A comparison of loop shaping techniques

Three control law design techniques that shape the singular values of the loop transfer function frequency response to meet performance and robustness objectives are presented. The well known linear quadratic Gaussian synthesis with loop transfer recovery is presented as a basis of comparison with two other techniques: H_∞ synthesis with loop transfer recovery and mixed H₂ and H_∞ synthesis with loop transfer recovery. The three techniques are each applied to a simple numerical example