Publications
The reports listed below are available in their entirety when requested directly from the Center. A nominal fee may be charged. Please e-mail requests to Carol Camm at: camm@ece.osu.edu.
Table of Contents
#96-07 "Real-time Curve Warning System"
#96-06 "An Articulated Vehicle Model"
#96-04 "Towards the Design of an Optimal Nonlinear Passive Vehicle Suspension System"
#96-03 "Implementation of a Longitudinal Controller for Use on an Automated Highway System"
#96-02 "Development of a Computationally Efficient Time-Domain Engine Model"
#96-01 "Design and Implementation of Parallel Time-Dependent Least Time Path Algorithms for ITS Applications"
#95-09 "Control of Lane Change Maneuvers for Autonomous Vehicles"
#95-08 "Sliding Mode Design for Robust Linear Optimal Control"
#95-07 "Vehicle Modeling and Simulation for IVHS Studies"
#95-06 "An Analytical Study of Vehicle Steering Control"
#95-05 "Fault Tolerant Longitudinal and Lateral Control for Automated Highway Systems"
#95-04 "Interface Between the COMPUTRAN UTCS 1.5 and the Freeway Management System for the Columbus Area"
#95-03 "From Functional Hierarchies to Hybrid Systems: A Design Framework"
#95-02 "Adaptive Control of a Class of Decentralized Nonlinear Systems"
#95-01 "Stable Adaptive Control Using Fuzzy Systems and Neural Networks"
#94-07 "INtelligent TRaffic Evaluator for Prompt Incident Detection in Virtual Reality environment (INTREPID-VR)"
#94-06 "One Aspect of IVHS: The Automated Highway System" (AHS Tutorial)
#94-05 "Optimum Path Algorithms for Intelligent Vehicle / Highway Systems (IVHS) Applications"
#94-04 "Modeling and Simulation of Automobile Dynamics for IVHS Studies"
#94-03 "ABS Control Using Optimum Search via Sliding Modes"
#94-02 "An Articulated Vehicle Model for Highway Studies"
#94-01 "An Interconnected System Model for Integrated Design of Vehicles"
#94-01
"An Interconnected System Model for Integrated Design of Vehicles"
Konur A. Unyelioglu, Umit Ozguner, Timbre Hissong, and Jim Winkelman
Abstract: This report presents a nonlinear vehicle model which is developed for the analysis of interactive automobile dynamics. The model consists of 17 states which represent the lateral/longitudinal, vertical, and tire bounce dynamics including their interactions. The report also contains a linear model which is obtained as an explicit linearization of the nonlinear model around a constant trajectory. The nonlinear model has been implemented in MATRIXx. The SystemBuild blocks of the model and some simulation results are also included in the report.
#94-02
"An Articulated Vehicle Model for Highway Studies"
#94-03
"ABS Control Using Optimum Search via Sliding Modes"
Abstract: The report presents the control design for Antilock Braking Systems via the Sliding Mode approach. In this study we formulate the problem as that of extremum searching in a highly uncertain situation. We consider the friction force as an output of the dynamic system which includes mechanical motion equations and the hydraulic circuit equations. This setting is complicated by the optimized function being a priori unknown, and the input (slip) not being measurable. A MATRIXx computer program simulating the model is also included.
#94-04
"Modeling and Simulation of Automobile Dynamics for IVHS Studies"
#94-05
"Optimum Path Algorithms for Intelligent Vehicle / Highway Systems (IVHS) Applications"
#94-06
TOPICS / SPEAKERS
"AHS: An Introduction and Historical Overview" by R.E. Fenton
"Overview of AHS Programs" by J. Pittenger
"Lanetrak: A Vision-Based Automatic Vehicle Steering System" by O. Altan
"Dual-Mode Truck: Automated and Manual Operation" by R. Bishel and G. Wilson
"Radar-Based Lane Following and Headway Control" by J. Young and U. Ozguner
"Vehicle Lateral Guidance for IVHS" by H. Peng
#94-07
Abstract: Time, money, and lives are continually lost due to inadequate verification assessment of, and response to, traffic accidents. Solutions have yet to be found. The INtelligent Traffic Evaluator for Prompt Incident Detection in a Virtual Reality environment (INTREPID-VR) may provide an opportunity to combat these problems. INTREPID-VR allows the users (traffic authorities) to immerse themselves in a simulation process that makes them feel as if they are present at an accident site. Because it offers this "first-hand" experience, INTREPID-VR can improve the authorities'
abilities in two ways: it can offer greater precision in verifying, assessing, and responding to traffic accidents, and can
perform a troubleshooting function to decrease the risk of inadequate verification and assessment of, and response to, traffic accidents. INTREPID-VR provides an entirely different approach to the application of an Intelligent Vehicle Highway System (IVHS) to reduce congestion, improve safety and mobility, and promote a more efficient use of emergency vehicles and highways. Furthermore, it is unique in that users can experience the accident scene in a multi- sensory media environment. Authorities can also use it for practical training purposes. Central to developing INTREPID-VR is the construction of 3-D schematic representations and video files. This report explains the development of these models.
#95-01
Abstract: Stable direct and indirect adaptive controllers are presented which use Takagi-Sugeno fuzzy systems,
conventional fuzzy systems, or a class of neural networks to provide asymptotic tracking of a reference signal for a class of continuous-time nonlinear plants with poorly understood dynamics. The indirect adaptive scheme allows for the inclusion of a priori knowledge about the plant dynamics in terms of exact mathematical equations or linguistics while the direct adaptive scheme allows for the incorporation of such a priori knowledge in specifying the controller. We prove that with or without such knowledge both adaptive schemes can "learn" how to control the plant, provide for bounded internal signals, and achieve asymptotically stable tracking of a reference input. In addition, for the direct adaptive scheme a technique is presented in which linguistic knowledge of the inverse dynamics of the plant may be used to accelerate adaptation. The performance of the indirect and direct adaptive schemes is demonstrated through the longitudinal control of an automobile within an automated lane.
#95-02
"Adaptive Control of a Class of Decentralized Nonlinear Systems"
Abstract: Within this brief paper, a stable indirect adaptive controller is presented for a class of interconnected
nonlinear systems. The feedback and adaptation mechanisms for each subsystem depend only upon local measurements to provide asymptotic tracking of a reference trajectory. In addition, each subsystem is able to adaptively compensate for disturbances and interconnections with unknown bounds. The adaptive scheme is illustrated through the longitudinal control of a string of vehicles within an Automated Highway System (AHS).
#95-03
Abstract: In this paper we describe our formal framework of the hierarchical decomposition and analysis of large scale systems. We provide a generic description of a goal/task hierarchy and show how it can be translated into a state machine representation. To illustrate this methodology, we describe the hierarchical analysis and decomposition of an advanced cruise control system for automobiles.
#95-04
Abstract: The ultimate goal of this project is to develop an interface that by utilizing the existing traffic signal
control systems infrastructure (control devices, software and hardware) and by building relatively inexpensive software and hardware, will produce a prototype for an integrated freeway-surface street control system. This is anticipated to be done in two phases: the first phase will address the feasibility and spell out the requirements for this interface, and the second phase will actually implement and test the interface on real-time basis. Consequently,the two systems will be able to communicate properly.
#95-05
Abstract: Increasing highway traffic congestion and real estate costs that limit the building of new highways has brought about a renewed interest in an Automated Highway System (AHS) where the vehicle steering task ("lateral control") and the braking/throttle tasks ("longitudinal control") are taken over by computers to increase the throughput of existing highways. Since safety plays a key role in the developments of an AHS, fault tolerant control is vital. In this paper, we develop longitudinal and lateral fault tolerant sliding mode control algorithms and prove
that these control algorithms are stable for a variety of faults (e.g. in the braking, powertrain, and steering systems). Next, stability of the control algorithms is proven and we show that intervehicle spacing errors will not become amplified along the AHS in the event of a loss of lead vehicle information. The performance of the sliding mode controllers is demonstrated through a series of simulations incorporating various vehicle and AHS faults.
#95-06
Abstract: A feedback controller is presented to automatically steer the ground vehicles. The controller needs only
two on line measurements: the longitudinal velocity of the vehicle and a special angle information which determines the orientation and posititon of the vehicle with respect to the roadway. The stability of the closed loop system is analytically proven for a generic set of vehicle parameters. Some simulation results are also included to demonstrate the successful performance of the controller at steady state. Keywords: Automotive control, vehicle dynamics, advanced control systems, nonlinear control.
#95-07
Abstract: In this report, a mathematical and computer model of a four-wheeled automobile is developed to study the vehicle's dynamical behavior under a variety of operating conditions. The modeling is accomplished through first principles and aims to capture the dominant dynamics of the vehicle subsystems including the engine, transmission, vehicle body, suspension, and wheels. To validate the vehicle model, a computer simulation is
developed in MATLAB and SIMULINK. The vehicle model is tested extensively with differenct scenarios that include braking, acceleration, and steering on various road surfaces and terrains. The model is flexible in the sense that a wide variety of vehicles can be simulated with the change of a few simple parameters, such as the mass of the vehicle or the suspension characteristics. Finally, a graphical interface to the vehicle dynamics is developed to
complement MATLAB's plots. The three views of the vehicle, top, side, and front, are displayed in a single frame, based upon the simulation data. The idea is similar to a movie in that the frames are strung together in sequence and the car's pitch, yaw, and roll motions are observed as the vehicle executes the driving maneuvers. Although the primary intention is for demonstration, this graphical model could also provide the additional insight that is so often
vital in control design and implementation, particularly for investigating effects related to disturbances (road surface
and vehicle faults).
#95-08
Abstract: In this paper we introduce a robust control design method for solving linear optimal control problems with fixed terminal time, and fixed terminal constraints, a class of problems which the existing designs of sliding mode manifolds do not adequately address. For systems with uncertainties, we propose a class of time varying sliding mode manifold design which is shown to be optimal with respect to quardratic cost defined over a finite time interval.
#95-09
Abstract: In this report, the necessary and sufficient conditions tobe satisfied by the steering signal and the vehicle dynamics during a lane change maneuver is analyzed. Specific types of lane change steering signals with generic parameters are considered. For each signal, the values of the associated parameters are determined by solving an optimization problem. The problem is defined to achieve the desired lateral offset within a minimum period while the magnitudes of the lateral acceleration and the lateral jerk are constrained. Finally, it is shown that it is possible to achieve the lane change maneuvers in a closed-loop system by suitably modifying a lane following controller developed in an earlier study.
#96-01
Abstract: The development of Intelligent Transportation Systems (ITS) and the resulting need for real-time traffic management and route guidance models require fast shortest path algorithms that can account for the dynamics of traffic networks. The objective of this paper is to introduce parallel design for time-dependent shortest path algorithms that can be used in real-time ITS applications. In this paper, two shared memory and one message passing algorithms are designed, implemented, coded and computationally tested on actual and random networks. The reported tests are performed on CRAY supercomputers, but the algorithms can be readily ported to lower-end multiprocessor machines.
#96-02
Abstract: This report is concerned with the development of a computationally efficient, modular time-domain engine model. The proposed model can be coupled with a transmission model to perform detailed powertrain control studies via simulations. The developed model aims to offer most of the sophisticated engine characteristics while minimizing the computational cost. Various optimization techniques are employed to shorten the simulation time. The model is implemented on MATLAB Simulink. Many simulation cases are considered and the performance of the new model is compared to those of a highly sophisticated model and a relatively simpler model throughout the report. The block diagrams and the simulation initialization file are given in the Appendix.
#96-03
Abstract: In this thesis the methods used to implement a car-following algorithm on a 1992 Honda Accord are described. The car-following algorithm is sub-divided into four controllers: throttle-angle, brake-pressure, speed, and car-following controllers. Throttle angle regulation is achieved using a sliding mode controller and the original cruise control actuator while brake pressure regulation is accomplished using a PID controller and a Delphi Chassis Systems ABS brake unit. The speed controller uses a kalman filter to estimate the vehicle speed from noisy speed measurements and depending on the needed acceleration, either a PID controller for calculating the desired throttle angle or a feedback linearizing controller inconjunction with a PID controller for calculating the desired brake pressure. The desired throttle angle and desired brake pressure are then passed to the two lower-level throttle angle and brake pressure controllers. The car-following controller uses a multi-mode approach which divides the phase plane consisting of the relative velocity and distance between the lead and following car into eight regions. Depending on the region, a different acceleration is applied in order to drive the relative velocity and distance to zero.
Experimental results are shown throughout the thesis illustrating the performance of each of the controllers. In addition, models for all the actuators and test vehicle are provided.
#96-04
Abstract: Generally, there are trade-offs between different ride comfort criteria when designing a suspension system for a vehicle. While active suspension systems are the most effective in reducing these trade-offs, they are also characterized by high costs and low reliability. This thesis is a preliminary attempt at designing a nonlinear passive suspension system which tries to minimize the trade-offs between two ride comfort criteria; optimizing the sprung mass acceleration and limiting the suspension travel for a given road input.
The suspension system and the associated parts of the vehicle are modeled as a single loop feedback system, with the suspension parameters forming the feedback gain matrix. A general method is developed to optimize a quadratic cost function (a weighted sum of quadratic costs of the two ride comfort criteria) for such a feedback linear system, at the same time minimizing the effect of a specific known disturbance input. In the context of the ride control problem, the road condition acts as the disturbance input. The analysis is applied to both single and a two mass quarter car model. Optimal feedback gains are designed for a specific known input in the form of a pulse. Since, realistic road conditions can be approximated by different combinations of multiple pulses, this analysis can be extended to such a case.
Cem Hatipoglu, Konur A. Unyelioglu, and Umit Ozguner
Abstract: This report is concerned with the development of a generic tractor-trailer model which includes a tractor, a semitrailer, and two trailers. Each body is described by a nonlinear bicycle model where the following degrees of freedom are considered: longitudinal velocity, lateral velocity, and yaw rate. The overall system has nine degrees of freedom and contains 15 states. A MATRIXx computer program simulating the model is also described in the report.
Sergey Drakunov and Umit Ozguner
Jeffrey T. Spooner and Kevin M. Passino
Abstract: A model of a complete automobile is presented and simulated. Each component of the automobile is described in terms of physical quantities to provide further insight into the workings of the composite automotive system so that advanced control may be effectively applied. The model preserves the dominant dynamics of each automotive subsystem, including engine, transmission, suspension, and brake dynamics. The composite model allows for throttle, brake, suspension, and steering inputs along with highway path and road condition selection. A series of simulations were used to validate the model over a range of driving scenarios.
Athanasios K. Ziliaskopoulos
Abstract: Almost every functional component of intelligent vehicle / highway systems (IVHS) requires the computation of one or more paths that satisfy certain problem-specific requirements. Some of these path problems have been modeled and solved in the literature, or could be addressed by modifying existing approaches (10, 11, 13, 14). However, others
have not been encountered previously and must be specifically designed for IVHS applications. Furthermore, the real-time information and control features of IVHS, the large scale of the networks under consideration, and the particular complex realities of traffic networks impose additional requirements on the algorithms. These requirements preclude ready applicability of existing algorithms in most cases. In this report, the requirements in path computations by the various IVHS components are identified, some of their properties are discussed, and general schemes are introduced to compute optimum paths both for the continuous and the discrete time case.
"One Aspect of IVHS: The Automated Highway System"
(AHS Tutorial)
for ISIC 94 Conference
"INtelligent TRaffic Evaluator for Prompt Incident Detection in Virtual Reality environment (INTREPID-VR)"
Fabian C. Hadipriono, Ashraf S. Barsoum, James Tsay and Zoltan Z. Nemeth
"Stable Adaptive Control Using Fuzzy Systems and Neural Networks"
Jeffrey T. Spooner and Kevin M Passino
Jeffrey T. Spooner and Kevin M. Passino
"From Functional Hierarchies to Hybrid Systems: A Design Framework"
Keith Redmill and Umit Ozguner
"Interface Between the COMPUTRAN UTCS 1.5 and the Freeway Management System for the Columbus Area"
Ahmad Al-Akhras, P.E. and Athanasis Ziliaskopoulos
"Fault Tolerant Longitudinal and Lateral Control for Automated Highway Systems"
Jeffrey T. Spooner and Kevin M. Passino
"An Analytical Study of Vehicle Steering Control"
Konur A. Unyelioglu, Cem Hatipoglu, and Umit Ozguner
"Vehicle Modeling and Simulation for IVHS Studies"
Lewis P. Fulcher III, Jeffrey T. Spooner, Stephen Yurkovich
and Kevin M. Passino
"Sliding Mode Design for Robust Linear Optimal Control"
K. David Young and Umit Ozguner
"Control of Lane Change Maneuvers for Autonomous Vehicles"
Cem Hatipoglu, Konur A. Unyelioglu, and Umit Ozguner
"Design and Implementation of Parallel Time-Dependent Least Time Path Algorithms for ITS Applications"
Athanasios Ziliaskopoulos, Dimitrios Kotzinos and Hani Mahmassani
"Development of a Computationally Efficient Time-Domain Engine Model"
Cem Hatipoglu and Martin Sommerville
"Implementation of a Longitudinal Controller for Use on an Automated Highway System"
Martin Sommerville
"Towards the Design of an Optimal Nonlinear Passive Vehicle Suspension System"
Shyamala Raghunathan