Novel capacitive-based sensor technology for augmented proximity detection

Embedded and environmental sensors are widely used to provide information regarding human-robot and robot-robot cooperation within unstructured environment. Worldwide, several research laboratories and companies are focusing on researching and developing autonomous self-adaptive machines capable of cooperating and interacting in swarm-based configurations and/or with human beings (e.g. autonomous vehicle, collaborative industrial and also medical robots). On this regard, a robust knowledge and awareness of the environment the robotic agent operates in, has been one of the main bottleneck for the diffusion of robotic cooperative systems, either in industrial or medical scenarios. In order to provide such information, based on contact and proximity detection, Tonietti et al. [1] proposed to enhance human-robot interaction through variable impedance actuators (VIA) embedded onto robotic manipulator, whereas De Maria et al. [2] developed a force/tactile sensor for monitoring the interactive forces of a robotic end-effector with the external environment. Still relying on contact/pre-contact detection (up to 20 mm) Mazzocchi et al. [3] developed a sensorized external skin used for covering industrial manipulators and providing closed-loop force/pressure information through piezoresistive sensors. Moving to proximity technologies, Ye et al. [4] developed a capacitive technology capable of detecting proximity of an iron bullet at a maximum distance of 600 mm. These are just a few significant examples of developed sensor technologies, but more details are reviewed and reported in [5]. Other technologies, such as optical, ultrasound and laser are mainly integrated and applied into mobile robotic platforms, as presented in [6], [7], and [8], even if they are strongly affected by the shape and the material of the object to be detected. For enabling environmental awareness for robotic agents and human beings, this work focused on the design and characterization of a novel capacitive-based technology for high-range proximity detection.