CN103345157A - Unmanned aerial vehicle three freedom degree model building method - Google Patents

Abstract

The invention provides an unmanned aerial vehicle three freedom degree model building method. An unmanned aerial vehicle three freedom degree model is composed of an unmanned aerial vehicle data module and an aerial vehicle particle motion dynamics module, the aerial vehicle particle motion dynamics module can be used in the model-building processes of all the unmanned aerial vehicles in a repetitive mode, and therefore the workload of unmanned aerial vehicle three freedom degree model building is reduced. Complex functions such as aerodynamic computation, model resolving and calculating and auxiliary physical-quantity calculation are given to a computer through packaging of unmanned aerial vehicle three freedom degree model software. A user simply needs to set model input, and then can obtain the complete physical quantities of aerial vehicle three freedom degree motion, and the unmanned aerial vehicle three freedom degree model can be used simply and conveniently.

Description

A kind of unmanned vehicle Three Degree Of Freedom model building method

Technical field

The invention belongs to the automatic control technology field, especially relate to a kind of unmanned vehicle Three Degree Of Freedom model building method.

Background technology

Usually, the modeling of aircraft is based on the aircraft rigid motion and sets up the six degree of freedom model, to realize the non-linear emulation to aircraft guidance and control.But, the track of aircraft and guidance design are the particle movements at aircraft, the particle movement Three Degree Of Freedom model of aircraft has been ignored angular motion and the moment loading of aircraft, and suppose that aircraft is not subjected to the effect of side force and yaw angle, so set up the Three Degree Of Freedom particle movement nonlinear mathematical model of unmanned vehicle, not only simplified the research to aircraft movements, track and the guidance technology for the individual authentication aircraft has great significance simultaneously.Conventional aircraft Three Degree Of Freedom mathematical model is set up in the process, at first selects appropriate coordinate system; Secondly from the blowing data, ask for aerodynamic derivative according to the aircraft current state, and further find the solution aircraft on the basis of engine mockup, Atmospheric models and gravity field model and make a concerted effort; Resolve on the basis of equation of particle motion then and upgrade the aircraft quantity of state; Finally utilize new quantity of state to calculate other physical quantity.During at different aircraft modeling, this method has following weak point:

1. owing to the calculating of aircraft aerodynamic database and aerodynamic force is all variant, modeling need repeat said process, the process complexity, and modeling efficiency is low.

2. aircraft equation of particle motion, atmospheric density model, gravity field model etc. are constant, and traditional modeling does not have these parts of modularization, have not only strengthened the workload that repeats modeling, and have used simple and convenient inadequately.

Summary of the invention

Technical matters to be solved by this invention is to overcome the deficiencies in the prior art, has proposed a kind of unmanned vehicle Three Degree Of Freedom model building method.Described method is divided into two modules with unmanned vehicle Three Degree Of Freedom model: unmanned vehicle data module and aircraft particle movement dynamics module, and by reasonable standard and the framework of simplifying each module, use simply, revise unmanned vehicle Three Degree Of Freedom model building method easily thereby form.

For solving the problems of the technologies described above, the technical solution adopted in the present invention is:

A kind of unmanned vehicle Three Degree Of Freedom model building method, comprise unmanned vehicle data module and aircraft particle movement dynamics module, described unmanned vehicle data module comprises unmanned vehicle data, lift function and resistance function, and described aircraft particle movement dynamics module comprises particle movement dynamics state equation, relative wind movement function and acceleration of gravity function; Concrete steps are as follows:

Step 1: obtain the unmanned vehicle data, comprise aircraft geometric area, quality and blowing data;

Step 2: according to the unmanned vehicle data that step 1 obtains, set up aircraft lift function and resistance function;

Step 3: the unmanned vehicle data of step 1 acquisition, lift function and the resistance function that step 2 is set up are made up and encapsulate, obtain the unmanned vehicle data module;

Step 4: set up particle movement dynamics state equation, described equation quantity of state comprises that aircraft velocity inertial, track pitch angle, course angle and aircraft relative inertness are the position;

Step 5: at the influence of wind to aircraft speed, set up the aircraft airspeed function; Further according to ARDC model atmosphere ARDC, set up aircraft relative wind movement function, calculating aircraft relative wind motion physical quantity; Aircraft relative wind motion physical quantity comprises air speed, Mach number and dynamic pressure;

Step 6: according to earth gravity field model, calculate unmanned vehicle acceleration of gravity function;

Step 7: the particle movement state equation of step 4 acquisition, the relative wind movement function that step 5 obtains, the acceleration of gravity function that step 6 obtains are made up and encapsulate, obtain aircraft particle movement dynamics module;

Step 8: to the unmanned vehicle data module of step 3 acquisition, aircraft particle movement dynamics module combinations and the encapsulation that step 7 obtains, obtain unmanned vehicle Three Degree Of Freedom model.

The invention has the beneficial effects as follows: the invention provides a kind of unmanned vehicle Three Degree Of Freedom model building method.Described unmanned vehicle Three Degree Of Freedom model is made up of unmanned vehicle data module and aircraft particle movement dynamics module, but described aircraft particle dynamics module repeated application is in the Three Degree Of Freedom modeling process of all unmanned vehicles, thereby the workload of minimizing unmanned vehicle Three Degree Of Freedom modeling; Further by encapsulation unmanned vehicle Three Degree Of Freedom prototype software, with aerodynamic force calculate, sophisticated functionss such as model resolves, auxiliary Physical Quantity Calculation give computing machine, the user only need arrange the model input, just can obtain complete aircraft three-degree-of-freedom motion physical quantity, and is easy to use.

Description of drawings

Fig. 1 is that the unmanned vehicle data module makes up synoptic diagram.

Fig. 2 is unmanned vehicle data module encapsulation synoptic diagram.

Fig. 3 is aircraft particle movement dynamics module package synoptic diagram.

Fig. 4 is that model adds wind and air speed is calculated synoptic diagram.

Fig. 5 is unmanned vehicle Three Degree Of Freedom model encapsulation synoptic diagram.

Fig. 6 is unmanned vehicle Three Degree Of Freedom model applicating flow chart.

Embodiment

Below in conjunction with accompanying drawing, a kind of unmanned vehicle Three Degree Of Freedom model building method that the present invention is proposed is elaborated:

The unmanned vehicle Three Degree Of Freedom model that present embodiment makes up is made up of unmanned vehicle data module and aircraft particle movement dynamics module, described unmanned vehicle data module comprises unmanned vehicle data, lift function and resistance function, and described aircraft particle movement dynamics module comprises particle movement dynamics state equation, relative wind movement function and acceleration of gravity function.

1, the unmanned vehicle data module makes up

The unmanned vehicle data module makes up as shown in Figure 1, comprises that step is as follows:

Step 1: obtain the unmanned vehicle data, comprise aircraft geometric area, quality and blowing data;

Step 2: according to the unmanned vehicle data that step 1 obtains, set up aircraft lift function and resistance function;

Step 3: as shown in Figure 2, the unmanned vehicle data of step 1 acquisition, lift function and the resistance function that step 2 is set up are made up and encapsulate, obtain the unmanned vehicle data module.

Described unmanned vehicle data module is input as the aircraft angle of attack, aircraft particle movement relative wind physical quantity, and module is output as parameters such as aircraft lift, resistance, quality.

2, aircraft particle movement dynamics module

Aircraft particle movement dynamics module as shown in Figure 2, its construction step comprises:

Step 1: set up particle movement dynamics state equation, described equation quantity of state comprises that aircraft velocity inertial, track pitch angle, course angle and aircraft relative inertness are the position; Set up corresponding numerical value calculation method at the particle movement state equation, present embodiment is chosen Adams4 exponent number value integral algorithm computing differential equation, according to equation quantity of state derivative solving equation quantity of state;

Particle movement dynamics state equation is described below:

$\left\{\begin{array}{c}\stackrel{\·}{V}=\frac{-D}{m}-g\sin \mathrm{\θ}\\ \stackrel{\·}{\mathrm{\θ}}=\frac{L\cos \mathrm{\φ}}{\mathrm{mV}}-\frac{g\cos \mathrm{\θ}}{V}\\ \stackrel{\·}{\mathrm{\ψ}}=-\frac{L\sin \mathrm{\φ}}{\mathrm{mV}\cos \mathrm{\θ}}\end{array}\right.---\left(1\right)$

$\left\{\begin{array}{c}\stackrel{\·}{H}=V\sin \\ {\stackrel{\·}{P}}_N=V\cos \mathrm{\θ}\cos \mathrm{\ψ}\\ {\stackrel{\·}{P}}_E=-V\cos \mathrm{\θ}\sin \mathrm{\ψ}\end{array}\right.---\left(2\right)$

Wherein:

L, D, φ are respectively aircraft aerodynamic lift, resistance and aircraft roll angle;

V, θ, ψ are respectively aircraft velocity inertial, track pitch angle and track crab angle;

M is the unmanned vehicle quality, and g is acceleration of gravity;

H, P _N, P _EBe respectively aircraft height, north orientation distance and the east orientation distance under the huge ground level coordinate system northeastward;

Adams4 exponent number value integral algorithm is described below:

$y_{n+4}=y_{n+3}+\frac{h}{24}(55{\stackrel{\·}{y}}_{n+3}-59{\stackrel{\·}{y}}_{n+2}+37{\stackrel{\·}{y}}_{n+1}-9{\stackrel{\·}{y}}_n)---\left(3\right)$

Truncation error is

Wherein:

H represents simulation step length;

Represent n+3, n+2, n+1, the n derivative of y constantly respectively; y ⁽⁵⁾5 subderivatives of expression y;

y _N+4, y _N+3Represent n+4, the n+3 value of y constantly respectively;

Step 2: at the influence of wind to aircraft speed, set up the aircraft airspeed function as shown in Figure 4; Further according to ARDC model atmosphere ARDC, set up aircraft relative wind movement function, relative wind motion physical quantitys such as calculating aircraft air speed, Mach number, dynamic pressure; Present embodiment is quoted 1962 United States standard atmosphere models, sets up the atmospheric parameter function, and described atmospheric parameter comprises atmospheric density, local velocity of sound, local Static Air Temperature and local atmosphere static pressure;

The air speed function representation is as follows:

$\left\{\begin{array}{c}{V}_{e2\mathrm{wind}}=V_e-V_{\mathrm{wind}\_e}\\ V_{n2\mathrm{wind}}=V_n-V_{\mathrm{wind}\_n}\\ V_{u2\mathrm{wind}}=V_u-V_{\mathrm{wind}\_n}\end{array}\right.---\left(4\right)$

Wherein:

V _e, V _n, V _uBe respectively the aircraft velocity inertial east orientation, north orientation, day to component;

V _{Wind_e}, V _{Wind_n}, V _{Wind_u}Be respectively air-flow east orientation, north orientation, day to speed component;

V _E2wind, V _E2wind, V _U2windBe respectively air speed east orientation, north orientation, day to component;

The atmospheric parameter function representation is as follows:

ρ looks into table of standard atmosphere (5) in 1962

V _SonicLook into table of standard atmosphere (6) in 1962

$\mathrm{\σ}=\frac{\mathrm{\ρ}}{{\mathrm{\ρ}}_{\mathrm{sea}\_\mathrm{level}}}---\left(7\right)$

H _e=3.2808×H (8)

$T_s=0.55556\&times;\left\{\begin{array}{cc}518.7\&times;(1.0-6.875\&times;{10}^{-6}\&times;H);& 0<H_e\&le;36089\\ 518.7\&times;0.751985;& 36089<H_e<240000\end{array}\right.---\left(9\right)$

$P_s=47.88018\&times;\left\{\begin{array}{cc}2113.8\&times;{(1.0-6.875\&times;{10}^{-6}\&times;H)}^{5.256};& 0<H_e\&le;36089\\ 2113.8\&times;0.2234\&times;e^{-4.806\&times;{10}^{-5}\&times;(H-36089)};& 36089<H_e<240000\end{array}\right.---\left(10\right)$

Wherein:

H, H _eBe respectively metric system and the expression made in Great Britain of sea level elevation;

ρ is the atmospheric density at current height place;

V _SonicVelocity of sound for current height place;

σ is the atmospheric density ratio on current height and sea level;

T _sStatic temperature for current height place atmosphere;

P _sStatic pressure for the atmosphere at current height place;

Step 3: according to earth gravity field model, calculate unmanned vehicle acceleration of gravity;

The acceleration of gravity function representation is as follows:

$\left\{\begin{array}{c}{K}_R=0.00108263{\left(\frac{H+R_e}{R_e}\right)}^2\\ K_g=\sqrt{2.25\&times;(5{\sin }^4\left(D\right)-2{\sin }^2\left(D\right)+1)K_R^2+3\&times;(-3{\sin }^2\left(D\right)+1)K_R+1}\\ g=K_g\frac{\mathrm{GM}}{{(H+R_e)}^2}\end{array}\right.---\left(11\right)$

Wherein:

R _eBe earth radius;

D is latitude;

G is gravitational constant;

M is earth quality;

Step 4: the particle movement state equation of step 1 acquisition, the relative wind movement function that step 2 obtains, the acceleration of gravity function that step 3 obtains are made up and encapsulate, obtain aircraft particle movement dynamics module as shown in Figure 3; The acceleration of gravity function obtains acceleration of gravity according to particle movement state equation positional information calculation, the particle movement state equation obtains the equation quantity of state of acceleration of gravity and iterative computation, and the relative wind movement function is finished the calculating of aircraft relative wind physical quantity according to the equation of particle motion quantity of state.

Described aircraft particle movement dynamics module is input as lift, resistance, vehicle mass and aircraft roll angle, module output comprises aircraft equation of particle motion quantity of state, quantity of state derivative and aircraft relative wind motion physical quantity, this module does not rely on aircraft data, but repeated application is in the Three Degree Of Freedom modeling process of different aircraft.

3, unmanned vehicle Three Degree Of Freedom model construction

As shown in Figure 5, unmanned vehicle data module, aircraft particle movement dynamics module are made up and encapsulate, obtain unmanned vehicle Three Degree Of Freedom model.

Described unmanned vehicle data module and aircraft particle movement dynamics module input/output relation are: the unmanned vehicle data module is obtained aircraft relative wind physical quantity (as Mach number, dynamic pressure etc.) from aircraft particle movement dynamics module, and finish the calculating of aerodynamic lift, resistance, thereby output lift, resistance and vehicle mass are to particle movement dynamics module, and aircraft particle movement dynamics module can be finished the iterative computation of equation of motion quantity of state and relative wind physical quantity.

At unmanned vehicle Three Degree Of Freedom model package requirements, set up unmanned vehicle Three Degree Of Freedom model input-output operation function, described model input-output operation function comprises:

1) basic operation function: Three Degree Of Freedom model input (the aircraft angle of attack, roll angle, control rudder face) is set, and trigger model is upgraded, the replacement model state;

2) the basic quantity of state function of Three Degree Of Freedom model is set: initialization aircraft particle movement basic status; 3) obtain the basic quantity of state of model, quantity of state derivative function: output model basic status amount and quantity of state derivative;

4) relative wind power function: model is set adds wind, obtain aircraft relative wind physical quantity;

The Simulation Application of the aircraft Three Degree Of Freedom prototype software that present embodiment makes up as shown in Figure 6, its flow process is: 1. the user arranges the basic quantity of state of model, initial aircraft particle movement basic status; 2. the user arranges model input, the aircraft angle of attack, roll angle and primary control surface; The user further selectivity model be set add wind; 4. trigger model is upgraded (model inside is finished the lift resistance automatically and calculated, and adopts Adams4 exponent number value integral algorithm to upgrade the basic quantity of state of model); 5. the automatic calculating aircraft relative wind of model physical quantity; 6. model is exported aircraft basic status amount, quantity of state derivative, relative wind physical quantity; 7. repeating step 2 can be realized the non-linear emulation of aircraft particle movement to step 7.

Claims (1)

1. unmanned vehicle Three Degree Of Freedom model building method, it is characterized in that, comprise unmanned vehicle data module and aircraft particle movement dynamics module, described unmanned vehicle data module comprises unmanned vehicle data, lift function and resistance function, and described aircraft particle movement dynamics module comprises particle movement dynamics state equation, relative wind movement function and acceleration of gravity function; Concrete steps are as follows:

Step 1: obtain the unmanned vehicle data, comprise aircraft geometric area, quality and blowing data;

Step 2: according to the unmanned vehicle data that step 1 obtains, set up aircraft lift function and resistance function;

Step 3: the unmanned vehicle data of step 1 acquisition, lift function and the resistance function that step 2 is set up are made up and encapsulate, obtain the unmanned vehicle data module;

Step 4: set up particle movement dynamics state equation, described equation quantity of state comprises that aircraft velocity inertial, track pitch angle, course angle and aircraft relative inertness are the position;

Step 5: at the influence of wind to aircraft speed, set up the aircraft airspeed function; Further according to ARDC model atmosphere ARDC, set up aircraft relative wind movement function, calculating aircraft relative wind motion physical quantity; Aircraft relative wind motion physical quantity comprises air speed, Mach number and dynamic pressure;

Step 6: according to earth gravity field model, calculate unmanned vehicle acceleration of gravity function;

Step 7: the particle movement state equation of step 4 acquisition, the relative wind movement function that step 5 obtains, the acceleration of gravity function that step 6 obtains are made up and encapsulate, obtain aircraft particle movement dynamics module;

Step 8: to the unmanned vehicle data module of step 3 acquisition, aircraft particle movement dynamics module combinations and the encapsulation that step 7 obtains, obtain unmanned vehicle Three Degree Of Freedom model.

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