Research On Image Measurement Method Of Vehicle's Three-dimensional Dimension

The safety of highway traffic has a great influence on the economic development of the country and the property safety of the people,while the overload and oversize of transportation is the key factor of road traffic accidents.At present,the detection method of oversize mainly include manual measurement method and laser measurement method.However,the shortcomings of manual measurement methods are large measurement error,slow speed,and low efficiency.Besides,the laser measurement method has a high cost,inconvenient installation,and maintenance.In order to solve the existing detection problems of oversize,this paper proposes a method for rebuilding the 3D model of vehicles and measuring the height,length,and width of vehicles.The solution of this paper is mainly composed of project design,RGBD camera calibration,calculation of target vehicle displacement and 3D model reconstruction of the target vehicle.This paper aims at the practical application of oversize detection.To that end,this paper leverages two RGBD cameras installed on both sides of the detection area,which improves the accuracy of the vehicle three-dimensional model's reconstruction and measurement.This paper calculates the intrinsic and extrinsic parameters of the camera based on the plane calibration method.After that,the moving distance of the vehicle is calculated based on FAST feature points which are extracted by a sliding window matching method.Then,this paper proposed a solution to accelerate the matching method.In order to measure the length of a vehicle,for each coming image,the moving distance of this vehicle is accumulated based on the manually setting ROI.Finally,we can get the vehicle's 3D model and its parameters including height,length,and width.Finally,this paper carries on the experiment tests in the outdoor environment.Meanwhile,this paper processes and analyzes the measured data.By analyzing the measurement accuracy of the experiment and the stability of the multiple measurement results,the solution of this paper has high stability and measurement accuracy.The measurement accuracy satisfies the requirement that the measurement error must be guaranteed less than 1% in the national standard.