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A generalized approach for the analysis of large scale systems under uncertainty: Applications to transportation planning and engineering
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Recent doctoral dissertation
Also, a gain scheduling rule base is designed to choose the appropriate controller based on the velocity of the vehicle and the traction conditions between the road and the vehicle tires. To achieve an acceptable level of performance, methods are considered to investigate the automatic tuning of the FLC parameters. The first method uses genetic algorithms (GA) and the second approach uses a novel idea to adjust the FLC parameters on-line to follow a reference closed-loop model, modeled by a fuzzy system. In the latter method, using Lyapunov theory, a supervisory control term is introduced to ensure that the closed-loop system under fuzzy logic control will maintain stability. Experimental test results of the manually tuned FLCs are shown, and a comparison is made to similar tests conducted using a frequency shaped linear quadratic (FSLQ) controller as well as a proportional, integral, plus derivative (PID) controller.
already been proposed for platooning. Each vehicle is governed by a hybrid controller consisting of a discrete event system called the coordination layer, that coordinates platoon maneuvers with its neighbors, and a set of continuous controllers that calculate throttle, brake and steering inputs, called the regulation layer. Coordination layer protocols have already been designed. The design of regulation layer control laws and their interaction with the coordination layer is the topic of this dissertation. First, an autonomous cruise controller for the lead vehicle of a platoon is designed which maintains safe spacing from the preceding vehicle while following its velocity. Longitudinal control laws for platooning maneuvers are also designed. These control laws achieve a balance between safety and passenger comfort. An interface is designed to combine the regulation layer control laws with the coordination layer protocols.
A generalized approach for the analysis of large scale systems under uncertainty: Applications to transportation planning and engineering. Vijayakumar, Perincherry, Ph.D. University of Delaware. 1994. 267 pp. Professor In Charge: Shinya
The influence of user information systems on transport demand. Schwarzmann, Rainer. Universitiit Karlsruhe (Germany), 1995. 126 pp. (in German).
Kikuchi. Order Number DA!840565
This dissertation develops a generalized approach for the analysis of large-scale systems under uncertainty. The key elements of the approach are formal methods and principles to decompose a large-scale system into smaller subsystems, to aggregate the results from analyzing the small subsystems, and to evaluate the uncertainty associated with the analysis. It recognizes that the amount of uncertainty (or the amount of information desired) is dependent on the specific problem that is being addressed and the specific analyst or analysts who conduct the analysis. The application of the proposed approach is illustrated using three specific problems: dynamic control of stochastic traffic flow on a city street network; estimation of route choice decisions under route guidance with uncertainties in the advisory information; and examination of the feasibility of achieving regional transportation goals through the implementation of certain Intelligent Transportation System (ITS) alternatives in the region.
Hierarchical hybrid control of automated highway systems. Godbole. Dattaprabodh Narhar, Ph.D. University of Califarnia. Berkeley, 1994. 143 pp.
Recent developments in the field of advanced transport telematics offer new opportunities for the design of transportation demand management strategies. Provision of user information (e.g. in-vehicle navigation systems. information at public transit stops, and computer-aided in-home trip planning systems) will allow planners to more directly influence transportation demand. This dissertation develops and implements a model which represents transportation demand as a result of individual activity chains. Choice models for departure time and mode that take into account available information were integrated. The use of rules. based on individuals’ knowledge under the influence of information, compensates for the lack of empirical knowledge. Through a pilot installation in the city of Cologne, the impacts of large-scale applications of different user information systems were investigated by simulation. These systems refer to different transport modes (private vehicles and public transport) and different target groups (car drivers, public transport passengers, and all users). The use of modeling enables the study of interdependencies between different system approaches. The results of this pilot study deal mainly with modal and temporal effects (mode and departure time choice). Their aggregation to general impacts offers interesting insights for the development of user information systems in transportation.
Chair: Shankar Sastry. Order Number DA9529322
The goal of this dissertation is to design controllers that guarantee collision-free operation of vehicles on an Automated Highway Systems (AHS) using platooning. In this scheme, traffic is organized into closely spaced platoons to increase capacity and safety of the existing highways. Platooning requires vehicles to be automatically controlled. A hierarchical control architecture has
An integrated route assignment and traffic simulation system with massively parallel computing arcbitecture. Junchaya, Thanavat, Ph.D. University of Maryland, 1994. 190 pp. Adviser: Gang-Len
Chang. Order Number DA9526231
This research presents an integrated system for applications in an Advanced Traveler Information
Recent doctoral dissertation
Also, a gain scheduling rule base is designed to choose the appropriate controller based on the velocity of the vehicle and the traction conditions between the road and the vehicle tires. To achieve an acceptable level of performance, methods are considered to investigate the automatic tuning of the FLC parameters. The first method uses genetic algorithms (GA) and the second approach uses a novel idea to adjust the FLC parameters on-line to follow a reference closed-loop model, modeled by a fuzzy system. In the latter method, using Lyapunov theory, a supervisory control term is introduced to ensure that the closed-loop system under fuzzy logic control will maintain stability. Experimental test results of the manually tuned FLCs are shown, and a comparison is made to similar tests conducted using a frequency shaped linear quadratic (FSLQ) controller as well as a proportional, integral, plus derivative (PID) controller.
already been proposed for platooning. Each vehicle is governed by a hybrid controller consisting of a discrete event system called the coordination layer, that coordinates platoon maneuvers with its neighbors, and a set of continuous controllers that calculate throttle, brake and steering inputs, called the regulation layer. Coordination layer protocols have already been designed. The design of regulation layer control laws and their interaction with the coordination layer is the topic of this dissertation. First, an autonomous cruise controller for the lead vehicle of a platoon is designed which maintains safe spacing from the preceding vehicle while following its velocity. Longitudinal control laws for platooning maneuvers are also designed. These control laws achieve a balance between safety and passenger comfort. An interface is designed to combine the regulation layer control laws with the coordination layer protocols.
A generalized approach for the analysis of large scale systems under uncertainty: Applications to transportation planning and engineering. Vijayakumar, Perincherry, Ph.D. University of Delaware. 1994. 267 pp. Professor In Charge: Shinya
The influence of user information systems on transport demand. Schwarzmann, Rainer. Universitiit Karlsruhe (Germany), 1995. 126 pp. (in German).
Kikuchi. Order Number DA!840565
This dissertation develops a generalized approach for the analysis of large-scale systems under uncertainty. The key elements of the approach are formal methods and principles to decompose a large-scale system into smaller subsystems, to aggregate the results from analyzing the small subsystems, and to evaluate the uncertainty associated with the analysis. It recognizes that the amount of uncertainty (or the amount of information desired) is dependent on the specific problem that is being addressed and the specific analyst or analysts who conduct the analysis. The application of the proposed approach is illustrated using three specific problems: dynamic control of stochastic traffic flow on a city street network; estimation of route choice decisions under route guidance with uncertainties in the advisory information; and examination of the feasibility of achieving regional transportation goals through the implementation of certain Intelligent Transportation System (ITS) alternatives in the region.
Hierarchical hybrid control of automated highway systems. Godbole. Dattaprabodh Narhar, Ph.D. University of Califarnia. Berkeley, 1994. 143 pp.
Recent developments in the field of advanced transport telematics offer new opportunities for the design of transportation demand management strategies. Provision of user information (e.g. in-vehicle navigation systems. information at public transit stops, and computer-aided in-home trip planning systems) will allow planners to more directly influence transportation demand. This dissertation develops and implements a model which represents transportation demand as a result of individual activity chains. Choice models for departure time and mode that take into account available information were integrated. The use of rules. based on individuals’ knowledge under the influence of information, compensates for the lack of empirical knowledge. Through a pilot installation in the city of Cologne, the impacts of large-scale applications of different user information systems were investigated by simulation. These systems refer to different transport modes (private vehicles and public transport) and different target groups (car drivers, public transport passengers, and all users). The use of modeling enables the study of interdependencies between different system approaches. The results of this pilot study deal mainly with modal and temporal effects (mode and departure time choice). Their aggregation to general impacts offers interesting insights for the development of user information systems in transportation.
Chair: Shankar Sastry. Order Number DA9529322
The goal of this dissertation is to design controllers that guarantee collision-free operation of vehicles on an Automated Highway Systems (AHS) using platooning. In this scheme, traffic is organized into closely spaced platoons to increase capacity and safety of the existing highways. Platooning requires vehicles to be automatically controlled. A hierarchical control architecture has
An integrated route assignment and traffic simulation system with massively parallel computing arcbitecture. Junchaya, Thanavat, Ph.D. University of Maryland, 1994. 190 pp. Adviser: Gang-Len
Chang. Order Number DA9526231
This research presents an integrated system for applications in an Advanced Traveler Information