Disturbance-observer-based attitude control under input nonlinearity

Disturbance Observer-Based Simple Nonlinearity Compensation for Matrix Converter Drives

This paper presents a new method to compensate the nonlinearity for matrix converter drives using disturbance observer. The nonlinearity of matrix converter drives such as commutation delay, turn-on and turn-off time of switching device, and on-state switching device voltage drop is modeled by disturbance observer and compensated. The proposed method does not need any additional hardware and of...

Time-domain Approaches for Input Disturbance Observer

In the paper, algorithms for disturbance observers are newly presented in the time-domain. Attention is paid to observing a ramp disturbance by introducing an integral term to the output equation of a constant disturbance observer. In order to reduce the sensitivity to the measurement noise, the disturbance observer is combined with the state observer. It will be shown that the estimation dynam...

Nonlinear disturbance observer-based control for multi-input multi-output nonlinear systems subject to mismatching condition

Nonlinear Predictive Attitude Control of Spacecraft under External Disturbance

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. ...

Voltage Control and Load Sharing in a DC Islanded Microgrid Based on Disturbance Observer

Increasing DC loads along with DC nature of distributed energy resources (DERs) raises interest to DC microgrids. Conventional droop/non-droop power-sharing in microgrids suffers from load dependent voltage deviation, slow transient response, and requires the parameters of the loads, system and DERs connection status. In this paper, a new nonlinear decentralized back-stepping control strategy f...