CONTROLS DESIGN CHALLENGE - A VARIABLE-STRUCTURE APPROACH

The purpose of this paper is to investigate variable structure control as a tool for the design of night control systems. Variable structure control allows the direct incorporation of model uncertainties and no nlinearities in the design process, yielding a piecewise continuous st ructure for the compensator that maintains the system dynamics along s pecified stable trajectories (sliding hypersurfaces). Under mild restr ictions, the resulting control law is robust with respect to unknown b ut bounded parameter variations and other uncertainties. A linearized model of an aircraft is used for the design, and a night control syste m is synthesized, which gives desired response to initial conditions a nd tracks a commanded altitude, The control synthesis and simulation a re performed using computer-aided software on a personal computer.