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077 Predictive control of turbo-alternator terminal voltage
890
Abstracts
075 On-Line Estimation of Substrate and Blomass in Activated Sludge Process R. Moreno, C. De Prada, I. Serra, M. Pooh, J. Robuste, pp 467-472
model based on the test firings of the thruster. Simulation results will be provided for a 20N catalytic hydrazine thruster.
One of the main problems to control the activated sludge process in real-time lies in the difficulty of getting reliable on-line measurements of two of the most important states: substrate and biomass concentrations. This paper presents two different designs of a software sensor for on-line (estimated) substrate and biomass estimation. The f'trst is a two-step on-line identification approach, based on the RLS algorithm and non-linear Kalman filtering. The second is based on a linear digital model of substrate and biomass dynamics. Specific developments and comparative results are presented and discussed for both. Results are compared with experimental data collected in a wastewater treatment plant, located near Barcelona.
080 ITACA: An Intelligent Urban Traffic Controller A. Bahamonde, S. Lopez, P. Hernandez-Arauzo, A. Bilbao-Terol, C.R. Vela, pp 495-500
076 Advanced Governor for Hydroelectric Turbines J. Riera, R. Cardoner, pp 473-478 This paper deals with a prototype of a speed and power control system for a hydroelectric power unit. Its structure and basic features are described. The main characteristics are the controller adaptive parameter algorithm with preprogrammed gains, the functions incorporated in sensors and actuators like autocalibration and self-diagnosis.
077 Predictive Control of Turbo-Alternator Terminal Voltage M. Saidy, F.M. Hughes, pp 479-484 A predictive form of generator excitation control is proposed which has the potential for consistent and significantly improved performance characteristics over conventional schemes. The basic principles of the proposed form of control are presented. Its performance capabilities are demonstrated via simulation studies on a test system and compared with those of a conventional Automatic Voltage Regulator (AVR).
078 Survivability in Satellite Instrument Control Applications M.H. Jing, L.J.C. Woolliscroft, pp 485-490 A small fault-tolerant system is described which has been designed as an instrument controller for space applications. It uses three processor modules and some limited shared resources. Central to the operation of this system is the manner in which the information on the performance of both hardware and software is updated and voted on, using adaptive voters. The system uses triplicated TMR to construct a dual-level architecture and is capable of graceful degradation to duplex and even simplex configurations. A possible extension to five processors is outlined.
079 Simulation Model for Catalytic Monopropellant Hydrazine Thrusters A. Cavalio, G. de Maria, P. Marino, pp 491-494 Hydrazine thrusters are often used as actuators for spacecraft attitude and orbit control systems In order to design the spacecraft attitude and orbit system it is necessary to provide the control engineers with a simulation model of the thruster which provides information about all possible system conditions, and especially during pulsed mode firings. An analytical model, based on a complete description of the chemical and physical phenomena occurring during thruster firing is not easy to obtain. This paper presents a simulation
In this paper a new urban traffic controller called 1TACA is presented. This system embodies a new architectural scheme to provide an integrated environment where both procedural and declarative knowledge can run cooperatively. To communicate between those subsystems, the so called virtual problem model has been devised. The paper stresses the advantage of using this methodology in order to get effectively running intelligent controllers.
081 Adaptive Control of a Traffic Intersection by Means of a Neural Network C.J. Barnard, I.S. Shaw, pp 501-506 This study was undertaken to assess the feasibility of using a neural network as a traffic controller. In particular, the optimization of the total traffic flow rate through an isolated three-phase intersection is discussed. A backpropagation-type neural network used samples of traffic density as inputs, while the green times of the different phases constituted the outputs. The network, trained with the desired target vectors, was found to provide good estimates of the outputs on the basis of actual traffic flows. It is felt that a neural network can successfully implement a dynamic, self-learning, adaptive control system, subject to trade-offs between sensor cost constraints and control performance.
082 UNI-TELWAY Bus Management in a UNIX Environment J. Perez-Turlel, J.C. Fraile, J.R. Peran, pp 507-510 This paper describes a concrete implementation of the local area network UNI-TELWAY for the interconneetion of NUM Numerical Controllers (NUM-760 and ROBONUM-800) with a process management computer, in order to develop a Distributed Numerical Control (DNC) system in a flexible machining cell. The software modules for controlling and managing the cell elements have been developed under the UNIX Operating System, allowing different concurrent processes to access the UNITELWAY bus without conflicts. A polling strategy, implemented in the master computer, takes into account the temporal requirements of the different messages on the network, allowing both synchronous and asynchronous traffic to share the communication medium.
083 Intelligent Supervisory System for Microwave Telecommunication Networks K. Tilly, I. Kerese, T. Zsemlye, B. Vadasz, Z. Szalay, pp 511-516 To effectively supervise a telecommunication network an intelligent supervisory system is proposed, consisting of traditional process-monitoring, fault-diagnostic, communication-handling and database-management subsystems. The whole system is based on a generic expert-system shell designed to operate in industrial environments. The diagnostic subsystem contains a twolevel inference engine to operate on structural information and traditional if-then rules. To ensure easy mapping of the supervisory system to any telecommunication network a configuration environment consisting of several compilers integrated into a multi-window editor was also
Abstracts
075 On-Line Estimation of Substrate and Blomass in Activated Sludge Process R. Moreno, C. De Prada, I. Serra, M. Pooh, J. Robuste, pp 467-472
model based on the test firings of the thruster. Simulation results will be provided for a 20N catalytic hydrazine thruster.
One of the main problems to control the activated sludge process in real-time lies in the difficulty of getting reliable on-line measurements of two of the most important states: substrate and biomass concentrations. This paper presents two different designs of a software sensor for on-line (estimated) substrate and biomass estimation. The f'trst is a two-step on-line identification approach, based on the RLS algorithm and non-linear Kalman filtering. The second is based on a linear digital model of substrate and biomass dynamics. Specific developments and comparative results are presented and discussed for both. Results are compared with experimental data collected in a wastewater treatment plant, located near Barcelona.
080 ITACA: An Intelligent Urban Traffic Controller A. Bahamonde, S. Lopez, P. Hernandez-Arauzo, A. Bilbao-Terol, C.R. Vela, pp 495-500
076 Advanced Governor for Hydroelectric Turbines J. Riera, R. Cardoner, pp 473-478 This paper deals with a prototype of a speed and power control system for a hydroelectric power unit. Its structure and basic features are described. The main characteristics are the controller adaptive parameter algorithm with preprogrammed gains, the functions incorporated in sensors and actuators like autocalibration and self-diagnosis.
077 Predictive Control of Turbo-Alternator Terminal Voltage M. Saidy, F.M. Hughes, pp 479-484 A predictive form of generator excitation control is proposed which has the potential for consistent and significantly improved performance characteristics over conventional schemes. The basic principles of the proposed form of control are presented. Its performance capabilities are demonstrated via simulation studies on a test system and compared with those of a conventional Automatic Voltage Regulator (AVR).
078 Survivability in Satellite Instrument Control Applications M.H. Jing, L.J.C. Woolliscroft, pp 485-490 A small fault-tolerant system is described which has been designed as an instrument controller for space applications. It uses three processor modules and some limited shared resources. Central to the operation of this system is the manner in which the information on the performance of both hardware and software is updated and voted on, using adaptive voters. The system uses triplicated TMR to construct a dual-level architecture and is capable of graceful degradation to duplex and even simplex configurations. A possible extension to five processors is outlined.
079 Simulation Model for Catalytic Monopropellant Hydrazine Thrusters A. Cavalio, G. de Maria, P. Marino, pp 491-494 Hydrazine thrusters are often used as actuators for spacecraft attitude and orbit control systems In order to design the spacecraft attitude and orbit system it is necessary to provide the control engineers with a simulation model of the thruster which provides information about all possible system conditions, and especially during pulsed mode firings. An analytical model, based on a complete description of the chemical and physical phenomena occurring during thruster firing is not easy to obtain. This paper presents a simulation
In this paper a new urban traffic controller called 1TACA is presented. This system embodies a new architectural scheme to provide an integrated environment where both procedural and declarative knowledge can run cooperatively. To communicate between those subsystems, the so called virtual problem model has been devised. The paper stresses the advantage of using this methodology in order to get effectively running intelligent controllers.
081 Adaptive Control of a Traffic Intersection by Means of a Neural Network C.J. Barnard, I.S. Shaw, pp 501-506 This study was undertaken to assess the feasibility of using a neural network as a traffic controller. In particular, the optimization of the total traffic flow rate through an isolated three-phase intersection is discussed. A backpropagation-type neural network used samples of traffic density as inputs, while the green times of the different phases constituted the outputs. The network, trained with the desired target vectors, was found to provide good estimates of the outputs on the basis of actual traffic flows. It is felt that a neural network can successfully implement a dynamic, self-learning, adaptive control system, subject to trade-offs between sensor cost constraints and control performance.
082 UNI-TELWAY Bus Management in a UNIX Environment J. Perez-Turlel, J.C. Fraile, J.R. Peran, pp 507-510 This paper describes a concrete implementation of the local area network UNI-TELWAY for the interconneetion of NUM Numerical Controllers (NUM-760 and ROBONUM-800) with a process management computer, in order to develop a Distributed Numerical Control (DNC) system in a flexible machining cell. The software modules for controlling and managing the cell elements have been developed under the UNIX Operating System, allowing different concurrent processes to access the UNITELWAY bus without conflicts. A polling strategy, implemented in the master computer, takes into account the temporal requirements of the different messages on the network, allowing both synchronous and asynchronous traffic to share the communication medium.
083 Intelligent Supervisory System for Microwave Telecommunication Networks K. Tilly, I. Kerese, T. Zsemlye, B. Vadasz, Z. Szalay, pp 511-516 To effectively supervise a telecommunication network an intelligent supervisory system is proposed, consisting of traditional process-monitoring, fault-diagnostic, communication-handling and database-management subsystems. The whole system is based on a generic expert-system shell designed to operate in industrial environments. The diagnostic subsystem contains a twolevel inference engine to operate on structural information and traditional if-then rules. To ensure easy mapping of the supervisory system to any telecommunication network a configuration environment consisting of several compilers integrated into a multi-window editor was also