Construction of control lyapunov functions for damping stabilization of control affine systems

This paper considers the construction of control Lyapunov functions (CLF) for the stabilization of nonlinear control affine systems that satisfy Jurdjevic-Quinn conditions. First, we obtain a one-form for the system by taking the interior product of a non vanishing two-form with respect to the drift vector field. We then construct a homotopy operator on a star-shaped region centered at a desired equilibrium point that decomposes the system into an exact part and an anti-exact one. Integrating the exact one-form, we obtain a dissipative potential that is used to generate the damping feedback controller. Applying the same decomposition approach on the entire control affine system under damping feedback, we obtain a control Lyapunov function for the closed-loop system. Under Jurdjevic-Quinn conditions, it is shown that the obtained damping feedback is locally stabilizing the system to the desired equilibrium point provided that it is the maximal invariant set for the controlled dynamics, which is associated with the structure of the anti-exact part. An example is presented to illustrate the method.