Multidimensional Loads Criteria for Active Load Alleviation Control Design

Kurzfassung

This paper presents a new approach allowing the high-level decomposition of multidimensional load envelope, sometimes referred to as “load potatoes”, targets, leading to a set of requirements to complement established control design criteria on the individual load types at each load station. As the key element of the presented method, load case trajectories are mapped onto specific, often skewed, directions of the considered multidimensional space, enabling converting multidimensional load envelope targets into series of elementary one-dimensional optimisation requirements. The stated method addresses the opportunity to formulate optimisation criteria which enable the flight control designer to express target deformations of multidimensional load envelopes. Combined with a tightening/relaxation of the weights and constraints, the method allows shaping these multidimensional load envelopes, provided that sufficient control authority is available. Whilst the control design method is applicable to all types of load alleviation controllers or any similar multi-dimensional problems, its principle is explained and illustrated with the example of the design of a gust load alleviation controller.