International Journal of Computer Applications in Technology http://www.inderscience.com/browse/index.php?journalID=5&year=2011&vol=42&issue=1 Inderscience Publishers Ltd en-uk International Journal of Computer Applications in Technology 0952-8091 1741-5047 © 2011 Inderscience Publishers Ltd editor@inderscience.com https://www.inderscience.com/images/files/coverImgs/ijcat_scoverijcat.jpg http://www.inderscience.com/browse/index.php?journalID=5&year=2011&vol=42&issue=1 http://www.inderscience.com/link.php?id=43881 This paper presents a new method to approximate optimal control strategies of discrete time large-scale nonlinear systems using intelligent approaches. The idea is based on the decomposition principle of the global system into interconnected subsystems for which nonlinearities are located in the interconnection terms. Then, the mixed coordination procedure between different subsystems is formulated as a hierarchical method for the solution of large-scale optimal control problems. So, for each subsystem, local optimal feedback gains are expressed in terms of the interconnection vector. For this purpose, neural networks and fuzzy logic controllers have been constructed in order to identify these gains. A comparison with the differential dynamic programming procedure as a reference method is done. Simulation results of two numerical examples show that the proposed method yields to satisfactory performances, and the robustness of the proposed approaches has been tested. Hierarchical control for discrete large-scale complex systems by intelligent controllers
Najla Krichen Masmoudi; Chokri Rekik; Mohamed Djemel; Nabil Derbel
International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 1 - 12
This paper presents a new method to approximate optimal control strategies of discrete time large-scale nonlinear systems using intelligent approaches. The idea is based on the decomposition principle of the global system into interconnected subsystems for which nonlinearities are located in the interconnection terms. Then, the mixed coordination procedure between different subsystems is formulated as a hierarchical method for the solution of large-scale optimal control problems. So, for each subsystem, local optimal feedback gains are expressed in terms of the interconnection vector. For this purpose, neural networks and fuzzy logic controllers have been constructed in order to identify these gains. A comparison with the differential dynamic programming procedure as a reference method is done. Simulation results of two numerical examples show that the proposed method yields to satisfactory performances, and the robustness of the proposed approaches has been tested.

]]> 10.1504/IJCAT.2011.043881 International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 1 - 12 Najla Krichen Masmoudi; Chokri Rekik; Mohamed Djemel; Nabil Derbel Research Unit on Intelligent Control, Design and Optimisation of Complex Systems (ICOS), University of Sfax, National Engineering School of Sfax (ENIS), BP W 3038 Sfax, Tunisia. ' Research Unit on Intelligent Control, Design and Optimisation of Complex Systems (ICOS), University of Sfax, National Engineering School of Sfax (ENIS), BP W 3038 Sfax, Tunisia. ' Research Unit on Intelligent Control, Design and Optimisation of Complex Systems (ICOS), University of Sfax, National Engineering School of Sfax (ENIS), BP W 3038 Sfax, Tunisia. ' Research Unit on Intelligent Control, Design and Optimisation of Complex Systems (ICOS), University of Sfax, National Engineering School of Sfax (ENIS), BP W 3038 Sfax, Tunisia decomposition coordination interconnected systems large-scale systems neural networks fuzzy logic intelligent control hierarchical control optimal control nonlinear systems fuzzy logic controllers FLCs fuzzy control simulation. 2011-11-27T23:20:50-05:00 42 1 1 12 2011-11-27T23:20:50-05:00 http://www.inderscience.com/link.php?id=43882 In this paper, application of self-tuning fuzzy PI scheme (STPIFLC) for Direct Torque Controlled Induction Motor (DTC IM) drive is proposed. In the proposed approach, the output scaling factor (SF) is adjusted online by fuzzy rules according to the current trend of the controlled process. The rule base for tuning the output SF is defined on error (e) and change of error (?e) of the controlled variable using triangular equally overlapped membership functions (MFs). The performance of the proposed self-tuning fuzzy PI controller is compared with the corresponding fuzzy logic controller and PI controller. The performance index based on speed error is assigned to provide a numerical comparison among different controllers. Simulation results show that the proposed STPIFLC for DTC IM drive gives remarkably improved performance and high robustness compared with those obtained by the application of a conventional controller (PI). A robust self-tuning fuzzy PI scheme for DTC induction motor drive
K. Naga Sujatha; K. Vaisakh
International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 13 - 22
In this paper, application of self-tuning fuzzy PI scheme (STPIFLC) for Direct Torque Controlled Induction Motor (DTC IM) drive is proposed. In the proposed approach, the output scaling factor (SF) is adjusted online by fuzzy rules according to the current trend of the controlled process. The rule base for tuning the output SF is defined on error (e) and change of error (?e) of the controlled variable using triangular equally overlapped membership functions (MFs). The performance of the proposed self-tuning fuzzy PI controller is compared with the corresponding fuzzy logic controller and PI controller. The performance index based on speed error is assigned to provide a numerical comparison among different controllers. Simulation results show that the proposed STPIFLC for DTC IM drive gives remarkably improved performance and high robustness compared with those obtained by the application of a conventional controller (PI).

]]> 10.1504/IJCAT.2011.043882 International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 13 - 22 K. Naga Sujatha; K. Vaisakh Department of Electrical Engineering, AU College of Engineering, Andhra University, Visakhapatnam 530003, AP, India. ' Department of Electrical Engineering, AU College of Engineering, Andhra University, Visakhapatnam 530003, AP, India direct torque control induction motors SVM space vector modulation self-tuning PI controllers fuzzy logic controllers FLC fuzzy control speed error simulation robust control. 2011-11-27T23:20:50-05:00 42 1 13 22 2011-11-27T23:20:50-05:00 http://www.inderscience.com/link.php?id=43883 A sensor’s model for resolver manufacturers is developed. This model compensates deviations in product characteristics due to the variability of the assembly process, through computed corrections on the production’s controllable variables ewinding parameters. The model follows a two-step strategy. On the first step a traditional transformer’s model computes the resolver’s nominal physical parameters: electric and magnetic resistances and leakage impedances of primary and secondary windings. On the second step a linear model computes the increments on the controllable variables to compensate small deviations in design assumptions, due to the variability of the manufacturing processes. In this model the in-plant controllable variables are adjusted (number of windings and wire diameters). The incremental model develops a set of correction tools that allows the resolver manufacturer to change some controllable variables in order to correct assembled resolvers that without any action would be scrap to the production line. A pancake-resolver model for sensor manufacturers
João Manuel Gouveia Figueiredo
International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 23 - 31
A sensor’s model for resolver manufacturers is developed. This model compensates deviations in product characteristics due to the variability of the assembly process, through computed corrections on the production’s controllable variables ewinding parameters. The model follows a two-step strategy. On the first step a traditional transformer’s model computes the resolver’s nominal physical parameters: electric and magnetic resistances and leakage impedances of primary and secondary windings. On the second step a linear model computes the increments on the controllable variables to compensate small deviations in design assumptions, due to the variability of the manufacturing processes. In this model the in-plant controllable variables are adjusted (number of windings and wire diameters). The incremental model develops a set of correction tools that allows the resolver manufacturer to change some controllable variables in order to correct assembled resolvers that without any action would be scrap to the production line.

]]> 10.1504/IJCAT.2011.043883 International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 23 - 31 João Manuel Gouveia Figueiredo CEM Mechatronics Engineering Centre/IDMEC, Universidade de Évora, R. Romão Ramalho, 57, 7000-757 Évora, Portugal magnetic sensors angular sensors pancake resolver technological applications sensor manufacturing modelling winding parameters electric resistance magnetic resistance leakage impedance assembly variability controllable variables. 2011-11-27T23:20:50-05:00 42 1 23 31 2011-11-27T23:20:50-05:00 http://www.inderscience.com/link.php?id=43884 This paper presents the design and development of a fuzzy controller using UPFCs to damp out the oscillations in FACTS-based integrated multi-machine power system when faults takes place at different buses. The combination of a fuzzy coordination scheme with a POD-based UPFC is used to suppress the oscillations upon the occurrence of a fault at the generator side. Three Simulink models are developed with and without the controller by considering the occurrence of one fault at a time near each generator. The three-phase to ground symmetrical fault is made to occur near first generator for 200 ms in the model 1, next at second generator in model 2 and finally at third generator in model 3. Simulations are performed with and without the controller. The three models are compared for the effectiveness of the fault occurrence near each of the generators. Simulation results show the effectiveness of the developed method. Design and development of a fuzzy coordinated control strategy for faults occurring at different buses in an interconnected power system
Dakka Obulesu; S.F. Kodad; B.V. Sanker Ram
International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 32 - 48
This paper presents the design and development of a fuzzy controller using UPFCs to damp out the oscillations in FACTS-based integrated multi-machine power system when faults takes place at different buses. The combination of a fuzzy coordination scheme with a POD-based UPFC is used to suppress the oscillations upon the occurrence of a fault at the generator side. Three Simulink models are developed with and without the controller by considering the occurrence of one fault at a time near each generator. The three-phase to ground symmetrical fault is made to occur near first generator for 200 ms in the model 1, next at second generator in model 2 and finally at third generator in model 3. Simulations are performed with and without the controller. The three models are compared for the effectiveness of the fault occurrence near each of the generators. Simulation results show the effectiveness of the developed method.

]]> 10.1504/IJCAT.2011.043884 International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 32 - 48 Dakka Obulesu; S.F. Kodad; B.V. Sanker Ram Department of Electrical & Electronics Engineering, Jawaharlal Nehru Technological University, Hyderabad-85, Andhra Pradesh, India; Department of Electrical & Electronics Engineering, Vemu Institute of Technology, Chittoor, Andhra Pradesh, India. ' Krishna Murthy Institute of Technology & Engineering, Ranga Reddy Dist., Hyderabad, Andhra Pradesh, India. ' Department of Electrical & Electronics Engineering, College of Engineering, Jawaharlal Nehru Technological University, Kukatpally, Hyderabad-85, Andhra Pradesh, India UPFC unified power flow controllers power oscillation damping fuzzy logic coordination fuzzy control oscillations stability simulation state space modelling coordinated control multi-machine power systems bus faults generators fault occurrence. 2011-11-27T23:20:50-05:00 42 1 32 48 2011-11-27T23:20:50-05:00 http://www.inderscience.com/link.php?id=43885 This paper presents the simulation study of magnetorheological semi-active suspension system controlled by a new proposed algorithm. The control algorithm named as Semi-Active Damping Force Estimator (SADE) is proposed to control the operations of the magnetorheological damper. The simulation of semi-active suspension system was done by considering actual dynamics behaviour of a custom-made magnetorheological damper, where its characteristic testing and modelling are described. The performance of magnetorheological semi-active car suspension system controlled by SADE in term of ride comfort is evaluated in comparison with normal suspension system. The performance of SADE semi-active suspension system is also compared with the skyhook-controlled semi-active suspension system performance. It is shown that magnetorheological semi-active suspension system controlled by SADE is able to improve vehicle’s ride comfort significantly compared to passive suspension system. The SADE-controlled semi-active suspension system performs more or less the same as skyhook-controlled semi-active suspension system. Modelling of magnetorheological semi-active suspension system controlled by semi-active damping force estimator
Saiful Anuar Abu Bakar; Hishamuddin Jamaluddin; Roslan Abd. Rahman; Pakharuddin Mohd. Samin; Ryosuke Masuda; Hiromu Hashimoto; Takeshi Inaba
International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 49 - 64
This paper presents the simulation study of magnetorheological semi-active suspension system controlled by a new proposed algorithm. The control algorithm named as Semi-Active Damping Force Estimator (SADE) is proposed to control the operations of the magnetorheological damper. The simulation of semi-active suspension system was done by considering actual dynamics behaviour of a custom-made magnetorheological damper, where its characteristic testing and modelling are described. The performance of magnetorheological semi-active car suspension system controlled by SADE in term of ride comfort is evaluated in comparison with normal suspension system. The performance of SADE semi-active suspension system is also compared with the skyhook-controlled semi-active suspension system performance. It is shown that magnetorheological semi-active suspension system controlled by SADE is able to improve vehicle’s ride comfort significantly compared to passive suspension system. The SADE-controlled semi-active suspension system performs more or less the same as skyhook-controlled semi-active suspension system.

]]> 10.1504/IJCAT.2011.043885 International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 49 - 64 Saiful Anuar Abu Bakar; Hishamuddin Jamaluddin; Roslan Abd. Rahman; Pakharuddin Mohd. Samin; Ryosuke Masuda; Hiromu Hashimoto; Takeshi Inaba Department of Automotive Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai, Johor 81310, Malaysia. ' Department of System Dynamics and Control, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai, Johor 81310, Malaysia. ' Department of System Dynamics and Control, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai, Johor 81310, Malaysia. ' Department of Automotive Engineering, Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, Skudai, Johor 81310, Malaysia. ' Department of Applied Computer Engineering, School of Information Science and Technology, Tokai University, 1117 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan. ' Department of Mechanical Engineering, School of Engineering, Tokai University, 1114 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan. ' Department of Applied Computer Engineering, School of Information Science and Technology, Tokai University, 1117 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan semi-active damping force estimators skyhook control magnetorheological dampers ride performance semi-active suspension systems simulation modelling ride comfort vehicle suspension. 2011-11-27T23:20:50-05:00 42 1 49 64 2011-11-27T23:20:50-05:00 http://www.inderscience.com/link.php?id=43886 The ultrasonic image guided radio frequency ablation surgery is an effective technique in liver tumour treatment. However, the traditional surgery imposes a constraint for surgeons to have high precision in their hand eye coordination. This paper discusses the design of an assisted medical robot system to reduce these requirements; the needle-driven robot system consists of needle-driven robot, 3D model navigation and a magnetic tracker. In the pre-operative phase, 3D model of the liver tumour is reconstructed and the needle insertion path is planed. In the intra-operative phase, the surgeon matches the pre-operative 3D model of the liver with real patient’s liver. Then, the needle-driven robot moves accurately at the target point where the surgeon inserts the needle into the liver tumour to destroy the tumour with microwave coagulation. A small and compact medical robot is proposed based on workspace optimisation in this paper. Experimental results show that the needle-driven robot location errors are less than 0.2 mm, whereas the robot ultrasound navigation system errors are less than 2.5 mm. Design of the needle-driven robot for radio frequency ablation therapy based on ultrasound navigation
Qinjun Du; Xueyi Zhang; Hui Chen
International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 65 - 72
The ultrasonic image guided radio frequency ablation surgery is an effective technique in liver tumour treatment. However, the traditional surgery imposes a constraint for surgeons to have high precision in their hand eye coordination. This paper discusses the design of an assisted medical robot system to reduce these requirements; the needle-driven robot system consists of needle-driven robot, 3D model navigation and a magnetic tracker. In the pre-operative phase, 3D model of the liver tumour is reconstructed and the needle insertion path is planed. In the intra-operative phase, the surgeon matches the pre-operative 3D model of the liver with real patient’s liver. Then, the needle-driven robot moves accurately at the target point where the surgeon inserts the needle into the liver tumour to destroy the tumour with microwave coagulation. A small and compact medical robot is proposed based on workspace optimisation in this paper. Experimental results show that the needle-driven robot location errors are less than 0.2 mm, whereas the robot ultrasound navigation system errors are less than 2.5 mm.

]]> 10.1504/IJCAT.2011.043886 International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 65 - 72 Qinjun Du; Xueyi Zhang; Hui Chen School of Electrical & Electronic Engineering, Shandong University of Technology, 12 Zhangzhou road, Shandong Zibo, 255091 China. ' School of Electrical & Electronic Engineering, Shandong University of Technology, 12 Zhangzhou road, Shandong Zibo, 255091 China. ' School of Electrical & Electronic Engineering, Shandong University of Technology, 12 Zhangzhou road, Shandong Zibo, 255091 China needle-driven robots workspace optimisation ultrasound navigation radio frequency ablation surgery liver tumours cancer treatment liver cancer medical robots assistive technology robot navigation robot tracking magnetic tracker 3D modelling needle insertion path path planning microwave coagulation. 2011-11-27T23:20:50-05:00 42 1 65 72 2011-11-27T23:20:50-05:00 http://www.inderscience.com/link.php?id=43887 This paper considers the H<SUB align=“right”>? synchronisation of a class of time-delayed chaotic systems with external disturbance. Based on delay-dividing approach, a delay-dependent synchronisation condition is obtained by constructing a new Lyapunov functional, and one simulation example is given to show the effectiveness of the proposed chaos synchronisation scheme. A new delay-dependent synchronisation criterion for Lur’e systems with delay feedback control
Jin Xu; Huibin Zhu; Baotong Cui
International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 73 - 80
This paper considers the H<SUB align=“right”>? synchronisation of a class of time-delayed chaotic systems with external disturbance. Based on delay-dividing approach, a delay-dependent synchronisation condition is obtained by constructing a new Lyapunov functional, and one simulation example is given to show the effectiveness of the proposed chaos synchronisation scheme.

]]> 10.1504/IJCAT.2011.043887 International Journal of Computer Applications in Technology, Vol. 42, No. 1 (2011) pp. 73 - 80 Jin Xu; Huibin Zhu; Baotong Cui College of Communication and Control Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China. ' College of Communication and Control Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China. ' College of Communication and Control Engineering, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China external disturbance delay-dependent synchronisation delay dividing time-delayed chaotic systems feedback control simulation chaos synchronisation. 2011-11-27T23:20:50-05:00 42 1 73 80 2011-11-27T23:20:50-05:00