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Multi-objective optimal chemotherapy control model for cancer treatment

MEDICAL & BIOLOGICAL ENGINEERING & COMPUTING 2011年第1期49卷 51-65页

作者： Algoul, S. Alam, M. S. Hossain, M. A. Majumder, M. A. A. Univ Bradford Dept Comp Bradford BD7 1DP W Yorkshire England Univ Dhaka Dept Appl Phys Elect & Commun Engn Dhaka 1000 Bangladesh Univ Bradford Sch Life Sci Bradford BD7 1DP W Yorkshire England

This article presents an investigation into the development of a multi-objective optimal chemotherapy control model to reduce the number of cancer cells after a number of fixed treatment cycles with minimum side effects. Mathematical models for cancer chemotherapy are designed to predict the number of tumour cells and control the tumour growth during treatment. This requires an understanding of the system in the absence of treatment and a description of the effects of the treatment. In order to achieve multi-objective optimal control model, we used the proportional, integral and derivative (PID) and I-PD (modified PID with Integrator used as series) controllers based on Martin's model for drug concentration. To the best of our knowledge, this is the first PID/IPD-based optimal chemotherapy control model used to investigate the cancer treatment. The proposed control schemes are designed based on the optimal solution of three objective functions, which include (i) maximising tumour cell killing, for (ii) minimum toxicity, and (iii) tolerable drug concentration. Multi-objective genetic algorithm (MOGA) is used to find suitable parameters of controllers that trade-off among design objectives considered in this work. The results of the different optimal scheduling patterns of the proposed models are presented and discussed through a set of experiments. Finally, the observations are compared with the existing models in order to demonstrate the merits and capabilities of the proposed multi-objective optimisation models. It is noted that the proposed model offers best performance as compared to any models reported earlier.

关键词： Cancer chemotherapy Drug scheduling Tumour growth control algorithm Optimisation

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Development of a new fault-tolerant induction motor control strategy using an enhanced equivalent circuit model

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IET ELECTRIC POWER APPLICATIONS 2011年第8期5卷 618-627页

作者： Jasim, O. Sumner, M. Gerada, C. Arellano-Padilla, J. Alstom Grid UK Ltd PEA Stafford ST17 4LX England Univ Nottingham Sch Elect & Elect Engn Nottingham NG7 2RD England

Variable speed induction motor drives operating with an open circuit phase fault generally have a high harmonic current content and impose a large torque ripple on the load. These effects result from the unbalanced nature of the faulted machine, and under these conditions, the effects of machine and converter non-linearities become more pronounced. It is important to include these non-linearities when modelling drive systems which may operate under fault conditions, and developing fault ride-through control algorithms. This paper proposes a modelling method for induction motor drives which includes machine saturation and space harmonics effects as well as inverter non-linearities, which does not require significant computation times. Results from an experimental test rig are presented to validate the model. The second part of the paper describes how the model was used to develop a new fault ride through control strategy for a voltage-fed vector controlled drive. Experimental results demonstrate the improved drive behaviour with an open-circuit winding fault when controlled with the new strategy.

关键词： fault-tolerant induction motor control strategy machine vector control converter nonlinearity control nonlinearities control of electric power systems enhanced equivalent circuit model inverter nonlinearity equivalent circuits open circuit winding fault machine windings Power convertors and power supplies to apparatus Nonlinear control systems invertors variable speed drives machine fault ride power convertors machine saturation Mechanical variables control variable speed induction motor drive system high harmonic current content fault tolerance machine control Asynchronous machines control algorithm open circuit phase fault condition voltage-fed vector controlled drive space harmonics effect induction motor drives torque ripple torque control Drives

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Ratio control Strategy for an Electromechanical Continuously Variable Transmission Based on Engine Models

Ratio Control Strategy for an Electromechanical Continuously...

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International Conference on Advanced Engineering Materials and Technology (AEMT2011)

作者： Jiang, Qiang Liu, Hongyi Hao, Jianjun Cheng, Yue Northeastern Univ Sch Mech Engn & Automat Shenyang 110004 Liaoning Peoples R China Chongqing Univ Technol Sch Automot Chongqing 400050 Peoples R China

ISBN: (纸本)9783037851937

Electromechanical control CVT (EM-CVT) is a new type of continuously variable transmission, and its ratio quality is an important parameter validated the performance of vehicle. In order to study the dynamical coupling technology between EM-CVT and engine under the running state of vehicle, the special character of two working models is obtained by engine experiment;according to the principle of the EM-CVT, the relation between vehicle speed and ration is theoretically analyzed. Based on the basic theory of PID control, the improved PID control algorithm is proposed for the speed ratio control of the EM-CVT, and experimental verification is made. The experimental results show that there is a significant effect on the system with this algorithm.

关键词： continuously variable transmission control algorithm improved PID speed ratio

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Optimization of Helicopter Rotor Using Polynomial and Neural Network Metamodels

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JOURNAL OF AIRCRAFT 2011年第2期48卷 553-566页

作者： Saijal, K. K. Ganguli, Ranjan Viswamurthy, S. R. Indian Inst Sci Dept Aerosp Engn Bangalore 560012 Karnataka India Natl Aerosp Labs Bangalore 560012 Karnataka India

This study aims to determine optimal locations of dual trailing-edge flaps and blade stiffness to achieve minimum hub vibration levels in a helicopter, with low penalty in terms of required trailing-edge flap control power. An aeroelastic analysis based on finite elements in space and time is used in conjunction with an optimal control algorithm to determine the flap time history for vibration minimization. Using the aeroelastic analysis, it is found that the objective functions are highly nonlinear and polynomial response surface approximations cannot describe the objectives adequately. A neural network is then used for approximating the objective functions for optimization. Pareto-optimal points minimizing both helicopter vibration and flap power ale obtained using the response surface and neural network metamodels. The two metamodels give useful improved designs resulting in about 27% reduction in hub vibration and about 45% reduction in flap power. However, the design obtained using response surface is less sensitive to small perturbations in the design variables.

关键词： Helicopter Blade Multilayer Perceptron Trailing Edge Flap Aeroelastic Stability control algorithm Kinetic Energy Rotor Blades Stiffness Matrices Active control Airframes

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control strategy for multi-pump emulsion power station in coal mine face

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Journal of Coal Science & Engineering(China) 2011年第4期17卷 443-446页

作者： LI Wen-ying WEI Jin-hong Research Institute of Mechano-electronic Engineering Taiyuan University of Technology Taiyuan 030024 China

Shearer and hydraulic support are matching equipments. To increase the operating speed of the shearer, the following speed of hydraulic support must be increased. This means increasing the volume of flow from emulsion power station. Analyzing the operating characteristics of hydraulic supports, the number of simultaneously operating supports is obtained by means of pressure parameter and time history at a certain time, which is a theory base for development of control system to multi-pump emulsion power station.

关键词： emulsion pump mining face hydraulic support control algorithm

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Time-Efficient Angular Steering Laws for Rigid Satellites

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JOURNAL OF GUIDANCE control AND DYNAMICS 2011年第3期34卷 878-892页

作者： Verbin, Dov Lappas, Vaios J. Ben-Asher, Joseph Z. Univ Surrey Guildford GU2 7XH Surrey England Technion Israel Inst Technol IL-32000 Haifa Israel

This paper proposes a new integrative control logic for rapid maneuvering of a rigid satellite using reaction wheels. The proposed control algorithm is of a state feedback nature and is designed to accommodate a variety of conditions, such as the general three-dimensional direction of rotation, initial and/or final angular rates, general alignment of three or four reaction wheels, torque and angular rate limits, and system time response limits. Simulations indicate that the new algorithm allows smooth control, free of chattering. The new controller also uses a tuning capability to compensate for time delays and parasitic dynamics. The tuning capability can be varied in order to enhance performance or robustness. Robustness of the algorithm is proven through a stability analysis and supported by detailed and practical simulations.

关键词： Infrared Astronomical Satellite Reaction Wheels Steering Law control algorithm Quaternions Closed Loop Variable Structure control Kinematics Equation Time Optimal control Damping Coefficient

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Autopilot Abstraction and Standardization for Seamless Integration of Unmanned Aircraft System Applications

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JOURNAL OF AEROSPACE COMPUTING INFORMATION AND COMMUNICATION 2011年第7期8卷 197-223页

作者： Royo, Pablo Pastor, Enric Barrado, Cristina Santamaria, Eduard Lopez, Juan Prats, Xavier Manuel Lema, Juan Castelldefels Sch Technol EPSC UPC Off C4 010 Castelldefels 08860 Catalonia Spain Castelldefels Sch Technol EPSC UPC Off C4 002 Castelldefels 08860 Catalonia Spain Castelldefels Sch Technol EPSC UPC Off C4 013 Castelldefels 08860 Catalonia Spain Castelldefels Sch Technol EPSC UPC Off C4 005 Castelldefels 08860 Catalonia Spain Castelldefels Sch Technol EPSC UPC Off C3 104 Castelldefels 08860 Catalonia Spain Castelldefels Sch Technol EPSC UPC Off C4 015 Castelldefels 08860 Catalonia Spain

Nowadays many autopilot manufacturers are available in the commercial market for fixed wing small/mini Unmanned Aircraft System. Several autopilot configurations exist with a wide variety of selected sensors, sizes, control algorithms, and operational capabilities. However, selecting the right autopilot to be integrated in a given Unmanned Aircraft System is a complex task because none of them are mutually compatible. Moving from one autopilot to another may imply redesigning from scratch all the remaining avionics in the Unmanned Aircraft System. This paper presents the Virtual Autopilot System to facilitate exploitation of data obtained from the autopilot to be used by other applications on board. At the same time, it provides a hardware-independent interface that isolates payload and mission components from the autopilot specificities, thus eliminating dependencies on a particular autopilot solution. This subsystem is integrated into an Unmanned Aircraft System mission-oriented architecture called Unmanned Aircraft System Service Abstraction Layer, which promotes the development of automated concepts of operation keeping the Unmanned Aircraft System pilot fully under control. The VAS and its surrounding architecture have been implemented for a variety of autopilots, ranging from the commercial AP04 from UAV NAVIGATION, to the Paparazzi autopilot and even autopilots for ground-based vehicles. In all cases the selected Virtual Autopilot System interface was maintained, overall capabilities increased due to the flight-plan and mission-oriented perspective offered by the surrounding architecture, and development times exponentially reduced as the Virtual Autopilot System design is consolidated. This wealth of experimentation demonstrates that employing a standardized interface facilitates the integration of new Auto Pilots, but at the same time capabilities are not only maintained but dramatically increased by developing flight-management systems on top of the Virtua

关键词： Autopilot Unmanned Aircraft System Flight Operation Sensors Pilot control algorithm Telemetry Communication Middleware Indicated Airspeed Ailerons

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control algorithm influence on the compromise movement time/vibration - Application to a high speed machine

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MECANIQUE & INDUSTRIES 2007年第5期8卷 429-436页

作者： Colas, Frederic Dieulot, Jean-Yves Barre, Pierre-Jean ENSAM L2EP Equipe Rech CEMODYNE F-59046 Lille France

While improving the dynamical performance of a flexible motion control system, additional stresses are generated which induce undesirable vibrations. The design of adequate control algorithms makes it possible to enhance the overall behaviour of the machine while limiting its deformation modes vibrations. This paper presents a comparative study of the influence of different control algorithms on the trade-off between the cycle time and the amplitude of the residual vibrations, which have been applied to a Cartesian robot. While this selection of control algorithms is not exhaustive, these can all easily be implemented in current industrial systems. Each selected control algorithm is analysed along with experimental validations.

关键词： control algorithm movement time residual vibration flexible system

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Multivehicle Coordination in an Estimated Time-Varying Flowfield

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JOURNAL OF GUIDANCE control AND DYNAMICS 2011年第1期34卷 177-191页

作者： Peterson, Cameron Paley, Derek A. Univ Maryland Dept Aerosp Engn College Pk MD 20742 USA

Unmanned vehicles are an effective platform for tracking, surveillance, and reconnaissance missions. Existing control algorithms promote collaboration of unmanned aerial vehicles and other autonomous vehicles. However, these algorithms often fail to account for the degradation of control performance caused by flowfields. This paper presents decentralized multivehicle coordination algorithms designed for operation in a spatially or temporally varying flowfield. Each vehicle is represented using a Newtonian particle traveling at constant speed relative to the flow and subject to a steering control. An algorithm is described that stabilizes a circular formation in a time-varying spatially nonuniform flowfield, assuming that the flowfield is known and does not exceed the particle speed relative to the flow. For a time-varying and spatially uniform flowfield, an algorithm is provided to stabilize a circular formation in which the temporal spacing between particles is regulated. These algorithms are extended by relaxing the assumption that the flow is known: each particle dynamically estimates the flow and uses that estimate in the control. It is shown that including a turning-rate bound does not alter the main results. The theoretical results are supported by numerical simulations that illustrate the coordinated encirclement of a maneuvering target.

关键词： control algorithm UAV Unmanned Vehicles Numerical Simulation External Flows GPS Flow Velocity Bank Angle Vehicle Trajectories Number of Particles

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Traveling-Salesman Problem for a Class of Carrier-Vehicle Systems

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JOURNAL OF GUIDANCE control AND DYNAMICS 2011年第4期34卷 1272-1276页

作者： Garone, Emanuele Naldi, Roberto Casavola, Alessandro Univ Libre Bruxelles Dept Control & Syst Theory B-1050 Brussels Belgium Univ Bologna Dept Elect Comp Sci & Syst I-40136 Bologna Italy Univ Calabria Dept Elect Comp Sci & Syst I-87036 Arcavacata Di Rende Italy

This Note has addressed the traveling-salesman problem for a class of carrier–vehicle systems in which a slow carrier with infinite operating range cooperates with a faster vehicle that, on the contrary, has a limited operating range. A heuristic solution has been proposed and an analytical bound on its conservativeness has been derived. Extensive numerical simulations have given an insight of the effectiveness of the proposed method in some cases of interest.

关键词： Unmanned Surface Vehicles Unmanned Aerial Vehicle Convex Optimization Mobile Robots Planetary Exploration Numerical Simulation Autonomous Systems control algorithm Path Planning

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