Alstom develops and markets mobility solutions that provide the sustainable foundations for the future of transportation. Alstom’s product portfolio ranges from high-speed trains, metros, monorails and trams to integrated systems, customised services, infrastructure, signalling and digital mobility solutions.
The Alstom team required 3D measurements to perform final adjustments on train cars located in the United States. They asked to their long-term partner Amrikart Ultraprecision to perform the 3D measurements. Amrikart is a company with expertise in 3D metrology applied to large-scale products and structures. They support customers worldwide by offering 3D services, consulting, specialised metrology tooling and accessories. The company also designs and integrates automated solutions for various applications.
Alstom’s train car inspection project required the inspection of several cars on an outside bench at an Alstom service facility. They needed to measure the location of each door-floor threshold in reference to the car’s longitudinal axis, and asked Amrikart to submit reports with recommended threshold adjustments to ensure a functional gap.
Measurements will allow for adjusting the width of the train to the level of the railway platform, and so also the functional gap required between the train and the railway platform. This gap is controlled to meet construction standards to prevent safety issues such as falls or collisions.
The Amrikart 3D services team responded quickly to this request, suggesting onsite measurements with a laser tracker.
Laser tracker systems are very versatile for large-scale metrology and enable high-precision measurements. They are composed of a laser embedded in a 360° rotatable head that tracks a handheld spherical reflector. The reflector is used as a probe and allows the operator to acquire the 3D coordinates of specific points on surfaces. The data generated by this process allows for verification of the engineering requirements thanks to 3D metrology analysis.
A Leica Absolute Tracker AT403
laser tracker model was used in this project. The instrument can be transported in cabin by plane, has a set-up time of less than 10 minutes and has a unique but essential PowerLock function: the ability to recover the reflector automatically if laser beam breaks because of obstruction. This feature makes the measurement process far more efficient.
The Amrikart team simply jumped on a plane with the laser tracker and its accessories and were ready to start the measurements the next day.
The Leica AT403 is the best laser tracker for travelling and working abroad with, as it’s small enough to bring along as cabin luggage. We used this tracker in a lot of different places and environments around the world.
The first measurements consisted of probing the rotational axes of the two bogies to create the car longitudinal axis to be used as a reference.
Then measurements of each door threshold were performed, and a final report was produced. Amrikart engineers are used to preparing and automating inspections, so a final report is automatically printed at the end of each measurement session. The total measurement process took less than an hour per car thanks to the versatility of the AT403 and the automated reporting.
Measuring the bogie axis was challenging, as it wasn’t possible to reach it by hand with the reflector. The team instead used a custom-made reflector perch long enough to reach the axis and probe points on it. Thanks to the PowerLock function, the laser tracker always recovered the reflector even through all the train’s cables and wires.
As usual, the Amrikart team demonstrated its flexibility in performing a remote onsite inspection with speed and efficiency. The proposed measurement method was accepted by Alstom, the team went onsite to perform the measurements and quickly delivered fully understandable inspection reports with recommended adjustments to be made on each threshold to respect the final functional gap. In doing so, Alstom was guaranteed to obtain high-quality measurements with a very short lead time.
It’s really important to have technology you can always count on, especially when your customers need you onsite fast. The short setup time means you’re ready to take measurements really quickly.
This operation was performed at a specific service centre, but the entire measurement and adjustment process can be integrated directly within car production lines to ensure an accelerated high-quality production cycle; Amrikart activities also include measurement and alignment automation as well as production toolings integrations for production lines.