基于FBG阵列的滑动探测系统设计

为了实现机械结构中夹持状态的实时监测,避免施力过大造成损坏或施力过小造成滑落,设计了一种基于FBG阵列的滑动探测系统。利用正交分布FBG阵列实现对不同方向滑动的感知,通过解算各位置上FBG波长偏移量完成对目标位置与滑动状态的分析。给出了系统结构设计及计算方法,仿真分析了不同参数的FBG对物体的滑动测试效果。仿真结果显示,采用lFBG=10 mm,h=4 mm的参数选择可以在保证空间分辨精度的基础上达到最大灵敏度。实验中,传感单元采用60 mm×40 mm×10 mm的硅胶体构成,内部预埋5个FBG构成传感阵列。实验结果显示,在x轴和y轴方向上,其灵敏度分别为0.0051 nm/N和0.0063 nm/N。FBG波长偏移量的变化曲线可以明确表征在传感模块上被测物的状态(静止、开始滑动、稳定滑动)。针对不同滑动速度进行了测试,FBG产生的波长偏移量变化所占时长与滑动时长成比例,即可通过波形完成滑动时长的解算。

Design of sliding detection system based on FBG array

In order to realize real-time monitoring of the clamping state in the mechanical structure,to avoid damage caused by excessive force or excessive force,a sliding detection system based on FBG array is designed. The orthogonal distribution FBG array is used to realize the perception of sliding in different directions. The analysis of the target position and sliding state is completed by solving the FBG wavelength offset at each position. The system structure design and calculation method are given. The sliding test effect of FBG with different parameters on the object was simulated and analyzed. The simulation results show that the parameter selection with lFBG=10 mm and h=4 mm can achieve the maximum sensitivity based on ensuring the spatial resolution accuracy. In the experiment,the size of the sensing unit was 60 mm×40 mm×10 mm,and a sensing array of five FBGs was embedded in its interior. The experimental results show that the sensitivity is 0.0051 nm/N and 0.0063 nm/N in the x-axis and y-axis directions,respectively. The variation of the FBG wavelength shift can clearly characterize the state of the object being measured on the sensing module (stationary,starting to slide,stable sliding). Tested for different sliding speeds,the variation of the wavelength shift caused by FBG is proportional to the sliding duration,and the solution of the sliding duration can be completed by the waveform.