Auditory, Visual And Tactile Stimuli System ? A Senior Design Project

This paper describes the design and development of an instrumentation system to study the human response time while driving an automobile to visual, auditory and tactile stimuli. The human response time to the applied stimuli along with results from other ongoing research projects will be used in the development of safety features in the automobile. The project was successfully completed by two students as a senior design project. The project provided a unique opportunity for the students, to learn project development from a concept, time management and achieving the final results within cost constraints. Introduction The Tactile and Auditory Stimuli, an intra-departmental project came out of a casual conversation between the author and a research professor from the department of Behavioral Science. The project idea was conceived by the professor of the Behavioral Science department who wanted to study the effect of auditory, visual and tactile response of elderly people driving an automobile. Most vehicle crashes occur due to human errors. According to US Department of Transportation there were 6,328,000 auto crashes in 2003, of those 42643 fatalities and 2,888,601 sustaining injuries. In many accidents the drivers were distracted by various audio and visual distractions and took crash remedial action rather slowly. The goal of this project is to measure the response times to different stimuli and provide a tactile signal to warn the driver that an impact may occur. The tactile signal warning will be especially useful for drivers who may have hearing problems. System Description The system consists of a driving simulator comprised of a steering wheel with gas and brake pedal assembly with transducers to convert mechanical movements to electrical signals. Precision potentiometers are connected to the pedals and the steering wheel. The change of potentiometer position due to the movements of the pedals and the steering wheel provided a current variation signal for analysis. The current signal is sent to the game port of a computer where it is converted from analog to digital signal for reading into a file. A Program written in C (Appendix-A) analyzes the data on pedal and wheel positions. The Program also calculates the response time with respect to the stimuli and P ge 12301.2 the reaction of the driver in taking a corrective action. The Program has the provision to choose which sequence of stimuli should be activated. For visual stimuli, a set of six LEDs are used. A set of four buzzers are utilized for audio stimuli. The tactile assembly is for providing tactile stimuli. Figure-1 shows an overview of the project. Fig-1 System overview.