Stability Analysis of a Predecessor-Following Platoon of Vehicles With Two Time Delays

The problem of controlling a platoon of vehicles moving in one dimension is considered so that they all follow a lead vehicle with constant spacing between successive vehicles. The stability and the string stability of a platoon of vehicles with two independent and uncertain delays, one in the inter-vehicle distance and the other in the relative velocity information channels, are considered. The main objectives of this paper are: (1) using a simplifying factorization procedure and deploying the cluster treatment of characteristic roots (CTCR) paradigm to obtain exact stability boundaries in the domain of the delays, and (2) for the purpose of disturbance attenuation, the string stability analysis is examined. Finally, a simulation example of multiple vehicle platoon control is used to demonstrate the effectiveness of the proposed method

Shockwave damping on freeways using magnetometers and probe vehicle data

This master thesis focuses on the problem of shockwave damping on freeways. To this purpose, we implement two algorithms for detecting shockwaves and a mitigation algorithm. They are tested using simulation in test networks and finally, they are evaluated in the model of a real freeway, the AP7

Conservation in signal processing systems

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 205-209).Conservation principles have played a key role in the development and analysis of many existing engineering systems and algorithms. In electrical network theory for example, many of the useful theorems regarding the stability, robustness, and variational properties of circuits can be derived in terms of Tellegen's theorem, which states that a wide range of quantities, including power, are conserved. Conservation principles also lay the groundwork for a number of results related to control theory, algorithms for optimization, and efficient filter implementations, suggesting potential opportunity in developing a cohesive signal processing framework within which to view these principles. This thesis makes progress toward that goal, providing a unified treatment of a class of conservation principles that occur in signal processing systems. The main contributions in the thesis can be broadly categorized as pertaining to a mathematical formulation of a class of conservation principles, the synthesis and identification of these principles in signal processing systems, a variational interpretation of these principles, and the use of these principles in designing and gaining insight into various algorithms. In illustrating the use of the framework, examples related to linear and nonlinear signal-flow graph analysis, robust filter architectures, and algorithms for distributed control are provided.by Thomas A. Baran.Ph.D

Suppressing Traffic Flow Instabilities

While many models of traffic flow predict the instabilities commonly observed—particularly at higher traffic densities—there are few suggestions for suppressing them. A method is described here for suppressing instabilities, thereby reducing gas consumption, accidents, wear and tear on vehicles and roadways as well as travel times while increasing traffic throughput. The method uses information about the following vehicle as well as the leading vehicle. Using information from both sources allows the gain of feedback to be reduced below one, thus eliminating the instability characteristic of "car following." The needed inputs to the control system can be provided by machine vision (or radar or lidar). Previous proposals for smoothing traffic flow instabilities do not use information about the vehicles behind— "car following" cruise control methods, for example, focus only on the vehicle ahead. The method presented here is based on information flowing both downstream and upstream, in distinction to traditional approaches where information flows only upstream

Suppressing Traffic Flow Instabilities

While many models of traffic flow predict the instabilities commonly observed-particularly at higher traffic densities-there are few suggestions for suppressing them. A method is described here for suppressing instabilities, thereby reducing gas consumption, accidents, wear and tear on vehicles and roadways as well as travel times while increasing traffic throughput. The method uses information about the following vehicle as well as the leading vehicle. Using information from both sources allows the gain of feedback to be reduced below one, thus eliminating the instability characteristic of “car following.” The needed inputs to the control system can be provided by machine vision (or radar or lidar). Previous proposals for smoothing traffic flow instabilities do not use information about the vehicles behind-“car following” cruise control methods, for example, focus only on the vehicle ahead. The method presented here is based on information flowing both downstream and upstream, in distinction to traditional approaches where information flows only upstream