A key requirement of smart manufacturing is the interconnection of measuring instruments, production systems and machine tools. In combination with full measurement automation, this can lead to a step change in performance. The following use case introduces how high-resolution optical 3D measurement and production systems can be connected, resulting in the possibility of measuring tool and workpiece automatically and directly in the machine tool.
In many production facilities, the use of measurement technology for quality assurance is still realized off line. Inspection equipment is often located at the end of a production chain and the quality of a component is only determined when it has already been manufactured.
In the worst case, the component fails to meet the specified tolerances, making it necessary to move through all phases of the production cycle again.
The concept of smart manufacturing, as it is understood by the global optical 3D measurement provider Alicona, actively engages measurement as an integral part of the production chain where production steps are automatically corrected when a single component does not meet defined tolerances.
As a result, faulty components are no longer produced; the first parts are the good parts.
The use of measurement technology as an integral part of manufacturing is based on optimized communication and networking of all interfaces. Production systems, machines and measurement technology form a closed loop in constant communication, making it possible to produce the first part directly as a good part. The integrated measurement technology verifies dimensions, tolerances and surface quality at a very early stage of production. If the measuring sensor detects that a component is faulty, this information is fed into the production circuit, which adapts accordingly.
In order to implement smart manufacturing as an advanced production strategy, fully automated measuring systems are needed. In addition, complex components with tight tolerances require optical, high-resolution measurement sensors that are compatible with production and provide traceable and repeatable measurements.
Alicona´s Focus-Variation technology offers an ideal platform for using optical 3D measurement technology in production because it is combined with areal-based high-resolution 3D measurement sensors that can be flexibly integrated. All involved systems are digitized and linked using intelligent interface technology. Provided measurement solutions can be individually customized. This gives manufacturers real-time data on production processes, allowing them to intervene at an early stage.
Progress made at Element Six
One option to integrate high-resolution optical 3D metrology into production is the use of Alicona´s collaborative systems, called “cobots.”
Cobots combine collaborative robots and an optical 3D measurement sensor. They require no prior knowledge of metrology and make handling, programming and executing of measurement series very easy. This is made possible by hand-guided controls for the teach-in of measurements, automatic measurement and a non-enclosures safety concept.
Element Six uses such a cobot system. Element Six designs, develops and manufactures supermaterials for use in cutting, milling, drilling and grinding applications in the production of aerospace components and systems. Element Six recently applied the Alicona Cobot for the development of a new PCBN material designed for productivity gains and reduced tooling costs. A decisive factor in the test phase for the new PCBN generation was the implementation of automated test series, achieved with the collaborative measuring system “CompactCobot” to analyze various types of tool wear and behavior during different machining conditions.
The focus was on the measurement of flank, crater and notch wear. The ability to automate test series has helped to make the development process as efficient as possible and ready for production.
“Our productivity in the testing of cutting tools is limited by our information gathering process, primarily regular measurement of cutting tool wear,” said Wayne Leahy, head of applications for cutting and grinding at Element Six.
“We purchased the Alicona Cobot system so that we could start to automate the cutting process. Gathering a large number of data points on wear behavior under varying machining conditions was instrumental in helping us to optimize the new technology. This in turn helped us to deliver the step change in performance we were looking for.”
Element Six is also active in the development and implementation of integrated production strategies in machining technology. The aim is the communication and networking of production systems, machines and measurement technology.
In the medium term, fully automated production with machine-to-machine communication should be achieved. As far as the use of 3D measurement systems is concerned, requirements such as production suitability, automation and the ability to connect to existing production and quality management systems, have to be met.
The Alicona Cobot enables this integration and networking in several ways.
On the one hand, the optical collaborative measuring system is so robust that also in production, high-resolution measurements are achieved in a high measuring speed and in high repeatability. Automated and therefore unmanned measurements in production are realized with the interface AutomationManager.
On the other hand, the cobot offers interfaces such as TCP/IP, Modbus/TCP or Anybus, and can thus be connected to existing production systems. This integration enables communication between the individual machines and thus contributes to the implementation of self-controlling, self-correcting production.
Measuring directly in the lathe With the cobot, Element Six has begun to implement a modern manufacturing concept toward self-optimized production. Both the tool, an insert and surface finish of the workpiece are measured in the lathe.
“A central control system starts the testing process,” Leahy said. “At a defined point the lathe stops, the door opens and a further signal sets the cobot in motion. The robot arm with 3D measuring sensor is automatically manipulated into the lathe and first measures predefined cutting edge parameters of the insert. The sensor then moves on to the workpiece and measures its roughness, which enables us to verify the surface quality. Then the robot arm returns into its original position. All measurements are carried out without unclamping components.”
The next step in planning is the automatic correction of machine parameters based on the measurement results. The cobot transmits measured values or an “OK”/“not OK” signal to the lathe.
“If tool or workpiece do not meet the specified tolerances, the lathe automatically changes machine parameters and testing continues. In this way, the first part is already produced as a good part”, Leahy said.
There is another aspect that is decisive for the implementation of integrated production strategies with automated measurement technology. Measuring systems must be easy to operate without programming knowledge. Alicona meets this condition.
The teach-in of measurement series by an administrator is carried out in only three steps. Special programming skills are not necessary.
The measurement is started at the push of a button and the measurement result is independent of the operator.
“It took about a day to train an operator on the cobot,” Leahy said. “Handling and user guidance is extremely simple and intuitive.”
Turbine blade measurement, automatic defect analysis
High-resolution optical 3D measurement systems by Alicona are also used in other aerospace-relevant applications. These include turbine blade measurement, automatic defect analysis, MRO or hole measurement.
Turbine parts do a good job of showing that requirements on the manufacturing quality are extremely high. However, to ensure that the 3D shape of the manufactured parts lies within desired tolerances is often difficult due to the size of the parts and the necessity to measure in very high resolution.
One key measurement application is to check whether turbine discs or blisks are free of sharp edges and have local curvatures below a certain threshold.
A second application is to measure the size and shape of defects on turbine blades to ensure that only defect-free blades are used.
Alicona metrology enables the measurement of complex parts with steep slope angles and varying reflectance properties while allowing measurement resolutions down to 20nm. Users verify the local curvature and can automatically measure size and shape of defects.
Measurement systems are available in various formats, including stand-alone systems for the measurement of miniaturized components (“table systems”) and robot-based solutions for the measurement of small features on large components.
All relevant surface features on large components are accessible and hence measurable through the combination of a robot arm and 3D measurement sensor.
Regardless of the system used, all types offer full measurement automation. An administrator teaches in measurement programs and an operator in a shop-floor or other production environment starts the measurement with the push of a button.
The measurement and evaluation of surface roughness and shape parameters proceeds automatically, the result is user-independent.
At the end an “OK”/“not OK” report is provided.
Edited by SME Media, using information provided by Alicona.