| China’s construction of railway,especially high-speed rail,developed rapidly in recent years,and has proposed faster and more accurate requirements for the railway detection equipment.As we all know,for the lines with speeds of more than 250 kilometers per hour,the detection of their long wave irregularities is very essential to ensure safe and comfortable driving.At present,the domestic long-wave detection method is not efficient or not accurate,while the price of the foreign emerging inertial navigation static inspection equipment is extremely expensive,this suppressed situation needs to be improved.The research team used the track inspection instrument produced by Jiangxi Riyue Ming Company as the experimental hardware foundation,and explored the long-wave fast precision measurement technology under the low equipment transformation cost.In this paper,the basic scheme for improving the accuracy of the existing long-wave semi-observation method is to compensate the real-time measuring error from the earth’s self-rotation for the two Fiber Optic Gyroscopes which are amounted on the track detector for separately detecting the track longitudinal and alignment irregularities,trying to reduce the systematic error caused by the incomplete earth’s self-rotation compensation for long-wave measurement.Because the difference between the actual line and the design line on shape and position is not large(especially for the high-speed rail),this paper first proposes the primary long-wave fast precision measurement method which compensate the earth’s self-rotation error according to the design data.This method has obvious compensation effect on the line with little deviation from the design line,but little effect on the line with large deviation.In view of this,this paper proposes an intermediate long wave fast precision measurement method to compensate the earth’s rotation by solving the real-time attitude angles of the track detector.The method combines the measurement information of the gyroscopes and the inclination sensor,then uses the multi-sample rotation vector algorithm to solve the attitude angles of each measuring point one after one;and finally replaces the angular velocity integral measured by the gyroscope with the attitude-angle increment to perform the long-wave calculation,avoiding Chaos caused by angular superposition in the moving coordinate system.Experiments prove that this method promotes the measuring accuracy of the line with large deviation from the design line largely,while the measuring accuracy of the line with less deviation is also improved some.The advanced long-wave fast fine measurement method further corrects the long-wave measurement values on the basis of the intermediate method.The advanced fine measurement method firstly calculates the point-by-point coordinates of the measured line according to the attitude angles solved by the intermediate method,then integrates the absolute measurement data every 200 meters to correct the attitude-angle increments,eliminating the long-wave error caused by the measuring error of the gyroscope’s zero offset on the starting point and its zero drift.The method suspends the track detector once every 200 meters for mileage correction and absolute measurement using the free-level vehicle total station.Experiments have shown that the long-wave values having been corrected by the advanced method is more accurate than the ones measured by the intermediate method.When using sensors with enough high precision and stability,this advanced long-wave fast precision measurement method can reliably ensure that the long-wave measurement error is within the Class I tolerance. |
