Coordinated Use of Structure-Integrated Bistable Actuation Modules for Agile Locomotion

It is difficult to design agile soft-bodied robots owing to their inherent softness. To overcome this problem, we propose a structure-integrated bistable module that uses snap-through buckling for agile motions. First, we confirmed that a 0.05-m-long module was able to jump to 0.13 m high. Through investigation, we found a range of command parameters within which the module jumps consistently. Moreover, we showed that jumping performance had strong relation to the bending amplitude. Next, we induced a robot with two serially connected modules to roll forward and jump over an obstacle. In rolling, the robot became round for quick locomotion. In jumping, we found that buckling in one module induced buckling in the other module. The difference in buckling time between the two modules was shortened from the order of 0.1 s to the order of 0.01 s. This might be effective for error correction or useful for coordinated motions. These results show the effectiveness of the proposed structure-integrated bistable modules for making agile soft-bodied robots, and suggest ways of exploiting them.