In this work, we show how the double-Youla parameterization can be used to recast the robust tuning of a feedback controller as a robust estimation problem. The formulation as an estimation problem allows tuning of the controller in realtime on the basis of closed loop data. Furthermore, robust estimation is obtained by constraining the parameter estimates so that feedback stability will be mai...

A new hybrid adaptive control algorithm is proposed for the nonlinear system controller design of underwater robot. Compared with the previous works in the controller design of underwater robot, the main advantages of this work are: (1) A new disturbance prediction and compensation model is proposed; (2) A new adaptive fuzzy smoother is proposed for the control input; (3) A time-varying flow di...

This paper investigates two chattering-free finite-time controllers for the rigid spacecraft attitude tracking control problem considering modeling uncertainty and external disturbance. First, the basic controller is designed utilizing integral terminal sliding mode surface (ITSMS) with prior knowledge of the total system uncertainty consisting of modeling uncertainty and external disturbance. ...

In the paper we present tuning rules for PI and PID controllers and the first order plus dead time (FOPDT) process model. The settings respect both performance and stability indices and provide a high degree of robustness for any value of the dead time parameter. As the performance index we are using the well known modulus optimum criterion, which requires that the amplitude of the closed-loop ...

This paper is concerned with the output feedback control design for a class of nonlinear uncertain systems subject to multiple sources of disturbances including model uncertainties, unknown constant disturbances, harmonic disturbances with unknown frequency and amplitude. The total disturbances and uncertainties are delicately represented by a compact exogenous model first. By incorporating the...

The mathematical solutions of the stability convergence are important problems in system control. In this paper, such problems are analyzed and resolved for system control using multilayer neural networks. We describe an algorithm to control an unknown nonlinear system with a disturbance, using a multilayer neural network. We include a disturbance among the modeling error, and the weight update...

In this paper, a robust sliding mode observer (SMO) design problem is investigated for the purpose of reconstruction of actuator faults in a class of uncertain linear systems. A sufficient condition for the existence and the stability of the SMO is established by solving a set of linear matrix inequalities (LMIs). Also, a new design method for the robust SMO with H∞ techniques is proposed to gu...

The paper investigates consensus problem for continuous-time multi-agent systems with time-varying communication graphs subject to process noises. Borrowing the ideas from input-to-state stability (ISS) and integral input-to-state stability (iISS), robust consensus and integral robust consensus are defined with respect to L∞ and L1 norms of the disturbance functions, respectively. Sufficient an...

A notion of robust stability is developed for iterative learning control in the context of disturbance attenuation. The size of the unmodelled dynamics is captured via a gap distance, which in turn is related to the standardH gap metric, and the resulting robustness certificate is qualitatively equivalent to that obtained in classical robust H∞ theory. A bound on the robust stability margin for...

Forest dynamics encompass changes in stand structure, species composition, and species interactions with disturbance and environment over a range of spatial and temporal scales. For convenience, spatial scale is defined as individual tree, neighborhood, stand, and landscape. Whether a given canopy-leveling disturbance will initiate a sequence of development in structure with little change in co...