Research On Multi-information Perception System Based On Bionic Tactile Sensor

Tactile perception is an important sensory function of human body.From the perspective of tactile perception,people can communicate and interact with the outside world.With the continuous progress of automation,information technology and intelligence,tactile sensors can effectively imitate human tactile perception ability and identify the attribute information of objects,such as hard and soft,texture,temperature,stickiness and shape.Sensitivity and accuracy are important indicators to test tactile sensors.Many scholars improve the tactile sensing system's perception ability by improving sensitive materials,optimizing the structure design and improving the detection system.However,most of the sensing systems can only obtain single physical quantity information,and the detection system is complex and the separation of signals is not easy.Therefore,enhancing the sensitivity of tactile sensors and designing multi-physical quantities are necessary.Information cognitive scheme and construction of miniaturized and integrated high-perception system are the key directions of tactile sensing system research.In this paper,a multi-information sensing system based on bionic tactile sensor is developed.The system takes the manipulator as the carrier.When the index fingertip is attached to the tactile sensor,when the mechanical finger touches the object,the system can perceive the soft and hard degree,rough texture and cold and warm information of the object.The piezoelectric effect mechanism of PVDF piezoelectric thin film was studied based on human hand tactile sensation and the characteristics of various mechanical sensors in fingertip skin.A double-convex arch structure tactile sensor was designed based on bionics principle.The sensitivity of the double-convex structure sensor was verified by testing and comparing different structure sensors.The conditioning circuit optimizes the signal conversion,amplification and filtering,designs the Microcontrollers module and Bluetooth communication module,effectively links the pre-acquisition unit with the host computer system,and processes the signal with LabVIEW software,realizes signal analysis,digital display,discrimination and separation,as well as touch,slip and thermal multi-information perception ability.In order to verify the validity and accuracy of the sensing system,bionic tactile sensor test,soft and hard discrimination accuracy test and finger stroking heating plate signal separation experiment were carried out.In the sensor test experiment,combined with the characteristics of tactile,slip and thermal signals,the carrier manipulator is used to imitate the human hand to knock,stroke and touch the object separately.The maximum of tactile signal amplitude,the standard deviation of slip signal amplitude and the mean of thermal signal amplitude are used to realize the sensor's multi-information perception of the soft and hard degree,rough texture and cold and warm state of the object.The system can effectively identify the soft and hard sequence of air cushion,foam,rubber and hardwood,and the accuracy rate is above 90%.The system can also distinguish the slip and thermal signals,and perceive the roughness and the cold and hot condition of the objects.This study aims at realizing human touch sense simulation,and provides reference for the development of human-machine interaction,intelligent application and bionic machine.