Skin-Type Proximity Sensor by Using the Change of Electromagnetic Field

This article presents a sensor, called a skin-type dual proximity sensor (STPS) that can provide distance information in the form of impedance between a sensor and an approaching object before the collision. Meanwhile, a new method regarding the selection of the resonant frequency range for optimizing the measured distance is validated. The sensor adopts the combined sensing principle of inductive-capacitive proximity sensing. STPS can be fabricated with various dimensions and shapes, and easily attached to robot surfaces. Represented by the series of sensors studied with the dimensions of 100 × 100 × 2.75 \text{mm}, the proposed sensor can detect an approaching human body up to 300 mm away. In this article, sensor system modeling and simulation are conducted, followed by fabrication and signal processing methods. Finally, the performances of the sensor are experimentally validated, thoroughly analyzed concerning various parameters, and demonstrated with the collaboration between human and robots.