Flexible Tactile Sensor For Position Detecting Based On Distributed Planar Electric Field

With the development of robot applications,more intelligent robots are expected to participate in the daily life to replace humans in completing a variety of complex tasks.These activities make the robots interact with the environments or human being.However,robots are likely to collide with objects or humans in unstructured environments.Thus,necessary actions are required to ensure the security during the process of physical human-robot interaction.A tactile sensor is capable of sensing the environment changes and can obtain real-time contact information,which allows robots to avoid collision or to interact with humans in their environment.At present the research on tactile sensor are mostly based on microelectromechanic systems(MEMS)technology.With the development of MEMS technology,the tactile sensor has gradually formed many kinds of type such as piezoresistive,capacitance,piezoelectric,and other sensitive elements and materials.However,due to the lack of flexibility and the defects of not able to use in large area,more and more researchers began to research on non-array structure,and they have been designed some tactile sensors with good flexibility,can realize continuous detection,and can be used for full-body robot clothing.This study is supported by the National Natural Science Foundation of China(No.51575111).This study based on the distributed planar electric field designed a flexible tactile sensor capable of detecting the collision position.Attaching the tactile sensor to a robot surface to detect collision information could achieve the transformation of the instruction information and improve the security during the process of human-robot interaction.This paper demonstrates firstly the uniqueness theorem of steady current field,and explains the principle of position detection.And design a tactile sensor structure which can detect contact position based on the mathematical model.Secondly,analyzes the model of electric field distribution in regional contact and the influence of edge effect on electric field.Then,a 3D finite element model is built in software COMSOL Multiphysics to simulate the position detecting,which verified the rationality and feasibility of the sensor.More simulations are done to describe the influence factors of electric field and the capacitor edge effect and multi points contact situation.Finally,selecting the appropriate material to fabricate the sensor samples and do some tests on the sensor samples.The experimental results show that the sensor proposed in feasible and has better detection precision and good stability.The sensor can be effectively used in robot arm,which could meet the safety requirements for human-robot interactionThis paper proposes a new non-array tactile sensor,which is effective in sensing the contact position of the robot surface.The sensor is flexible to be used for full-body robot clothing,which could provide a safety solution for human-robot interaction.