measurement, which can adaptively compensate the pitching angle, the angular rate and the pitching angle error of a speed according to a pitching angle error signal and a pitching angle rate signal, construct an equivalent control item through a model aerodynamic coefficient, and combine the pitching angle rate, the pitching angle error, a pitching angle error integral and a self-adaptive signal to form a thrust steering total control signal so as to realize the regulation and control of an aircraft on an expected pitching angle.
In addition, according to the specific characteristics and flight task requirements of the aircraft, the self-adaptive control is optimized by adjusting the flight control parameters so as to adapt to different flight requirements of each stage, and error information can be accumulated by the control signals, so that the control strategy is gradually adjusted in the long-term flight process so as to adapt to the change trend of the attitude of the aircraft, and the integral term can continuously act when facing external interference, so that the aircraft is restored to the expected flight state.
The above examples are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the scope of protection defined by the claims of the present invention without departing from the spirit of the present invention.