A robust H∞ observer-based tracking control of stochastic immune response is proposed for therapeutic enhancement to track a prescribed immune response under uncertain initial states, environmental disturbances and measurement noises. The statistics of initial condition, environmental and measurement noises are assumed unavailable. Further, the state variables may not all be available and may b...

In this paper, a robust DC-link voltage control scheme is proposed to improve the tolerance of photovoltaic (PV) grid-connected inverter disturbances. The sensitive characteristic complicates dynamics system and limits its overall performance, especially when uncertain disturbances are considered. To cope with issue, controller based on linear active disturbance rejection (LADRC) designed. By e...

Due to the hostile marine environment, there will inevitably be unpredictable factors during operation of unmanned underwater vehicles, including changes in ocean currents, hull dimensions, and velocity measurement uncertainties. An improved finite-time adaptive tracking control issue is considered for autonomous vehicles (AUVs) with uncertain dynamics, unknown external disturbances, unavailabl...

This work designed a disturbance-observer-based nonlinear sliding mode surface controller (SMC) and validated the using simulated PX4-conducted quadcopter. To achieve this goal, research (1) developed dynamic mathematical model; (2) built PX4-based UAV following model-based design process; (3) appropriate control laws for each degree of freedom; (4) implemented disturbance observers on proposed...

Offshore floating wind turbine (OFWT) has gained increasing attention during the past decade because of the offshore high-quality wind power and complex load environment. The control system is a tradeoff between power tracking and fatigue load reduction in the above-rated wind speed area. In allusion to the external disturbances and uncertain system parameters of OFWT due to the proximity to lo...

Disturbances acting on the track-following servo system of an optical disk drive inherently contain significant periodic components that cause tracking errors of a periodic nature. Such disturbances can be effectively rejected by employing a repetitive controller, which must be implemented carefully in consideration of system stability. Plant uncertainty makes it difficult to design a repetitiv...

Predictive control employs future and past information to maintain servo performance and stability in uncertain environment. Nevertheless, nonlinear friction and unknown disturbances still challenge application of predictive control to precision positioning in typical electromechanical transmission systems due to strict demands on accuracy and control performance. In this paper, a modified pred...

This paper investigates the problem of robust output feedback control of uncertain continuous-time timedelay systems with both external disturbances and saturating actuators. Both the system uncertainties and the external disturbances are assumed to be time-varying and bounded, and the states of the system under consideration are not available but detectable. First, in the absence of external d...

This paper focuses on the iterative learning tracking control problem for a class of nonlinear system with time-varying disturbances. First, because of the mismatches in time-varying disturbances functions, a high-order feed-forward iterative learning control (ILC) is employed to change the original system into an iterative system. Secondly, a variable forgetting factor is developed to stabiliz...