A soft barometric tactile sensor to simultaneously localize contact and estimate normal force with validation to detect slip in a robotic gripper

Soft tactile sensing technologies provide the potential to endow a sense of touch to robots for grasping and manipulating objects. During the execution of such tasks, having accurate knowledge on the contact location and quantitative forces in broad exerted force ranges is key. For industrial adoption such sensor needs to be low-cost, robust with limited or no calibration procedures and easy to manufacture. In this work we present a microelectromechanical (MEMS) based barometric sensor array covered with an elastomer layer, with the sensor signals being interpreted in real-time on the basis of a parameterized Gaussian type of distribution. The contact location is determined by finding in real-time the corresponding parameters of the Gaussian distribution that on its turn is used for normal contact force estimation. Results show accuracies in terms of localization of 0.5 mm and normal force errors of 10 % in force ranges up to 25 N and 15 % in high force ranges of 25 - 50 N. The proposed soft tactile sensor has furthermore been validated to provide the ability to detect slip when gripping various objects