Extremum seeking for moderately unstable systems and for autonomous vehicle target tracking without position measurements

We remove the long standing restriction that plant dynamics in extremum seeking (ES) must be stable and provide an extension that allows single integrators, double integrators, and moderately unstable single poles. An application for single and double integrators is in control of autonomous vehicles. ES can be used for finding a source of a signal (chemical, electromagnetic, etc.) whose strength decays with the distance. This can be achieved without the measurement of the position vector and using only the measurement of the scalar signal. Extremum seeking extracts the position information implicit in the scalar measurement and needed for tracking through non-model based gradient estimation