Kind Of Adaptive Controller Research Articles

PDE Based Adaptive Control of Flexible Riser System With Input Backlash and State Constraints

In this paper, a class of flexible riser systems modeled by partial differential equations (PDEs) with the backlash is considered. The backlash is formulated as the addition of a linear input and a interference-like term, then an new auxiliary item is introduced to compensate for the impact of this backlash. In addition, the constraint problem for the position and the velocity is also taken into consideration. To solve this constrain problem, the logarithmic barrier Lyapunov function is employed. For the flexible riser system, two kinds of adaptive controllers are proposed under the following two cases. One controller is designed when only the parameter of backlash is unknown. On the basis of this result, the other controller is presented when some system parameters cannot be measured through actual measurement. Then, combing the theory of Lyapunov stability, the two controllers can guarantee the boundedness of all signals in the closed-loop flexible riser system. Further, both the position and the velocity satisfy their corresponding constraint condition. Finally, the simulation example verifies that the proposed control method is effective.

PHILOSOPHICAL ASPECTS OF ADAPTIVE MANAGEMENT OF SOCIAL AND PEDAGOGICAL SYSTEMS

Abstract. The article describes the deployment of market transformations in all spheres of the economy of Ukrainian society, including in education. This causes changes in human living conditions and requirements for its social formation and development, which is what is happening in the education system. The authors distinguish socio-pedagogical systems, which includes educational institutions and institutions at all levels of educational organization, from pre-school to postgraduate education.
 The article emphasizes that any socio-pedagogical system needs management, the requirements to which are similarly changed during the formation and development of a new the socio-economic structure of society. Management from authoritarian is gradually becoming really flexible, affiliate, adaptive. The practical use of new management requires consideration of its philosophical aspects, since it is linked to the involuntary restructuring of the ideological positions of the executives.
 Transformation processes are the subject of research on domestic and foreign scientists.
 Analytical review of literary sources, as noted by the authors, testifies to the study of issues on changing the world outlook of the person, modernization of the educational process in educational institutions, development of synergetic principles of management, etc. The issues of the emergence and affirmation of reflective control as a kind of adaptive control are highlighted separately. In Ukraine, there is a School of Adaptive Management of Social and Pedagogical Systems, whose representatives disseminate knowledge and experience of using content, forms, and technologies of a new type of management activity in educational practice. In general, research on this topic is diverse and conducted at the intersection of different sciences, technology, pedagogy, psychology, and inter-scientific relations. However, the authors identify a lack of research on the philosophical aspect of adaptive management.
 Usually, the philosophical foundations of management in the traditional system was the philosophy of determinism, which is characterized by the causal conditionality of phenomena / processes. The development of the information society and market relations have brought to life the synergistic processes that occur under conditions of instability and accompany the self-organization of complex systems.
 The authors distinguish from the synergetic position four stages of self-development: destabilization - the result: swaying ties; orientation - result: orientation to a certain direction of development; organizational - result: self-structuring, the appearance of neoplasm; productive -result: qualitative and quantitative changes, self-development.
 The article provides a comparative analysis of the philosophical and functional basis of traditional and adaptive management. The authors conclude that the philosophical basis of adaptive management is the theory of instability, which explains the nonlinear development. Finally, the direction of further research is identified.

Variable Universe Fuzzy Control of Adjustable Hydraulic Torque Converter Based on Multi-Population Genetic Algorithm

In order to optimize the control method of guide vane opening in an adjustable hydraulic torque converter, this paper presents a variable universe fuzzy control method for servo system of the adjustable hydraulic torque converter based on the multi-population genetic algorithm. This control method got a kind of adaptive control as optimizing proportional exponential contraction–expansion factors of the current loop with a genetic algorithm, thus transforming the fuzzy variable universe of the current loop. In this method, we designed a variable universe adaptive fuzzy controller with S-function on an adjustable hydraulic torque converter servo system and conducted some simulation experiments. The simulation results showed that the variable universe control based on genetic algorithm improved the anti-interference and robustness of adjustable hydraulic torque converter servo system compared with control methods in the previous literature. This control method could be a desirable way to adjust guide vane opening with the properties of better accuracy, rapidity, and reliability. Thus, the control method we designed will provide an effective, fast, and stable control strategy for the uncertain system with the properties of nonlinearity, strong disturbance, and uncertain time-varying.

Distributed optimization for a class of high‐order nonlinear multiagent systems with unknown dynamics

SummaryIn this paper, we study a distributed optimization problem for a class of high‐order multiagent systems with unknown dynamics. In comparison with existing results for integrators or linear agents, we need to overcome the difficulties brought by the unknown nonlinearities and the optimization requirement. For this purpose, we employ an embedded control‐based design and first convert this problem into an output stabilization problem. Then, two kinds of adaptive controllers are given for these agents to drive their outputs to the global optimal solution under some mild conditions. Finally, we show that the estimated parameter vector converges to the true parameter vector under some well‐known persistence of excitation condition. The efficacy of these algorithms was verified by a simulation example.

Mode-independent control of singular Markovian jump systems: A stochastic optimization viewpoint

In this paper, the mode-independent control problem of singular Markovian jump systems is firstly studied by exploiting a stochastic optimization viewpoint. A new kind of mode-independent H∞ controller satisfying a minimum variance approximation is constructed, whose gain is composed of some mode-dependent control gains. The available probability of system mode is described by the Bernoulli variable and taken into account. It shows that such a probability plays an important role in system analysis and associates mode-independent controller with mode-dependent controllers. When the probability is unknown, a kind of adaptive controller is proposed such that the resulting closed-loop system is robust stochastically admissible with an H∞ performance. All the proposed conditions are given in terms of linear matrix inequalities. Two numerical examples are used to demonstrate the effectiveness of the proposed methods.

Adaptive Control of Dynamically Complex Networks with Saturation Couplings

This paper considers the control problem of dynamically complex networks with saturation couplings. Two novel control schemes in terms of adaptive control are presented to deal with such saturation couplings. Based on the robust idea, the underlying complex network is firstly transformed into a strongly connected network having time-varying uncertainty. However, the upper bound of uncertainty is unknown. Because of such an unavailable bound, a kind of adaptive controller added to each node is proposed such that the closed-loop auxiliary network is uniformly bounded. In particular, the original system states are asymptotically stable. Moreover, in order to avoid adding the desired controller to every node, another different kind of adaptive controller based on the pinning control idea is proposed. Compared with the former method, it is only applied to a part of nodes and has a good operability. Finally, a numerical example is provided to show the effectiveness of our results.

VSS robust adaptive control including a self‐tuning controller for a rotary inverted pendulum

AbstractThere are many publications on the stabilization of an inverted pendulum because it is a typical unstable system and is well used as an example to verify many control theories. However, few approaches consider the inverted pendulum as an unknown parameter system. This paper proposes a new VSS (Variable Structure System) robust adaptive control system including a self‐tuning controller for a rotary inverted pendulum all of whose parameters are unknown. The control system provides two kinds of adaptive controllers, and stabilization of the inverted pendulum is achieved by separating the system into two parts, the pendulum and the rotary arm. The rotational angle of the pendulum is stabilized by a tracking‐type VSS adaptive control method, and the rotary arm is simultaneously stabilized by an STC (self‐tuning control) system that assures the boundary reference angle of the pendulum. It is then not sufficient to construct an STC system using only the adjustable parameters of the VSS adaptive control system. Therefore, all basic parameters are recursively estimated in order to realize the STC system by using the least squares parameter adaptive law, and this is achieved by superimposing the perturbation signal on the stable adaptive control input over a limited short interval. Furthermore, the STC system designs an LQ controller by developing an efficient QR method for real‐time operation. Finally, the validity of the proposed system is demonstrated by numerical simulations and practical experimental results. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(6): 48–58, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10179

適応制御器を用いた回転型二重倒立振子の二段階による制御系

Inverted pendulums are very often used to verify many control theories, because they are typical unstable systems and also are interesting objects. However, few innovative methods with respect to the adaptive control of inverted pendulum (IP) are reported. This paper presents a stabilization method by using the adaptive control for a serial rotary-type double inverted pendulum (SRDIP) whose whole basic parameters are unknown. The control system of a SRDIP is achieved by separating the control mode to two stages. The first stage is an adaptive control mode of the single IP placing the second IP in downward directions and another stage is a LQ control mode of the SRDIP. The control system prepares two kinds of adaptive controllers, which are a variable structure system (VSS) robust adaptive control and a self-tuning control (STC). The rotational angle of the first IP is stabilized by the VSS adaptive control, and the stability of the rotary arm is also achieved by constructing the STC that guarantees the boundary reference angle of the first IP. It is then difficult to construct the STC by only adjustable parameters of the VSS adaptive control system. Whole basic parameters of a SRDIP are estimated by adopting the recursive least squares (RLS) estimation method in order to accomplish both of the STC system and the LQ design of a SRDIP. The RLS algorithm is performed by superposing an available perturbation signal to the adaptive manipulated variable on a limited short interval. The STC system updates a LQ controller based on the QR methods devised for the real time operation. Before completing the first stage, a LQ controller for the SRDIP is obtained through a state space description from the estimated basic parameters. The control law is changed to a LQ control for the SRDIP from an adaptive control mode in the second stage. Finally, it is verified by simulation studies and practical experiments that the proposed system is useful as a control strategy of the SRDIP with an unknown parameter.

セルフチューニング制御器を組込んだ回転型倒立振子のVSSロバスト適応制御

There are many publications on the stabilization of an inverted pendulum because it is a typical unstable system and is well used as an example to verify many control theories. However, few approaches consider the inverted pendulum as an unknown parameter system. This paper proposes a new VSS (Variable Structure System) robust adaptive control system including a self-tuning controller for a rotary inverted pendulum all of whose parameters are unknown. The control system provides two kinds of adaptive controllers, and stabilization of the inverted pendulum is achieved by separating the system into two parts, the pendulum and the rotary arm. The rotational angle of the pendulum is stabilized by a tracking-type VSS adaptive control method, and the rotary arm is simultaneously stabilized by an STC (self-tuning control) system that assures the boundary reference angle of the pendulum. It is then not sufficient to construct an STC system using only the adjustable parameters of the VSS adaptive control system. Therefore, all basic parameters are recursively estimated in order to realize the STC system by using the least squares parameter adaptive law, and this is achieved by superimposing the perturbation signal on the stable adaptive control input over a limited short interval. Furthermore, the STC system designs an LQ controller by developing an efficient QR method for real-time operation. Finally, the validity of the proposed system is demonstrated by numerical simulations and practical experimental results. © 2011 Wiley Periodicals, Inc. Electron Comm Jpn, 94(6): 48–58, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.10179

Automatic control of respiration to deal with difference of individual characteristics

A clinical technology generally consistent with a difference of individuals is discussed on the basis of adaptive control theory taking into account the automatic control of alveolar CO2-concentration in both controlled- and assisted-respiration. An experimental system for this purpose is proposed which consists of a newly developed respirator and controlling and measuring devices. Its control system requires safe and accurate operation in the different experimental environments in controlled- and assisted-respiration, which are characterized by pattems of ventilatory rhythms. In order to satisfy both requirements, a control system is designed on the basis of an adaptive pole assignment method, which is capable of compensating characteristic and environmental changes of a controlled object. It yields, thus, a stable control of alveolar CO2-concentration dealing with some disorder of the equipment, mainly with the different characteristics of a respiratory regulation system inclusive of its individual difference such as nonlinearity and chronic change. From clinical experiments on healthy subjects, the performance of the control system is confirmed to follow-up a given desired alveolar CO2-concentration with assurance of its clinical safety. This kind of adaptive control is confirmed to lead to the useful concept and method for the control of an organic function relied upon its less exact recognition because of its time-varying and ambiguous characteristics.

Adaptive control strategies for a precision machine tools axis

This paper evaluates two different kinds of adaptive controllers in the context of robust control of a precision machine tool axis. These include an adaptive proportional-integrative-derivative controller and an adaptive phase-lead compensator. The latter is modified further to account for the effects of input saturation, and the resulting performance is studied. A proportional-integrative-derivative controller is also included for comparison purposes. The experimental results obtained confirm the overall performance superiority of adaptive controllers with respect to both transient and steady-state responses. In addition, the adaptive phase-lead controller is shown to be significantly more robust with respect to various changes in system parameters and trajectory shapes.