| Static gauge is the projection profile of the non-load rolling stock sitting on the straight rails.It is one of the crucial criteria to evaluate whether the rolling stock is qualified or not,and it is also a basic element for the safe operation of rolling stock on the rails.Currently,in our country,the measurement of static gauge is artificial-contact measurement mainly based on the national standard GBT160904.The precision of this measurement method is highly related to the operator’s working experience and measurement process.It also involves long detection time,high intensity of workload,low safety factor and other potential weaknesses.This project made use of industrial vision measurement,developed special vision measurement sensor,designed automatic measurement and controlling system,and achieved visual,fast and automatic measurement of rolling stock’s static gauge.Its measurement precision is 1mm.Based on the technology requirements of static gauge measurement and the international research backgrounds,this study develops the automatic measuring system for static gauge of rolling stock.The main contents contain designing and development of the measurement system,designing of a measurement sensor,designing of the calibration method for system and implementing experiments to analyze the precision of the system.Firstly,this study illustrates the scheme of the system,which involves critical technique study and designing system workflow.To achieve scanning measurement of a rolling stock,this system uses servo-motor to drive a measuring cart to move on the linear guide,the cart also mounts with a vision sensor.Then,based on the measurement requirement,this study develops a vision sensor which is special for static gauge measuring and finishes its calibration.By improving the checkboard calibration target,it achieves automatic angle-point sorting.During the calibration of structured light plane,designing a method which is suitable for fast calibration of structured light plane in the industrial field.Besides,the scheme of whole system calibration is developed,and it achieves a uniform of multi coordinate systems.The laser tracking system and self-developed calibration target are used to calibrate the system.By analyzing and measuring the movement process of the cart,completes the calibration of the linear guide,and it completes the transformation among multiple coordinate systems.Finally,this study implements error analyzing and experiment verification.Designing experiments to verify the precision and repeatability of the vision sensor.The precision and repeatability of the measurement system is verified by three-dimensional scanning experiment with a high precision machined cylinder standard as the measurement object.The precision of the system is better than 1mm,and its repeatability is better than0.5mm.The detection precision of static gauge is satisfied,and this system can achieve precise and reliable measurement of the static gauge. |
