This paper presents a model predictive control approach for regulating the attitude of magnetically actuated satellites. Unlike other contributions in this area, a predictive control approach is developed which guarantees closed-loop stability of satellite configurations with unstable open-loop pitch dynamics. With the pitch axis being unstable, two magnetic dipoles are used exclusively for reg...

Stability in presence of (possibly varying) time-delays in a control loop consisting of a continuous-time plant and a discrete-time controller is studied. A simple stability criterion is developed, consisting of a graphical test in a Bode plot of the closed loop system. The graphical test makes it very easy to design the controller for time-delay robustness.

This paper is concerned with the stabilization problem for networked control systems (NCSs) with packet-dropouts and delays. A state estimator is incorporated into the controller node, and the controller uses the estimated states when packet-dropouts occur. By using such a estimator-based controller, the closed-loop NCS is modelled as a discrete-time switched systems with both stable and unstab...

Based on a novel robust integral sliding mode surface (RISM), method of designing nonlinear robust sliding mode control is presented. Firstly, the closed-loop system under the sliding mode is proved to be asymptotically stable by using Lyapunov stability theories. Then variable structure control (VSC) is constructed to ensure the reachability of the sliding surface. Robustness of the closed-loo...

Published methods establish how plant-model mismatch in the process gain and dead time impacts closed-loop stability. However, these methods assume no plant-model mismatch in the process time constant. The work presented here proposes the robust stability factor metric, RSF, to examine the effect of plant-model mismatch in the process gain, dead time, and time constant. The RSF is presented in ...

We consider the problem of controlling a linear system when the state is available with a non-negligible delay (delayed-state-feedback control). In such conditions, the resulting closed-loop system is always a time-delay-system. The solution proposed in this paper consists in partially assigning the spectrum of the closed-loop system while ensuring the exponential zero-state stability with a pr...

The paper investigates the closed-loop stability issue of finite-precision realizations for digital controllers implemented in floating-point arithmetic. Unlike the existing methods which only address the effect of the mantissa bits in floating-point format to the sensitivity of closed-loop stability, the sensitivity of closed-loop stability is analyzed with respect to both the mantissa and exp...

Background: Impairment of cervical sensory input in patients with neck pain may disturb postural stability. The purpose of present study was to assess the dynamic postural stability of subjects with chronic neck pain compared to a matched control group.    Methods: In this case-control study, 22 chronic non-specific neck pain and 22 healthy individuals participated. Postural stabilit...

A new control algorithm has been developed for linear stochastic ARMAX systems subjected to arbitrary random inputs. The purpose is to make the shape of the output probability density function (PDF) to be as close as possible to a target PDF. A feedback control function is formulated to re-configure the open-loop linear system into a non-linear closed-loop system, where the vector of control pa...