MATLAB Answers

Matlab function can't reach 2nd element of the input.

2 views (last 30 days)
Ahmet Erikan
Ahmet Erikan on 24 Jul 2021
Commented: Ahmet Erikan on 24 Jul 2021
When I try to run the simulink file shown below, I get the following error.
"Index expression out of bounds. Attempted to access element 2. The valid range is 1-1. More informationFunction '6DOF_Body/wb2Euler' (#29.69.70), line 5, column 13: "2" Launch diagnostic report."
However, the input signal is a 3 element vector. It's the output of 3 integrators joined with a mux. All the dimensions on the simulink file seems alright to me but I keep getting the same error. Why do you think that happens? Thank you for your answers. Here's the code and the simulink file:
function Euler_dot = wb2Euler(wb, Euler)
phi=Euler(1);
theta=Euler(2);
if (theta==pi/2)
theta=(pi/2)+0.001;
end
Rinv=[1 sin(phi)*tan(theta) cos(phi)*tan(theta);0 cos(phi) -sin(theta);0 -sin(phi)*sec(theta) cos(phi)*sec(theta)];
Euler_dot=Rinv*wb;
  1 Comment
Ahmet Erikan
Ahmet Erikan on 24 Jul 2021
Update: The problem seems to be with the Matlab Fcn or my code. I used a subsystem of simulink blocks to replace my Matlab Fcn block and it works just fine now. I'm still curious about what I did wrong with that part so any comment is appreciated. Thanks.

Sign in to comment.

Answers (1)

Sulaymon Eshkabilov
Sulaymon Eshkabilov on 24 Jul 2021
In your simulink model, a mutiplication block (?) has to have matrix multiplication operation. The elementwise multiplication is by default that has to be changed to a matrix multiplication operation.
  1 Comment
Ahmet Erikan
Ahmet Erikan on 24 Jul 2021
Thank you. I believe you're referring to the multiplication with Lbe and yes, I have indeed missed that part. However, that wasn't the problem. I fixed it and I still get the same error. The "Euler" input of the Matlab Fcn "wb2Euler" has 3 element input but when I try to reach the 2nd element, it tells me that the index is out of bounds.
Thanks again for noticing another mistake that would create a problem in the future though. Here's the full picture of the simulink file:

Sign in to comment.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by