On the morning of September 14th, a test train departed from Chengdu East Station, and the operation test of the new section of the Sichuan Qinghai Railway from Qingbaijiang to Zhenjiangguan was launched. This is a key link before the opening of the new railway section. The Chuanqing Railway is an important component of the Lanzhou Guangzhou Passage in the "Eight Verticals and Eight Horizontals" high-speed railway network. It is the first railway line in China to cross the Longmenshan Fault Zone, filling the gap in the absence of railways in the northwest region of Sichuan.

Experimental train at Zhenjiangguan Station on the Chuanqing Railway

By 2023, it is expected that more than 3000 kilometers of new railway lines will be put into operation nationwide, with a total operating mileage of over 158000 kilometers. Among them, 2500 kilometers of new high-speed railway lines will be put into operation, with a total operating mileage of about 44500 kilometers! The continuously increasing mileage of high-speed rail has also brought huge opportunities to the railway operation and maintenance market, while traditional track precision measurement methods are also facing difficulties that are difficult to overcome.

Unknown Hard Work

Nowadays, when we ride high-speed trains, we can leisurely stroll in the high-speed train carriages running at a speed of 350 kilometers per hour, and stand coins on the windows without tipping over, all thanks to the high smoothness of the high-speed railway line. Once the track is not smooth enough, it will cause system vibrations in locomotives and vehicles, which will directly affect wheel rail noise, wheel rail interaction forces, as well as ride comfort and safety.

To ensure the maximum smoothness of the track, the staff need to accurately obtain the three-dimensional position coordinates, track spacing, etc. of the track, and achieve high-precision measurement of various geometric parameters such as track orientation, height, gauge, and level. In the early stages of railway construction and maintenance, technicians needed to manually measure the track using a gauge, which resulted in very low operational efficiency.

Manual measurement of track with gauge ruler

In the later stage, high-precision total stations were used for track measurement. The surveyors would temporarily set up a tripod on the centerline of the track, and then mount the high-precision total station on the tripod to measure the information of the selected sample points through photoelectric scanning, and then calculate the coordinate data of the steel rail. Each rail sleeper had to be repeated once, and could only measure 200-300 meters per hour.

High precision total station frame working screen

The "inertial navigation car" has emerged

With the rapid development of high-speed rail construction in China, track precision measurement technology is also constantly evolving. The inertial integrated navigation railway track geometry state measuring instrument, also known as the "inertial navigation car", has emerged. Based on inertial technology, the track inspection car can automatically measure track parameters such as track height, track orientation, level, torsion, and gauge, in order to find track irregularities.

Technicians using the "inertial navigation car" for work

The "inertial navigation car" mainly includes an inertial navigation system composed of gyroscopes and accelerometers, as well as a satellite positioning system. Because the car moves in three-dimensional space, it is possible to establish spatial coordinate axes and collect data from three directions during the measurement process to calculate the spatial coordinates of each part of the track through a computer. Then, the continuous point values can be further calculated to determine if there are any abnormal deviations.

Working photo of "inertial navigation car"

With inertial navigation technology, a measuring car device can accurately locate the geometric position of the track at any position, and the measurement data can be processed in a one-stop integrated manner, significantly improving operational efficiency while ensuring accuracy. The detection efficiency can reach 2km/h~4km/h, which is nearly 10 times higher than traditional optical equipment. Moreover, after handing over the railway track data collection mode to the inertial navigation car, automatic collection and data processing can be achieved by simply pushing the car lightly, without the need for excessive on-site operations.

At present, China's high-speed rail and speed have also gained worldwide recognition. With the development of technology, the inertial technology for autonomous track inspection vehicles based on inertial precision measurement will provide increasingly professional services for high-speed rail inspection, successfully helping China's high-speed rail soar!