| Tactile information is of great significance for people to perceive the world.Flexible tactile sensors have been widely used in the fields of intelligent robots and biological medicine.At present,the design of flexible tactile sensors has become one of the hot topics of academic research.However,the improvements in the performance of tactile sensors are continuing,and most of them pick up only a single or small portion of tactile information.In this paper,two kinds of piezoresistive tactile sensors,two kinds of capacitive tactile sensors and a double-layer tactile sensor based on bionic mechanism are designed.The sensor signal acquisition and performance analysis are completed,and the application of tactile sensors is realized.Firstly,a 4*6 array flexible piezoresistive tactile sensor based on conductive rubber and a distributed thin film pressure sensor were fabricated.At the same time,two kinds of 2*2 array flexible capacitive tactile sensors with different dielectric layer structure are designed,including dislocation structure and stack structure.The voltage signal of piezoresistive tactile sensor and the capacitance signal of capacitive tactile sensor are collected respectively by designing hardware circuit,underlying software and upper computer.Then the stability,hysteresis error,linearity,sensitivity and repeatability of each sensor were analyzed.The results show that the tactile sensor based on conductive rubber has good linearity and small hysteresis error.The distributed film pressure sensor has good stability,large measuring range and certain repeatability.Both capacitive tactile sensors have small hysteresis errors and good repeatability.Among them,the sensor with dislocation structure has better linearity,while the sensor with stack structure has better sensitivity in small range.After then,the distributed thin film pressure sensor is placed on the capacitive tactile sensor with dislocation structure to form a bionic double-layer tactile sensor.The MATLAB neural network fitting toolbox was used to fuse the output signals,and the performance differences between single and double layers of tactile sensors were analyzed.The results show that the double-layer tactile sensor with data fusion has high linearity and good repeatability,and the hysteresis error is between piezoresistive and capacitive tactile sensors.Finally,a spinal orthopedic device system based on tactile force detection was designed by combining the tactile sensor with the medical spinal orthopedic brace,including the orthopedic brace,hardware circuit and APP software design,which can realize the function of intelligent reminder and real-time supervision of the bad posture of patients with scoliosis.APP software is helpful for patients to understand their degree of scoliosis and recovery.The experiment proves that the system has good practicability. |
