Hi, i’m looking for some mathematical tools for analysis or classification of solutions of optimal control problems/variational. Equations of motions and optimized function depend on some parameters eg. dX1/dt = f(X1,X2, u1, p1) dX2/dt = f(X1,X2, u2, p2) where X1,X2 are state variables, u1,u2 are controls and p1,p2 are parameters. I would be interested in answer the question for what p1,p2 there is u2 = 0 for whole time. I’m looking for something like bifurcation theory/phase portrait from dynamical system which might be applied for optimal control problems.