Longitudinal control of the lead car of a platoon
TL;DR: In this paper, the authors present control schemes that perform the major longitudinal tasks that will be required from the lead vehicle of a platoon moving on an automated highway, such as maintaining safe spacing, tracking an optimal velocity and performing various maneuvers (forming, breaking up platoons and changing lanes).
Abstract: Presents longitudinal control laws for vehicles moving in an intelligent vehicle highway system (IVHS). In particular, the scenario where cars move along the highway in tightly spaced platoons is considered. The authors present control schemes that perform the major longitudinal tasks that will be required from the lead vehicle of a platoon moving on an automated highway. More specifically, schemes that maintain safe spacing, track an optimal velocity and perform various maneuvers (forming, breaking up platoons and changing lanes) are described. Simulation results are given. >
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TL;DR: Simulation results show that the proposed methodology provides a reliable tool for a systematic and efficient design of platoon controllers within IVHS.
Abstract: A methodology is proposed for longitudinal control design of platoons of automotive vehicles within intelligent vehicle/highway systems (IVHSs). The proposed decentralized overlapping control law is obtained by using the inclusion principle, i.e., by decomposing the original system model by an appropriate input/state expansion, and by applying the linear quadratic (LQ) optimization to the locally extracted subsystems. The local quadratic criteria directly reflect the desired system performance. Optimization is carried out by using a sequential algorithm adapted to the lower block triangular (LBT) structure of the closed-loop system model. Contraction to the original space provides a decentralized platoon controller which preserves the asymptotic stability and the steady-state behavior of the controller obtained in the expanded space. Conditions for eliminating the "slinky effect" and obtaining the strict string stability are defined; it is shown that the corresponding constraints on the controller parameters are not too restrictive. A new dynamic platoon controller structure, consisting of a reduced order observer and a static feedback map, is obtained by applying the inclusion principle to the decentralized overlapping platoon control design in the case when the information from the preceding vehicle is missing. Numerous simulation results show that the proposed methodology provides a reliable tool for a systematic and efficient design of platoon controllers within IVHS.
588 citations
01 Jul 2000
TL;DR: This work presents a method to design controllers for safety specifications in hybrid systems, using analysis based on optimal control and game theory for automata and continuous dynamical systems to derive Hamilton-Jacobi equations whose solutions describe the boundaries of reachable sets.
Abstract: We present a method to design controllers for safety specifications in hybrid systems. The hybrid system combines discrete event dynamics with nonlinear continuous dynamics: the discrete event dynamics model linguistic and qualitative information and naturally accommodate mode switching logic, and the continuous dynamics model the physical processes themselves, such as the continuous response of an aircraft to the forces of aileron and throttle. Input variables model both continuous and discrete control and disturbance parameters. We translate safety specifications into restrictions on the system's reachable sets of states. Then, using analysis based on optimal control and game theory for automata and continuous dynamical systems, we derive Hamilton-Jacobi equations whose solutions describe the boundaries of reachable sets. These equations are the heart of our general controller synthesis technique for hybrid systems, in which we calculate feedback control laws for the continuous and discrete variables, which guarantee that the hybrid system remains in the "safe subset" of the reachable set. We discuss issues related to computing solutions to Hamilton-Jacobi equations. Throughout, we demonstrate out techniques on examples of hybrid automata modeling aircraft conflict resolution, autopilot flight mode switching, and vehicle collision avoidance.
571 citations
01 Jul 2000
TL;DR: The design and safety verification of the on-board vehicle control system and the design of the link-layer traffic-flow controller are discussed and some questions of implementation are addressed.
Abstract: Describes the design of an automated highway system (AHS) developed over the past ten years in the California PATH program. The AHS is a large, complex system, in which vehicles are automatically controlled. The design and implementation of the AHS required advances in actuator and sensor technologies, as well as the design, analysis, simulation, and testing of large-scale, hierarchical hybrid control systems. The paper focuses on the multilayer AHS control architecture and some questions of implementation. It discusses in detail the design and safety verification of the on-board vehicle control system and the design of the link-layer traffic-flow controller.
466 citations
TL;DR: This work discusses the design of safe and efficient hybrid controllers for regulation of vehicles on an AHS and uses game theoretic techniques to deal with the multiagent and multiobjective nature of the problem.
Abstract: The objective of an automated highway system (AHS) is to increase the safety and throughput of the existing highway infrastructure by introducing traffic automation. AHS is an example of a large scale, multiagent complex dynamical system and is ideally suited for a hierarchical hybrid controller. We discuss the design of safe and efficient hybrid controllers for regulation of vehicles on an AHS. We use game theoretic techniques to deal with the multiagent and multiobjective nature of the problem. The result is a hybrid controller that by design guarantees safety, without the need for further verification. The calculations also provide an upper bound on the performance that can be expected in terms of throughput at various levels of centralization.
335 citations
TL;DR: This paper aims to clarify the relationship of ambiguous definitions and various analysis methods, providing a rigorous foundation for future studies on platoon control, and provides insights for practical selection of analyzing methods for vehicle platoons.
300 citations
References
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Book•
01 Jan 1985
TL;DR: In this paper, a systematic feedback design theory for solving the problems of asymptotic tracking and disturbance rejection for linear distributed parameter systems is presented, which is intended to support the development of flight controllers for increasing the high angle of attack or high agility capabilities of existing and future generations of aircraft.
Abstract: : The principal goal of this three years research effort was to enhance the research base which would support efforts to systematically control, or take advantage of, dominant nonlinear or distributed parameter effects in the evolution of complex dynamical systems. Such an enhancement is intended to support the development of flight controllers for increasing the high angle of attack or high agility capabilities of existing and future generations of aircraft and missiles. The principal investigating team has succeeded in the development of a systematic methodology for designing feedback control laws solving the problems of asymptotic tracking and disturbance rejection for nonlinear systems with unknown, or uncertain, real parameters. Another successful research project was the development of a systematic feedback design theory for solving the problems of asymptotic tracking and disturbance rejection for linear distributed parameter systems. The technical details which needed to be overcome are discussed more fully in this final report.
8,525 citations
TL;DR: Key features of one automated intelligent vehicle/highway system (IVHS) are outlined, it is shown how core driver decisions are improved, and a basic IVHS control system architecture is proposed and a design of some control subsystems is offered.
Abstract: Key features of one automated intelligent vehicle/highway system (IVHS) are outlined, it is shown how core driver decisions are improved, a basic IVHS control system architecture is proposed, and a design of some control subsystems is offered. Some experimental work is summarized. A system that promises a threefold increase in capacity is outlined, and a four-layer hierarchical control architecture that decomposes this problem into more manageable units is proposed. >
1,334 citations
01 Dec 1991
TL;DR: In this paper, an automated intelligent vehicle/highway system (IVHS) is described, and a four-layer hierarchical control architecture is proposed to decompose this problem into more manageable units.
Abstract: Key features of one automated intelligent vehicle/highway system (IVHS) are outlined, it is shown how core driver decisions are improved, a basic IVHS control system architecture is proposed, and a design of some control subsystems is offered. Some experimental work is summarized. A system that promises a threefold increase in capacity is outlined, and a four-layer hierarchical control architecture that decomposes this problem into more manageable units is proposed. >
1,268 citations
TL;DR: The accomplishments to date on the development of automatic vehicle control technology in the Program on Advanced Technology for the Highway (PATH) at the University of California, Berkeley are summarized in this article.
Abstract: The accomplishments to date on the development of automatic vehicle control technology in the Program on Advanced Technology for the Highway (PATH) at the University of California, Berkeley, are summarized. The basic principles and assumptions underlying the PATH work are identified, and the work on automating vehicle lateral (steering) and longitudinal (spacing and speed) control is explained. For both lateral and longitudinal control, the modeling of plant dynamics is described, and the development of the additional subsystems needed (communications, reference/sensor systems) and the derivation of the control laws are presented. Plans for testing on vehicles in both near and long term are discussed. >
774 citations
01 Jan 1992
TL;DR: In this paper, an autonomous intelligent cruise control (AICC) system for automatic vehicle following, examine its effect on traffic flow and compare its performance with that of the human driver models.
Abstract: The purpose of this paper is to develop an autonomous intelligent cruise control (AICC) system for automatic vehicle following, examine its effect on traffic flow and compare its performance with that of the human driver models. The AICC system developed is not cooperative, i.e., it does not exchange information with other vehicles and yet is free of oscillations and slinky-effects. The elimination of the slinky-effect is achieved by using a safety distance separation rule that is proportional to the vehicle velocity (constant time headway). The performance of the AICC system is found to be superior to that of the human driver models considered. It has a faster and better transient response that leads to a much smoother and faster traffic flow. Computer simulations and dynamic visualization tools are used to study the performance of the proposed AICC system and analyze vehicle following under manual and automatic control.
661 citations