Robotic Measuring Cell Transforms Traditional Low Volume Manufacturing
A 122 years old railway wagon manufacturer in Russia has recently made a huge leap from using ‘old-school’ measuring equipment of calipers, gages and rulers to a high-performance fully automated 3D robot measuring cell. The project demonstrates that the leap from the past to Industry 4.0 and ‘The Smart Factory’ of the future can be made in one giant leap – even by very traditional manufacturing operations.
TVZ was founded by a French-Belgian joint stock company in 1898. More recently, the company was facing a production ramp-up along with an internal demand to improve quality assurance processes, and overall performance levels, at its huge 9000 employee plant manufacturing 1200 railway wagons a year.
Current Quality Inspection Technique
Within the production cycle of a railway wagon, one of the key activities is carried out within the Frame & Body Shop where large and small parts, sub-assemblies and fabrications come together from other departments, and external providers, to assemble the carriage frame and body. Quality inspection processes takes place after each assembly operation with measurements performed using calipers, gages and by visual inspection.
Automated Quality Control Project Goals
The ambitious project to fully automated inspection of the carriage and wagon bogie frames mandated the following be achieved:
– Inspection of 35 geometrical parameters of carriage bogie frames and inspection of weld seam and welded elements.
– Improvement of control processes quality by eliminating operator errors.
– Increase number of controlled elements inspected.
– Decrease of control process cycle time
– Presence/Absence and position control of welded elements.
For such an ambitious project it took time to develop the measuring cell’s engineering design, and in addition, the training and support required to assist the customer to adapt to the significant process change along with the necessary training to achieve full benefits from the system.
The complete measuring cell design was simulated as part of a initial verification study using the Metrologic Group SILMA X4 virtual simulation software.
The robot measuring cell was integrated by Pro Integration, based in St Petersburg Russia, and comprised a Leica T Scan-5 mounted on a 6 axis industrial robot with the 7- axis robot motion being provided by a linear rail. The Leica T Scan-5 laser line scanner’s position was tracked real-time, to eliminate robot inaccuracies having an impact on measuring accuracy, by a Leica AT960 Laser Tracker model.
Parts were located into a fixture mounted onto a rotary mount and orientated as required automatically to provide measuring access for the laser line scanning sensor.
Metrologic’s i-Robot measuring software was responsible for control of all aspects of the measuring cell including robot motion, robot tracking, fixture rotation and initiation and collection of all scanned data.
iRobot has been specifically developed by Metrologic for next generation robot measuring cells and includes the ability to extract, real-time, geometry from the generated point cloud while also accurately rendering the point cloud for direct comparison and analysis with the nominal CAD model.
All robot programming, simulation, along with the creation of measuring reports were created virtually using the Metrolog SILMA X4 software module. The software includes full robot path panning, collision detection and collision avoidance along with the automatic generation of robot poses to scan CAD selected part features and characteristics.
Metrologic iRobot metrology software, which is seamless integrated with SILMA X4, runs the robot inspection cell.
iRobot is suitable for all industrial robots providing a production ready metrology solution that is accurate, reliable and flexible while providing high metrological accuracy. iRobot provides full measuring cell performance control perfectly synchronizing robot trajectories with measurements while providing the necessary system accuracy through real-time robot tracking and positioning precision. iRobot locks to the laser tracker reflector before initiating each robot scanning sequence along with managing the ‘line of sight’ between laser tracker and scanning sensor.
The measuring cell is capable of measuring all wagon variants manufactured by TVZ inspecting automatically of all 35 geometrical parameters along with the additional dimensions of the carriage bogie frame. The robot system measures a full frame and assembly in 50 minutes with the weld seams and 35 minutes without weld seams.
The measuring cell achieves a measuring accuracy of 0.06 mm, which is very comparable to Horizontal Arm CMM measuring in a temperature controlled laboratory, which has been traditionally used for measuring large welded fabrications and sheet metal assemblies through manufacturing industries.
The flexibility and accuracy of measuring solutions, driven by Metrologic’s unique robot programming and integrated iRobot metrology software, clearly demonstrate that robotic production measuring cells have a key role in the transformation of very traditional manufacturing industries, characterized by relatively low volume production along with a high variety of models.
For more information: www.metrologicgroup.com