Research On High-Precision Absolute Distance Measurement System Based On Laser Self-Mixing Interference

As modern science and technology are more and more marching to the small scale,high-precision sensing technology is increasingly showing its important position and role.High-precision technologies such as chip manufacturing,weapon processing,biomedical sensing,and 3D shape reconstruction are all inseparable from highprecision sensing.Optical sensing has received more and more attention and research due to its noncontact,high accuracy and other characteristics.Among them,laser sensing technology has received extensive attention due to its advantages of good collimation,strong antiinterference ability and large detection range.In 1963,a technique that uses the optical feedback effect to modulate the output of the laser,laser self-mixing interference technology,has been discovered by scientists.This method not only has the detection accuracy of the traditional two-beam interference half-wavelength,but also has easy collimation and measurement systems It has the advantages of compactness and low requirement for the type of laser.Therefore,it has been widely researched and applied in the field of measurement of various physical parameters such as distance,displacement,angle and speed.In the field of absolute distance measurement,the traditional optical distance measurement mostly adopts the dual optical path method,and requires an expensive laser as a light source,which is not easy to integrate.Therefore,the cheap and compact laser self-mixing interference current modulation ranging technology has become the focus of researchers in recent years.Based on the traditional current modulation ranging technology,this paper innovatively applies the even power algorithm to it,which effectively improves the measurement accuracy and resolution.This paper introduces the development process of laser self-mixing interference technology,and derives the mathematical model of laser self-mixing interference phenomenon from different theoretical angles.Innovatively apply the even power algorithm to the traditional current modulation technology,combined with the denoising algorithm and the envelope removal algorithm,the ranging accuracy is improved from the average accuracy of the traditional ranging to 1.7943%to 0.4676%,and the accuracy is given.Restricted factors.A set of hardware system for laser selfmixing ranging is built,and the constitution principle of each module and the reason for parameter selection are introduced in detail.In theory,the limiting factors of the ranging range and resolution of the ranging system are given,as well as the relationship between the factors and the measurement resolution and measurement range.Mobile devices and handheld devices will be more and more widely used in the future,and more and more distance measurement systems will be installed on them.Semiconductor current modulation ranging technology will be more applied to these products around us because of its easy integration.I believe that the high-precision ranging technology based on semiconductor current modulation technology proposed in this paper will be more and more widely used.