Plotting as intregral the acceleration of a thing

Hello.

Im stuck at a problem. Cant figure out how to plot my ploblem and if its my plot at fault or the math. Any help would be great !

I've tried to plot it and get right equtions for the acceleratons lines.

This is the plot im trying to get from the math/plot

Let me know if this doesnt belong here.

This is my code :

clear all

t1=1;
t2=2;
t3=3;
T=11;
A =2;

v(1) = 0

v = 0

s(1) = 0

s = 0

N=100

N = 100

dt=T/N

dt = 0.1100

t=0:dt:T;


a1=2*t;
a2=A

a2 = 2

a3=-2*t+8

a3 = 1×101

8.0000 7.7800 7.5600 7.3400 7.1200 6.9000 6.6800 6.4600 6.2400 6.0200 5.8000 5.5800 5.3600 5.1400 4.9200 4.7000 4.4800 4.2600 4.0400 3.8200 3.6000 3.3800 3.1600 2.9400 2.7200 2.5000 2.2800 2.0600 1.8400 1.6200

a4=0

a4 = 0

a5=-2*t+14

a5 = 1×101

14.0000 13.7800 13.5600 13.3400 13.1200 12.9000 12.6800 12.4600 12.2400 12.0200 11.8000 11.5800 11.3600 11.1400 10.9200 10.7000 10.4800 10.2600 10.0400 9.8200 9.6000 9.3800 9.1600 8.9400 8.7200 8.5000 8.2800 8.0600 7.8400 7.6200

a6=A

a6 = 2

a7=2*t-22

a7 = 1×101

-22.0000 -21.7800 -21.5600 -21.3400 -21.1200 -20.9000 -20.6800 -20.4600 -20.2400 -20.0200 -19.8000 -19.5800 -19.3600 -19.1400 -18.9200 -18.7000 -18.4800 -18.2600 -18.0400 -17.8200 -17.6000 -17.3800 -17.1600 -16.9400 -16.7200 -16.5000 -16.2800 -16.0600 -15.8400 -15.6200

 % < less than
 % > greater than
 
a=a1.*(t<=t1)  +  a2.*((t>t2)&(t>=t1))  +  a3.*(t>t1)    +  a4.*(t==t3)    +  a5.*(t>t1)   +  a6.*(t==t2)   +  a7.*(t>t1);


v(1)=0

v = 0

s(1)=0

s = 0

for k=1:N
    v(k+1)=v(k)+a(k)*dt;
    s(k+1)=s(k)+v(k)*dt+1/2*a(k)*dt^2;
end
figure(4)
subplot(3,1,1)
plot(t,a,'linewidth',2)
grid
subplot(3,1,2)
plot(t,v,'linewidth',2)
grid
subplot(3,1,3)
plot(t,s,'linewidth',2)
grid

[Les Beckham]

You haven't explained what the problem is. What are you seeing vs. what you expect?

I don't think your calculation of a is doing what your sketch shows.

[pauli relanderi]

Okey. Its a object moving forward. Trying to and atleat i think ive calculated the accelerations righ. The lines goin up, down, down, up. and i need to make a plot by calculating it with the : a=a1.*(t<=t1) + a2.*((t>t2)&(t>=t1)) + a3.*(t>t1) + a4.*(t==t3) + a5.*(t>t1) + a6.*(t==t2) + a7.*(t>t1);

But i cant for the life of me figure out how to plot with that a line goint forward in x but not changing y

Answer 1

[Sulaymon Eshkabilov]

This is how you can solve this exercise:

N=100;        
T=11;
dt=T/N;
t=0:dt:T;
F =    [0 2  2  0  0  -2  -2  0];   % Acceleration pattern
Time = [0 1  3 4   7  8  10 11];    % Time intervals corresponding the Acceleration pattern 
FF = griddedInterpolant(Time, F);   % Grid interpolation w.r.t time intervals
a = FF(t);                          % Compute the gridded acceleration values according to time signal values of t

v(1)=0;
s(1)=0;
for k=1:N
    v(k+1)=v(k)+a(k)*dt;
    s(k+1)=s(k)+v(k)*dt+1/2*a(k)*dt^2;
end
figure
subplot(3,1,1)
plot(t,a,'linewidth',2, 'DisplayName','Acceleration: a(t)', 'Color','r')
grid on; legend show
ylabel('$a(t)$', 'Interpreter','latex')

subplot(3,1,2)
plot(t,v,'linewidth',2, 'DisplayName', 'Velocity: v(t)', 'Color',[0 .75 .5])
grid on; legend show
ylabel('$v(t)$', 'Interpreter','latex')

subplot(3,1,3)
plot(t,s,'linewidth',2, 'DisplayName','s(t)', 'Color',[0 0.25 0.85])
legend show; grid on
ylabel('$s(t)$', 'Interpreter','latex')
xlabel('Time, [s]')