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Masayoshi Tomizuka - One of the best experts on this subject based on the ideXlab platform.

  • modeling and control of steering system of heavy vehicles for automated Highway Systems
    IEEE-ASME Transactions on Mechatronics, 2004
    Co-Authors: Meihua Tai, Pushkar Hingwe, Masayoshi Tomizuka
    Abstract:

    This work presents modeling, analysis, and controller design of the steering subsystem of heavy vehicles as a subsystem of vehicle lateral control system for the automated Highway Systems. A physical model of the steering subsystem is derived where the hydraulic power assist unit is modeled as a family of static nonlinear boost curves. Based on open-loop frequency tests and analysis of the physical model structure and its dynamical characteristics, a nominal second order linear model of the steering subsystem is obtained. Then, a linear robust loop-shaping controller is designed to provide a good tracking performance of the closed-loop dynamics of the steering subsystem for varying gain cross over frequencies which is a result of the nonlinear characteristics of the hydraulic power assist. The controller has been successfully incorporated as an inner-loop controller into the nested lateral control architecture for autonomous driving and its efficacy has been demonstrated experimentally.

  • adaptive vehicle traction force control for intelligent vehicle Highway Systems ivhss
    IEEE Transactions on Industrial Electronics, 2003
    Co-Authors: Hyeongcheol Lee, Masayoshi Tomizuka
    Abstract:

    This paper is concerned with robust longitudinal control of vehicles in intelligent vehicle Highway Systems by adaptive vehicle traction force control. Two different traction force controllers, adaptive fuzzy logic control and adaptive sliding-mode control, are proposed and applied to the fastest stable acceleration/deceleration and robust vehicle platooning problems. The motivation for investigating adaptive techniques arises from the unknown time-varying nature of the tire/road surface interaction that governs vehicle traction. Synchronous application of the engine or brake torques is also proposed for more stable vehicle maneuvers. The lack of controllability during braking (only one net input torque for the two control objectives, i.e., front and rear wheel slips) is partly overcome by applying auxiliary engine torque. Simulations of the two control methods are conducted using a complex nonlinear vehicle model which fully describes the dynamic behavior of the vehicle. Both controllers result in good performance under time-varying operating conditions.

  • automated Highway Systems an intelligent transportation system for the next century
    International Conference on Advanced Intelligent Mechatronics, 1997
    Co-Authors: Masayoshi Tomizuka
    Abstract:

    Summary form only given. The California PATH program was established in 1986 by the California Department of Transportation (Caltrans) and the Institute of Transportation Studies (ITS) at the University of California at Berkeley to conduct research on transportation Systems, which include automated Highway Systems (AHS), to find solutions for California transportation problems such as congestion, mobility and productivity of system, safety, air quality and environment, energy consumption, cost effectiveness and regional and state wide economic health. This paper focuses on recent activities on AHS at the California PATH. AHS will include control problems from the vehicle level to the Highway network level. The topics described cover PATH work at all levels, but an emphasis is given to control problems at the vehicle level, which will offer a number of challenging opportunities to control engineers.

  • AUTOMATED Highway Systems RESEARCH IN CALIFORNIA PATH
    1996
    Co-Authors: Masayoshi Tomizuka
    Abstract:

    This paper covers the following topics: automated Highway Systems intelligent control, hierarchical control, and advanced vehicle control Systems. IN JAPANESE WITH SUMMARY IN ENGLISH

  • steering and independent braking control for tractor semitrailer vehicles in automated Highway Systems
    Conference on Decision and Control, 1995
    Co-Authors: Chieh Chen, Masayoshi Tomizuka
    Abstract:

    A steering and independent braking control for a tractor-semitrailer vehicle is proposed to achieve lane following in automated Highway Systems. Independent braking force of the semitrailer is utilized to stabilize the trailer yaw motion and thus to prevent the potential occurrence of jack-knifing. The control algorithm is designed by the input/output linearization and the adaptive backstepping design methodologies.

Panayiotis A Ioannou - One of the best experts on this subject based on the ideXlab platform.

  • Macroscopic modeling of automated Highway Systems
    Proceedings of the 36th IEEE Conference on Decision and Control, 1997
    Co-Authors: H. Raza, Panayiotis A Ioannou
    Abstract:

    An accurate macroscopic traffic flow model of automated Highways is necessary not only for analyzing the collective dynamical behaviour of automated vehicles but also for designing control laws to improve system level performance. In this paper a macroscopic model for describing the traffic flow on automated Highways is developed by using the microscopic control laws that govern the motion of individual vehicles. Some assumptions were used to derive the instantaneous speed and density profiles from the kinematics of individual vehicles. We have given enough structure to the modeling task, so that the model is independent of the implementation details, hence can be applied to a wide variety of automated Highway concepts. The developed model can be used to analyze the steady state behaviour of AHS traffic flow for different operating conditions and is currently under study.

  • traffic density control for automated Highway Systems
    Automatica, 1997
    Co-Authors: C.c. Chien, Youping Zhang, Panayiotis A Ioannou
    Abstract:

    In this paper, the authors design, analyze and simulate a roadway controller for an automated Highway system (AHS) that achieved desired traffic densities along the freeway lane. A macroscopic traffic flow model that is modified for AHS operation is used for control design and analysis. Simulation results illustrate the effectiveness of the proposed controller and the benefits that AHS can bring to traffic flow.

  • vehicle following control design for automated Highway Systems
    PATH research report, 1997
    Co-Authors: H. Raza, Panayiotis A Ioannou
    Abstract:

    Automatic vehicle following is an important feature of a fully or partially automated Highway system (AHS). The on-board vehicle control system should be able to accept and process inputs from the driver, the infrastructure and other vehicles, perform diagnostics and provide the appropriate commands to actuators so that the resulting motion of the vehicle is safe and compatible with the AHS objectives. The purpose of this paper is to design and test a vehicle control system in order to achieve full vehicle automation in the longitudinal direction for several modes of operation, where the infrastructure manages the vehicle following. These modes include autonomous vehicles, cooperative vehicle following and platooning. The vehicle control system consists of a supervisory controller that processes the inputs from the driver, the infrastructure, other vehicles and the on-board sensors and sends the appropriate commands to the brake and throttle controllers. In addition, the controller makes decisions about normal, emergency and transition operations. Simulation results of some of the basic vehicle following maneuvers are used to verify the claimed performance of the designed controllers. Experiments on 1-15 that demonstrate the performance of the throttle controller with and without vehicle-to-vehicle communications in an actual Highway environment are also included.

  • vehicle following control design for automated Highway Systems
    IEEE Control Systems Magazine, 1996
    Co-Authors: H. Raza, Panayiotis A Ioannou
    Abstract:

    Automatic vehicle following is an important feature of a fully or partially automated Highway system (AHS). The on-board vehicle control system should be able to accept and process inputs from the driver, the infrastructure, and other vehicles, perform diagnostics, and provide the appropriate commands to actuators so that the resulting motion of the vehicle is safe and compatible with the AHS objectives. The purpose of this article is to design and test a vehicle control system in order to achieve full vehicle automation in the longitudinal direction for several modes of operation, where the infrastructure manages the vehicle following. These modes include autonomous vehicles, cooperative vehicle following, and platooning. The vehicle control system consists of a supervisory controller that processes the inputs from the driver, the infrastructure, other vehicles, and the on-board sensors and sends the appropriate commands to the brake and throttle controllers. In addition, the controller makes decisions about normal, emergency, and transition operations. Simulation results of some of the basic vehicle following maneuvers are used to verify the claimed performance of the designed controllers. Experiments on Interstate-15 that demonstrate the performance of the throttle controller with and without vehicle-to-vehicle communications in an actual Highway environment are also included.

  • Fuzzy Traffic Density Homogenizer For Automated Highway Systems
    PATH research report, 1995
    Co-Authors: C.c. Chien, Panayiotis A Ioannou
    Abstract:

    In this paper, a fuzzy traffic density homogenizer is proposed to alleviate or avoid congestion by smoothing the traffic density distribution profile over freeway lanes. The proposed fuzzy homogenizer consists of two parts: the fuzzy mean speed controller and the fuzzy on- ramp controller. Simulation results are used to demonstrate that the proposed controllers can eliminate traffic flow instabilities leading to smooth traffic flows.

Pravin Varaiya - One of the best experts on this subject based on the ideXlab platform.

  • Address Resolution in One Lane Automated Highway Systems
    PATH research report, 1999
    Co-Authors: Soheila V. Bana, Pravin Varaiya
    Abstract:

    This report describes how address resolution protocols (ARP) are used in automated Highway Systems (AHS) to establish communication among vehicles. The ARP determines the network address of neighboring vehicles. In this report, the authors propose a method which initially uses the road infrastructure for providing addresses. The communication network is then used for updating the address in a one lane automated Highway system. The protocol is modeled and simulated with results showing that automate vehicles in a single lane remain accurately informed about the communication addresses of their neighbors despite maneuvers on the road.

  • DISTRIBUTED INTERACTIVE SIMULATION FOR INTELLIGENT VEHICLE Highway Systems
    1997
    Co-Authors: Pravin Varaiya
    Abstract:

    Abstract : The aim of this project is to combine DIS (Distributed Interactive Simulation), database, and computer visualization technologies with knowledge about transportation engineering in order to create synthetic environments in which alternative ITS( Intelligent Transportation Systems) designs can be simulated and their performance displayed.

  • a theory of traffic flow in automated Highway Systems
    Transportation Research Part C-emerging Technologies, 1996
    Co-Authors: Mireille E Broucke, Pravin Varaiya
    Abstract:

    This paper presents a theory for automated traffic flow, based on abstraction of vehicle activities such as entry, exit and cruising, derived from a vehicle's automatic control laws. The theory formulates TMC traffic plans as the specification of the activities and speed of vehicles, and the entry and exit flows for each Highway section. The theory permits the study of transient phenomena such as congestion, and TMC feed back traffic rules designed to deal with transients.

  • design and evaluation tools for automated Highway Systems
    Proceedings of the DIMACS SYCON workshop on Hybrid systems III : verification and control: verification and control, 1996
    Co-Authors: Akash Deshpande, Datta N Godbole, Aleks Gollu, Pravin Varaiya
    Abstract:

    In this paper, the authors present a brief description of the California Partners for Advanced Transit and Highways (PATH) hierarchical control architecture for Automated Highway Systems (AHS). They describe the framework for AHS design and evaluation and give a summary of simulation and analysis tool needs. Some of the tools being developed which are based on the hybrid Systems approach are also described.

  • Automated Highway Systems
    IFAC Proceedings Volumes, 1996
    Co-Authors: Datta N Godbole, Farokh Eskafi, Pravin Varaiya
    Abstract:

    Abstract Automated Highway System (AHS) is an example of a large-scale, multi-agent, hybrid dynamical system. In this paper, the use of computer aided simulation tool for design and evaluation of control laws, for an AHS based on platooning, is outlined. The hierarchical control architecture for AHS is described along with the details of the simulation tool SmartPath. The role of SmartPalh in design and evaluation of AHS control laws is also depicted in the paper.

Steven E Shladover - One of the best experts on this subject based on the ideXlab platform.

  • automated vehicles for Highway operations automated Highway Systems
    Proceedings of the Institution of Mechanical Engineers Part I: Journal of Systems and Control Engineering, 2005
    Co-Authors: Steven E Shladover
    Abstract:

    AbstractConsiderable research effort has been devoted within the past 15 years to automating the driving of Highway vehicles in order to improve their safety and efficiency of operation and to help to reduce traffic congestion. Although the Highway environment is in some ways more structured than other environments in which automated vehicles have been proposed to operate, the density and complexity of road traffic still make the sensing and control problems challenging. Because Highway vehicles are not ‘unmanned’ but are expected to carry passengers and to coexist with other passenger-carrying vehicles, the reliability and safety considerations in the design of their control Systems are much more important than they are for vehicles that are truly unmanned. This paper reviews the progress that has been made in recent research on Highway vehicle automation and indicates the important research challenges that still need to be addressed before Highway automation can become an everyday reality.

  • INTRODUCTION [TO SPECIAL ISSUE ON INTELLIGENT VEHICLE Highway Systems]
    1994
    Co-Authors: Steven E Shladover
    Abstract:

    This paper serves as an introduction to a special issue of Vehicle System Dynamics on Intelligent Vehicle Highway Systems. Many of the traditional areas of emphasis within vehicle dynamics serve as enabling technologies for the broader issues that arise in the context of Intelligent Vehicle Highway Systems (IVHS). The author outlines the interactions of these disciplines.

  • Design options for operating automated Highway Systems
    Proceedings of VNIS '93 - Vehicle Navigation and Information Systems Conference, 1993
    Co-Authors: H.-s.j. Tsao, R.w. Hall, Steven E Shladover
    Abstract:

    Automated Highway Systems (AHS) have the potential for offering large capacity and safety gains without requiring significant amounts of additional right-of-way. The feasibility of an AHS hinges upon the automation technology, including the vehicle design, infrastructure design and operating strategy. The major design options for operating a fully automated AHS are discussed. For each of the options, the major potential impact on AHS performance is indicated. Six fully automated AHS operating scenarios featuring variations in three design options critical to the human factors of AHS operations are proposed.

  • DESIGN OPTIONS FOR OPERATING FULLY AUTOMATED Highway Systems
    1993
    Co-Authors: H S Jacob Tsao, R.w. Hall, Steven E Shladover
    Abstract:

    Automated Highway Systems (AHS) have the potential for offering large capacity and safety gains without requiring significant amounts of additional right-of-way. The feasibility of an AHS hinges upon the automation technology, including the vehicle design, infrastructure design and operating strategy. The paper begins with a summary of the U.S. Department of Transportation's AHS vision statements, which are used a guideline in developing the design options and scenarios. Following this, the paper presents two major components. The first focuses on the major design options for operating a fully automated Automated Highway System ( AHS). For each option, the major potential impacts on AHS performance are discussed. The second component proposes six fully automated AHS operating scenarios featuring variations in three design options critical to the human factors of AHS operations.

  • Vehicle Modelling and Control for Automated Highway Systems
    American Control Conference (ACC) 1990, 1990
    Co-Authors: D. H. Mcmahon, J. Karl Hedrick, Steven E Shladover
    Abstract:

    This study evaluates the feasibility of longitudinal control of a platoon of automated vehicles. As a prerequisite to controller design, a nine state nonlinear model including an internal combustion engine, engine transmission dynamics, and tire friction characteristics has been developed. Parametric studies revealed that simple linear models cannot predict the vehicle transients. Due to this highly nonlinear nature of the vehicle, the use of a nonlinear controller was proposed. A nonlinear control strategy using throttle engine control for a platoon of two vehicles was studied using the technique of Sliding Control. In our analysis, the quantities of primary concern are position and velocity tracking errors. Simulation results demonstrate excellent tracking even in the presence of sizable modelling errors and disturbance inputs.

J. Karl Hedrick - One of the best experts on this subject based on the ideXlab platform.

  • constant spacing strategies for platooning in automated Highway Systems
    Journal of Dynamic Systems Measurement and Control-transactions of The Asme, 1999
    Co-Authors: D Swaroop, J. Karl Hedrick
    Abstract:

    This paper focuses on the spacing of vehicles in a traffic platoon. The authors first describe a framework for establishing conditions for string stability. A metric for analyzing the performance of a platoon is then developed. In the remainder of the paper, the authors outline and analyze different constant spacing vehicle follower algorithms.

  • Vehicle Control Issues in Intelligent Vehicle Highway Systems
    IFAC Proceedings Volumes, 1995
    Co-Authors: J. Karl Hedrick
    Abstract:

    Abstract This paper gives an overview of vehicle control issues associated with Intelligent Vehicle Highway Systems (IVHS), in particular it treats the technology required for autonomous control of vehicles in an Automated Highway System (AHS). This is not a true survey paper in that research results of the California PATH program are presented, whereas ongoing work in Europe (Prometheus) and Asia is not treated. The primary issues dealt with in this paper concern the longitudinal and lateral control of autonomous vehicles.

  • control issues in automated Highway Systems
    IEEE Control Systems Magazine, 1994
    Co-Authors: J. Karl Hedrick, Masayoshi Tomizuka, Pravin Varaiya
    Abstract:

    This article describes vehicle control issues that must be faced in designing a fully automated Highway system (AHS). In particular, requirements for a control system architecture as well as issues of lateral and longitudinal "platoon" control are addressed. Interest in AHS is clearly expanding at a rapid pace due to the ever-increasing problems of freeway congestion and the potential for a technological solution. The approach described is based on five years of research as part of the California PATH program. >

  • vehicle modeling and control for automated Highway Systems
    PATH research report, 1993
    Co-Authors: J. Karl Hedrick, D H Mcmahnon, D Swaroop
    Abstract:

    This report summarizes recent work done in the area of longitudinal control of a platoon of autonomous vehicles. As a prerequisite to controller design, a twelve state nonlinear model including an internal combustion engine, engine transmission dynamics, and tire friction characteristics has been developed. Two simplified models for simulation and controller design are presented. After outlining the control problem, two platooning strategies, based on spacing or headway criterion, are proposed. To solve the control requirements, decentralized nonlinear control strategies using throttle angle and brake torque control for a platoon were developed using a modification of the technique of Sliding Control and Input-Output Linearization. The quantities of primary concern are position and velocity tracking errors. Simulation results on multiple vehicle platoons demonstrate excellent tracking using the spacing-based controllers. The control strategies were implemented experimentally on the Integrated Platoon Control System (IPCS) during two and four car platoon testing.

  • Vehicle Modelling and Control for Automated Highway Systems
    American Control Conference (ACC) 1990, 1990
    Co-Authors: D. H. Mcmahon, J. Karl Hedrick, Steven E Shladover
    Abstract:

    This study evaluates the feasibility of longitudinal control of a platoon of automated vehicles. As a prerequisite to controller design, a nine state nonlinear model including an internal combustion engine, engine transmission dynamics, and tire friction characteristics has been developed. Parametric studies revealed that simple linear models cannot predict the vehicle transients. Due to this highly nonlinear nature of the vehicle, the use of a nonlinear controller was proposed. A nonlinear control strategy using throttle engine control for a platoon of two vehicles was studied using the technique of Sliding Control. In our analysis, the quantities of primary concern are position and velocity tracking errors. Simulation results demonstrate excellent tracking even in the presence of sizable modelling errors and disturbance inputs.