In recent years, with the development of intelligent processes, more and more researches have been conducted on flexible wearable devices and sensing devices. However, the signal acquisition and processing in a flexible environment have the disadvantages of low signal acquisition resolution, poor environmental adaptability, and narrow information flow. In order to improve the flexibility and performance of the sensing system, a self-powered piezoelectric nanogenerator was used to perform attitude tracking in high-resolution array signal sensing and human-machine interaction, and the interference mechanism and correction measures of the electrode signal were explored.
Polyvinylidene difluoride (PVDF) piezoelectric nanogenerators were prepared using high-voltage electrostatic spinning technology. The piezoelectric effect and sensing principle, pyroelectric effect and sensing principle of PVDF film were analyzed, and the finite element model of sensor and its equivalent circuit model were established. The flexible board made of polyimide film is used as the contact layer to realize multi-site signal sensing. Through the analysis of the piezoelectric and thermoelectric characteristics of the nanogenerator, the linear working area and the limit working state of the sensor are obtained. By establishing the mapping relationship between the piezoelectric /thermoelectric signals, the piezoelectric component and the thermoelectric component can be effectively extracted from the composite signal. Through the analysis of the signal response period and recovery period, the correction and decoupling of the composite signal are realized. The sensor electrode synchronization and signal interference tests were carried out, and the sensing errors caused by the sensor structure were analyzed. The prepared PVDF flexible multi-site tactile/thermal sensor can map external pressure/thermal radiation stimuli to output voltage/current signals, and dynamically observe the response distribution on the three-dimensional interface. It realizes image perception and dynamic target tracking, and records the two-dimensional trajectory of the tracked target at the same time. Human-machine interaction testing based on flexible sensors was carried out to realize human-machine motion recognition and tracking. Through the feedback control of the closed-loop system, the equivalent behavior trigger of the capacitive touch sensor and the flexible sensor of the intelligent robot is realized. The sensing error of the flexible sensor and the robot Hall rotation position sensor is small, and the remote signal feedback and behavior control of the intelligent robot are realized through wireless transmission equipment. The prepared flexible sensor has potential applications in the internet of things, health status detection and intelligent auxiliary equipment.