For the blood cell production model with a unimodal (hump) feedback function dy dt 1⁄4 cyðtÞ þ bh yðt sÞ h þ ynðt sÞ ; we review the known results and investigate generalizations of this equation. Permanence, oscillation and stability of the positive equilibrium are studied for non-autonomous equations, including equations with a distributed delay. In addition, a linear control is introduced, a...

In this paper, we investigate equilibrium points of tine nonlinear control systems and construct a scheduled control law composed of a feedforward control and a family of state feedbacks. Representing the system by a parameterized family of linear models along its equilibrium points, a scheduled control law with a feedforward control and local linear robust controllers is designed so that the o...

Recent results show that a nonsmooth time invariant feedback control law can be used to stabi lize an axi symmetric rigid body using only two con trol torques to the zero equilibrium This method however may require a signi cant amount of con trol e ort especially for initial conditions close to an equilibrium manifold In this paper we propose a control law which reduces the control e ort re qui...

The role of continuous auditory feedback in multimodal embodied interfaces is advocated. Examples of physicsbased cartoon sound models (rolling and friction) are used to display deviation from equilibrium and exerted effort in manipulative interfaces.

Starting from a symmetric state-feedback solution ensuring α-exponential convergence in an ellipsoidal sublevel set, with asymmetric saturation and single-input linear plants, we propose novel scheduled extension preserving the original that set extending guaranteed stability region to union of all possible contractive ellipsoids centered at shifted equilibrium. Our design being based on parame...

We consider digital feedback control systems with time-varying sampling periods consisting of an interconnection of a continuous-time nonlinear plant, a nonlinear digital controller and appropriate interface elements between the plant and controller (A/D and D/A converters). For such systems we study the stability properties of an equilibrium (in the Lyapunov sense) and apply these results in t...

Atmospheric response to SST variability was estimated using generalized equilibrium feedback analysis (GEFA) in the SST EOF space with synthesis data from an idealized climate model. Results show that the GEFA atmospheric response to the leading SST EOF modes is much more accurate and robust than the GEFA feedback matrix in physical space. Therefore, GEFA provides a practical method for assessi...

We define bifurcations of control-affine systems in the plane and classify all generic 1-parameter bifurcations at control-regular points. More precisely, we classify topological bifurcations of invariants of usual feedback equivalence. Such bifurcations form six different classes: two bifurcations of equilibrium sets, two bifurcations of critical sets, and two bifurcations of pairs of invarian...

In this letter, a new four-dimensional continuous autonomous hyperchaotic system, which is constructed based on a modified finance system by introducing a nonlinear state feedback controller. The detailed dynamical behaviors of this hyperchaotic system are further investigated, including equlibria and stability, various attractors, bifurcation analysis, and Lyapunov exponents spectrum. Furtherm...

A feedback control method and an adaptive feedback control method are proposed for Chua’s circuit chaos system, which is a simple 3D autonomous system. The asymptotical stability is provenwith Lyapunov theory for both of the proposedmethods, and the system can be dragged to one of its three unstable equilibrium points respectively. Simulation results show that the proposed methods are valid, an...