• International Journal of Control, Automation, and Systems
• /
• v.5 no.6
• /
• pp.621-629
• /
• 2007

In the adaptive fuzzy control field for affine nonlinear systems, there are two basic configurations: direct and indirect. It is well known that the direct configuration needs more restrictions on the control gain than the indirect configuration. In general, these restrictions are difficult to check in practice where mathematical models of plant are not available. In this paper, using a simple extension of the universal approximation theorem, we show that the only required constraint on the control gain is that its sign is known. The Lyapunov synthesis approach is used to guarantee the stability and convergence of the closed loop system. Finally, examples of an inverted pendulum and a magnet levitation system demonstrate the theoretical results.

• 제어로봇시스템학회:학술대회논문집
• /
• 1994.10a
• /
• pp.183-188
• /
• 1994

A passivity-based adaptive controller for robots executing fine motion tasks is proposed. The robot dynamics is modelled such that it is subject to holonomic constraints and hence it can be treated as a particular case of constrained motion tasks. Energy-motivated stability analysis is used to conclude the asymptotic stability. Remarks regarding the structure of the controller are given. A computer simulations study is presented and a robust constraint stabilization algorithm is also proposed.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.90-95
• /
• 2003

In this paper, an Adaptive Nonlinear Constrained Model Predictive Control (ANCMPC) is presented for a pH control in a fed-batch bio-reactor. The pH model is represented with Hammerstein Model. The static nonlinear part of Hammerstein model is described with the static pH model, and the dynamic linear part of the Hammerstein model is described with the CARIMA model. The parameters of the CARIMA model is estimated on-line with the input and output measurements of the system using a recursive least squares type of identi�cation algorithm. The e�ectiveness of the proposed controller is shown through simulations.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.5
• /
• pp.320-325
• /
• 2016

This paper presents a robust finite-time sliding mode control (SMC) scheme for unknown disturbance and unmodeled nonlinear friction and dynamics in the robotic manipulator. A finite-time SMC (FSMC) surface and finite-time sliding mode controller are constructed to obtain faster error convergence than the conventional infinite-time based SMC. By adding prescribed constraint control term to a finite-time SMC to compensate for unknown disturbance and uncertainties, a robust control scheme can be designed as well as faster convergence control. In addition, simpler controller structure is built by using feed-forwarding upper bound coefficients of each manipulator dynamic parameters instead of model-based control or adaptive observer to estimate unknown manipulator parameters. Simulation and experimental evaluations highlight the efficacy of the proposed control scheme for an articulated robotic manipulator.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1996.11a
• /
• pp.690-694
• /
• 1996

In order to regulate the cutting force at a desired level during peripheral end milling processes, a feedrate override Adaptive Control Constant system was developed. This paper presents an explicit pole-assignment PI-control law through spindle motor current monitoring and its application to cutting force regulation for feedrate optimization. An experimental set-up is constructed for the commercial CNC machining center without any major changes of the structure. A data transfer system is constructed with standard interface between an IBM compatible PC and a CNC of the machining center. Experimental results show the validity of the system.

• Smart Structures and Systems
• /
• v.14 no.4
• /
• pp.617-641
• /
• 2014

The energy constraint is still a common issue for the practical application of wireless sensors, since they are usually powered by batteries which limit their lifetime. In this paper, a practical compound energy efficiency strategy is proposed and realized in the implementation of a real time wireless sensor platform. The platform is intended for wireless structural monitoring applications and consists of three parts, wireless sensing unit, base station and data acquisition and configuration software running in a computer within the Matlab environment. The high energy efficiency of the wireless sensor platform is achieved by a proposed adaptive radio transmission power control algorithm, and some straightforward methods, including adopting low power ICs and high efficient power management circuits, low duty cycle radio polling and switching off radio between two adjacent data packets' transmission. The adaptive transmission power control algorithm is based on the statistical average of the path loss estimations using a moving average filter. The algorithm is implemented in the wireless node and relies on the received signal strength feedback piggybacked in the ACK packet from the base station node to estimate the path loss. Therefore, it does not need any control packet overheads. Several experiments are carried out to investigate the link quality of radio channels, validate and evaluate the proposed adaptive transmission power control algorithm, including static and dynamic experiments.

• International Journal of Aeronautical and Space Sciences
• /
• v.15 no.2
• /
• pp.146-152
• /
• 2014

In this paper, a new adaptive nonsingular terminal sliding mode control theory based impact angle guidance law for intercepting maneuvering targets was documented. In the design procedure, a new adaptive law for target acceleration bound estimation was presented, which allowed the proposed guidance law to be used without the requirement of the information on the target maneuvering profiles. With the aid of Lyapunov stability criteria, the finite-time convergent characteristics of the line-of-sight angle and its derivative were proven in theory. Numerical simulations were also performed under various conditions to demonstrate the effectiveness of the proposed guidance law.

• Proceedings of the KIEE Conference
• /
• 2003.11b
• /
• pp.255-258
• /
• 2003

It is hard to centrol the wheeled mobile robot because of uncertainty of modeling, non-holonomic constraint and so on. To solve the problems, we design the controller of wheeled mobile robot based on fuzzy-neural network algorithm. In this paper, we should research the problem of classical controller for path-tracking algorithm and design of Fuzzy-Neural Network algorithm controller. Classical controller acquired different control value according to change of initial position and direction. In this control value having very difficult and having acquired a lot of trial and error Fuzzy is implemented to adaptive adjust control value by error and change of error and neural network is implemented to adaptive adjust the control gain during the optimization. The computer simulation shows that the proposed fuzzy-neural network controller is effective.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.10
• /
• pp.4823-4843
• /
• 2017

In this paper, an improved utility-based cross-layer dynamic subcarrier allocation (DSA) algorithm is proposed for single carrier frequency division multiple access (SC-FDMA) system, which adopts adaptive service rate control (ASRC) to eliminate the service rate waste and improve the spectral efficiency in heterogeneous network including non-real-time traffic and real-time traffic. In this algorithm, furthermore, a first in first out (FIFO) queuing model with finite space is established on the cross-layer scheduling framework. Simulation results indicate that by taking the service rate constraint as the necessary condition for optimality, the ASRC algorithm can effectively eliminate the service rate waste without compromising the scheduling performance. Moreover, the ASRC algorithm is able to further improve the quality of service (QoS) performance and transmission throughput by contributing an attractive performance trade-off between real-time and non-real-time applications.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.8 no.5
• /
• pp.211-219
• /
• 2008

This paper is proposed context-aware based access control, model by extending original access control model. In this paper, we survey the recent researches about security model based context-aware such as xoRBAC and CAAC. For exactly policy evaluation, we make an addition Context Broker and Finder in existing CAAC security model. By this security model, Context information and context decision information is able to be collected easily for more correct policy decision. This paper controlled access of possible every resources that is able to access by user's event and constraint from primitive access resources. In this paper proposed security model can be offer dynamically various security level and access authority method alone with specified policy and constraint adjustment at user's role.