Error Analysis And Visual Guidance Technology Of Fiber Grating Probe

With the continuous development of precision machining technology,a number of micro-holes with micro-scale features have appeared in the field of micro-machining.The four-core fiber grating probe sensor and its measurement system realize a high-precision measurement effect on micro-holes.However,this methods haven't analyse the measurement error comes from the four-core fiber grating probe sensor,therefore,no further compensation can be made of the signal returned by the probe sensor;In addition,the probe sensor has not been combined with the visual system,so it is necessary to further study the relationship between the optical fiber Bragg grating probe with the visual system.It also involves the research about the tilt adjustment and coordinate system calibration.According to the current research status that lacking error analysis and compensation of the signals returned by probe sensors,as well as the study of the visual guidance of probe sensors,combine the existing technology of the four-core fiber grating microscale probe,further analyze the error of the four-core fiber grating probe in the measurement process,compensate the signal returned by the probe sensor;In addition,get the relationship of coordinate system between tilting system,imaging system and probe system,complete the reasearch in visual guidance of the fiber grating probe and the coordinate system transformation or calibration.The main research contents of the paper are as follows:1.Probe radius compensation and sphericity calibration: For lacking the error analysis and compensation of the signal returned by the probe sensor,the radius compensation vector model from the probe return signal to the contact point coordinates is established,realize the compensation from the probe return signal to the contact point and improve the accuracy of probe sensor measurement.2.Probe measurement system error analysis: When the probe is equiped on the motion platform,the error comes from the rotation dislocation and the deflection of the probe itself is exsited.Analyse the root cause of the error and compensate it further.finally,the errors in the actual measurement process are comprehensively analyzed.3.Trim system calibration and visual guidance research of the probe: The coordinate transformation of the tilting system and the rotary system are studied,get the corresponding tilting center and rotation center,as well as the spatial position information at different angles after the attitude adjustment.The relationship between the probe coordinate system and the image coordinate system is analyzed,so as to realize the visual guidance of the fiber Bragg grating probe.4.Platform construction and test experiment of measurement system: The experimental measurement system is built and the error of radius compensation method is compared.The sphericity calibration of the spherical tip of the probe was carried out,and the average radius of the probe in the direction of sampling point was 83.37?m,the sphericity was 5.78?m;The system error in the measurement process is tested;the relationship between the image and the probe coordinate system is calibrated.The repeatability in the experiment reaches 0.2?m and the positioning error is less than 1.7?m.Tilt system and coordinate system is calibrated,and the positioning error is less than 1?m and 0.8?m respectively.In this paper,the error of the four-core fiber grating probe is further studied,and the signal returned by the probe sensor is compensated.Combined with the visual measurement system and the tilt table system,the probe measurement can be guided,and the optical guide of the fiber grating probe and the coordinate system calibration can be realized.