Multimodal Bio-Inspired Tactile Sensing Module

Tactile sensors are the last frontier to robots that can handle everyday objects and interact with humans through contact. To be effective, such sensors have to sense the geometry of touched surfaces and objects, as well as any other relevant information for their tasks, such as forces, vibrations, and temperature, that allow them to safely and securely interact within an environment. Given the capability of humans to easily capture and interpret tactile data, one promising direction in order to produce enhanced robotic tactile sensors is to explore and imitate human tactile sensing capabilities. In this context, this paper presents design and hardware implementation issues related to the construction a novel bio-inspired tactile sensing module. Drawing inspiration from the type, functionality, and organization of cutaneous tactile elements, the proposed solution comprises two shallow sensors, namely, a 32-taxel-tactile array and a nine DOF magnetic, angular rate, and gravity sensor, a flexible compliant structure, and a deep pressure sensor placed in a structure similar to human skin. The module's compliant structure and sensor placement provides useful data to overcome the problem of estimating nonnormal forces accommodating sensing modalities essential for acquiring tactile images, and classifying surfaces by vibrations and accelerations. Issues related to the module calibration, its sensing capabilities and possible real world applications are also presented.