For loop in for loop

Question

Vinay Basagare 2021-12-19

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1614125-for-loop-in-for-loop

评论： Vinay Basagare 2021-12-19

k11=28.21;
k21=-4.23;
k12=-18.133;
k22=2.59;
k13=20.815;
k23=-2.97;
t=0:0.1:3;
num_t=length(t);
t4=0;
t3=-0.3588;
t2=0.2433;
t1=-0.81;
R21 = [cos(t2) -sin(t2) 0;
    sin(t2) cos(t2) 0;
    0 0 1];
R32=[cos(t3) -sin(t3) 0;
    sin(t3) cos(t3) 0;
    0 0 1];
D4=[0 0 0.450+0.092];
D3=[0.440 0 0];
D2=[0; 0.33; 0];
D1=[0.05; 0; 0];
t = 0:.1:3;
num_t = length(t);
for i=1:num_t
    
    tdot1=k11+2*k21*t(i);
    tdot2=k12+2*k22*t(i);
    tdot3=k13+2*k23*t(i);
    t2dot1=2*k21;
    t2dot2=2*k22;
    t2dot3=2*k23;
    w1=[0;0;tdot1*2*pi/360];
    w2=R21*w1+[0;0;tdot2*2*pi/360];
    w3=R32*w2+[0;0;tdot3*2*pi/360];
    
    uW1(i)=w1(3,1);
    uW2(i)=w2(3,1);
    uW3(i)=w3(3,1);
    
    v2=R21*cross(w1,D1);
    v3=R32*(v2+cross(w2,D2));
    uV2(i)=norm(v2);
    uV3(i)=norm(v3);
    W1=[0;0;w1(i)];
    alfa1=t2dot1;
    Tdot2=[0;0;tdot2(i)];
    alfa2=t2dot2+R21*alfa1+R21*cross(W1,Tdot2);
    W2=[0;0;w2(i)];
    Tdot3=[0;0;tdot3(i)];
    alfa3=t2dot3+R32*alfa2+R32*cross(W2,Tdot3);
    ua2(i)=alfa2(3,1);
    ua3(i)=alfa3(3,1);
    
end
Index exceeds the number of array elements. Index must not exceed 1.
hold on
figure(1)
plot(t,uW1,'-*')
xlabel('time[s]');
ylabel('w1[rad/s]');
figure(2)
plot(t,uW2,'*')
xlabel('time[s]');
ylabel('w2[rad/s]');
figure(3)
plot(t,uW3,'*')
xlabel('time[s]');
ylabel('w3[rad/s]');
figure(4)
plot(t,uV2,'.')
xlabel('time[s]');
ylabel('v2[m/s]');
figure(5)
plot(t,uV3,'.')
xlabel('time[s]');
ylabel('v3[m/s]');
hold on 
figure(1)
plot(t,ua2,'*')
xlabel('time[s]');
ylabel('alfa2[rad/s^2]');
figure(2)
plot(t,ua3,'*')
xlabel('time[s]');
ylabel('alfa3[rad/s^2]');

Should I be using another For loop for the plot of Alpha vs time? I am unable to understand how can I get rid of the error at line 48.Please help me. Thanks in advance.

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Vinay Basagare 2021-12-19

I understood and I am expecting a vector of length 3.

Vinay Basagare 2021-12-19

I just want to take it as the first element of w(i) should be taken when the first element of tdot1 is taken and thats why i thought to use it that way. but, i got your point. Thanks for the whole explaination. I really apprecaite it.

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Answer 1

VBBV 2021-12-19

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1614125-for-loop-in-for-loop#answer_858335

在 MATLAB Online 中打开

 k11=28.21;
k21=-4.23;
k12=-18.133;
k22=2.59;
k13=20.815;
k23=-2.97;
t=0:0.1:3;
num_t=length(t);
t4=0;
t3=-0.3588;
t2=0.2433;
t1=-0.81;
R21 = [cos(t2) -sin(t2) 0;
sin(t2) cos(t2) 0;
0 0 1];
R32=[cos(t3) -sin(t3) 0;
sin(t3) cos(t3) 0;
0 0 1];
D4=[0 0 0.450+0.092];
D3=[0.440 0 0];
D2=[0; 0.33; 0];
D1=[0.05; 0; 0];
t = 0:.1:3;
num_t = length(t);
for i=1:num_t
tdot1=k11+2*k21*t(i);
tdot2=k12+2*k22*t(i);
tdot3=k13+2*k23*t(i);
t2dot1=2*k21;
t2dot2=2*k22;
t2dot3=2*k23;
w1=[0;0;tdot1*2*pi/360];
w2=R21*w1+[0;0;tdot2*2*pi/360];
w3=R32*w2+[0;0;tdot3*2*pi/360];
uW1(i)=w1(3,1);
uW2(i)=w2(3,1);
uW3(i)=w3(3,1);
v2=R21*cross(w1,D1)
v3=R32*(v2+cross(w2,D2))
uV2(:,i)=norm(v2)
uV3(:,i)=norm(v3)
W1=[0;0;w1];
alfa1=t2dot1;
Tdot2=[0;0;tdot2];
alfa2=t2dot2+R21*alfa1+R21*cross(w1,Tdot2);
W2=[0;0;w2];
Tdot3=[0;0;tdot3];
alfa3=t2dot3+R32*alfa2+R32*cross(w2,Tdot3);
ua2(i)=alfa2(3,1)
ua3(i)=alfa3(3,1)
end;
figure(1)
plot(t,uW1,'-*')
xlabel('time[s]');
ylabel('w1[rad/s]');
figure(2)
plot(t,uW2,'*')
xlabel('time[s]');
ylabel('w2[rad/s]');
figure(3)
plot(t,uW3,'*')
xlabel('time[s]');
ylabel('w3[rad/s]');
figure(4)
plot(t,uV2,'.')
xlabel('time[s]');
ylabel('v2[m/s]');
figure(5)
plot(t,uV3,'.')
xlabel('time[s]');
ylabel('v3[m/s]');
figure(6)
plot(t,ua2,'*')
xlabel('time[s]');
ylabel('alfa2[rad/s^2]');
figure(7)
plot(t,ua3,'*')
xlabel('time[s]');
ylabel('alfa3[rad/s^2]');