In this paper, we study a class of discrete-time switched linear systems affected by both parameter variations and additive l∞ bounded disturbances. The problem of determining upper bounds on the l∞ norm of the output is investigated. First, we study the condition under which the switched systems have finite l∞ induced gain. Secondly, the l∞ induced gain is calculated for such switched system u...

In this paper, the design of linear active disturbance rejection control (LADRC) for high order systems is presented and the frequency response is analyzed. First, the LADRC for minimum-phase processes is introduced, and the parameterization of tuning paramters, which reduces the tuning parameters to controller bandwidth and observer bandwidth, is given. With the transfer function of the LADRC,...

The algorithm with compensation of parametric uncertainties, external disturbances and measurement noises for linear time-invariant plants is designed. It is assumed, that the dimension of the noise can be equaled to the state vector dimension and the disturbance can be presented in any equation of the plant model. Analytical condition for algorithm feasibility is proposed. Simulation results s...

In the paper, an output-based disturbance observer of reduced order is presented for a class of discretetime linear systems. First, a general form of a disturbance observer is proposed when full states are available. Then, by combining a state function estimator of minimal order, an output-based disturbance observer is derived. The existence condition will be formulated in the form of a static ...

In this paper we study the question under which conditions a linear multi-modal system is disturbance decoupled. We establish necessary and sufficient geometric conditions from which the existing results on switched linear systems and conewise linear systems can be recovered as special cases. Also, we apply these conditions to a class of linear complementarity systems in order to obtain a more ...

Gorgonian octocorals are the most abundant corals in Alaska where they provide important structural habitat for managed species of demersal fish and invertebrates. Fifty-nine gorgonian species have been reported from Alaska waters but little is known about their life history characteristics to help us gauge their ability to recover from seafloor disturbance. Colonies of the holaxonian Calcigorg...

This paper proposes an adaptive approximation-based controller for uncertain strict-feedback nonlinear systems with unknown dead-zone nonlinearity. Dead-zone constraint is represented as a combination of a linear system with a disturbance-like term. This work invokes neural networks (NNs) as a linear-in-parameter approximator to model uncertain nonlinear functions that appear in virtual and act...

The problem of adaptive fault-tolerant control for linear systems with time-varying actuator faults including outage and loss of effectiveness is investigated in this paper. After presenting a time-varying actuator fault model, a novel adaptive observer is designed so that the fault parameter can be estimated fast. Here, the inevitable fault estimation error, as well as the exogenous disturbanc...

Higher productivity requires high-speed motion of machine tool axes. The iron core linear DC motor (LDM) is widely accepted as a viable candidate for high-speed machine tool feed unit. LDM, however, has two inherent disturbance force components, namely cogging and thrust force ripple. These disturbance forces directly affect the tracking accuracy of the feeding system and must be eliminated or ...