About optimal performance and approximation of open-channel hydraulic systems

Investigates the optimal performance of feedback controlled open-channel systems represented by a linear advection-diffusion equation. We show that the performance given by the maximal achievable bandwidth over which the sensitivity function stays below one for such a system is structurally limited. This result is obtained using different tools. Firstly, an approximate value is computed with stability considerations. A close result is also obtained putting the problem in the H_∞ framework. We finally compare the previous results with a qualitative approach using Bode´s ideal loop transfer function