Tactile Compensation for Artificial Whiskered Sensor System Under Critical Change in Morphology

In this letter, we describe a novel design soft whiskersensor system that compensates for tactile deficiency in events of change in sensor morphology upon being broken, torn, or trimmed. A fiber-reinforced air chamber at the sensor root is coupled with a strain gauge, and compressor. The strain gauge provides tactile information to the central control system (CCS) when the whisker contacts an object. If the whisker is trimmed at a certain length from its tip, to adapt for this change, air pressure in the chamber alters its morphology inducing a change in the sensitivity of the strain gauge that compensates for whisker length loss. Finite element method (FEM) analysis and genetic algorithm (GA) optimization were applied to determine optimal designs satisfying all performance requirements especially related to compensation ability, namely adaptive range. Two trials of adaptive ranges 5 mm and 10 mm were conducted, and optimal designs, where the corresponding fitness score of the former is bigger than the latter, were experimentally validated. Experimental results demonstrated tactile sensing performance of approximately 87% and 72% recovery, respectively, showing reliability of the proposed method. This study reinforces the concept that application of morphological control has potential to bring added abilities in applied soft robotic systems with minimum burden on the CCS.