Buggspray is an agricultural robot developed by the CMU RI's Field Robotics Center to autonomously traverse and spray pesticide over crop rows.  To maximize terrain mobility, Buggspray features 4 wheel steering, a differential bar suspension, and a width-actuated wheelbase.

My contribution to the project was designing the chassis components. Using the already-designed wheel spars and motors, I was tasked with the challenge of building a chassis-suspension interface capable of lateral expansion and differential rocking. My solution was to use a rotatry ball spline bearing to connect the wheel spars to the chassis in order to permit both rotary and linear motion of the wheel base relative to the chassis. The rotary component of the bearing was then connected to a differential bar through linkages, and the shaft ends actuated laterally with dual-threaded screw shafts.