On the swing-up of the Pendubot using virtual holonomic constrains

We investigate the problem of stabilizing energy level sets for Euler-Lagrange systems subject to virtual holonomic constraints. We present an energy level set stabilization technique with a guaranteed domain of attraction which preserves the invariance of the constraint manifold. As an illustration of the theory, we present a controller which swings up the Pendubot system while guaranteeing that the unactuated link does not fall over during transient.