Graduation Year

2010

Document Type

Thesis

Degree

M.S.M.E.

Degree Granting Department

Mechanical Engineering

Major Professor

Rajiv Dubey, Ph.D.

Keywords

AEVIT, SSI, Drive by wire, Simulator, Reaction time

Abstract

Virtual simulators have proven to be extremely effective tools for training individuals for tasks that might otherwise be cost-prohibitive, dangerous, or impractical. One advantage of using a virtual simulator is that it provides a safe environment for emergency scenarios. For many years the United States military and NASA have used simulators, including those affixed with drive-by-wire (DBW) controls, effectively and efficiently to train subjects in a variety of ways. A DBW system utilizes electrical circuits to actuate servo motors from a given input signal to achieve a desired output. In DBW systems the output is not directly mechanically connected to a control surface (steering, acceleration, deceleration, etc.); usually, the input controller is linked by electrical wires to a localized servo motor where direct control can be given.

This project is aimed at developing a novel simulator for a future training program using DBW systems that caters specifically to individuals who currently use or will be using for the first time vehicle modifications in order to drive and maintain their independence. Many of these individuals use one or a combination of powered steering, acceleration, braking, or secondary DBW controls to drive. The simulator integrates a virtual training environment and advanced electronic vehicle interface technology (AEVIT) DBW controls (4-way joystick, gas-brake lever/small zero-effort steering wheel). In a 30 participant study of three groups (able-bodied individuals, elderly individuals, and individuals with disability), it was found that training with a DBW joystick steering system will require more instruction and simulator practice time than a gas-brake lever/small steering wheel combination (GB/S) to obtain a similar level of competency.

Drivers using the joystick completed predetermined driving courses in longer times, at slower speeds, with more errors than the other DBW system. On average, the reaction time to a stopping signal was fastest with the gas-brake lever at 0.54 seconds. Reaction times for the standard vehicle controls and the joystick were 0.741 and 0.677 seconds respectively. It was noted that reaction times using DBW controls were shorter overall. When driving in traffic, drivers committed 4.9, 5.1, and 8.3 driving infractions per minute using standard vehicle controls (No Drive by Wire, (NDBW)), the gas/brake and steering system, and joystick system respectively. Most drivers felt that the GB/S system was easier to learn, easier to operate, safer, and more reliable than the joystick system.

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