Comments on the benchmark for "Design and optimization of restricted complexity controllers" : towards a non-parametric model based solution

Benchmark models and specifications for "Design and Optimization of Restricted Complexity Controllers" are discussed and analyzed in relation with previous works on control of flexible structures. Then, a very classical frequency domain design based on the non-parametric model (that is: on experimental data) and phase control is proposed.Graphical tools developed and used to guide this trials and errors design are provided to the reader.