Table of Contents
Some initial comparison on ultra sonic sensors can be found on this spreadsheet
Concept Development (generation, improvement, selection)Our concept was developed through morph chart and pugh chart analysis. They can be found below:
Below are some photos of the original concepts that were developed:
Optimal Bump Height and Shape TestThis testing quantifies the Customer Requirements CR 7
In order to determine the most effective bump height as well as bump frequency going across the palm, we constructed the following test rig, consisting of a variable speed servo motor, a gear holding bearings that mimic bumps, a motor mount, a motor housing, a cover plate, shims for height adjustment, and a low friction cover. Powered by an Arduino microcontroller, the rig gave us the ability to determine the effectiveness of bump height and frequency going across the palm. By measuring test subjects' sensitivity to direction as well as perceived comfort on a 1 to 5 scale, we determined that the best characteristics for the user to see were where sensitivity met comfort, because they are opposing in nature. As sensitivity rises, comfort decreases, in all of our tests. We executed an ANOVA test to see if the heights that were tested were statistically different from one another in terms of comfortability and sensitivity. It was determined that height 2 and 3 were statistically different yet showed to be the best heights to meet both comfort and sensitivity. We determined that the lower palm with cylindrical rollers is the best at meeting comfort and sensitivity for the user. The rig and results are displayed in the following images.
Optimal Roller Speed Range TestThis testing quantifies the Customer Requirements CR 1
This test was done to determine the optimal roller speed range. Subjects were asked to determine the direction of the roller at 7 different speeds. The direction of the rollers in a randomly selected for each speed. The results for this test can be found in the linked spreadsheet .