For my 2015 summer internship, I was tasked with designing the tangible user interaction for the handle of a motorized wagon.
After creating dozens of modular prototype handles that directly controlled the speed of the motor with Arduino and stock controller-based electronics, I tested two leading handle candidates. One was a more direct throttle based handle and the other had more precise user-controlled speed settings.
A key insight from testing was based on the observation that when users were asked to use the eWagon, every single user’s first question was “so do I just pull it?” The eWagon’s UI needed to be as intuitive as an analog wagon – all a user should need to do is turn it on and pull it!
With that in mind, I put more focus into the closed-loop PID feedback handle UI I had been parallel pathing. By measuring the force a user was pulling on the handle, the motor’s speed would automatically adjust so that the force was as close to 0 lbs as possible in any load or terrain condition, matching a user’s walking pace.
At the end of my three month internship, I created a functional works-like prototype that was sent to and later bought by Toys ‘R’ Us and was awarded a patent for the SmartSense™ handle technology.
