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In order to improve the vehicle’s fuel economy while in cruise, the Model Predictive Control (MPC) technology has been adopted utilizing the road grade preview information and allowance of the vehicle speed variation. In this paper, a focus is on robustness study of delivered fuel economy benefit of Adaptive Nonlinear Model Predictive Controller (ANLMPC) reported earlier in the literature to several noise factors, e.g. vehicle weight, fuel type etc. Further, the vehicle position is obtained via GPS with finite precision and source of road grade preview might be inaccurate. The effect of inaccurate information of the road grade preview on the fuel economy benefits is studied and a remedy to it is established.

In this paper, a series of design, development, and implementation details for testing and evaluation of Lane Departure Warning and Prevention systems are being discussed. The approach taken to generate a set of repeatable and relevant test scenarios and to formulate the test procedures to ensure the fidelity of the collected data includes initial statistical analysis of applicable statistics; growth and probabilistic pruning of a test matrix; simulation studies to support procedure design; and vehicle instrumentation for data collection. The success of this comprehensive approach strongly suggests that the steps illustrated in this paper can serve as guidelines towards a more general class of vehicular safety and advanced driver assistance systems evaluation.

Vehicle tracking problem is of crucial importance in intelligent vehicles research, as it is amongst the basic components of any comprehensive situation awareness technology. In mixed-traffic environments, where vehicles with varying degrees of sensing and communication capabilities coexist, the vehicle-tracking problem becomes particularly more demanding. In this paper, a collaborative vehicle tracking approach is presented, where onboard sensing and inter-vehicular communication resources are utilized in an efficient manner to provide track lists to all participating vehicles in a mixed-traffic environment. The approach is implemented on SimVille, our indoor testbed for urban driving, in accordance with our system development philosophy. The performance of the approach is evaluated using entropy values of vehicle tracks-an information theoretic measure of uncertainty. The experimental results of our scaled-down tests demonstrate the effectiveness of our approach.

The Ohio State University has fielded teams at all three of the DARPA Grand Challenge and DARPA Urban Challenge autonomous vehicle competitions, using three very different vehicle platforms. In this paper we present our experiences in these competitions, comparing and contrasting the different requirements, strategies, tasks, and vehicles developed for each challenge. We will discuss vehicle control and actuation, sensors, sensor interpretation, planning, behavior, and control generation. We will also discuss lessons learned from the engineering and implementation process for these three vehicles.

This paper focuses on the design of a self-optimizing nonlinear controller for a “simplified” pneumatic brake system in the continuous time domain. The specific controller under investigation periodically excites the brake system in the direction towards the maximum tire forces without apriori knowledge on the initial direction of motion. The nonlinearity and complexity of pneumatic systems (as opposed to hydraulics) introduce a higher level challenge. The developed controller employs multiple observers to estimate tire forces in a highly unpredictable environment with bounded parameter uncertainties. The controller explicit inputs are the wheel speeds and chamber pressures. A longitudinal accelerometer is also recommended.

The primary objective of this paper is to develop a model that accurately represents the dynamics of air flowing through the components of a pneumatic system configuration, which is common in many heavy duty vehicle applications, that eventually translates into braking force. This objective is met using the dynamic compressible airflow equations, which describe flow through an orifice. These equations are coordinated to describe the directional motion of dynamic airflow as commanded by the driver at the foot-pedal and as modified downstream by a modulator to facilitate ABS activity. The solenoid actuated relay valve also includes the motion dynamics of a piston in the existence of hysteresis and coulomb friction type built-in non-smooth nonlinearities. The adoption of an isentropic process, as opposed to the more general case of polytropic behavior, is experimentally determined to suffice for accuracy while yielding significant mathematical convenience.

The Ohio State University Center for Intelligent Transportation Research (CITR) has developed three automated vehicles demonstrating advanced cruise control, automated steering control for lane keeping, and autonomous behavior including automated stopping and lane changes in reaction to other vehicles. Various sensors were used, including a radar reflective stripe system and a vision based system for lane position sensing, a radar system and a scanning laser rangefinding system for the detection of objects ahead of the vehicle, and various supporting sensors including side looking radars and an angular rate gyroscope. These vehicles were demonstrated at the National Automated Highway System Consortium (NAHSC) 1997 Technical Feasibility Demonstration in a scenario involving mixed autonomous and manually driven vehicles. This paper describes the demonstration, the vehicle sensing, control, and computational hardware, and the vehicle control software.

This study is concerned with the development of a radar reflective patch to be used with a look-ahead radar in a convoying application for ground vehicles. The system considers a vehicle following configuration where the leader vehicle has a radar patch attached to its rear and the follower vehicle has a radar transmitter/receiver which obtains headway and orientation information by tracking the radar patch. The headway and orientation information is then conveyed to an onboard controller for automatic speed and steering control of the follower. The study has a number of different aspects including development of a frequency selective surface for the patch development of the radar system for determination of spacing and orientation analysis and development of the control system for speed and steering control in a vehicle following configuration.

In this paper an automotive speed controller is developed for use in a car following scenario on an automated highway system. The throttle actuator used with the manufacturer's standard cruise control unit is used for throttle angle positioning and a multi-level control algorithm is developed for overall speed control. In addition, models of the throttle actuator, vehicle engine, torque converter, transmission, and longitudinal dynamics are presented.

We consider a vehicle-roadway system where the control of vehicle movement is based on the instrumentation located both in the vehicle and the roadway. In addition to the sensors which are used for obtaining the information on the vehicle, a radar based sensor system is used for providing information on the position of the car relative to a vehicle ahead, and with respect to a reflective strip placed on the road. The roadway traffic includes standard vehicles with no automatic control as well as the vehicles with automatic control units. Communication between the vehicles is not considered. For longitudinal control, we consider an Radar Based Cruise Control problem where the main goal is to maintain a desired speed set by the driver. At the same time, the controller will decelerate the vehicle if the distance and/or the relative speed between the controlled vehicle and the vehicles traveling in front are below certain limits.

This paper is concerned with Advanced Transportation Systems, in particular, the design of controllers for Fully-Automated Vehicle Operation. We specifically consider the design and implementation of a lateral controller for a cooperative vehicle system being developed at The Ohio State University. The objective of the lateral controller is to steer the vehicle to follow a retroreflector stripe placed on the roadway pavement using radar sensors. The structure and the parameters of the controller are determined during simulations and analytic studies. The controller models are then downloaded into two high-speed computer systems which are interconnected to simulate the operation of the closed loop system in real time and provide a “hardware-in-the-loop” environment. Finally, the computer containing the controller dynamics is installed in the vehicle and field experiments are conducted.

The state of Ohio has recognized the importance and potential impact of Intelligent Vehicle-Highway Systems (IVHS) to its citizens and business enterprises. In response to the identified need, a small group of individuals representing Federal and state government, academia, and the private sector have worked together over the past year to initiate a statewide IVHS effort. This initiative is referred to as IVHS~Ohio. The objective of the effort is to "coordinate and foster a public, private, and academic partnership to make the urban and rural surface transportation system in the state of Ohio significantly safer, more effective, and more efficient by accelerating the identification, development, integration, and deployment of IVHS technologies." A May 1993 symposium was attended by over 220 people from government, academia, and the private sector. The result was a unanimous decision to establish a statewide IVHS program.