A sensorized robot to study physical interaction in limbless locomotion in complex 3-D terrain

Snakes can transition between different strategies quickly and stably using distributed body-terrain contact forces. Although snake robots hold the promise of doing the same, they are far from being able to move well in complex 3-D terrain with many large obstacles. We aim to understand how snakes sense and control physical interaction with the obstacles to generate effective locomotion. Towards this goal, we developed a sensorized snake robot physical model that uses a low-cost, flexible, piezoresistive sensor array distributed over its body to measure normal contact forces. Despite disturbance caused by self-deformation during the robot motion, calibration showed that the sensor array can measure forces of up to 10% body weight at 30 locations along the body at 10 Hz. We will study the robot as a physical model to understand the principles of how to control body deformation and terrain contact to generate forces while maintaining stability. This will not be informed by and in turn help understand our animal observation (see talk by Fu et al. How snakes traverse large obstacles in complex 3-D terrain). We are also exploring ways to increase the sensitivity of the sensor array and developing a sensorized complex terrain platform to measure distributed contact forces in snakes.