why my code is running so slowly in the while loop

Hi, im new at Matlab and im trying to implement a guidance for Uav but my while loop running so slowly.

Any suggestions for fix this trouble ?

clc;

clear all;

close all;

r = 1250;

O = [2500 2500]

Px = 2500; Py = 1000;

P = [ Px Py ];

Va = 100;

To = 4;

q22 = 0.1

psi = -0.4;

delta = 10;

K =0.5;

Rmin = 75

K2 = 35;

B = 0 : 0.001 : 2*pi;

c = (r* (cos(B)))+O(1);

d = (r* (sin(B)))+O(2);

N = (r * (cos(B)))+O(1);

M = (r * (sin(B)))+O(2);

% Wa = [0 300]; %

% Wb = [0 300]; %

Vx = Va * cos( psi );

Vy = Va * sin( psi );

thetaU = atan2(( Px - O(2)),( Py - O(1)));

d = abs(sqrt (( O(1) - Py )^2 + ( O(2) - Px )^2) - r)

xt = ((r * (cos ( thetaU+delta ))) + O(1));

yt = ((r * (sin ( thetaU+delta ))) + O(2));

Vd = Va*sin(psi-thetaU);

q11 = sqrt(abs(To / (To-d)));

psiD = atan2(( yt -Py ),( xt - Px ));

u =- ((d*q11) + sqrt(2*q11+q22^2)*Vd);

while d > 0

t = 0.05;

d = abs(sqrt (( O(1) - Py )^2 + ( O(2) - Px )^2) - r)

thetaU = atan2(( Px - O(2)),( Py - O(1)));

xt = ((r * (cos ( thetaU+delta ))) + O(1));

yt = ((r * (sin ( thetaU+delta ))) + O(2));

Vd = Va*sin(psi-thetaU);

q11 = sqrt(abs(To / (To-d)));

psiD = atan2(( yt -Py ),( xt - Px ));

u =- ((d*q11) + sqrt(2*q11+q22^2)*Vd);

psi = psiD ;

if(abs(u) > (Va^2)/Rmin)

if (u > 0)

u = (Va^2)/Rmin;

else

u = -(Va^2)/Rmin;

end

end

Vy = Va * sin ( psi ) + u * t;

Vx = Va * cos(psi) + u * t;

Px = Px + Vx *t;

Py = Py + Vy *t;

t = t + 0.1;

hold on;

plot (Px ,Py ,"r--.",O(1) , O(2) ,'b-o');

plot (c,d,'r')

plot(N,M,'k')

title("2D Carrot Chase Trajectory")

xlabel("Position");

ylabel("Position"),

end

Answer 1

[VBBV]

clc;
clear all;
close all;
r = 1250;
O = [2500 2500]

O = 1×2

2500 2500

Px = 2500; Py = 1000;
P = [ Px Py ];
Va = 100;
To = 4;
q22 = 0.1

q22 = 0.1000

psi = -0.4;
delta = 10;
K =0.5;
Rmin = 75

Rmin = 75

K2 = 35;
B = 0 : 0.001 : 2*pi;
 
c = (r* (cos(B)))+O(1);
 
d = (r* (sin(B)))+O(2);
 
N = (r * (cos(B)))+O(1);
 
M = (r * (sin(B)))+O(2);
% Wa = [0 300]; %
% Wb = [0 300]; % 
Vx = Va * cos( psi );
Vy = Va * sin( psi );
thetaU = atan2(( Px - O(2)),( Py - O(1)));
d = abs(sqrt (( O(1) - Py )^2 + ( O(2) - Px )^2)  - r)

d = 250

xt = ((r * (cos ( thetaU+delta ))) + O(1));
yt = ((r  * (sin ( thetaU+delta ))) + O(2));
Vd = Va*sin(psi-thetaU);
q11 = sqrt(abs(To / (To-d)));
psiD = atan2(( yt -Py ),( xt - Px ));
u =- ((d*q11) + sqrt(2*q11+q22^2)*Vd);
i = 1

i = 1

t = 0.05;
while d > 0


thetaU = atan2(( Px - O(2)),( Py - O(1)));
xt = ((r * (cos ( thetaU+delta ))) + O(1));
yt = ((r  * (sin ( thetaU+delta ))) + O(2));
Vd = Va*sin(psi-thetaU);
q11 = sqrt(abs(To / (To-d)));
psiD = atan2(( yt -Py ),( xt - Px ));
u =- ((d*q11) + sqrt(2*q11+q22^2)*Vd);
psi = psiD ;
  if(abs(u) > (Va^2)/Rmin)
        if (u > 0)
            u = (Va^2)/Rmin;
        else
            u = -(Va^2)/Rmin;
        end
    end
Vy = Va * sin ( psi ) + u * t;
Vx = Va * cos(psi) + u * t;
Pxx(i) = Px + Vx *t;
Pyy(i) = Py + Vy *t;
t = t + 0.1;
d = d-1;   % use one counter to check the while conditon 
i = i+1;

end
 
plot (Pxx ,Pyy ,"r--.",O(1) , O(2) ,'b-o');
% subplot(211)
% plot (c,d,'or') 
% subplot(212)
% plot(N,M,'+k')
 
title("2D Carrot Chase Trajectory")
xlabel("Position");
ylabel("Position"),

[VBBV]

use one counter to check the while conditon saturation

[Muhammed Emin Yavuzaslan]

@VBBV when i try it a different code, i get same error with your solution. What should i do ?

clc;

clear all;

close all;

r = 1250;

O = [2500 2500]

Px = 2500; Py = 1000;

P = [ Px Py ];

Va = 200;

alpha = 1;

k = 1;

Rmin = 75;

psi = -0.4;

delta = 0.1;

Vx = Va * cos( psi );

Vy = Va * sin( psi );

K =0.5;

B = 0 : 0.001 : 2*pi;%plot of circle

c = (r* (cos(B)))+O(1);

d = (r* (sin(B)))+O(2);

N = (r * (cos(B)))+O(1);

M = (r * (sin(B)))+O(2);

d = abs(sqrt (( O(2) - Py )^2 + ( O(1) - Px )^2));

theta = atan2(Py-O(2),Px-O(1));

xt = ((r * (cos ( theta+delta ))) + O(1));

yt = ((r * (sin ( theta+delta ))) + O(2));

psiD = atan2(( yt -Py ),( xt - Px ));

if d > 2*r

psid = theta-pi+asin(r/d)

psic = psid+ (Va*sin(psi-theta) /(alpha*d))

else

psid = (theta-(pi/2) - (pi/3)*(((d-r)/r)^k) );

psic = psid-(Va*sin(psi-theta)/(alpha*d))- (k*Va*pi*(d^(k-1))) / (3*(r^k)*alpha);

end

u = K*(psic-psi)*Va;

i = 1;

while abs (d) > 0

t = 0.05;

d = abs(sqrt (( O(2) - Py )^2 + ( O(1) - Px )^2) - r)

theta = atan2(Py-O(2),Px-O(1));

xt = ((r * (cos ( theta+delta ))) + O(1));

yt = ((r * (sin ( theta+delta ))) + O(2));

psiD = atan2(( yt -Py ),( xt - Px ));

if d > 2*r

psid = theta-pi+asin(r/d)

psic = psid+ (Va*sin(psi-theta) /(alpha*d))

else

psid = (theta-(pi/2) - (pi/3)*(((d-r)/r)^k) );

psic = psid-(Va*sin(psi-theta)/(alpha*d))- (k*Va*pi*(d^(k-1))) / (3*(r^k)*alpha);

end

psi = psiD;

if(abs(u) > (Va^2)/Rmin)

if (u > 0)

u = (Va^2)/Rmin;

else

u = -(Va^2)/Rmin;

end

end

Vy = Va * sin ( psi ) + u * t;

Vx = Va * cos(psi) + u * t;

Pxx(i) = Px + Vx *t;

Pyy(i) = Py + Vy *t;

t = t + 0.01;

d = d-1;

i = i+1;

hold on;

plot (Pxx ,Pyy ,"r--.",O(1) , O(2) ,'b-o');

plot (c,d,'r')

plot(N,M,'k')

title("2D Carrot Chase Trajectory")

xlabel("Position");

ylabel("Position"),

end

[VBBV]

t = 0.05;
d = abs(sqrt (( O(2) - Py )^2 + ( O(1) - Px )^2) - r)

Thats because you are putting the above 2 lines inside while loop This makes the condition always true and while loop runs indefinitely. The above lines must be outside of while loop and before beginning of loop

[VBBV]

clc;
clear all;
close all;
r = 1250;
O = [2500 2500]

O = 1×2

2500 2500

Px = 2500; Py = 1000;
P = [ Px Py ];
Va = 200;
alpha = 1;
k = 1;
Rmin = 75;
psi = -0.4;
delta = 0.1;
Vx = Va * cos( psi );
Vy = Va * sin( psi );
K =0.5;
B = 0 : 0.001 : 2*pi;%plot of circle
 
c = (r* (cos(B)))+O(1);
 
d = (r* (sin(B)))+O(2);
 
N = (r * (cos(B)))+O(1);
 
M = (r * (sin(B)))+O(2);
d = abs(sqrt (( O(2) - Py )^2 + ( O(1) - Px )^2));
theta = atan2(Py-O(2),Px-O(1));
xt = ((r * (cos ( theta+delta ))) + O(1));
yt = ((r  * (sin ( theta+delta ))) + O(2));
psiD = atan2(( yt -Py ),( xt - Px ));
if d > 2*r
    psid = theta-pi+asin(r/d)
    psic = psid+ (Va*sin(psi-theta) /(alpha*d))
else
    psid = (theta-(pi/2) - (pi/3)*(((d-r)/r)^k)  );
    psic = psid-(Va*sin(psi-theta)/(alpha*d))- (k*Va*pi*(d^(k-1))) / (3*(r^k)*alpha);
end
u = K*(psic-psi)*Va;
i = 1;
t = 0.05;
d = abs(sqrt (( O(2) - Py )^2 + ( O(1) - Px )^2) - r)

d = 250

while abs (d) > 0

theta = atan2(Py-O(2),Px-O(1));
xt = ((r * (cos ( theta+delta ))) + O(1));
yt = ((r  * (sin ( theta+delta ))) + O(2));
psiD = atan2(( yt -Py ),( xt - Px ));
if d > 2*r
    psid = theta-pi+asin(r/d)
    psic = psid+ (Va*sin(psi-theta) /(alpha*d))
else
    psid = (theta-(pi/2) - (pi/3)*(((d-r)/r)^k)  );
    psic = psid-(Va*sin(psi-theta)/(alpha*d))- (k*Va*pi*(d^(k-1))) / (3*(r^k)*alpha);
end
psi = psiD;
if(abs(u) > (Va^2)/Rmin)
        if (u > 0)
            u = (Va^2)/Rmin;
        else
            u = -(Va^2)/Rmin;
        end
    end
Vy = Va * sin ( psi ) + u * t;
Vx = Va * cos(psi) + u * t;
Pxx(i) = Px + Vx *t;
Pyy(i) = Py + Vy *t;
t = t + 0.01;
d = d-1;
i = i+1;

end
hold on;
plot (Pxx ,Pyy ,"r--.",O(1) , O(2) ,'b-o');
plot (c,d,'r')
plot(N,M,'k')
title("2D Carrot Chase Trajectory")
xlabel("Position");
ylabel("Position"),

[Muhammed Emin Yavuzaslan]

@VBBV Thanks for answering my quesiton. But i have a little question more.

You changed my equation

Px = Px + Vx *t;

Py = Py + Vy *t;

to this

Pxx(i) = Px + Vx *t;

Pyy(i) = Py + Vy *t;

why we did this ?

and my another quesiton is theta is related with Px and Py variables. When we did

Px--Pxx and Py--Pyy theta doesnt change. its stuck at zero but it must be change.

So what should i do

Sorry for my English. I'm trying my best

Thanks a lot

[VBBV]

This is done to save computed values in a new array during iteration in while loop.

clc;
clear all;
close all;
r = 1250;
O = [2500 2500]

O = 1×2

2500 2500

Px = 2500; Py = 1000;
P = [ Px Py ];
Va = 200;
alpha = 1;
k = 1;
Rmin = 75;
psi = -0.4;
delta = 0.1;
Vx = Va * cos( psi );
Vy = Va * sin( psi );
K =0.5;
B = 0 : 0.001 : 2*pi;%plot of circle
 
c = (r* (cos(B)))+O(1);
 
d = (r* (sin(B)))+O(2);
 
N = (r * (cos(B)))+O(1);
 
M = (r * (sin(B)))+O(2);
d = abs(sqrt (( O(2) - Py )^2 + ( O(1) - Px )^2));
theta = atan2(Py-O(2),Px-O(1));
xt = ((r * (cos ( theta+delta ))) + O(1));
yt = ((r  * (sin ( theta+delta ))) + O(2));
psiD = atan2(( yt -Py ),( xt - Px ));
if d > 2*r
    psid = theta-pi+asin(r/d)
    psic = psid+ (Va*sin(psi-theta) /(alpha*d))
else
    psid = (theta-(pi/2) - (pi/3)*(((d-r)/r)^k)  );
    psic = psid-(Va*sin(psi-theta)/(alpha*d))- (k*Va*pi*(d^(k-1))) / (3*(r^k)*alpha);
end
u = K*(psic-psi)*Va;
i = 1;
t = 0.05;
d = abs(sqrt (( O(2) - Py )^2 + ( O(1) - Px )^2) - r);
while abs (d) > 0

theta = atan2(Py-O(2),Px-O(1))
xt = ((r * (cos ( theta+delta ))) + O(1));
yt = ((r  * (sin ( theta+delta ))) + O(2));
psiD = atan2(( yt -Py ),( xt - Px ));
if d > 2*r
    psid = theta-pi+asin(r/d)
    psic = psid+ (Va*sin(psi-theta) /(alpha*d))
else
    psid = (theta-(pi/2) - (pi/3)*(((d-r)/r)^k)  );
    psic = psid-(Va*sin(psi-theta)/(alpha*d))- (k*Va*pi*(d^(k-1))) / (3*(r^k)*alpha);
end
psi = psiD;
if(abs(u) > (Va^2)/Rmin)
        if (u > 0)
            u = (Va^2)/Rmin;
        else
            u = -(Va^2)/Rmin;
        end
    end
Vy = Va * sin ( psi ) + u * t;
Vx = Va * cos(psi) + u * t;
Px = Px + Vx *t;  % 
Py = Py + Vy *t;
t = t + 0.01;
d = d-1;
i = i+1;
hold on;
plot (Px ,Py ,"ro",O(1) , O(2) ,'b-o');
title("2D Carrot Chase Trajectory")
xlabel("Position");
ylabel("Position"),

end

theta = -1.5708

theta = -1.5684

theta = -1.5656

theta = -1.5622

theta = -1.5584

theta = -1.5540

theta = -1.5490

theta = -1.5433

theta = -1.5367

theta = -1.5293

theta = -1.5207

theta = -1.5110

theta = -1.5000

theta = -1.4877

theta = -1.4740

theta = -1.4591

theta = -1.4432

theta = -1.4264

theta = -1.4090

theta = -1.3912

theta = -1.3733

theta = -1.3553

theta = -1.3376

theta = -1.3201

theta = -1.3031

theta = -1.2866

theta = -1.2707

theta = -1.2556

theta = -1.2412

theta = -1.2277

theta = -1.2151

theta = -1.2035

theta = -1.1930

theta = -1.1836

theta = -1.1754

theta = -1.1685

theta = -1.1629

theta = -1.1586

theta = -1.1559

theta = -1.1546

theta = -1.1549

theta = -1.1569

theta = -1.1606

theta = -1.1661

theta = -1.1735

theta = -1.1828

theta = -1.1941

theta = -1.2074

theta = -1.2229

theta = -1.2406

theta = -1.2606

theta = -1.2830

theta = -1.3078

theta = -1.3350

theta = -1.3649

theta = -1.3973

theta = -1.4323

theta = -1.4698

theta = -1.5097

theta = -1.5518

theta = -1.5958

theta = -1.6412

theta = -1.6875

theta = -1.7339

theta = -1.7798

theta = -1.8245

theta = -1.8674

theta = -1.9080

theta = -1.9461

theta = -1.9814

theta = -2.0138

theta = -2.0435

theta = -2.0705

theta = -2.0949

theta = -2.1171

theta = -2.1371

theta = -2.1551

theta = -2.1714

theta = -2.1861

theta = -2.1994

theta = -2.2114

theta = -2.2223

theta = -2.2322

theta = -2.2411

theta = -2.2492

theta = -2.2566

theta = -2.2634

theta = -2.2695

theta = -2.2752

theta = -2.2803

theta = -2.2850

theta = -2.2894

theta = -2.2934

theta = -2.2971

theta = -2.3005

theta = -2.3036

theta = -2.3065

theta = -2.3092

theta = -2.3117

theta = -2.3141

theta = -2.3162

theta = -2.3182

theta = -2.3201

theta = -2.3219

theta = -2.3235

theta = -2.3251

theta = -2.3265

theta = -2.3279

theta = -2.3291

theta = -2.3303

theta = -2.3315

theta = -2.3325

theta = -2.3335

theta = -2.3345

theta = -2.3354

theta = -2.3362

theta = -2.3370

theta = -2.3377

theta = -2.3385

theta = -2.3391

theta = -2.3398

theta = -2.3404

theta = -2.3410

theta = -2.3415

theta = -2.3420

theta = -2.3425

theta = -2.3430

theta = -2.3435

theta = -2.3439

theta = -2.3443

theta = -2.3447

theta = -2.3451

theta = -2.3454

theta = -2.3458

theta = -2.3461

theta = -2.3464

theta = -2.3467

theta = -2.3470

theta = -2.3473

theta = -2.3476

theta = -2.3478

theta = -2.3481

theta = -2.3483

theta = -2.3485

theta = -2.3487

theta = -2.3489

theta = -2.3491

theta = -2.3493

theta = -2.3495

theta = -2.3497

theta = -2.3499

theta = -2.3501

theta = -2.3502

theta = -2.3504

theta = -2.3505

theta = -2.3507

theta = -2.3508

theta = -2.3509

theta = -2.3511

theta = -2.3512

theta = -2.3513

theta = -2.3514

theta = -2.3515

theta = -2.3517

theta = -2.3518

theta = -2.3519

theta = -2.3520

theta = -2.3521

theta = -2.3522

theta = -2.3523

theta = -2.3523

theta = -2.3524

theta = -2.3525

theta = -2.3526

theta = -2.3527

theta = -2.3527

theta = -2.3528

theta = -2.3529

theta = -2.3530

theta = -2.3530

theta = -2.3531

theta = -2.3532

theta = -2.3532

theta = -2.3533

theta = -2.3533

theta = -2.3534

theta = -2.3535

theta = -2.3535

theta = -2.3536

theta = -2.3536

theta = -2.3537

theta = -2.3537

theta = -2.3538

theta = -2.3538

theta = -2.3538

theta = -2.3539

theta = -2.3539

theta = -2.3540

theta = -2.3540

theta = -2.3541

theta = -2.3541

theta = -2.3541

theta = -2.3542

theta = -2.3542

theta = -2.3542

theta = -2.3543

theta = -2.3543

theta = -2.3543

theta = -2.3544

theta = -2.3544

theta = -2.3544

theta = -2.3545

theta = -2.3545

theta = -2.3545

theta = -2.3546

theta = -2.3546

theta = -2.3546

theta = -2.3546

theta = -2.3547

theta = -2.3547

theta = -2.3547

theta = -2.3547

theta = -2.3548

theta = -2.3548

theta = -2.3548

theta = -2.3548

theta = -2.3548

theta = -2.3549

theta = -2.3549

theta = -2.3549

theta = -2.3549

theta = -2.3549

theta = -2.3550

theta = -2.3550

theta = -2.3550

theta = -2.3550

theta = -2.3550

theta = -2.3551

theta = -2.3551

theta = -2.3551

theta = -2.3551

theta = -2.3551

theta = -2.3551

theta = -2.3551

theta = -2.3552

theta = -2.3552

theta = -2.3552

theta = -2.3552

theta = -2.3552

theta = -2.3552