Is it possible to update the bounds of `Constraint`?

Question

I'm using KinematicTrajecotyOptimization. I want to update the coefficients for some constraints and then resolve the problem. Some of the constraints can be updated because they are LinearConstraint, but others can't be updated because they are Constraint which does not have API like UpdateCoefficients. For example the constraints 1 and 2 in the following code:

trajopt = KinematicTrajectoryOptimization(...)
goal_constraint = PositionConstraint(...)
trajopt.AddPathPositionConstraint(goal_constraint, 1)  # constraint 1
dq_constraint = LinearConstraint(...)
trajopt.AddVelocityConstraintAtNormalizedTime(dq_constraint, 0)  # constraint 2

It seems updating coefficients of goal_constraint is not effective.

Answer 1

You're right. The PathConstraint in use here makes a copy of the bounds of the wrapped Constraint, so any further updates to the wrapped constraint's bounds will be ignored.

If this is in Python, possibly you can figure out a way to identify the PathConstraint in the list of trajopt.get_mutable_prog().generic_constraints() and call set_bounds on that object.