Development And Experimental Study Of Triboelectric Circular Motion Sensor

With the rapid development of automation equipment towards intelligence and high integration,the circular motion platform widely used in industrial robots needs real-time feedback of speed and position to the circular motion unit through sensors.However,the traditional mechanical motion sensor is only suitable for the detection of linear or rotary motion,and for the circular motion with large radius of motion trajectory,it has problems such as complex structure,low integration and difficult maintenance.Triboelectric nanogenerator based on the coupling effect of mechanical interface friction electrification and electrostatic induction,which can sensitively sense the external mechanical motion and has the outstanding advantages of self-powered,high integration,small size,simple structure and low cost,which provides a feasible technical solution for the sensing of circular motion.In this paper,based on the principle of triboelectric nanogenerator,triboelectric circular motion sensors integrated in circular motion platform are developed,and the operating characteristics of the sensor are experimentally studied from the aspects of the structure of slider,friction type and material,which provides the technical basis for the closed-loop control of the high-precision circular motion platform.Triboelectric circular motion sensors with different friction types are developed.The electrode and the slider are designed.The stator electrode adopts a four-way differential annular staggered electrode structure,which effectively improves the angular displacement resolution of the sensor.The structure of the slider adopts three friction types: sliding friction,rolling friction and sweeping sliding friction,and the sensors of the three friction types are integrated into the circular motion platform;The working principle of the triboelectric circular motion sensor with three kinds of friction is analyzed,and its potential distribution is analyzed through the simulation of electrostatic field,and the rationality of the sensor structure design is verified.The electrical characteristics and durability tests of different friction types of triboelectric circular motion sensors are carried out.The effects of the type and thickness of electronegative materials on the electrical characteristics of the sensor are analyzed by experiments;The durability of sensors with different friction types and different friction layers are tested;The electrical characteristics of sensors of three friction types,including open-circuit voltage,short-circuit current and load characteristics,are studied,which provides the basis for sensor signal processing.The material,structure and friction type of the triboelectric layer were determined by the durability and electrical characteristics of the sensor.The real-time hardware signal processing method of the triboelectric circular motion sensor is proposed.The original signal of the triboelectric circular motion sensor is transformed into standard digital square wave signal,and the number of signal acquisition ports of the sensor is reduced;The testing platform for the triboelectric circular motion sensor is built to realize the real-time acquisition of sensing characteristic parameters;The precision photoelectric encoder was used to calibrate the sensor,and the speed and angular displacement sensing accuracy of sensors of three friction types are tested and compared.For the final triboelectric circular motion sensor,the absolute speed error rate,angular displacement accuracy and repeated positioning accuracy of the sensor are tested experimentally.