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Index exceeds the number of array elements (1) error

Asked by Zafer Duyenli on 10 Nov 2018
Latest activity Commented on by Zafer Duyenli on 10 Nov 2018
Greetings,
I'm trying to make a position analysis of a mechanism via Newton-Raphson algorithm and when I constructed my model matrixes, I have this error "Index exceeds the number of array elements (1)" and I couldn't decide how to reduce my index. Could that error occurs because of that I'm missing something while giving the parameters? Whole model is given below:
clc, clear all;
%initiating physical parameters
a2=29;a3=15;a4=16;a5=27;a6=25;th4=332*pi/180;thd=240*pi/180;
%initiating max iteration
Nmax=100;
%initiating guess values for th3, th5, th6, to
x=[14*pi/180,59*pi/180,323*pi/180,32];
%initiate error tolerance
xe=0.001*abs(x);
%initiating system inputs
dth=5*pi/180;
th2=-30*pi/180:dth:30*pi/180;
w2=35*ones(1,length(th2));
al2=0*ones(1,length(th2));
%-------------------------
xe=transpose(abs(xe));
kerr=1;
for k=1:1:length(th2);
for n=1:Nmax
%-------------------
%assign initial gues to unknowns
th3(k)=x(1);th5=x(2);
th6=x(3);to=x(4);
%jacobian matrix
J=zeros(4,4)
J(1,1)=-a3*sin(th3(k));J(2,1)=a3*cos(th3(k));
J(3,2)=-a5*sin(th5(k));
J(3,3)=-a6*sin(th6(k));
J(3,4)=-1;
J(4,2)=a5*cos(th5(k));J(4,3)=a6*cos(th6(k));
%INPUT: FUNCTIONS
f=zeros(4,1);
f(1,1)=(a2*cos(th2(k))+a3*cos(th3(k))+a4*cos(th4)+a5*cos(thd)-43);
f(2,1)=(a2*sin(th2(k))+a3*sin(th3(k))+a4*sin(th4)+a5*sin(thd)+31);
f(3,1)=(a5*cos(th5(k))+a6*cos(th6(k))-to(k));
f(4,1)=(a5*sin(th5(k))+a6*sin(th6(k))-12);
%----------------
eps=inv(J)*f;x=x+transpose(eps);
if abs(eps)<xe
kerr=0;break
end
end
if kerr==1
'Error nr'
end
th3(k)=x(1);th5(k)=x(2);
th6(k)=x(3);to(k)=x(4)
end
thank you for answers.

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1 Answer

Answer by Bruno Luong
on 10 Nov 2018
 Accepted Answer

%assign initial gues to unknowns
th3(k)=x(1);th5=x(2);
th6=x(3);to=x(4);
I think it should be
th3(k)=x(1);
th5(k)=x(2);
th6(k)=x(3);
to(k)=x(4);

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