Quadbot is a four-legged (or tentacle) based robot with a unique style of locomotion. Developed to have organic qualities, I modeled the kinetic geometry of its motion and engineered an actuated system using a single motor.
Quadbot has a distinctive locomotion. Using four tentacle appendages, the toy pushes and rolls its spherical body in a continuous fashion. The resulting motion has the Quadbot rolling about in a zigzag pattern. Tentacles are actuated by a double wire system which allows them to move in two directions. Inside the spherical body is a cam to which all the tentacle wires are attached. A single motor is able to drive this cam and simultaneously articulate each of the tentacles. When two tentacles are actuated they bend to create a fulcrum, while a third tentacle pushes the center of mass over this fulcrum, and allows the body to roll forward. The sequence is then repeated with a different combination of tentacles, resulting in the same movement but at 120 degrees apart, leading to a zigzagging motion.