Book Description

This report presents methodologies for the direct digital control of vehicles with flexible modes. The techniques yield robust control system designs with modest or minimal requirements on the number of sensors and control actuators. the digital system techniques used include primarily the w-transforms for direct design and stability assessment, and the 'hybrid' frequency response, for assessment and understanding of digital system peculiarities. The 'sawtooth Bode' is used as the basic control system design concept. These three elements are applied to several examples, including a comprehensive case study for a fighter aircraft flight and flexible mode control system. Both continuous and discrete system designs are considered and the continuous system characteristics are contrasted with an optimal control design. This comparison pinpoints some of the features needed to make optimal control procedures more practical and mature for flexible vehicle control applications. An important step is taken in this direction by determining the nature of performance criteria which yield, for an example case, a highly robust, extremely simple controller derived from an optimal control procedure.