Robot Building Lab

Lisa Anthony
Graduate Final Project

Fall 01



Project Purpose:

I propose to investigate the accuracy of the sonar sensors we have been using in class; many groups received readings which did not make sense, given certain assumptions that were made about the operation of these sensors. To attain a more reliable sonar sensor would be both interesting and practical for future use of these sensors.

Objective: Determine the situations in which either sonar_closeup() and sonar_sample() are most useful and accurate, based on the following possible confounding variables:

Results: I determined, through extensive empirical study, that the sonar_sample() method is really very accurate under most circumstances (regarding timing specifically) for obstacles above 12 inches away. The sonar_closeup() method, on the other hand, in its default form is rather useless. I altered the default blanking period used in that method from 0.5ms to 0.7ms and saw immense improvements. I recommend using the altered sonar_closeup() especially for obstacles under 12 inches (but according to my results, above 4.75 inches); sonar_sample() now is not any more useful, but can be used to support or average values obtained with sonar_closeup().


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