Contact Localization via Active Oscillatory Actuation

Abstract

Many robotic tasks rely on physical interactions with the task environment. Sensing when and where links make physical contacts can be crucial in several applications, including but not limited to grasping, locomotion, collaborative robotics and navigation. While sensorizing robot end effectors with intrinsic tactile devices is a logical approach, current and accessible options are often expensive or require invasive modifications. This paper presents a prototype method of both sensing and localizing contacts along a rigid link that can be readily incorporated into existing machines. The mechanism is lightweight and low-cost, and functions by actively providing an oscillatory mechanical actuation signal to a rigid link, whose mechanical response is measured with an inertial device and is used to localize touch at one of five designated contact points. Classification is performed with supervised methods using transient behavior and spectral features. Evaluation is conducted with five-fold cross validation, and preliminary results indicate promising performance in localizing the point of contact on the rigid link with accuracy of over 97%.