Control of systems with sector-bounded nonlinearities: robust stability and command effort minimization by disturbance rejection

Abstract

The paper shows that a control strategy with unknown disturbance rejection is able to reduce the control effort to a minimum, ensuring at the same time a desired performance level. The disturbance to be rejected is completely unknown except for a sectorial bound. The control unit is endowed with an extended state observer which includes a disturbance dynamics, whose state tracks the unknown disturbance to be rejected. In summary, the novel contributions of the paper are the following. First, we derive a robust stability condition for the proposed control scheme, holding for all the nonlinearities that are bounded by a known (or estimated) maximum slope. Second, we propose a novel approach for designing the observer and state feedback gains, which guarantee robust closed-loop stability. Third, we show that the designed control system yields, with a minimum control effort, the same control performance as a robust state feedback control, which on the contrary may require a larger command activity. Two simulated case studies are presented to show the effectiveness of the proposed approach.

A novel algorithm for integrated control model using swarm robots for intruder detection and rescue schedules

“…ICM involves extended observer and a control law, used for measuring of state values and performing of active disturbance rejection respectively. On the basis of these mentioned capabilities, ICM is very efficient to remove the uncertainty in situations where relevant disturbances, modeling errors and non-linearity are there [5,37]. Standard PID controller was compared with the present ICM controller test results, and it was found from the above discussion, that performance of ICM is far better than that of normal and standard PID controller methods in terms of accuracy and precision with disturbance rejection as swarm robot is affected by non-linearity and uncertainty [17,29,38].…”

“…Investment has been made and waterborne robots have been studied to facilitate research control and development of driverless/hydroplanes to work in a naval environment in real-world conditions [3,4]. They focus on automated control systems (robots) with a high degree of software and hardware complexity [5,6]. Automated systems have been tested in a variety of different circumstances for monitoring, searching and data mining with good sensing capabilities and with positive results/outcomes financially and commercially as given in [7].…”