6. Nonlinear Adaptive Control

Exact linear models are obtained using the technique known as input–output feedback linearization, that is applied to a bilinear finite-dimensional state-space approximation of the dynamics of a distributed collector solar field. A control Lyapunov function is then used to jointly design the adaptation law for the uncertain parameter that measures the mirror efficiency, and the gain of the pole-placement controller. Provided that the plant is represented by the finite-dimensional bilinear model considered, this approaches ensures the stability of the overall controlled system, and that the outlet fluid temperature asymptotically approaches the reference. A reduced complexity controller designed along these lines is obtained and the resulting internal state dynamics is studied. Experimental results on a distributed collector solar field are shown.