Browsing by Author "Chen, Chih-Chiang"

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Almost Disturbance Decoupling for a Class of Nonlinear Systems Subject to Time-Delays Via Sampled-Data Output Feedback Control
(2018-01-01)
Meng, Qinghua
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Wang, Pan
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Sun, Zong-Yao
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Chen, Chih-Chiang
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電控工程研究所
This paper considers the problem of almost disturbance decoupling (ADD) via sampled-data output feedback control for a class of uncertain nonlinear systems subject to time-delays. Based on output feedback domination approach, a sampled-data output feedback controller is designed to globally stabilize the system under a lower-triangular linear growth condition. Gronwall-Bellman-like inequality and inductive method are introduced to estimate the state growth in the presence of time-delays, uncertain nonlinearities and unknown disturbances. The proposed controller can attenuate the influence of disturbances on the output to an arbitrary degree in the L-2 gain sense. Finally, simulation results show the effectiveness of the control method.
Fault Tolerant Control of Nonlinear Systems Via a CA-Based Integral Sliding Mode Technique
(2013-01-01)
Chen, Chih-Chiang
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Liang, Yew-Wen
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper explores the active fault tolerant control issue for a class of uncertain nonlinear systems using a control allocation (CA)-based integral sliding mode control (ISMC) technique. When the information of fault detection and diagnosis is available, the presented scheme can tolerate some of the actuators\' faults, while maintains the main advantages of both CA and ISMC techniques. A remarkable one is that, when the uncertainties and/or disturbances are matched, the state trajectories of the selected nominal system and the uncertain faulty system are identical. As a result, engineers can predictively address the performance of matched uncertain faulty system in accordance with the performance of a selected nominal system. The proposed analytic results are applied to the attitude control of a spacecraft to demonstrate the benefits of the proposed scheme.
Global Output Feedback Stabilization of a Class of Nonlinear Systems With Unknown Measurement Sensitivity
(2018-07-01)
Chen, Chih-Chiang
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Qian, Chunjiang
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Sun, Zong-Yao
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Liang, Yew-Wen
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電控工程研究所
This note investigates the problem of global output feedback stabilization for a class of nonlinear systems with unknown measurement sensitivity. A new design method, namely dual-domination approach, is proposed to explicitly construct a state observer as well as an output feedback control law, which globally asymptotically stabilizes the nonlinear systems. The novelty of this note owes to a distinct perspective in coping with unknown measurement sensitivity which has previously been a hurdle to solve the global output feedback stabilization problem of the nonlinear systems.
Global Stability of a System with State-Dependent Riccati Equation Controller
(2015-10-01)
Chen, Chih-Chiang
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Liang, Yew-Wen
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Jhu, Wei-Ming
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電控工程研究所
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Institute of Electrical and Control Engineering
Global stabilization of switched nonlinear systems under arbitrary switchings via smooth output feedback
(2017-01-01)
Lin, Xiangze
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Li, Xueling
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Chen, Chih-Chiang
;
Li, Shihua
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電控工程研究所
Global output feedback stabilization for a class of switched nonlinear systems is addressed. The tasks of finding a common Lyapunov function and designing state stabilizing feedback laws are solved simultaneously based on the adding a power integrator approach. Reduced-order compensators for the switched nonlinear system are constructed to estimate the unmeasurable states. Coupling the state feedback controllers with the developing nonlinear observers, global asymptotic stabilization of the switched nonlinear system under arbitrary switchings is achieved by the output feedback control.
Growth of zirconia and yttria-stabilized zirconia nanorod arrays assisted by phase transition
(2010)
Chen, Chih-Chiang
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Cheng, Wei-Yun
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Lu, Shih-Yuan
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Lin, Yi-Feng
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Hsu, Yung-Jung
Well-aligned, densely distributed ZrO(2) nanorod arrays were fabricated using a non-catalytic, template-free metal-organic chemical vapour deposition process at a reaction temperature of 1000 degrees C. The reaction temperature was found to play a key role in product morphology, with particle thin films obtained at 550 degrees C and nanorod arrays produced at 1000 degrees C. Increasing the reaction temperature led to the emergence of the medium-temperature tetragonal phase from the dominant low-temperature monoclinic phase, which is advantageous for anisotropic growth necessary for the nanorod formation. With the same deposition process, yttria-stabilized zirconia nanorod arrays of polycrystalline cubic phase were fabricated by co-feeding the dopant precursor, YCl(3), with the zirconia precursor, Zr(C(5)H(7)O(2))(4). The present work demonstrated the first example of monoclinic to tetragonal phase-transition assisted one-dimensional (1D) growth, and the concept can be extended to the formation of 1D nanostructures of materials possessing the monoclinic-tetragonal polymorphism.
Interval homogeneous domination approach for global stabilization of nonlinear systems with time-varying powers
(2016-01-01)
Chen, Chih-Chiang
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Qian, Chunjiang
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Liang, Yew-Wen
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Li, Shihua
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電控工程研究所
This paper considers the problem of global stabilization for a class of nonlinear systems with time-varying powers. A new design method based on the technique of adding a power integrator and the interval homogeneous domination approach, which can be thought as an evolution of the homogeneous domination approach, is developed to explicitly construct a smooth state feedback globally stabilizing controller. The novelty of this paper is the development of a systematic scheme, which provides us a new perspective to deal with the state feedback control problem for the nonlinear systems with time varying powers.
Mechanical stretch induces hair regeneration through the alternative activation of macrophages
(2019-04-03)
Chu, Szu-Ying
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Chu, Chih-Hung
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Hsien-DaHuang
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Yen, Meng-Hua
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Hong, Hsiao-Chin
Tissues and cells in organism are continuously exposed to complex mechanical cues from the environment. Mechanical stimulations affect cell proliferation, differentiation, and migration, as well as determining tissue homeostasis and repair. By using a specially designed skinstretching device, we discover that hair stem cells proliferate in response to stretch and hair regeneration occurs only when applying proper strain for an appropriate duration. A counterbalance between WNT and BMP-2 and the subsequent two-step mechanism are identified through molecular and genetic analyses. Macrophages are first recruited by chemokines produced by stretch and polarized to M2 phenotype. Growth factors such as HGF and IGF-1, released by M2 macrophages, then activate stem cells and facilitate hair regeneration. A hierarchical control system is revealed, from mechanical and chemical signals to cell behaviors and tissue responses, elucidating avenues of regenerative medicine and disease control by demonstrating the potential to manipulate cellular processes through simple mechanical stimulation.
Miniaturized microwave integrated circuit using complementary conducting surfaces
(2005-04-14)
Tzuang, Ching-Kuang
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Chen, Chih-Chiang
The invention discloses a two-dimensional array waveguide structure implemented with multi-layer process or monolithic integrated circuit process. The structure includes a first metal layer, a second metal layer and a dielectric layer. The dielectric layer lain between the first and the second metal layer is for isolating the first metal layer from the second metal layer. The first metal layer and the second metal layer respectively formed from a plurality of first unit cells and second unit cells arranged in rows and columns create the two-dimensional array waveguide structure. The first metal layer consists of a main body and a plurality of connecting arms, whereas the second metal layer consists of a metal wire loop. The second metal layer is located below the first metal layer, and each second unit cell corresponds to each first unit cell in a one-on-one manner to further build a complete unit cell. While the main body of each unit cell corresponds to an inductance element, the connecting arms of each unit cell linking the adjacent unit cells correspond to a capacitance element; therefore, a two-dimensional L-C array is formed.
Nonlinear Reliable Control With Application to a Vehicle Antilock Brake System
(2013-11-01)
Liang, Yew-Wen
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Chen, Chih-Chiang
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Liaw, Der-Cherng
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Wei, Yuan-Tin
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電控工程研究所
This paper explores the design of active reliable control systems for a class of uncertain nonlinear affine systems using an integral-type sliding mode control (ISMC) scheme. The presented scheme not only maintains the main advantages of the ISMC design, including robustness, rapid response and easy implementation, but it can also tolerate some actuator faults when fault detection and diagnosis information is available. In this study, the uncertainties and/or disturbances are not required to be of the matched type; however, when they are matched, the state trajectories of the nominal healthy subsystem and the uncertain faulty system are identical. As a result, engineers can predictively address the matched uncertain faulty system performance in light of the performance of the nominal healthy subsystem. The analytic results are also applied to the study of a vehicle brake reliable control system. Simulation results demonstrate the benefits of the proposed scheme.
On Existence of Stabilizing Switching Laws within a Class of Unstable Linear Systems
(2013)
Xu, Sendren Sheng-Dong
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Chen, Chih-Chiang
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電控工程研究所
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Institute of Electrical and Control Engineering
The equivalence of two conditions, condition (3) and condition (4) stated in Problem Statement section, regarding the existence of stabilizing switching laws between two unstable linear systems first appeared in (Feron 1996). Although Feron never published this result, it has been referenced in almost every survey on switched systems; see, for example, (Liberzon and Morse 1999). This paper proposes another way to prove the equivalence of two conditions regarding the existence of stabilizing switching laws between two unstable linear systems. One is effective for theoretical derivation, while the other is implementable, and a class of stabilizing switching laws have been explicitly constructed by Wicks et al. (1994). With the help of the equivalent relation, a condition for the existence of controllers and stabilizing switching laws between two unstabilizable linear control systems is then proposed. Then, the study is further extended to the issue concerning the construction of quadratically stabilizing switching laws among.. unstable linear systems and.. unstabilizable linear control systems. The obtained results are employed to study the existence of control laws and quadratically stabilizing switching laws within a class of unstabilizable linear control systems. The numerical examples are illustrated and simulated to show the feasibility and effectiveness of the proposed methods.
Resource Allocation and Minimum Rate for Precoded Non-orthogonal Multiple Access
(2017-01-01)
Chen, Chih-Chiang
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Tsai, Shang-Ho (Lawrence)
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Lin, Yuan-Pei
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Lin, Chia-Hua
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電機工程學系
In this paper, we propose user clustering and power allocation algorithms for a precoded NOMA system. The user clustering for the strong and the weak users, and corresponding power allocation can be optimized disjointedly when SNR is sufficiently high, and this leads to a great reduction in computational complexity. Moreover this proposed power allocation algorithm can maximize sum achievable rate subject to a minimum target rate. Furthermore, from the analytical results, we suggest a reasonable minimum target rate for the weak user so that this rate can always be achieved, i.e, with outage probability 1. Using the suggested target rate, the NOMA system can avoid failing in achieving this target rate even if all power is allocated to the weak user. Simulation results corroborate theoretical results.
Robust Guidance Law via Integral-Sliding-Mode Scheme
(2014-05-01)
Liang, Yew-Wen
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Chen, Chih-Chiang
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Liaw, Der-Cherng
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Feng, Yang-Ching
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Cheng, Chiz-Chung
Smooth output feedback stabilization for a class of nonlinear systems with time-varying powers
(2017-12-01)
Chen, Chih-Chiang
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Qian, Chunjiang
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Lin, Xiangze
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Sun, Zong-Yao
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Liang, Yew-Wen
This paper investigates the global asymptotic stabilization problem for a class of nonlinear systems with time-varying powers. First, adding a power integrator technique is revamped to design a smooth state feedback controller, which is implementable with only upper and lower bounds of the time-varying powers. When the system state is not fully available and the time-varying power is exactly known, a smooth output feedback controller constituted by a state feedback and a nonlinear state observer is constructed to globally stabilize the system. Copyright (c) 2017 John Wiley & Sons, Ltd.
Smooth output feedback stabilization for nonlinear systems with time-varying powers
(2016-01-01)
Chen, Chih-Chiang
;
Qian, Chunjiang
;
Lin, Xiangze
;
Liang, Yew-Wen
;
電控工程研究所
This paper considers the global asymptotic stabilization problem for a class of nonlinear systems with time-varying powers. With only upper and lower bounds of the time-varying power, a smooth state feedback control law solving the problem is frst developed via the so-called adding a power integrator technique. When the system state is not fully available and the time-varying power is exactly known, a smooth output feedback control law constituted by a nonlinear state observer and a state feedback is constructed for achieving the stabilization task. In both cases, systematic approaches are explicitly presented for designing gains of control law and observer. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
Smooth output feedback stabilization of a class of planar switched nonlinear systems under arbitrary switchings
(2017-08-01)
Lin, Xiangze
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Chen, Chih-Chiang
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Qian, Chunjiang
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電控工程研究所
;
Institute of Electrical and Control Engineering
Smooth output feedback stabilization problem for a family of planar switched nonlinear systems is addressed. First, based on the adding a power integrator technique, the tasks of finding a common Lyapunov function and designing state feedback stabilizing control laws are accomplished simultaneously. Then, combining the state feedback control laws and the reduced-order nonlinear observers, output feedback control laws are designed to globally stabilize the switched nonlinear system under arbitrary switchings, whose subsystems may have uncontrollable/unobservable Jacobian linearizations. (C) 2017 Elsevier Ltd. All rights reserved.
Study of Nonlinear Integral Sliding Mode Fault-Tolerant Control
(2016-04)
Chen, Chih-Chiang
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Xu, Sendren Sheng-Dong
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Liang, Yew-Wen
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper studies an active fault-tolerant control (FTC) design based on an integral sliding mode control (ISMC) strategy for a class of uncertain nonlinear systems. It is shown that under the proposed scheme, the closed-loop system can tolerate certain allowable actuator faults whenever fault detection and diagnosis information is available, and the scheme also retains the main advantages of the ISMC technique. These advantages include robustness, rapid response, and ease of implementation. Moreover, the state response of the resulting closed-loop system under normal operation and different fault conditions is predictable from the response of a preselected fault-free certain system, which can be determined by the designer. Consequently, the engineer has the flexibility in selecting an (optimal) control law for the preselected system according to the system requirements. The analytical results obtained are also applied to the attitude control of a spacecraft. The simulation results clearly demonstrate the benefits of the proposed scheme.
Study of Nonsingular Fast Terminal Sliding-Mode Fault-Tolerant Control
(2015-06-01)
Xu, Sendren Sheng-Dong
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Chen, Chih-Chiang
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Wu, Zheng-Lun
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電控工程研究所
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Institute of Electrical and Control Engineering
This paper studies fault-tolerant control (FTC) designs based on nonsingular terminal sliding-mode control and nonsingular fast terminal sliding-mode control (NFTSMC). The proposed active FTC laws are shown to be able to achieve fault-tolerant objectives and maintain stabilization performance even when some of the actuators fail to operate. In comparison to existing sliding-mode control (SMC) fault-tolerant designs, the proposed schemes not only can retain the advantages of traditional SMC, including fast response, easy implementation, and robustness to disturbances/uncertainties, but also make the system states reach the control objective point in a finite amount of time. Moreover, they also resolve the potential singularity phenomena in traditional terminal and faster terminal SMC designs; meanwhile, the proposed NFTSMC fault-tolerant scheme also possesses the benefit of faster state convergence speed of NFTSMC. Finally, the proposed analytical results are also applied to the attitude control of a spacecraft. Simulation results demonstrate the benefits of the proposed schemes.
Study of Reliable Design Using T-S Fuzzy Modeling and Integral Sliding Mode Control Schemes
(2013-06-01)
Liang, Yew-Wen
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Chen, Chih-Chiang
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Xu, Sendren Sheng-Dong
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電控工程研究所
;
Institute of Electrical and Control Engineering
This paper investigates robust active reliable control issues using a combination of Takagi-Sugeno (T-S) fuzzy system modeling and Integral Sliding Mode Control (ISMC) schemes. The presented reliable scheme is shown to retain the benefits of both T-S modeling and ISMC design. It not only alleviates the online computational burden due to the use of the T-S model but also preserves the many advantages of the ISMC scheme. Using the presented reliable scheme, the control mission can be successfully achieved without prompt external support even when some of the actuators fail to operate. Moreover, because the ISMC design allows the engineer to predict the performance of the uncertain system from that of the nominal control system, the presented reliable scheme also possesses a degree of freedom in the design of the nominal controller for better system performance of normally operated and different faulty, uncertain situations. An illustrative example is also given to demonstrate the benefits of the proposed scheme.
Study on a Combined Scheme by Using T-S Fuzzy and TSMC Approaches
(2013)
Xu, Sendren Sheng-Dong
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Liang, Yew-Wen
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Wang, Kuo-Chin
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Chen, Chih-Chiang
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Cheng, Yi-Hsiang
This study investigates the hybrid design by using the Takagi-Sugeno (T-S) fuzzy system modeling method and the Terminal Sliding Mode Control (TSMC) technique. The combined scheme is shown to have the merits of both approaches. The presented scheme can alleviate the on-line computational burden because T-S fuzzy model can approximate the original nonlinear system and some of the parameters can be off-line computed. Moreover, it can also preserve the advantages of TSMC, including rapid response, robustness to uncertainties and/or external disturbance, and guaranteeing the fast finite-time state convergence. The proposed method is applied to a two-link robot manipulator dynamics, and it is also compared to the combination of T-S fuzzy system and conventional Sliding Mode Control (SMC) design. Simulation results demonstrate the benefits of the proposed scheme.