Zhaohui Jiang

Memory State Feedback Control for Singular Systems with Multiple Internal Incommensurate Constant Point Delays

Abstract In this paper, the problem of delay-dependent stabilization for singular linear continuous-time systems with multiple internal incommensurate constant point delays (SLCS-MIID) is investigated. The condition when a singular system subject to point delays is regular independent of time delays is given and it can be easily tested with numerical or algebraic methods. Based on the Lyapunov-Krasovskii functional approach and the descriptor integral-inequality lemma, a suficient condition for delay-dependent stability is obtained. The main idea is to design multiple memory state feedback control laws such that the resulting closed-loop system is regular independently of time delays, impulse free, and asymptotically stable via solving some strict linear matrix inequalities (LMIs) problem. An explicit expression for the desired memory state feedback control law is also given. Finally, a numerical example illustrates effectiveness and availability for the proposed method.

Delay-dependent Stabilization of Singular Linear Continuous-time Systems with Time-varying State and Input Delays

The descriptor integral-inequality method is a new method to deal with the delay-dependent stabilization problem for singular linear continuous-time systems with time-varying state and input delays. Delay dependent stabilization conditions are established by using the Lyapunov-Krasovskii functional approach combined with an descriptor integral-inequality. An LMI based algorithm to design a memoryless state feedback control that stabilizes the system is provided. Finally, a numerical example is presented to illustrate the effectiveness and the availability for the design.

Decentralized Robust H ∞ Output Feedback Control for Value Bounded Uncertain Large-scale Interconnected Systems

For large-scale interconnected systems with value bounded uncertainties existing in the state, control and interconnected matrices, the design of a decentralized robust Hinfin output feedback controller is investigated. Based on the bounded real lemma sufficient conditions for the existence of a decentralized robust Hinfin controller are obtained in terms of a set of matrix inequalities. According to Schur complement, a homotopy iterative linear matrix inequality method is put forward to construct a decentralized robust Hinfin controller by fixing different variables. The controller obtained enables the closed-loop large-scale systems robust stable and satisfies the given Hinfin performance. At last a numerical example is given to illustrate the effectiveness of the offered method

Delay-dependent stabilization of singular linear time delay systems based on memory state feedback control

In this paper, the delay-dependent stabilization problem for singular linear time-delay systems is studied by designing a delay-dependent memory state feedback controller which makes the singular linear time-delay systems regular, impulse free and asymptotically stable. Firstly, the lemma of descriptor integral-inequality is derived. Secondly, delay dependent stabilization conditions are established by using the Lyapunov-Krasovskii functional approach combined with a descriptor integral-inequality. Thirdly, an LMI based algorithm to design a memory state feedback control that stabilizes the system is provided. Finally, a numerical example is presented to illustrate the effectiveness and the availability for the design.

A Novel Device for Optical Imaging of Blast Furnace Burden Surface: Parallel Low-Light-Loss Backlight High-Temperature Industrial Endoscope

Accurate real-time optical imaging of the burden surface shape plays an important role in improving the gas flow distribution, reducing the coke ration, and reducing the emissions of a blast furnace. To overcome the high-temperature, high-dust, and lightless environment and obtain clear images of the burden surface, a parallel low-light-loss backlight high-temperature industrial endoscope is developed. The design of a parallel low-light-loss backlight path and a high-light-efficiency, low-light, color backlight source overcomes the lightlessness issue. Combined with the endoscopic optical imaging method, a high-temperature resistant image-capturing lens and a high-temperature non-resistant photosensitive chip are separated at two ends of the instrument. This separation design method together with the water cooling and industrial nitrogen cooling system enables the equipment to overcome the high temperature issue. Moreover, a new installation strategy, which avoids the material flow and high-dust region, is proposed to overcome the high dust issue. The strategy includes establishing a trajectory model of dust particles to determine the low-dust area and conducting a landing points experiment and a trajectory model of the material flow to determine the no-material-flow region. The industrial experiment results indicate that the developed device obtains real-time images of the burden surface and exhibits clear details of the coke and iron ore particles. The application also demonstrates the validity and better imaging performance of the proposed method compared with conventional detection methods.

An intelligent optimal setting approach based on froth features for level of flotation cells

In the flotation production process, the liquid level of flotation cells is usually set by on experiences. The liquid level can fluctuate in a large range such that the concentrate grade and tailings grade may not meet the requirement.In this paper, an intelligent optimal setting approach based on forth image features is proposed. On the basis of analysis of flotation cells working principle and relationship between level and froth image features, the pre-setting model based on CBR, the improved least squares support vector machine(LS-SVM) grade prediction model based on multiple froth features, and the self-learning fuzzy reasoning intelligent compensation model based on BP neural network are integrated together. This method is tested on a bauxite flotation process. The level fluctuation of rougher flotation cells decreases.The pass rates of concentrate and tailings grade in rougher flotation and the pass rate of the concentrate grade and recovery of the overall flotation increase.

A less conservative delay-dependent stability for uncertain singular linear systems with time-delays

In this paper, the delay-dependent stability problem is investigated for a class of singular time-delay (STD) systems with norm bounded parametric uncertainties. Without resorting to any bounding techniques for some cross terms and model transformation, the new less conservative delay-dependent stability criteria assuring the regularity, impulse-free and robust stability of the STD systems are derived by constructing a novel Lyapunov-Krasovskii functional (LKF). The present method incorporates a new integral-equality technique combined with a recently proposed idea of introducing free-weighting matrices. Numerical examples are provided to illustrate the effectiveness and less conservativeness of the developed techniques.

Decentralized Robust Delay-dependent Stabilization for Singular Large Scale Systems Based on Descriptor Output Feedback

This note considers the problem of decentralized robust delay-dependent stabilization for singular large scale systems based on descriptor output feedback. Using stability theory of Lyapunov, decentralized robust delay-dependent stabilization sufficient conditions for nominal system and uncertain system are established, which are expressed as LMI. The descriptor output feedback controller is solved by LMI. Numerical example is solved to show the usefulness and validness of the theoretical results

Delay-dependent Decentralized Stabilization of Multi-channel Singular Linear Continuous-time Systems with Multiple Point Delays

Abstract The delay-dependent decentralized stabilization problem of multi-channel singular time-delay time-invariant systems subject to multiple internal and external incommensurate constant point delays is discussed based on the descriptor integral-inequality approach. The descriptor integral-inequality Lemma is firstly established. Based on the new Lemma and the Lyapunov-Krasovskii functional approach, delay-dependent decentralized stabilization sufficient conditions are obtained. An LMI based algorithm to design the decentralized state feedback controls that stabilize the multi-channel singular time delays systems is provided. Finally, some numerical examples are presented to illustrate the effectiveness and the availability for the design.

Decentralized robust H ∞ output feedback control for value bounded uncertain large-scale interconnected systems

For large-scale interconnected systems with value bounded uncertainties existing in the state, control and interconnected matrices, the design of a decentralized robust Hinfin output feedback controller is investigated. Based on the bounded real lemma sufficient conditions for the existence of a decentralized robust Hinfin controller are obtained in terms of a set of matrix inequalities. According to Schur complement, a homotopy iterative linear matrix inequality method is put forward to construct a decentralized robust Hinfin controller by fixing different variables. The controller obtained enables the closed-loop large-scale systems robust stable and satisfies the given Hinfin performance. At last a numerical example is given to illustrate the effectiveness of the offered method