Research On Detection Method Of Inner Surface Roughness For Deep Hole Based On Fiber Optical Sensor

Surface roughness,as the main parameter to characterize the surface quality,affects the performance of the workpiece to a large extent.Therefore,the measurement and evaluation of surface roughness is an important basis for production process control and product quality control.Although there are many methods to measure the surface roughness of the workpiece,some of them are already mature,but the development of the full depth and multi bus roughness detection technology for the deep hole surface is still far from enough because of its large depth-diameter ratio and small internal space.It still has the problems of low measurement efficiency,large operation difficulty and low measurement precision.In view of the above problems,a method based on optical fiber sensor array is proposed to detect the inner surface roughness of the deep hole,and the function of the full depth multi bus roughness measurement is implemented.First,the intensity modulation function of Reflective Intensity Modulated Fiber Optical Sensor,RIM-FOS is derived from single sensor structure.Then the influence of the characteristic parameters of the sensor is simulated by computer.Combined with the measurement requirements of inner surface roughness,the design of single sensor is determined.The optical fiber sensor array based on single RIM-FOS and the corresponding photoelectric detection circuit were designed.The layout scheme of the sensor array was set up.The calibration test of the sensor was carried out on the made parts roughness sample,and the scale conversion relation curve was established,and the roughness full depth measurement was realized on the test platform.The main contents and conclusions of this thesis are as follows:(1)The influence of the characteristic parameters on the intensity modulation characteristic under the ideal condition is analyzed theoretically,and the single RIMFOS principle is designed according to the requirement of the inner surface roughness measurement.(2)The optical fiber sensor array is proposed,and the array structure is designed.The layout scheme of optical fiber sensor array is determined.(3)A mathematical model for measuring roughness of single RIM-FOS system is established.(4)The hardware and software of deep hole inner surface roughness measurement system are designed.The hardware includes a fiber optic array driven by a single light source,a low noise photoelectric detection circuit,and so on.The software part includes the multi-channel signal acquisition,processing,storage,display and data query software based on the STM32 board.(5)First,a characteristic test platform was built to verify the consistency of the actual intensity modulation characteristics of all RIM-FOS.Then,the calibration test platform was built,and the calibration test was carried out.The calculation formula of the specific voltage values and roughness values under different aperture was fitted.Finally,the deep hole surface roughness system test platform was built.The test results show that the relative error of the roughness measurement is less than 8%.