Study On Angle Static Measurement And Related Technology Based On Self-mixing Effect Of Multi-longitudinal Mode Laser

Laser self-mixing interference sensing technology has many advantages,such as simple structure,low cost,non-destructive,non-contact and so on.It has been widely used in the sensing of velocity,vibration,displacement and other physical quantities.In recent years,with the rapid development of precision manufacturing technology,high-precision,low-cost and miniaturized angle sensor has become a new research hot spot.Among them,the laser self-mixing interference sensing technology with single optical path structure is an important means to achieve high-precision and high-resolution angle measurement.However,the current laser self-mixing angle measurement scheme is mainly for dynamic angle measurement,which can not achieve angle static measurement.In view of the above problems,this paper proposes an angle static measurement system based on the self-mixing effect,which use the multi-longitudinal mode semiconductor laser as the light source.The theoretical model of the angle static measurement system based on self-mixing interference of the multi-longitudinal mode laser with different turning optical path structure is established.The angle static measurement system based on self-mixing interference of the multi-longitudinal mode laser is built,and relevant experiments are carried out.The specific work of this paper is as follows:1.The theoretical model of the angle static measurement system based on self-mixing interference of multi-longitudinal mode laser with plane mirror as turning optical path device is established,and the experimental system is built.The results show that the system can achieve an angular resolution of 0.500° and an absolute angular measurement error of less than 0.658° in the range of ±30.000°;2.The theoretical model of the angle static measurement system based on self-mixing interference of multi-longitudinal mode laser with biplane mirror as turning optical path device is established,and the experimental system is built.The results show that the system can achieve the measurement accuracy of 0.050° and the absolute angle measurement error is less than 0.370° in the range of ±22.000°;3.The theoretical model of the angle static measurement system based on self-mixing interference of multi-longitudinal mode laser with a right angle prism as the turning optical path device is established,and an experimental system is built.The results show that the system can achieve an angular resolution of 0.2000° and an absolute angular measurement error of less than 0.214° in the range of ± 6.000°;4.The theoretical model of the angle static measurement system based on self-mixing interference of multi-longitudinal mode laser with pentaprism as turning optical path device is established,and the experimental system is built.The results show that the system can achieve an angular resolution of 0.100° and an absolute angular measurement error of less than 0.2390 in the range of ± 8.000°;The main innovations of this paper are as follows:1.Combining the theoretical model of three-mirror cavity with the theory of interference mixing,and the relationship between angle and optical path,the theoretical model of multi-longitudinal mode laser self-mixing angle static measurement system with different turning optical path structure is established.2.An angle static measurement system based on self-mixing interference of the multi-longitudinal mode laser with different turning optical path structures is built.The influence of different turning optical path structures,such as plane mirror,biplane mirror,right angle prism and pentaprism,on the angle measurement range and measurement accuracy of the system is studied.3.A theoretical model for simultaneous measurement of temperature and strain based on the self-mixing effect of multiple-longitudinal mode laser is established.The multi-longitudinal mode laser self-mixing signal of temperature and strain measured at the same time is simulated.It provides a theoretical basis for the next step to build a multi-physical quantities measurement simultaneously system based on self-mixing interference of a multi-longitudinal mode laser.