How nestling birds respond to stressful situations may constitute an important survival component that has lasting developmental effects on the hypothalamic pituitary adrenal (HPA) axis. As birds are exposed to increasing amounts of potential anthropogenic stressors through land use change, understanding how these factors contribute to HPA development is important. We examined whether condition...

This paper proposes a hybrid control scheme for the synchronization of two chaotic Duffing oscillator system, subject to uncertainties and external disturbances. The novelty of this scheme is that the Linear Quadratic Regulation (LQR) control, Sliding Mode (SM) control and Gaussian Radial basis Function Neural Network (GRBFNN) control are combined to chaos synchronization with respect to extern...

This paper is devoted to the problem of force sensorless disturbance rejection in robot manipulators. In the proposed approach, the control system uses position sensor signals and estimated values of external forces, instead of force sensor signals. The estimation process is performed via an adaptive force estimator. Then the estimated force vector is utilized to compensate for the force distur...

Predictive control technique is applied to the three-axis attitude control of spacecraft. The principal idea of predictive control is to construct a priori reference trajectory and build control command so that the actual system follows the reference trajectory. In the case of this study, the controlled variables are the quaternion attitude parameters and angular rates of spacecraft body axes. ...

This paper investigates tracking performance limitations of a linear time invariant (LTI) multivariable plant subject to external disturbance or model uncertainty. It attempts to extend some recent results on tracking performance limitation in which neither the disturbance nor the uncertainty is considered. The reference signal to be tracked is a step signal. The tracking performance is measure...

Flexible membranes are envisioned as a key component of large, lightweight, space-based systems. This paper focuses on the problem of adaptive disturbance rejection, that is, the rejection of external disturbances with unknown spectral content. It describes the design and operation of a laboratory testbed involving a flexible membrane with acoustic excitation and optical sensing. The ARMARKOV a...

Adaptive back stepping control (ABC) is originally applied to a linearized model of an active magnetic bearing (AMB) system. Our control goal is to regulate the deviation of the magnetic bearing from its equilibrium position in the presence of an external disturbance and system uncertainties. Two types of ABC methods are developed on the AMB system. One is based on full state feedback, for whic...

one of the most important challenges in nonlinear, multi-input multi-output (mimo) and time variant systems (e.g., robot manipulator) is designing a controller with acceptable performance. this paper focused on design a new artificial non linear controller with on line tunable gain applied in the robot manipulator. the sliding mode fuzzy controller (smfc) was designed as 7 rules mamdani’s infer...

Index Terms—sliding mode control, uncertainty and disturbance estimation, flexible joint. Abstract—This paper proposes sliding mode control based on uncertainty and disturbance estimator (UDE), for trajectory tracking control of flexible joint robotic system. UDE is used to estimate plant uncertainty and disturbances. The controller does not requires knowledge of plant uncertainty and external ...