Dengping Duan

Exponential

This paper is concerned with the exponential H∞ filter design for a class of continuous-time singular Markovian jump systems with mixed mode-dependent time-varying delay. By constructing a new Lyapunov-Krasovskii functional and utilizing some advanced techniques, a less conservative delay-dependent bounded real lemma (BRL) is obtained in terms of linear matrix inequalities (LMIs), which guarantees the considered system is exponentially admissible with H∞ performance. Based on the BRL, the H∞ filtering problem is solved and an explicit expression of the desired filter can be given. Two numerical examples are presented to illustrate the effectiveness and the potential of the proposed techniques.

H_{\infty}

S TRATOSPHERE airships have an enormous potential as platforms for different purposes such as monitoring, transportation, telecommunication, and so on [1–5]. For the purpose of verifying some core technologies of stratosphere airship, the remote and autonomous control fuel-cell-powered ZHIYUAN-1 airship (see Fig. 1) was manufactured at the School of Aeronautics and Astronautics of Shanghai Jiao Tong University, China, in 2009. This airship serves both as a reference configuration for theoretical investigations and as a flying test platform for studies in aerodynamic, flight mechanics and control, aeroelasticity, structural design, and fuel cell propulsion systems. The aerodynamic characteristics of the airship are very important for the designs of control system and propulsion system. The conventional configuration layout of the airship consists of the hull, fins, and gondola. The studies of part aerodynamics and interfaces are very important for the aerodynamic configuration layout design of airship. Moreover, the availability and accuracy of aerodynamic calculation methods such as computational fluid dynamics and panel-boundary methods need verify for these airship configurations at low-speed and high Reynolds number conditions. For these reasons, the wind-tunnel tests of scale ZHIYUAN-1 airship were performed. The dimensions of the real and scale ZHIYUAN-1 airship as the experimental model in the wind-tunnel tests are shown in Table 1. This paper is organized as follows: The test facilities and windtunnel models are described in Sec. II. In Sec. III, experimental investigations on scale ZHIYUAN-1 airship are presented. In final section, we draw some conclusions on aerodynamic characteristics of general layout airship configurations.

Filtering for Singular Markovian Jump Systems With Mixed Mode-Dependent Time-Varying Delay

This paper is concerned with the guaranteed cost control for continuous-time singular Markovian jump systems with time-varying delay. Without using the free weighting matrices method, a delay-range-dependent condition is derived in terms of strict linear matrix inequality (LMI), which guarantees that the singular system is regular, impulse free and mean-square exponentially stable with an H(∞) performance. Based on this, the existence condition of the guaranteed cost state feedback controller is proposed. A numerical example is given to illustrate the effectiveness and less conservatism of the proposed design method.

Experimental Investigations on Aerodynamic Characteristics of the ZHIYUAN-1 Airship

A stratospheric airship is an airship flying at a high altitude of 20 km as a stratospheric platform. Due to the low atmospheric density and flight speed, the efficiency of a conventional actuator, such as an aerodynamic control surface, is decreased. Thus, a new multi-vectored thrust airship called a flat peach is discussed in this paper. This article describes the derivation, design and simulation implementation of a non-linear controller for an airship with multi-vector thrust. The controller is designed using a command-filtered, vector backstepping approach, and can set the airship track three Cartesian positions ( x , y , z ) and yaw angle to their desired values and stabilize the pitch and roll angles. The controller is non-linear to address the kinematics and airship dynamics. The approach guarantees exponential stability of a compensated tracking error in the sense of Lyapunov. Both the stability analysis and simulation results are included.

Robust guaranteed cost control for singular Markovian jump systems with time-varying delay.

A theoretical analysis of fiber Bragg grating (FBG)-based plane strain monitoring of aerostat envelope structures is presented. Plane strain analysis of FBG-based aerostat envelope structures is much more complex than the case along the axis of the optical fiber because the effect of transverse stress on the FBG should be taken into consideration. To achieve accurate strain measurement of the aerostat envelope, a theoretical model is set up by using two perpendicular fibers in the monitoring. An analytical formula that evaluates the relationship between the strain measured by FBG sensors and the real one in the aerostat envelope is established. On the other hand, the real strain of aerostat envelope strain is affected by two unknown parameters, axial transfer rate K(L) and the radial transfer rate K(R). An equation is derived to calculate the axial transfer rate K(L). Then, the finite element method results show that K(R) is a very small value, but it cannot be ignored in accurate measurement. This paper would lay a theoretical groundwork for the research and design of FBG sensors in the structural health monitoring of aerostat envelope structures.

Command-filtered backstepping control for a multi-vectored thrust stratospheric airship

An adaptive Huber-based Kalman filter (AHF) is presented to deal with model error and unknown measurement noise in this article. The adaptive method for model error is obtained using an upper bound for the predicted state error covariance matrix. The measurement noise uncertainty is tackled at each time step by minimizing a criterion function that is original from the Huber technique. A recursive algorithm is also provided to solve the criterion function. The proposed AHF algorithm has been tested in an attitude estimation problem using a gyroscope and star tracker sensors for a single spacecraft in flight simulations in the presence of both model error and non-Gaussian random measurement errors. Simulation results demonstrate the superior performance of the proposed filter compared with the previous filter algorithms. The main contribution of this work can be considered the new application of an existing method.

Fiber Bragg grating-based plane strain monitoring of aerostat envelope structures

This article derives an improved robust Huber-based divided difference filter by using the Huber’s technique, in which the nonlinear measurement function is directly used in the nonlinear regression equation instead of the linear or statistical approximation. The presented filtering algorithm exhibits robustness against the deviations from the Gaussian error distribution and has better estimate accuracy compared with the Huber-based divided difference filter. This filter is applied to a benchmark problem of estimating the trajectory of an entry body from discrete-time range data measured by a radar tracking station. Simulation results indicate that the proposed filter algorithm outperforms the previous methods in terms of robustness and accuracy.

Adaptive Huber-based Kalman filtering for spacecraft attitude estimation

This paper is concerned with passivity analysis and passivity-based controller design for uncertain singularly perturbed Markovian jump systems with time-varying delay in an interval. Firstly, a delay-dependent condition for the considered system to be mean-square exponentially stable and robustly passive is derived in terms of linear matrix inequality. Then, the passification problem is investigated. Based on the obtained passivity condition, the existence of the desired state feedback controller is established. Numerical examples are presented to show the effectiveness of the proposed method.

Improved robust Huber-based divided difference filtering

In this article, an output-feedback control law is designed for a multi-vectored thrust stratospheric airship. The proposed control law is designed using the adaptive backstepping method and with few model aerodynamics parameters besides the qualitative physical properties. The resulting feedback controller is able to follow the given references in three Cartesian positions ( x , y , z ) and yaw angle by actuating four thrusters and their deflection angles. Lyapunov function analysis is introduced to compensate for the engine physical limits and guarantees closed-loop system stability. A degraded scenario (wind disturbance) which renders the airship statically unstable is also considered to show the adaptation capabilities of the control law. The simulations are carried out using a realistic multi-vectored thrust stratospheric airship model that is also developed in this study. Simulation results are given to illustrate the effectiveness of the proposed adaptive backstepping control when saturations are present even in wind disturbance.

Delay-Dependent Passivity and Passification for Uncertain Singularly Perturbed Markovian Jump Systems with Time-Varying Delay

The problem of station-keeping attitude tracking control for an autonomous airship with system uncertainties and external disturbances is investigated. Adaptive laws are applied to estimate the upper bounds of uncertainties and disturbances, and a nonlinear finite time control scheme is proposed by combing input/output feedback linearization with integral sliding mode technique. Different from the existing works on attitude control of airship, the developed controller can guarantee the yaw, pitch and roll angle trajectories track the desired attitude in finite time in spite of uncertain system uncertainties and external disturbances. Simulation results are provided to illustrate the attitude tracking performance.