This paper summarizes the formulation of two distinct methods for high-bandwidth nonlinear adaptive flight control of an unmanned helicopter testbed, and presents an evaluation and comparison of the two controllers in both simulation and flight test when subject to unmodeled dynamics, time delay, and actuator position and rate saturation. The attitude command system functions as an inner loop, ...

Various types and techniques of on-line approximation have been used in feedback control of uncertain nonlinear systems. In many practical applications, saturation of the control input influences significantly the performance of adaptive and learning control systems. This article addresses the issue of control input saturation in on-line approximation based control of nonlinear systems. A modif...

Dark channel prior has been used widely in single image haze removal because of its simple implementation and satisfactory performance. However, it often suffers from halo artifacts or noise amplification, over-dark and over-saturation looking in some images containing heavy fog or large sky patches where dark channel prior is not established. To resolve these problems, this paper proposes a ro...

This paper presents neural adaptive control methods for a class of nonlinear systems in the presence of actuator saturation. Backstepping technique is widely used for the control of nonlinear systems. By introducing alternative state variables and implementing state transformation, the system can be reformulated as output feedback of a canonical system, which ensures that the controllers can be...

Distributed wireless sensor networks have been proposed as a solution to environment sensing, target tracking, data collection and other applications. Energy efficiency, high estimation accuracy, and fast convergence are important goals in distributed estimation algorithms for sensor network. This paper studies the problem of robust adaptive estimation in impulsive noise environment using robus...

A new method which is suitable for enhancing the color microscopic image quality based on HSV color space and curvelet transform is presented in this paper. The color microscopic image is firstly divided into hue, saturation and value components from RGB color space to HSV color space through the color space conversion. The value component is decomposed by the curvelet transform. A modulus squa...

Nonlinear vehicle control allocation is achieved by distributing the control task to tire forces with nonlinear saturation constraints. The overall vehicle control is accomplished by developing a hierarchical scheme. First, a high-level sliding mode control with adaptive gain is considered to obtain the body force/moment for stable vehicle motion. The proposed controller only requires online ad...

A robust control scheme is proposed for the position control of the electrohydrostatic actuator (EHA) when considering hardware saturation, load disturbance, and lumped system uncertainties and nonlinearities. To reduce overshoot due to a saturation of electric motor and to realize robustness against load disturbance and lumped system uncertainties such as varying parameters and modeling error,...

Unsharp Masking is a popular image processing technique used for improving the sharpness of structures on dental radiographs. However, it produces overshoot artefact and intolerably amplifies noise. On radiographs, often resembles indications prosthesis misfit, pathosis, pathological features associated with restorations. A noise- robust alternative to algorithm, termed Gradient-adaptive Nonlin...

This paper presents a new state-space self-tuning control scheme for adaptive digital control of continuous multivariable nonlinear stochastic hybrid systems with input saturation. Here, the continuous nonlinear stochastic system is assumed to have unknown system parameters, system and measurement noises, and inaccessible system states. The proposed method enables the development of a digitally...