where g : R × R × R → R is a C function. Once we specify a parameter path u(t), t ≥ t1, in the parameter space we can solve (1.1) uniquely for x(t), t ≥ t1, with the given initial condition x(t1) = x0. Alternatively if we specify a parameter path u(t), t ≤ t1, in the parameter space we can solve (1.1) uniquely for x(t), t ≤ t1, with the given terminal condition x(t1) = x0. Suppose now that for ...

Control theory is a mathematical description of how to act optimally to gain future rewards. In this paper I give an introduction to deterministic and stochastic control theory; partial observability, learning and the combined problem of inference and control. Subsequently, I discuss a class of non-linear stochastic control problems that can be efficiently solved using a path integral. In this ...

Feedback control is a control mechanism that uses information from measurements. In a feedback control system, the output is sensed. There are two main types of feedback control systems: 1) positive feedback 2) negative feedback. The positive feedback is used to increase the size of the input but in a negative feedback, the feedback is used to decrease the size of the input. The negative system...

Originally this word “cybernetics” came from the Ancient Greece, and it meant “the art of steersman”. Cybernetics is the “old-fashion” term for what is now called as the general system’s theory, or the system science. We can admit that cybernetics was born in 1948, when the book with the same title has been written by the famous American mathematician Norbert Wiener (1894-1964) [1]. The diction...

The control of quantum dynamics via specially tailored laser pulses is a longstanding goal in physics and chemistry. Partly, this dream has come true, as sophisticated pulse-shaping experiments allow us to coherently control product ratios of chemical reactions. The theoretical design of the laser pulse to transfer an initial state to a given final state can be achieved with the help of quantum...

The use of control theory in a LQG form for quantum mechanical situations has revealed a new conceptualization of knowledge, measurement and feedback. The benefits of state estimation by the Kalman filter has shown up in theoretical calculations for cooling and confining of an atom in a harmonic potential, surpassing previous proposals of direct feedback. The goal of this thesis is to explore t...

This paper gives a summary of a body of work at the intersection of control theory and smooth nonlinear dynamics. The main idea is to transfer the concept of uniform hyperbolicity, central to the theory of smooth dynamical systems, to controlaffine systems. Combining the strength of geometric control theory and the hyperbolic theory of dynamical systems, it is possible to deduce control-theoret...

The purpose of this paper is to present a brief sketch of the evolution of modern control theory. Systems theory witnessed different stages and approaches, which will be very shortly presented. The main idea is that, at present, Control Theory is an interdisciplinary area of research where many mathematical concepts and methods work together to produce an impressive body of important applied ma...