Solid-state Lidar System Based On Swept Laser Source

Combining modern laser technology with traditional radar technology,lidar technology is formed.It detects long-distance objects by laser,and obtains the relevant information of the target by analyzing the frequency,amplitude or phase of the received scattered light.Compared with microwave radar,lidar has the advantages of small size,light weight,high spatial and temporal resolution,strong anti-active jamming ability.Lidar technology has been applied in various fields since the 1970 s.In recent years,the rapid development of robot,UAVs and unmanned vehicle industries has put forward higher requirements for lidar,a large number of market demands make the lidar become an important research field and hotspot.A lidar system consists of imaging module and ranging module,in which the imaging module realizes the change of beam direction and the ranging module realizes the distance measurement in different directions.For distance measurement module,mature ranging technologies such as pulse time-of-flight method,triangular ranging method,and FMCW ranging method have been formed,the FMCW ranging method can realize ranging and velocity measurement simultaneously,and has the advantages of strong anti-interference ability,high ranging accuracy and long measuring distance,which has great development potential and application prospect.According to the technical realization form of imaging module,lidar can be divided into mechanical scanning lidar,hybrid solid-state lidar and pure solid-state lidar,in which the mechanical scanning lidar has many problems,such as large volume,high power consumption,high assembly cost,unstable mechanical movement and easy wear.Pure solid-state lidar is the research hotspot and development trend of lidar.Therefore,the research of lidar system which can simultaneously realize non-mechanical fast scanning and high-precision ranging has important development prospects and application value.In this paper,a fast and continuous non-mechanical beam scanning method using a swept laser source and first-order blazed grating is proposed.At the same time,it is combined with FMCW ranging method for the first time to achieve high-precision distance measurement.The system structure is simple and compact.In the experiment,the angular resolution of about 0.11° in the angular scanning range of 17°,and the distance resolution of 1.85 mm in the range of 1 m are achieved.The high precision contour imaging of metal arc surface and paper surface with large inclination angle out of 2 m is realized,what's more,the performance parameters such as angular resolution and distance resolution can be adjusted by flexible data processing methods.