Technology and design needs for precision pointing systems

World War II and the ensuing Cold War drove the development of sensing and weapon directing systems to the microradian level when the pointing systems are mounted on very dynamic hosts. Precision pointing, like all areas of aerospace-high technology, has come to be driven by the need to bring reliable, low risk, technically adequate systems to marketplace quickly and inexpensively. The development of new control design techniques and the commercial availability of software to use them has enabled the state of the art as practiced in industry to advance while simultaneously reducing development costs dramatically. In addition the rapid development of digital signal processing hardware allows the implementation of sophisticated algorithms that an analog designer using operational amplifiers would think are analysts' nightmares. This paper reviews current control systems research in view of the current market for precision pointing systems in the aerospace industry. Special emphasis will be paid to geometric nonlinear control, various forms of robust control, and control of systems with hysteresis.