The robust control problem for nonlinear systems is discussed from the standpoint of the amplitude sensitivity of the nonlinear plant and final control system. Failure to recognize and accommodate this factor may give rise to nonlinear control systems that behave differently for small versus large input excitation, or perhaps exhibit limit cycles or instability. Sinusoidal-input describing func...

In this paper we analyze the quantum control of squeezed states of harmonic oscillators as well as spin squeezing and its relationship to quadrature squeezed states of other bosonic fields. Squeezing provides a method for reducing noise below the quantum limit and provides an example of the control of under-actuated control systems in the stochastic and quantum context. We consider also the int...

In this paper, an observer-based adaptive feedback controller is developed for a class of chaotic systems. This controller does not need the availability of state variables. It can be used for tracking a smooth orbit that can be a limit cycle or a chaotic orbit of another system. This adaptive feedback controller is constructed with the aid of its H∞ control technique to achieve the H∞ tracking...

In this paper we present an economic model of optimal consumption and labour supply where we assume that working may generate stress which affects the wellbeing of the representative individual. As to stress we posit that it is influenced by cumulated past labour and capital. The latter reflects the fact that work-related stress evolves gradually over time and that it is more likely to occur in...

This paper presents a robust control strategy driving an actuated compass gait robot towards steady and periodic gaits. By robust we mean a large basin of attraction for the limit cycle. The originality lies in the generation of the swing leg reference angle and speed as a simple function of the supporting leg angle. Simulations and experimentation with a prototype showed that the system exhibi...

This paper considers a limit cycle control problem of a multi-modal and 2-dimensional piecewise affine control system. Limit cycle control means a controller design method to generate a limit cycle for given piecewise affine control systems. First, we deal with a limit cycle synthesis problem and derive a new solution of the problem. In addition, theoretical analysis on the rotational direction...

The paper presents a theoretical and numerical study of the existence problem of self-sustained periodic solutions in feedback control systems including a hysteresis nonlinearity with non-local memory. The presence of this type of nonlinearity in the feedback control system can cause undesired effects, e.g. limit cycles, instability, and thus must be taken into account in the design phase of th...

Abstract Combining external control with long spin lifetime and coherence is a key challenge for solid state qubits. Tunnel coupling electron Fermi reservoir provides robust charge in semiconductor quantum dots, but results undesired relaxation of nuclear spins through mechanisms that lack complete understanding. Here, we unravel the contributions tunnelling-assisted phonon-assisted by systemat...