该程序采用欧拉法求解了6个状态变量水平位置(x1和x2)、高度(x3)、真空速(x4)、航向角(x5)和飞机质量(x6)和3种控制输入发动机推力(u1)、岸角(u2)和飞行路径角(u3)的6自由度。在指定的时间间隔内执行不同的飞行机动。
Velocities.m、Cruise_Vel.m、Des_Vel.m、Thr_cl.m、Thr_cr.m、Thr_des.m、fuel_cl.m、fuel_cr.m、fuel_des.m、den.m、den_cr.m、den_des.m、drag.m、drag_cr.m、drag_des.m、lift.m、lift_cr.m、lift_des.m是独立制表符中的函数。主要代码是:
% Climb from h1=1100 [m] to h2=1600 [m] with α=5 flight path angle.
% Perform cruise flight for t=60 minutes.
% Turn with β=30 bank angle until heading is changed by η=270◦.
% Descent from h2=1600 [m] to h1=1100 [m] with ζ=4◦ flight path angle.
% Complete a 360◦ turn (loiter) at level flight.
% Descent to h3=800 [m] with κ=4.5◦ flight path angle.
% Aircraft Properties
W = .44225E+06; % .44225E+03 tons = .44225E+06 kg
S = .51097E+03; % Surface Area [m^2]
g0 = 9.80665; % Gravitational acceleration [m/s2]
% solving 1st order ODE using numerical methods
t0=0;
tend=3960;
h=0.05;
N=(tend-t0)/h;
t=t0:h:tend;
% Preallocations
x = zeros(6,length(t));
x1 = zeros(1,length(t));
x2 = zeros(1,length(t));
x3 = zeros(1,length(t));
x4 = zeros(1,length(t));
x5 = zeros(1,length(t));
x6 = zeros(1,length(t));
u1 = zeros(1,length(t));
u2 = zeros(1,length(t));
u3 = zeros(1,length(t));
C_D= zeros(1,length(t));
p = zeros(1,length(t));
Cl = zeros(1,length(t));
f = zeros(1,length(t));
dx1dt = zeros(1,length(t));
dx2dt = zeros(1,length(t));
dx3dt = zeros(1,length(t));
dx4dt = zeros(1,length(t));
dx5dt = zeros(1,length(t));
dx6dt = zeros(1,length(t));
% Initial conditions
x(:,1)=[0;0;3608.92;1.0e+02 * 1.161544478045788;0;W];
for i=2:length(t)
if and (t(1,i-1) >= 0,t(1,i-1)<60) % Climb from h1=1100 [m] to h2=1600 [m] with α=5 flight path angle.
x3 = linspace(3608.92,5249.3,79201);
x4 = Velocities(x3); % Changing speed [m/s]
x5 = 0; % Changing head angle [deg]
f = fuel_cl(x3); % Changing fuel flow [kg/min]
u1 = Thr_cl(x3); % Changing thrust [N]
u2 = 0; % Changing bank angle [deg]
u3 = 5; % Changing flight path angle [deg]
V_ver = x4*sin(u3); % Changing vertical speed [m/s]
C_D = drag(x3,x4); % Changing drag coefficient
Cl = lift(x3,x4); % Changing lift coefficient
p = den(x3); % Changing density [kg/m3]
elseif and (t(1,i-1) >= 60,t(1,i-1)<3660) % Perform cruise flight for t=60 minutes.
x3 = 5249.3;
x4 = Cruise_Vel(x3); % Changing speed [m/s]
x5 = 0; % Changing head angle [deg]
f = fuel_cr(x3); % Changing fuel flow [kg/min]
u1 = Thr_cr(x3); % Changing thrust [N]
u2 = 0; % Changing bank angle [deg]
u3 = 0; % Changing flight path angle [deg]
V_ver = x4*sin(u3); % Changing vertical speed [m/s]
C_D = drag_cr(x3,x4); % Changing drag coefficient
Cl = lift_cr(x3,x4); % Changing lift coefficient
p = den_cr(x3); % Changing density [kg/m3]
elseif and (t(1,i-1) >= 3660,t(1,i-1)<3720) % Turn with β=30 bank angle until heading is changed by η=270◦.
x3 = 5249.3;
x4 = Cruise_Vel(x3); % Changing speed [m/s]
x5 = 0:30:270; % Changing head angle [deg]
f = fuel_cr(x3); % Changing fuel flow [kg/min]
u1 = Thr_cr(x3); % Changing thrust [N]
u2 = 30; % Changing bank angle [deg]
u3 = 0; % Changing flight path angle [deg]
V_ver = x4*sin(u3); % Changing vertical speed [m/s]
C_D = drag_cr(x3,x4); % Changing drag coefficient
Cl = lift_cr(x3,x4); % Changing lift coefficient
p = den_cr(x3); % Changing density [kg/m3]
elseif and (t(1,i-1) >= 3720,t(1,i-1)<3780) % Descent from h2=1600 [m] to h1=1100 [m] with ζ=4◦ flight path angle.
x3 = linspace(5249.3,3608.92,79201);
x4 = Des_Vel(x3); % Changing speed [m/s]
x5 = 270; % Changing head angle [deg]
f = fuel_des(x3); % Changing fuel flow [kg/min]
u1 = Thr_des(x3); % Changing thrust [N]
u2 = 0; % Changing bank angle [deg]
u3 = 4; % Changing flight path angle [deg]
V_ver = x4*sin(u3); % Changing vertical speed [m/s]
C_D = drag_des(x3,x4); % Changing drag coefficient
Cl = lift_des(x3,x4); % Changing lift coefficient
p = den_des(x3); % Changing density [kg/m3]
elseif and (t(1,i-1) >= 3780,t(1,i-1)<3900) % Complete a 360◦ turn (loiter) at level flight.
x3 = 3608.9;
x4 = Cruise_Vel(x3); % Changing speed [m/s]
lon = [270 300 360 60 120 180 240 270];
x5 = wrapTo360(lon); % Changing head angle [deg]
f = fuel_cr(x3); % Changing fuel flow [kg/min]
u1 = Thr_cr(x3); % Changing thrust [N]
u2 = 0; % Changing bank angle [deg]
u3 = 0; % Changing flight path angle [deg]
V_ver = x4*sin(u3); % Changing vertical speed [m/s]
C_D = drag_cr(x3,x4); % Changing drag coefficient
Cl = lift_cr(x3,x4); % Changing lift coefficient
p = den_cr(x3); % Changing density [kg/m3]
elseif and (t(1,i-1) >= 3900,t(1,i-1)<3960) % Descent to h3=800 [m] with κ=4.5◦ flight path angle.
x3 = linspace(3608.92,2624.67,79201);
x4 = Des_Vel(x3); % Changing speed [m/s]
x5 = 270; % Changing head angle [deg]
f = fuel_des(x3); % Changing fuel flow [kg/min]
u1 = Thr_des(x3); % Changing thrust [N]
u2 = 0; % Changing bank angle [deg]
u3 = 4.5; % Changing flight path angle [deg]
V_ver = x4*sin(u3); % Changing vertical speed [m/s]
C_D = drag_des(x3,x4); % Changing drag coefficient
Cl = lift_des(x3,x4); % Changing lift coefficient
p = den_des(x3); % Changing density [kg/m3]
else
fprintf("A problem occured.");
end
dx1dt = x4 .* cos(x5) .* cos(u3);
dx2dt = x4 .* sin(x5) .* cos(u3);
dx3dt = x4 .* sin(u3);
dx4dt = -C_D.*S.*p.*(x4.^2)./(2.*x6)-g0.*sin(u3)+u1./x6;
dx5dt = -Cl.*S.*p.*x4./(2.*x6).*sin(u2);
dx6dt = -f;
x(1,i)= x(1,i-1) + h * dx1dt(1,i-1); %%%%%%%%% line 138 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
x(2,i)= x(2,i-1) + h * dx2dt(1,i-1);
x(3,i)= x(3,i-1) + h * dx3dt(1,i-1);
x(4,i)= x(4,i-1) + h * dx4dt(1,i-1);
x(5,i)= x(5,i-1) + h * dx5dt(1,i-1);
x(6,i)= x(6,i-1) + h * dx6dt(1,i-1);
end
tot=cell2mat(f); % Total fuel consumption during mission [kg/min]
Tot_fuel=sum(tot);
figure(1)
plot3(x1(:),x2(:),x3(:)); % 3D position graph
figure(2)
plot(t,x4(:)); % Vtas − Time graph
figure(3)
plot(t,V_ver(:)); % V_vertical − Time graph
figure(4)
plot(t,x5(:)); % Heading − Time graph
figure(5)
plot(t,x6(:)); % Mass − Time graph
figure(6)
plot(t,u1(:)); % Thrust − Time graph
figure(7)
plot(t,u2(:)); % Bank Angle − Time graph
figure(8)
plot(t,u3(:)); % Flight Path Angle − Time graph
fprintf('Total fuel consumption during mission is %.2f [kg]',Tot_fuel*tend/60);我使用79201大小数组的原因是长度(T)= 79201。当我跑的时候:
Index in position 2 exceeds array bounds (must not exceed 1).
Error in forum (line 138)
x(1,i)= x(1,i-1) + h * dx1dt(1,i-1);我该怎么办?
下面是单独选项卡中的一个函数,其余的都类似:
function [Vtas_cl] = Velocities(x3)
%%%%%%%%%%%%%%%%%%%% Constants %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Vcl_1 = 335; % Standard calibrated airspeed [kt]
Vcl_2 = 172.3; % Standard calibrated airspeed [kt] -> [m/s] (To find the Mach transition altitude)
Vcl_2_in_knots = 335; % Standard calibrated airspeed [kt] (To find the result in knots, if altitude is between 10,000 ft and Mach transition altitude)
M_cl = 0.86; % Standard calibrated airspeed [kt]
K = 1.4; % Adiabatic index of air
R = 287.05287; % Real gas constant for air [m2/(K·s2)]
Bt = - 0.0065; % ISA temperature gradient with altitude below the tropopause [K/m]
T0 = 288.15; % Standard atmospheric temperature at MSL [K]
g0 = 9.80665; % Gravitational acceleration [m/s2]
a0= 340.294; % Speed of Sound [m/s]
Vd_CL1 = 5; % Climb speed increment below 1500 ft (jet)
Vd_CL2 = 10; % Climb speed increment below 3000 ft (jet)
Vd_CL3 = 30; % Climb speed increment below 4000 ft (jet)
Vd_CL4 = 60; % Climb speed increment below 5000 ft (jet)
Vd_CL5 = 80; % Climb speed increment below 6000 ft (jet)
CV_min = 1.3; % Minimum speed coefficient
Vstall_TO = .14200E+03; % Stall speed at take-off [KCAS]
CAS_climb = Vcl_2;
Mach_climb = M_cl;
delta_trans = (((1+((K-1)/2)*(CAS_climb/a0)^2)^(K/(K-1)))-1)/(((1+(K-1)/2*Mach_climb^2)^(K/(K-1)))-1); % Pressure ratio at the transition altitude
teta_trans = delta_trans ^ (-Bt*R/g0); % Temperature ratio at the transition altitude
H_p_trans_climb = (1000/0.348/6.5)*(T0*(1-teta_trans)); % Transition altitude for climb [ft]
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% End of constants
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
H_climb = x3; %%%%%% Input %%%%%%%%%%%%%%%%%%%
Vnom_climb_jet = zeros(1, length(H_climb));
for k1 = 1:length(H_climb)
if (0<=H_climb(k1)&&H_climb(k1)<1500)
Vnom_climb_jet(k1) = CV_min * Vstall_TO + Vd_CL1;
elseif (1500<=H_climb(k1)&&H_climb(k1)<3000)
Vnom_climb_jet(k1) = CV_min * Vstall_TO + Vd_CL2;
elseif (3000<=H_climb(k1)&&H_climb(k1)<4000)
Vnom_climb_jet (k1)= CV_min * Vstall_TO + Vd_CL3;
elseif (4000<=H_climb(k1)&&H_climb(k1)<5000)
Vnom_climb_jet (k1)= CV_min * Vstall_TO + Vd_CL4;
elseif (5000<=H_climb(k1)&&H_climb(k1)<6000)
Vnom_climb_jet(k1) = CV_min * Vstall_TO + Vd_CL5;
elseif (6000<=H_climb(k1)&&H_climb(k1)<10000)
Vnom_climb_jet (k1)= min(Vcl_1,250);
elseif (10000<=H_climb(k1)&&H_climb(k1)<=H_p_trans_climb)
Vnom_climb_jet(k1) = Vcl_2_in_knots;
elseif (H_p_trans_climb<H_climb(k1))
Vnom_climb_jet(k1) = M_cl;
end
Vcas_cl(k1) = Vnom_climb_jet(k1)* 0.514; % [kn] -> [m/s]
H_climb (k1)= H_climb(k1) * 0.3048; % [feet] -> [m]
K = 1.4; % Adiabatic index of air
R = 287.05287; % Real gas constant for air [m2/(K·s2)]
Bt = - 0.0065; % ISA temperature gradient with altitude below the tropopause [K/m]
deltaT = 0; % Value of the real temperature T in ISA conditions [K]
T0 = 288.15; % Standard atmospheric temperature at MSL [K]
P0 = 101325; % Standard atmospheric pressure at MSL [Pa]
g0 = 9.80665; % Gravitational acceleration [m/s2]
p0 = 1.225; % Standard atmospheric density at MSL [kg/m3]
visc = (K-1)./K;
T(k1) = T0 + deltaT + Bt * H_climb(k1); % Temperature [K]
P (k1)= P0*((T(k1)-deltaT)/T0).^((-g0)/(Bt*R)); % Pressure [Pa]
p (k1)= P(k1) ./ (R*T(k1)); % Density [kg/m^3]
Vtas_cl(k1) = (2*P(k1)/visc/p(k1)*((1 + P0/P(k1)*((1 + visc*p0*Vcas_cl(k1)*Vcas_cl(k1)/2/P0).^(1/visc)-1)).^(visc)-1)).^(1/2); % True Air Speed [m/s]
end
% Output
end发布于 2022-01-04 20:51:24
位置2中的
索引超过数组边界(不能超过1)。
这是在尝试访问和不存在的元素时发生的错误。例如,如果我初始化一个x变量的大小(3,1),然后尝试从索引(4,4)中提取一个值,它会抛出这个错误。
x = zeros(3,1)
y = x(4,4)+1; % ERROR在第138行,变量dx1dt的索引存在问题。它试图访问当i=3不存在的元素(1,2)。
在代码开始时,您已经将dx1dt的大小初始化为(1,79201)
dx1dt = zeros(1,length(t));但是,在计算每个值时,将此数组的大小改写为(1,1)
dx1dt = x4 .* cos(x5) .* cos(u3);因此,当i=3调用以下索引时,dx1dt在(1,2)位置上没有任何值。这将引发索引超出界限的错误。
x(1,i)= x(1,i-1) + h * dx1dt(1,i-1);
x(1,3)= x(1,2) + h * dx1dt(1,2);问题是:dx1dt的变量应该是大小的数组(1,79201)还是简单的双倍?
https://stackoverflow.com/questions/70583843
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