################ #####Draw the envrionment: void NetDisplay() ################

define DrawRectangle(x,y,w,h). W: Width, H: Height, X : is normal, Y: top to bottom

The area is 600 x 600

Colour can be chosen

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Robot x_1 and y_1 is only used for drawing. No need for dunamics. More explanation later robot->p_x1=robot->p_x+0.0*(drand48()-0.5); robot->p_y1=robot->p_y+0.0*(drand48()-0.5);

Inilize Robot velocity robot->v_x=0.1*(drand48()-0.5); robot->v_y=0.1*(drand48()-0.5);

Best local and global position is the inital position robot->pbx=robot->p_x; robot->pby=robot->p_y;

robot->gbx=robot->p_x;
robot->gby=robot->p_y;

This fomulae is uesed for the initla position of the robot. y = a + b*(x-c); a: constant b: How speared particles should be c: Where should the particles be initlaized in both axis robot->p_x=0.5+0.25*(robot->p_x-0.5); robot->p_y=0.5+0.25*(robot->p_y-0.5);

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t=0L; p_d=P_D; bou=-0.21; rr1=RR1; rr2=RR2;

sc_x=(double)WINDOW_H; sc_y=(double)WINDOW_H; scx0=(double)WINDOW_H; scy0=(double)WINDOW_H; rw1=WINDOW_HRR1; rw2=WINDOW_HRR2;

w=0.9; a1=1.5; a2=1.5;

aw=0.9; ac=0.01;

sp=0.0001;

1. How the robot moves?

update velocity:

robot->v_x=w*robot->v_x+a1*drand48()*(robot->pbx-robot->p_x)+a2*drand48()*(robot->gbx-robot->p_x); //+ac*(robot->p_x-robots[mrad]->p_x)/(radmin+0.0001);
robot->v_y=w*robot->v_y+a1*drand48()*(robot->pby-robot->p_y)+a2*drand48()*(robot->gby-robot->p_y); //+ac*(robot->p_y-robots[mrad]->p_y)/(radmin+0.0001);

V_x = wV_x + a1(random)(P_x - x) + a2(random)(G_x - x) + a3(x - R_x)/(radmin+0.0001) V_y = wV_y + a1(random)(P_y - y) + a2(random)(G_y - y) + a3(y - R_y)/(radmin+0.0001)

w=0.9 a1=a2=1.5 ac= 0.01 R_x,y= x and y of the closest robot rad = (R_x - R2_x)^2 + (R_y - R2_y)^2 radmin = minimum differences between the two robot

update position: robot->p_x+=sprobot->v_x; robot->p_y+=sprobot->v_y;

sp=0.0001

2. How the robot avoids Obstacles?

robot->p_x+=sp*robot->v_x; if ((fabs(robot->p_y-0.5)>0.1)&&(((robot->p_xo<0.52)&&(robot->p_x>0.48))||((robot->p_xo>0.52)&&(robot->p_x<0.48)))) robot->p_x=robot->p_xo;

x = x + sp*V_x if |y - 0.5| > 0.1 and ( (x_0 < 0.52 and x > 0.48) or (x_0 > 0.52 and x < 0.48) ) ===> x = x_0

x : new position x_0: old position

3. How the robot avoids other robots?

The last part of velocity updation goes away from the closest one. Also:

oo=0; for (r=0;r<NR;r++) { if (r!=my_r) { rad=(robot->p_x-robots[r]->p_x)(robot->p_x-robots[r]->p_x)+(robot->p_y-robots[r]->p_y)(robot->p_y-robots[r]->p_y); if (rad<rr1*rr1) { robot->p_x=robot->p_xo; robot->p_y=robot->p_yo; oo=1; break; } } }

What does this do? I dont know.

if (oo==0) { if (robot->p_x<rr2) robot->p_x=rr2; if (robot->p_x>1.0-rr2) robot->p_x=1.0-rr2; if (robot->p_y<rr2) robot->p_y=rr2; if (robot->p_y>1.0-rr2) robot->p_y=1.0-rr2; }

rr1 = /* minimal wall distance */ 0.015

This is for avoiding walls. The walls of the arena. arena in robot dynamics is 1x1

4. How the robot updates glabal and local best position?

Take a random robot see if it finds the global position. if you have not found that position, update yours. for (r=0;r<NR;r++) { rg=(int)(drand48()*(double)NR); if ((robots[rg]->p_x<0.49)&&(robot->p_x>0.49)) { robot->gbx=robots[rg]->p_x; robot->gby=robots[rg]->p_y; break; } else { robot->gbx=robot->p_x; robot->gby=robot->p_y; } }

This needs a little fixing I think. if (robot->p_x<0.49) { robot->pbx=robot->p_x; robot->pby=robot->p_y; } else { robot->pbx=robot->p_x; robot->pby=robot->p_y; }