Constraints other than nonnegativity on ode solver?

4 views (last 30 days)
I'm using ode45 to solve the equations of motion of some robot arm. I know I can use the odeset option 'NonNegative' to tell the solver that certain states must be nonnegative, but what if I want certain states to be bounded by different numbers? So say, I have a state q: q = [q1 q2 q3] and I want q1 to be in between -pi/2 and pi/2 and I want q3 to be in between 0 and 1... Is there any way to do this?
Thanks in advance

Answers (1)

Matt J
Matt J on 13 Dec 2014
Edited: Matt J on 15 Dec 2014
You could try transforming the state variable like
where y is the transformed state variable. The derivatives in the state equation also have to rewritten in terms of y
dq3/dt= (cos(y)/2)*dy/dt
but it looks like the cos(y)/2 part can be accounted for using a mass matrix.
Iris on 15 Dec 2014
Normally I would add constraints to my equations, but this is an assignment for which I have to use the port-Hamiltonian formalism and I have not included the constraints. But I was just going to try to build in constraints now myself. I'll let you know if it worked. Thanx for your input so far though!

Sign in to comment.

Community Treasure Hunt

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

Start Hunting!