Design And Implementation Of Portable Semiconductor Laser Rangefinder

Laser is a kind of light produced by stimulated emission of atoms,so it is called "laser".It is known as another great invention of human being since twentieth Century,after nuclear energy,computer and semiconductor.Laser is a single color light,with a high concentration of energy,good direction and so on.It is called "the fastest knife","the most accurate ruler","the brightest light".Therefore,laser is used in laser processing,laser medical treatment,laser communication,laser ranging,laser weapons and other fields.Laser ranging is an important aspect of many laser applications.Laser rangefinder is an instrument for measuring distance using laser.With the development of laser application technology,laser ranging has been widely used in engineering construction,geological monitoring and military equipment.In recent years,the integration of high efficiency semiconductor laser technology and large-scale circuit integration technology has promoted the miniaturization of laser ranging devices.In view of the problems of low ranging precision,large volume,heavy weight,short life and inconvenience of carrying,a portable semiconductor laser rangefinder is developed in this thesis.The research work in this thesis has certain theoretical and practical significance for improving the theoretical level and application level of laser ranging.The main innovation work of this thesis includes: studying the principle of laser ranging,analyzing the current research status of laser range finder,summarizing the main technical bottlenecks of the current laser range finder,analyzing the function demand of the portable laser ranging based on the subject.Through the comparison of three typical ranging methods,the pulse laser range finding mode is selected as the technical scheme of the laser range finder.Through the reasonable selection of device and data analysis,the detailed design of the overall structure,optics,circuit and software of the laser range finder is completed.The maximum range and distance precision of the laser range finder are calculated and analyzed in theory,and the source of the error of the laser range finder is analyzed,and the prototype of the laser rangefinder is completed.The test results show that the functions and performance indexes meet the requirements of the project design and achieve the desired purpose.Finally,the work is summarized and the next work of the system is prospected.The main innovative achievements of this thesis include: a new coaxial optical structure is proposed by integrated optical design.The laser transmitter and the receiver are combined,the optical path,the emitter path and the receiving light path are combined,and the volume and weight of the laser rangefinder are compressed well.Using high efficiency and low power semiconductor laser as light source,high sensitivity avalanche photodiode is used as a laser detection sensor.The range circuit part uses TDC+ARM combination to achieve laser ranging and ranging accuracy under low voltage.Low power circuit design is added to the design of power circuit to distinguish different supply.The power supply mode under the electric mode avoids the power consumption caused by the continuous power supply and improves the endurance of the power supply.