Asynchronous Switching Control of Discrete-time Linear System Based on Mode-dependent Average Dwell Time

Jinjie Huang,Xianzhi Hao,Xiaozhen Pan 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.7

In this paper, we investigate the problem of asynchronous switching control for discrete-time linear systems with mode-dependent average dwell time (MDADT) switching and take the time elay constraints of mode-dependent controllers into consideration. In practical, owing to signal transmission, system detection, and the like, switching of controllers is often lagged behind their corresponding subsystems. Therefore, we divide the time interval of a subsystem operating into two parts: the controller-matched and the controller-mismatched. First, the controller of each subsystem is designed according to its mode-dependent parameters. Then, considering the lag time of controllers, the appropriate MDADT is derived based on Lyapunov stability conditions, and the global exponential stability of the asynchronous switched systems is guaranteed. Finally, a numerical example is provided to demonstrate the potential effectiveness of the proposed method.

Dynamic Output Feedback H∞ Control for Linear Parameter-varying Systems with Time-delay

Jinjie Huang,Xiaozhen Pan,Xianzhi Hao,Wanda Putra 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.12

In this paper, we address a synthesis problem of the parameter-dependent output feedback H∞ control for linear parameter-varying systems with time-delay. The scheme adopts the parameter-dependent past state information to construct the dynamic output feedback controller. In this case, on basis of the quadratic Lyapunov functional with parameter-dependence, we analyze the parameter-dependent H∞ stability conditions for the closedloop time-delayed linear parameter-varying system in terms of linear matrix inequalities. However, this stability condition is of an infinite-dimension. To derive computationally tractable criteria for the dynamic output feedback controller, several slack variables and a convex relaxation technique are employed to have the infinite-dimensional condition of linear matrix inequalities cast into a finite dimensional convex optimization problem. By solving theconvex optimization problem, we harvest the dynamic output feedback controller with memory for the time-delayed linear parameter-varying system. Finally, two examples are included to illustrate the effectiveness of the proposed approach.

Event-triggered Networked H∞ Output Tracking Control Based on Dynamic Compensation Controller

Jinjie Huang,Xiaozhen Pan,Xianzhi Hao 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.10

In this paper, the event-triggered H∞ output tracking problem is investigated for networked control systems. In order to reduce the output tracking error as well as to improve network resource utilization, we propose anidea of dynamic compensation controller with the discrete-time event-triggered mechanism, that is, the integral termof tracking error and the state of the reference system are introduced to form states of the augmented system. We firstexamine the dynamic compensation idea by the H∞ output tracking control problem for linear time-invariant (LTI)systems. Then, we model the closed-loop event-triggered networked control system as a time-delay augmented linear system. By constructing a Lyapunov-Krasovskii functional with the delay fractioning technique, the stabilityconditions with lower conservatism are derived in the form of the linear matrix inequalities (LMIs). Furthermore,a method is proposed to design the H∞ dynamic compensation controllers and the discrete-time event-triggeredmechanisms. Finally, the satellite tracking control problem is used as an example to show that the dynamical compensation idea is effective in reducing the tracking error and that the proposed method in this paper can achievebetter performance than that in the existing literature

Prediction of exploration targets based on integrated analyses of source rock and simulated hydrocarbon migration direction: a case study from the gentle slope of Shulu Sag, Bohai Bay Basin, northern China

Changqing Ren,Fugui He,Xianzhi Gao,Dongsheng Wu,Wenli Yao,Jianzhang Tian,Huiping Guo,Yuanxin Huang,Li Wang,Han Feng,Junwei Li 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.6

The Shulu Sag which is a rifted sag with NNE trend is located in the south of Jizhong Depression, Bohai Bay Basin, northern China. The gentle slope and three troughs are situated in the west and east of the sag, respectively. Both of the lower part of Shasan Member (Es3x) and the lower part of Shayi Member (Es1x) act as source rocks in this sag. Researches on the type, quantity, quality and thermal maturity of the respective organic matter have been conducted using Rock-Eval pyrolysis data. Type II is the dominant kerogen in Es1x of all troughs. However, Type II1 and III is the dominant kerogen in Es3x of Middle-Southern and Northern trough, respectively. TOC (total organic carbon) and pyrolysis S2 (hydrocarbon) values suggest that the Es1x source rocks in Middle-Southern and Northern trough are fair to good and poor to fair generative potential of hydrocarbon, separately. The Es3x source rocks in Middle-Southern and Northern trough possess fair to excellent and poor to fair generative potential of hydrocarbon, individually. Tmax (pyrolysis temperature at maximum S2) values indicate that most of Es3x samples are thermally mature, but all Es1x samples are thermally immature. Under large scale condition, the hydrocarbon secondary migration in the upper part of Shasan Member (Es3s), Shaer Member (Es2) and the upper part of Shayi Member (Es1s) have been simulated using fluid potential model with Arcgis 9.3 software. The simulation results reveal the direction of hydrocarbon secondary migration and the distribution of hydrocarbon migration-accumulation units (HMAUS), and also suggest that the hydrocarbon migration direction is obviously controlled by nose-like structure belts where most of hydrocarbons accumulate. That shows high reliability because they are consistent with the hydrocarbon exploration result in this area. On the basis of integrated analyses of source rocks and hydrocarbon migration direction, the following five areas in the gentle slope are identified to be the preferred hydrocarbon accumulation area: Taijiazhuang area, northern and southern Xicaogu area, as well as northern and southern Leijiazhuang area. It is considerably helpful to reduce the risk in hydrocarbon exploration of Shulu Sag.

Identification and Characterization of a Novel Angiotensin Iconverting Enzyme Inhibitory Peptide (ACEIP) from Silkworm Pupa

Xiyu Li,Yong Li,Xianzhi Huang,Jiong Zheng,Fusheng Zhang,Jianquan Kan 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.4

The angiotensin I-converting enzyme inhibitorypeptide (ACEIP) was isolated and characterized fromsilkworm pupae and purified using Sephadex G-25 gelfiltration. The structure and physicochemical properties ofpupa ACEIP were analyzed. The α-P3 fraction exhibitedthe most potent ACE inhibitory activity. After purificationvia semi-preparative reverse-phase HPLC (RP-HPLC) andHPLC, the α-P3-6-b component was revealed to have thehighest ACE inhibitory activity (IC50=28.3 μg/mL). Edmandegradation revealed a Val-Glu-Ile-Ser amino acid sequencein which novel active sequences were identified. Physicochemicalproperty testing showed that purified pupaACEIP exhibits good solubility, heat resistance, and acidresistance that all indicate ACEIP derived from silkwormpupa is an excellent food-derived ACEIP.

Simulation of the hydraulic isolation efficiency during multistage hydrajet fracturing

Xin Fan,Gensheng Li,Zhongwei Huang,Shouceng Tian,Xianzhi Song,Chen Yang 한국자원공학회 2015 Geosystem engineering Vol.18 No.5

Effective isolation between target zones is critical to multistage fracturing. Low pressure zone caused by the hydrajet is used to isolate stages in the multistage hydrajet fracturing technology. However, there are few researches available in the literature that investigates the hydraulic isolation efficiency considering the existence of multiple fractures. This paper builds a three-dimensional computational-fluid-dynamics model with FLUENT software to study the flow field along annular sections under different conditions. It is verified that the results obtained from the model are consistent with experimental data along the perforation tunnel. The mass flow rate ratio between two outlets is proposed to analyze the hydraulic isolation efficiency in hydrajet multistage fracturing. The results show that annular fluid converges into the perforation tunnel due to the high-speed hydrajet even though there is a pre-existing fracture behind. Effective hydraulic isolation can be generated by reducing the pressure differences between target zones and the annular injection velocity as well as by enlarging the jet velocity and the area ratio. It is found that there exists an optimum area ratio to get the maximum isolation efficiency. Sensitivity analysis indicates the pressure difference is the dominant factor affecting the hydraulic isolation efficiency. A fully quadratic model derived from the response surface method is presented to predict the hydraulic isolation efficiency for real fracturing. This study will be able to provide practical guidance for the optimization of hydrajet multistage fracturing.