Tribot, a Multi-Modal Locomotive Origami Robot: Construction and Control

Tribot is an origami robot (robogami) that has two modes of locomotion, jumping and crawling, that can be selected simultaneously upon meeting an obstacle. Designed in an origami-folding pattern combined with spring shape memory alloy (SMA) actuators, Tribot maintains the architecture rather simple by selectively and strategically activating different sets of actuators and sequences to switch between the two modes of locomotion. At each mode, Tribot (64 mm× 34 mm× 20 mm, 4 g) can crawl at 17 % of body length per gait cycle and jump seven times its height repeatedly without needing to be reset. To optimize the practicality of the nominally 2D design, we made two different approaches to build the prototypes. We adapted more “traditional” layer-by-layer robogami fabrication method as well as 3D printer to minimize the number of functional layers and enabling faster and cheaper alternative route. In the manuscript, we compare the prototypes made by these two different methods. The embedded sensors allow Tribot’s crawling gait pattern and jumping height to be modulated via closed loop control. We compare the expected gait step size and displacement to that of the presented prototype while describing the design and control parameters to achieve the experimental results. We also illustrate the preliminary graphical design tool platform developed to optimize the next design iteration of the multi-modal locomotive robot.