Design And Performance Research Of Self-powered Rotation Speed Sensor Driven By Different Power Sources

Rotational motion is one of the most basic forms of motion in daily life and industrial production,and has always been a hot research topic in engineering applications.Traditional rotational motion sensing is mainly based on photoelectric effect and electromagnetic induction,,but with the increasing degree of industrial automation,passive sensing technology with self-powered characteristics is receiving more and more attention from researchers.Selfpowered sensors can obtain environmental energy without any external power source and thus operate actively and independently,cutting off the last cable of the sensor,the power line,and thus are considered as a potential way to solve the power problem of large-scale wireless sensor networks.The triboelectric nanogenerator(TENG),which combines the triboelectric effect and electrostatic induction,is a cutting-edge technology for collecting environmental mechanical energy and converting it into usable electrical energy.Its output signal can accurately reflect the real-time changes of external excitation,and is widely used for monitoring and sensing various physical quantities.However,the speed sensor based on TENG developed in recent years still has defects such as single signal source,poor robustness and unsynchronized information transmission.In this article,according to the operation characteristics and speed monitoring requirements of different power source driving scenarios,two design schemes of self-powered speed sensors are proposed,and their electrical performance and reliability are tested and characterized,realizing the speed monitoring of heterogeneous drive based on the cooperative sensing of multiple sensing signals.The main points of this article are as follows.The necessity for rotational speed monitoring in a constant power source drive setting with a heavy-duty motor as an example is proposed and provided for with a self-powered rotational speed sensor based on triboelectric-electromagnetic coaxial integration.A self-made magnetic coupling is integrated in the device to synchronously transfer the rotational energy on the motor rotation axis to magnets of opposite polarity through non-mechanical contact to reduce the noise interference caused by rigid connection.Meanwhile,a rotating lead structure consisting of rolling metal balls and conductive fabric is proposed for the first time to solve the difficult problem of electrical energy transfer to the rotor in the rotating assembly.In addition,both triboelectric nanogenerators and electromagnetic induction generators in the device can be used separately as power supply devices or sensing signal sources,effectively improving the stability and durability of the sensor devices.In addition,thanks to the rational selection of friction materials and performance optimization,the signal linearity of the device is as high as 0.995,and its output electric energy can be used to power the system after energy management,which realizes the functional integration of energy self-supply and rotational speed co-sensing.Unlike the constant power source driving scenario,the variable power source driving scenario,represented by the natural low wind speed environment,has more demanding requirements on the starting performance and sensing capability of the device.To this end,a self-powered wind speed sensor with low frictional resistance and high sensitivity for breeze starting is proposed.Considering the operational reliability of the device in harsh environments,the device adopts a "hamburger" modular design,consisting of a wind drive module,a power supply module for environmental energy harvesting,and a sensing module for wind speed sensing.The key drive unit is a "Savonius-like wind wheel" as the core component,made of an array of wing-shaped blades with excellent flow field characteristics.The BAWS can be activated in breezes as low as 2.9 m/s thanks to the synergy of a low-friction drag drive module and a low-viscosity frictional material.The BAWS is capable of sensing the external wind speed in critical areas through synergistic analysis of voltage frequency and current amplitude.This research focuses on the acquisition and analysis of physical signals.According to the driving characteristics of different power source scenarios,through the optimization of the sensor device’s energy conversion principle,device structure,material selection and signal analysis,the design and performance research of the heterogenous drive speed sensor derived from power supply is carried out,and two self-powered speed sensing devices are proposed pertinently,which have been applied and verified in a variety of typical driving scenarios,It realizes real-time and accurate monitoring of variable/constant power source speed,and effectively expands the application prospects of self-powered sensing technology in industrial monitoring,environmental awareness and intelligent agriculture.