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ISA Transactions

A H Tahoun
This paper studies the problem of actuator-nonlinearities compensation in the multi-input uncertain neutral systems. The neutral systems with different unknown time-varying delays, unmodeled dynamics, nonlinear perturbations and disturbances are considered. A new methodology based on the online estimation of the delays to compensate for the effects generated by dead-zone and saturation, acting in series on a system's input are presented. The online estimations of the unknown delays are accomplished by adaptive laws that guarantee the exponential stabilities of the estimated delays...
July 19, 2017: ISA Transactions
Yu Ren, Guanghui Sun, Zhiguang Feng
This paper concerns the exponential stabilization problem for a class of switched positive systems. The switching signal satisfies mode-dependent average dwell time (MDADT) and the state variables are partially unmeasurable. A further explanation of mode-dependent average dwell time is included. By employing a set of quasi-time variables, which is first proposed for switched systems with MDADT, new stability results are obtained for the switched nonlinear systems and the underlying linear systems. Observer-based stabilization controllers, both for single-input case and multi-input case, are designed such that the closed-loop system converges exponentially...
July 19, 2017: ISA Transactions
Yang Yang, Dingy├╝ Xue
The operation processes for thermal power plant are measured by the real-time data, and a large number of historical interval data can be obtained from the dataset. Within defined periods of time, the interval information could provide important information for decision making and equipment maintenance. Actual load is one of the most important parameters, and the trends hidden in the historical data will show the overall operation status of the equipments. However, based on the interval grey parameter numbers, the modeling and prediction process is more complicated than the one with real numbers...
July 17, 2017: ISA Transactions
Ying-Jun Li, Cong Yang, Gui-Cong Wang, Hui Zhang, Huan-Yong Cui, Yong-Liang Zhang
This paper presents a novel integrated piezoelectric six-dimensional force sensor which can realize dynamic measurement of multi-dimensional space load. Firstly, the composition of the sensor, the spatial layout of force-sensitive components, and measurement principle are analyzed and designed. There is no interference of piezoelectric six-dimensional force sensor in theoretical analysis. Based on the principle of actual work and deformation compatibility coherence, this paper deduces the parallel load sharing principle of the piezoelectric six-dimensional force sensor...
July 14, 2017: ISA Transactions
Young-Rae Ko, Yoonkyu Hwang, Minji Chae, Tae-Hyoung Kim
In this study, we present an identification-based direct construction of the inverse generalized Prandtl-Ishlinskii (P-I) model to facilitate inverse model-based feedforward compensation of asymmetric hysteresis nonlinearities. Compared with the derivation of the inverse model analytically from a generalized P-I model, this direct modeling approach has the following advantages. First, direct inverse model identification is formulated as a nonlinear optimization problem, which is not subject to the constraint condition on the generalized P-I model's threshold and density functions, where this is indispensable for the analytical model inversion procedure...
July 14, 2017: ISA Transactions
Fethi Farhani, Chiheb Ben Regaya, Abderrahmen Zaafouri, Abdelkader Chaari
This paper describes a robust and efficient speed control of a three phase induction machine (IM) subjected to load disturbances. First, a Multiple-Input Multiple-Output (MIMO) PI-Backstepping controller is proposed for a robust and highly accurate tracking of the mechanical speed and rotor flux. Asymptotic stability of the control scheme is proven by Lyapunov Stability Theory. Second, an active online optimization algorithm is used to optimize the efficiency of the drive system. The efficiency improvement approach consists of adjusting the rotor flux with respect to the load torque in order to minimize total losses in the IM...
July 13, 2017: ISA Transactions
Rui Wang, Yanxiao Li, Hui Sun, Zengqiang Chen
The modern civil aircrafts use air ventilation pressurized cabins subject to the limited space. In order to monitor multiple contaminants and overcome the hypersensitivity of the single sensor, the paper constructs an output correction integrated sensor configuration using sensors with different measurement theories after comparing to other two different configurations. This proposed configuration works as a node in the contaminant distributed wireless sensor monitoring network. The corresponding measurement error models of integrated sensors are also proposed by using the Kalman consensus filter to estimate states and conduct data fusion in order to regulate the single sensor measurement results...
July 11, 2017: ISA Transactions
Pavin Mahmoudabadi, Mokhtar Shasadeghi, Jafar Zarei
This paper focuses on stability analysis and stabilization of nonlinear systems with interval time-varying delay, modeled by Takagi-Sugeno (T-S) fuzzy approach. To achieve more relaxation in the feasibility region, delay-partitioning approach is used for all integral terms in the Lyapunov-Krasovskii functional (LKF). A fuzzy Lyapunov function is proposed instead of non-integral term in LKF, and moreover, some slack matrices variables are offered to enlarge the design space. By doing this, new delay-dependent stability criteria are obtained...
July 11, 2017: ISA Transactions
Quan Yuan, Jingyuan Zhan, Xiang Li
In this paper, we present a multi-drone system featured with a decentralized model predictive control (DMPC) flocking algorithm. The drones gather localized information from neighbors and update their velocities using the DMPC flocking algorithm. In the multi-drone system, data packages are transmitted through XBee(®) wireless modules in broadcast mode, yielding such an anonymous and decentralized system where all the calculations and controls are completed on an onboard minicomputer of each drone. Each drone is a double-layered agent system with the coordination layer running multi-drone flocking algorithms and the flight control layer navigating the drone, and the final formation of the flock relies on both the communication range and the desired inter-drone distance...
July 11, 2017: ISA Transactions
Ko Ko Htet Kyaw, Kok Kiong Tan
The majority of current industrial process control systems are based on PID control. However, in many of these systems, once the initial setup has been carried out, it is difficult to implement subsequent continuous improvements on the control performance without shutting down the production and disarming the overall system to retrofit alternative controllers. These measures to integrate additional instruments for allowing such flexibility incur heavy costs in terms of time and resources. In this paper, we propose an approach towards achieving the control adaptations which cannot be achieved easily with an existing closed-architectural system...
July 11, 2017: ISA Transactions
Ke-Cai Cao, Bin Jiang, Dong Yue
Cooperative path following control problem of multiple nonholonomic mobile robots has been considered in this paper. Based on the framework of decomposition, the cooperative path following problem has been transformed into path following problem and cooperative control problem; Then cascaded theory of non-autonomous system has been employed in the design of controllers without resorting to feedback linearization. One time-varying coordinate transformation based on dilation has been introduced to solve the uncontrollable problem of nonholonomic robots when the whole group's reference converges to stationary point...
July 11, 2017: ISA Transactions
Ahmed G Radwan, Ahmed A Emira, Amr M AbdelAty, Ahmed T Azar
Due to the non-idealities of commercial inductors, the demand for a better model that accurately describe their dynamic response is elevated. So, the fractional order models of Buck, Boost and Buck-Boost DC-DC converters are presented in this paper. The detailed analysis is made for the two most common modes of converter operation: Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM). Closed form time domain expressions are derived for inductor currents, voltage gain, average current, conduction time and power efficiency where the effect of the fractional order inductor is found to be strongly present...
July 11, 2017: ISA Transactions
Cheng-Lin Liu
Scaled consensus problem is studied for a heterogeneous multi-agent system composed of non-identical stable linear agents, and a leader-following scaled consensus algorithm is designed. By using frequency-domain analysis, consensus conditions are obtained for the agents without communication delay under undirected and directed topologies, respectively. Moreover, consensus criteria are also gained for the agents suffering from communication delay under directed topology. Simulation examples show the correctness of theoretical results...
July 8, 2017: ISA Transactions
Wei Wang, Changyun Wen, Jiangshuai Huang, Huijin Fan
In this paper, a backstepping based distributed adaptive control scheme is proposed for multiple uncertain Euler-Lagrange systems under directed graph condition. The common desired trajectory is allowed totally unknown by part of the subsystems and the linearly parameterized trajectory model assumed in currently available results is no longer needed. To compensate the effects due to unknown trajectory information, a smooth function of consensus errors and certain positive integrable functions are introduced in designing virtual control inputs...
July 7, 2017: ISA Transactions
Lijing Dong, Jing Li, Qin Liu
This paper investigates a situation where smart agents capable of sensory and mobility are deployed to monitor a designated area. A preset number of agents start tracking when a target intrudes this area. Some of the tracking agents are possible to be out of order over the tracking course. Thus, we propose a cooperative relay tracking strategy to ensure the successful tracking with existence of damaged agents. Relay means that, when a tracking agent quits tracking due to malfunction, one of the near deployed agents replaces it to continue the tracking task...
July 7, 2017: ISA Transactions
Shamisa Shoja, Mahdi Baradarannia, Farzad Hashemzadeh, Mohammadali Badamchizadeh, Peyman Bagheri
In this paper, the surrounding control problem of a group of non-identical agents is considered, where a team of followers achieves an equidistant distributed formation to surround a team of moving leaders. An adaptive design method is presented for multi-agent systems where the dynamics of agents are supposed to be nonlinear with unknown parameters. First, an estimator for the center of the leaders is introduced. Then, two distributed adaptive controllers based on the estimated center are proposed for each follower...
July 7, 2017: ISA Transactions
Dawei Wu, Mou Chen, Huajun Gong
This article presents a robust finite-time maneuver control scheme for the longitudinal attitude dynamic of the aircraft with unsteady aerodynamic disturbances and input saturation. To efficiently eliminate the influence of unsteady aerodynamic disturbances, nonlinear finite-time observers are developed. Despite the existence of the nonlinearity and the coupling between aircraft states and unsteady aerodynamic disturbances, the proposed observers can still precisely estimate the unmeasurable unsteady aerodynamic disturbances in finite time...
July 6, 2017: ISA Transactions
A Rini Ann Jerin, Palanisamy Kaliannan, Umashankar Subramaniam
Fault ride through (FRT) capability in wind turbines to maintain the grid stability during faults has become mandatory with the increasing grid penetration of wind energy. Doubly fed induction generator based wind turbine (DFIG-WT) is the most popularly utilized type of generator but highly susceptible to the voltage disturbances in grid. Dynamic voltage restorer (DVR) based external FRT capability improvement is considered. Since DVR is capable of providing fast voltage sag mitigation during faults and can maintain the nominal operating conditions for DFIG-WT...
July 6, 2017: ISA Transactions
Rongzhi Cui, Yiheng Wei, Songsong Cheng, Yong Wang
This paper investigates the problem of parameter estimation for fractional order linear systems when the output signal is polluted by impulse noise. The conventional least square error objective function is replaced by a new approximate least absolute error (ALAE) function to restrain the influence of impulse noise. Then a novel parameter estimation approach is designed based on the stochastic gradient method, the fractional order parameter update law and the ALAE criterion, which improves estimation accuracy and enhances robustness at the same time...
July 6, 2017: ISA Transactions
Konstantinos G Papadopoulos, Praveen K Yadav, Nikolaos I Margaris
Analytical tuning rules for digital PID type-I controllers are presented regardless of the process complexity. This explicit solution allows control engineers 1) to make an accurate examination of the effect of the controller's sampling time to the control loop's performance both in the time and frequency domain 2) to decide when the control has to be I, PI and when the derivative, D, term has to be added or omitted 3) apply this control action to a series of stable benchmark processes regardless of their complexity...
July 5, 2017: ISA Transactions
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