910 publications from this institution
The book was inadvertently published with an incorrect Grant number. In Front Matter, 4th line of page number vii, the sentence “of China under Grants Z19F030002,…” has been replaced by “of China under Grants LZ19F030001,…”.
This paper investigates the network-based modelling, and fault detection filter and controller coordinated design for an unmanned surface vehicle. A network-based model for the unmanned surface vehicle subject to actuator faults and wave-induced disturbances is established for the first time by introducing an observer-based fault detection filter, and considering network-induced characteristics such as delays and packet dropouts in the control station-to-actuator communication network channel. Based on this model, network-based fault detection filter and controller coordinated design criteria are derived to asymptotically stabilize the residual system. The designed network-based fault detection filter and controller can guarantee the sensitivity of the residual signal to faults and the robustness of the unmanned surface vehicle to external disturbances. Fault detection performance analysis verifies the effectiveness of the proposed network-based fault detection filter and controller coordinated design scheme for the unmanned surface vehicle in network environments.
FACTS devices, such as STATCOMs and UPFCs can be directly applied in the low voltage distribution system to regulate the sequence voltages within a network while simultaneously cancelling zero and negative sequence currents that are introduced by load unbalance or by high levels of distributed photovoltaic generation. Instantaneous reactive power theory shows that for FACTS devices the DC-bus capacitor power will fluctuate at twice mains frequency during unbalanced operation. High rating non-polarized bus capacitors can be applied if the double frequency fluctuations are restricted. In combination with silicon carbide devices it becomes possible to produce compact pole mounted systems. This paper proposes control methods that allow distribution level or dFACTS compensators with finite rating to best allocate its capacity to voltage, current balancing and reactive power compensation.
This paper deals with the problem of odor source localization by designing and analyzing a cooperative control framework (CCF) for the particle swarm optimization (PSO) algorithm. The CCF consists of three items: 1) a position coordination item; 2) a velocity coordination item; and 3) a movement direction coordination item. The position coordination item is used to coordinate relative positions between particles and to improve the exploration and exploitation capabilities of particles. The velocity coordination item enables the velocities of particles to reach consensus in order to realize orderly movement behaviors of particles. The movement direction coordination item guides particles to trace plumes and to locate odor sources. Stability of dynamic systems of particles with the proposed CCF is analyzed and the corresponding stability conditions are given such that the functions of three items in the CCF are realized. The orderly movement behaviors of particles under the CCF are also investigated based on benchmark functions. Finally, the effectiveness of the PSO algorithm with the proposed CCF is illustrated for the problem of odor source localization.
No abstract is provided for this article.
This paper focuses on the stability analysis of a discrete-time linear system with an interval-like time-varying delay in the state. A novel inequality for finite-sum Σ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">j=(r1)</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(r2)-1</sup> ω <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">T</sup> (j)Rω(j) is first established, where r <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> and r <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> are integers or integer-valued functions and R is a symmetric definite positive matrix. One of advantages of this inequality is that the factor r <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -r <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> appears in the estimation of the finite-sum linearly. The new inequality together with convex combination technique results in a novel delay-dependent stability criterion, which has been proven theoretically to be less conservative than some existing ones reported in the literature. Two numerical examples are given to show the validity of the proposed method.
This note is concerned with event-triggered <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> controller design for networked control systems. A novel event-triggering scheme is proposed, which has some advantages over some existing schemes. A delay system model for the analysis is firstly constructed by investigating the effect of the network transmission delay. Then, based on this model, criteria for stability with an <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">∞</sub> norm bound and criteria for co-designing both the feedback gain and the trigger parameters are derived. These criteria are formulated in terms of linear matrix inequalities. Simulation results have shown that the proposed event-triggering scheme is superior to some existing event-triggering schemes in the literature.
In this paper, two new sliding mode state observers are developed for the lateral dynamics of road vehicles. It is shown that the observability of a general class of second-order linear time-varying systems (LTVSs) is investigated, the sliding observers for the LTVSs with both the known-input and the unknown-input are then proposed. The main contribution of this research is to use the learning concept from artificial intelligence for designing the sliding mode observers in the following ways: (i) The observer for the leading sub-system is defined with the finite time error convergence; (ii) The observers for other sub-systems are then independently designed to follow the desired error dynamics of the leading sub-system. Particularly, for the LTVSs with the unknown input, two extended states are added and the same learning strategy is adopted to construct the extended sliding observers, to ensure that both the system states and the unknown inputs can be accurately estimated in finite time. The simulations for the lateral dynamics of a typical road vehicle are conducted to confirm the advantages and effectiveness of the proposed sliding observer algorithms.
In this chapter, sliding mode H ∞ control for an offshore steel jacket platform subject to nonlinear self-excited wave force and external disturbance is developed. A sliding mode H ∞ controller is designed to reduce oscillation amplitudes of the offshore...
Shift variance bounds of critically sampled multirate filter banks are usually defined by using eigensystem analysis of the commutator operator. Computational methods are provided for two-channel FIR filter banks by Aach and Fuhr (2009). This paper investigates shift variance bounds in oversampled multi-channel filter banks and derives some general results which include some of Aach and Fuhr (2009) as special cases. Using polyphase representation, numerical methods are provided to compute the shift variance bounds for arbitrary filter banks. Examples are given to demonstrate the effectiveness of the obtained results.
Transform coding has been widely used in video coding standards, such as H.264 advanced video coding (H.264/AVC) and high efficiency video coding (HEVC). But the coded video sequences suffer from annoying coding artifacts, such as blocking and ringing artifacts. In this paper, we propose the quadtree-based non-local Kuan’s (QNLK) filter to suppress the quantization noise optimally and improve the objective and subjective quality of the reconstructed frame simultaneously. The proposed filter takes advantage of the non-local Kuan’s (NLK) filter to restore the quantized signal in transform domain. Restored coefficients are then projected onto designed quantization constraint sets (QCS). Quadtree-based signaling strategy is used at the end of QNLK for adaptive filtering on/off control. Experimental results of QNLK show that the proposed method achieves significant objective coding gain and visual quality improvement, compared with both H.264/AVC high profile and HEVC.
This chapter is concerned with active control for an offshore steel jacket platform subject to wave-induced force and parameter perturbations. The offshore steel jacket platform is shown in Fig. 2.2 [65, 72]. The dynamic model...
Addresses the problem of robust stabilization of uncertain constrained systems with pointwise and distributed time-varying delays. We develop delay-dependent methods of robust stabilization via memoryless state feedback. Upper bounds on the time-varying delays are presented to make the considered uncertain closed-loop system robustly globally asymptotically stable and to determine a positive invariant set and robust local asymptotic stability domain. The results contain the ones proposed by Han and Mehdi (1999) as a special case.
