PID Lead-lag tuning formulas are derived for integrating unstable processes based on proposed modified Internal Model Control (IMC) structure. The structure extends the standard Internal Model Control structure for stable processes to unstable processes. To achieve better output response, even in the presence of load disturbance a second order low pass filter is inserted in the loop to reduced ...

Two robust nonlinear controllers along with a nonlinear observer have been developed in this study to control a 1D nonlinear flexible spacecraft. The first controller is based on dynamic inversion, while the second one is composed of dynamic inversion and µ-synthesis controllers. The extension of dynamic inversion approach to flexible spacecraft is impeded by the non-minimum phase characteristi...

This paper proposes a new method for online secondary path modeling (OSPM) in active noise control (ANC) systems. The proposed method comprises two adaptive filters: a noise control filter and an OSPM filter. The noise control filter is adapted by the FxLMS algorithm, and using the same error signal as used in the adaptation of the OSPM filter. The OSPM filter is adapted using a variable step s...

Noise effect indexes have recently become a popular concept to estimate the impact of aircraft noise on people. Such indexes describe the integral effect(s) of aircraft noise (annoyance and/or sleep disturbance) on the population in the vicinity of airports. In this paper, we report on the Zurich Aircraft Noise Index (ZFI) which became operational as an effect-oriented monitoring tool serving n...

Noise is defined as "unwanted sound." Aircraft noise is one, if not the most detrimental environmental effect of aviation. It can cause community annoyance, disrupt sleep, adversely affect academic performance of children, and could increase the risk for cardiovascular disease of people living in the vicinity of airports. In some airports, noise constrains air traffic growth. This consensus pap...

In this contribution it is shown how an iterative learning control algorithm can be found for a disturbance rejection application where a repetitive disturbance is acting on the output of a system. It is also assumed that there is additive noise on the measurements from the system. When applying iterative learning control to a system where measurement disturbances are present it is shown that i...

This paper is concerned with the state-feedback H∞ control problem for a class of stochastic nonlinear systems with time-varying state delays, where both the disturbance and the white noise are considered. To synthesize the investigated system, the parameter-dependent storage functional is firstly constructed. By means of completing the square, the delay-dependent controller is designed such th...

OBJECTIVES Exposure to aircraft noise has been shown to have adverse health effects, causing annoyance and affecting the health-related quality of life, sleep, and mental states of those exposed to it. This study aimed to determine sleep quality in participants residing near an airfield and to evaluate the relationship between the levels of aircraft noise and sleep quality. METHODS NEIGHBORIN...

Increases in noise-generating human activities since the Industrial Revolution have changed the acoustic landscape of many terrestrial and aquatic ecosystems. Anthropogenic noise is now recognized as a major pollutant of international concern, and recent studies have demonstrated impacts on, for instance, hearing thresholds, communication, movement and foraging in a range of species. However, c...

Recent research in ecology has concentrated on the effect of environmental changes on ecosystem structure and function. In most cases the focus has been on how ecosystems respond to changes in the mean values of environmental parameters, while the impact of changes in the variance has seldom been studied. However, changes in environmental variability may be important. For example, recent climat...