宏弯光纤应变传感经编织物的设计

Design of warp knitted strain sensing fabric based on optical macro-bending sensor

为开发一种利用宏弯原理测量人体呼吸和心跳的光纤传感织物,设计了以棉纱编织的经绒斜为地组织,以直径为1 000μm的聚合物光纤为衬纬纱的经编衬纬复合织物。通过光纤弯曲实验研究了光纤弯曲曲率半径与光信号衰减之间的关系,确定了衬纬光纤的初始弯曲曲率半径为10 mm,选择传感循环单元数为2;通过比较分析双梳经编织物组织的特点,确定了传感织物的地组织。在此基础上设计了织物垫纱运动图和线圈密度,并在手动经编小样织机上编织出传感织物;最后对这些织物进行了测试。结果表明,传感织物可通过电压值变化的形式反映出拉伸过程中光信号相对于织物形状的变化。

In order to develop an optical macro-bending sensing fabric to detect respiration and heartbeat of human body,a warp knitted sensing fabric was designed by using a combined structure in which locknit stitches were knitted with cotton yarns and adopted as a ground structure,and optical fiber with a radius of 1 000 μm was used as the inlay yarn.The relationship between the bending curvature radius of the optical fiber and the loss of its optical signal output was investigated by experimental method.10 mm and 2 cycles were determined as the initial curvature radius of the optical fiber and the number of sensing unit,respectively.Then,the properties of two guide bar warp knitted structures were compared and analyzed,and the modified Sharkskin structure was chosen as the ground structure of sensing fabrics.Based on them,lapping diagram and stitch density were designed,and the sensing fabrics were produced on a hand driven warp-knitting machine.Finally,these fabrics were tested,and the results show that the optical signal changes can effectively reflect the change of the fabric shape by means of voltage changes in the stretching process.