Rotation sensing and gesture control of a robot joint via triboelectric quantization sensor.

Abstract In human-machine interaction, robotic hands are expected to work like human's hands and to be even more powerful or delicate in certain situations. To operate robotic hands via human gesture instead of handle or button will make this human-robot interface more natural and precise. Here, we designed a joint motion triboelectric quantization sensor (jmTQS) for constructing a robotic hand synchronous control system. Based on the ultrahigh sensitivity of a triboelectric nanogenerator (TENG) to mechanical displacement, the jmTQS designed as grating-sliding mode realized directly quantifying a joint's flexion-extension degree/speed. Through counting the pulses induced by jmTQS and signing the positive/negative of the pulses to represent flexion/extension, the joint's angular position can be determined with absolute value on the basis of the initial human-robotic synchronizing position value. In the whole operating course, the intuitionistic human-robotic hand two-dimensional motion mapping can be preserved. The minimum resolution angle of the fabricated jmTQSs is 3.8° and can be further improved by decreasing the grating width. This direct quantization and intuitionistic mapping at the sensing stage greatly simplified the signal processing and classification algorithms, which contributes to achieving the natural, high-precision and real-time interface. Graphical abstract Through counting the pulses induced by the triboelectric sensor's grating-sliding mode and signing the positive/negative pulses to represent flexion/extension, the finger joint's angular position can be determined with absolute value. Characterized on a hinge model, the sensor is demonstrated directly quantifying finger joint's flexion-extension degree/speed thus contribute to achieving the robotic hand synchronous control system. fx1 Highlights • A coupled sliding grating structure was designed to induce positive/negative pulses for counting. • The finger's flexion-extension degree, speed and direction can be directly quantified via counting pulses. • A hinge model was employed to verify the sensor's linearity. • The synchronous robotic control system can recover at any breakpoint in finger's flexion-extension process. [ABSTRACT FROM AUTHOR]