Loop Transfer Recovery

Loop Transfer Recovery (LTR) is a general method for designing linear control systems. The idea is, that the demands to the dimensioning are formulated as frequency domain properties, by prescribing desired behaviours for a number of transfer functions in the control system. Traditionally, linear and quadratic optimization has been applied in connection with LTR design methods. However, it is by far more natural to define the final demands in H-infinity norm, since the final target almost always contains a specification of robustness, which is easily handled with H-infinity Theory. Through several publications it has been described how H-infinity Theory may be applied for this purpose in theory as well as in practice.