A Spiny Claws Climbing Robot Based on Self-Sensing Soles

Adaptive climbing on different surfaces is a great challenge for conventional robots due to a lack of self-sensing capabilities. Inspired by the exceptional sensing ability of feline soles, this study proposes a quadrupedal climbing robot based on self-sensing spiny-claw soles. First, a spiny-claw sole was designed by embedding stainless steel spines into a soft substrate. Next, a tensile strain sensor was designed based on carbon nanotubes and carbonyl iron powder through the squash method and then was integrated into the spiny-claw sole to fabricate the self-sensing sole. Then, a quadrupedal climbing robot was designed using four self-sensing spiny-claw soles. Subsequently, the control strategy of the self-sensing climbing robot was designed. Finally, the climbing performance of the self-sensing robot was experimentally tested. It is demonstrated that the robot can climb on different inclined surfaces with an angle of 0 $^\circ$ to 75 $^\circ$ and on three different rough surfaces. In addition, the maximum load of the robot is 175 g when climbing on a 45 $^\circ$ inclined surface. More importantly, the robot can detect whether there is an obstacle in the climbing path through the self-sensing soles and perform appropriate obstacle avoidance operations accordingly.