Fuelled primarily by a necessity to increase productivity against the daunting backdrop of a global skills crisis, the need to automate manufacturing processes has never been so critically important. From machining to logistics, we’ve seen automation become an integral part of factory floor operations, but now with Hexagon Manufacturing Intelligence’s new standard automation cell, the technology extends even further to quality control and inspection. Dave Tudor reports.
The evolution behind Hexagon’s standard automation cell actually stems largely from technology that has been around for a while, but the crucial difference now is that everything is totally and seamlessly integrated whereas previously things were altogether much more manual and ad hoc.
“Our laser trackers – the measurement technology behind our new automated cell – have been around since the 1980s where they were used predominantly in aerospace applications for large volume, high accuracy measurement applications,” explains Jon Kimber, technical sales manager, large volume metrology, Hexagon Manufacturing Intelligence.
“For us, the next evolutionary step was to add a probing tool to the laser tracker to enable the convenient measurement of features like bores, grooves and inside diameters. Next, we introduced a laser stripe scanner into the equation; and then, as things evolved further, some customers used robots to operate the scanners and probes rather than have human operators do it.
“In principle, these were true inspection cells – but they were very bespoke, varied from company to company and were far from integrated,” Mr Kimber adds. “They also required a high level of skill to operate; people had to create their own robotic programs on the robot pendant so programming knowledge was required and you had to work out your own safety features in terms of things like guarding and operator protection.
“And if that wasn’t enough, you then had to create some kind of ‘handshake’ synchronisation between the robot program taking the measurements and the measurement software receiving the data.”
Total solution
Clearly not a sustainable way forward. Hexagon did develop one or two tools and software macros along the way to provide some degree of harmonisation between constituent elements of its customers’ disparate systems, but really it needed a coordinated focus on producing an ‘off the shelf’ automated inspection cell that was both powerful and easy to use – and used COTS (commercial off the shelf) parts.
And, as Jon Kimber reveals, that’s exactly why Hexagon’s new standard automation cell was developed which is totally modular and can be used inline, offline or nearline. “It’s a full hardware/software solution with just one software package (HxGN Robotic Automation) that takes care of everything and it’s so user-friendly,” he enthuses.
“You don’t even have to go anywhere near the robot pendant for manual jogging purposes; in fact you can keep it in the cabinet because you don’t need it. Operationally, you simply import the CAD model of the component you want to measure into the model of the cell, position it in the fixture on the turntable, select the features you want to measure in the software, automatically create a program and go.”
He continues: Essentially before any physical inspection takes place, you’re creating a digital twin of the cell and everything in it via the software, effectively validating the entire process virtually.
“And it’s totally all-encompassing. The HxGN Robotic Automation software controls the motion/coordination of all hardware – robot, scanner, turntable, fixtures, probes and laser tracker – as well as part positioning. Because everything is accurately modelled first, collision avoidance and operator safety is built-in. All the power is in the software; from the end user’s perspective, no robot programming at all is necessary. Once the features are selected, the program is created and validated automatically, when it comes to actually measuring the part, you simply hit the go button – and programs can be saved and recalled for future reference.”
Customise to your heart’s content
Although a ‘standard’ version of the cell is available – which incidentally should suit most applications – Hexagon can offer bespoke, customised configurations to suit specific customer requirements. This versatility is inherently designed into the software which makes it supremely powerful.
“The hardware platform is modular and can be expanded to include any kinematics, any number of robots, any number of turntables, any number of linear tracks and any format and size of cell,” Mr Kimber affirms. “For example, if we develop new sensors for the robot, we can simply define that within the software affording a high degree of future-proofing.”
Customisations could literally be anything. Jon Kimber cites two recent examples. One is for a customer using four turntables in a line with a single robot on a track, and then the tracker on a separate track behind that. The second is a defence application for a customer in Germany using the inspection cell to literally measure an entire main battle tank.
Components off the shelf
With the new standard automation cell, Hexagon has gone to great lengths to use as many COTS components as possible – the logic being that there will already be a high degree of customer familiarity. For example, Hexagon usually supplies FANUC robots, but if you happen to prefer a different robot manufacturer or favour a different PLC supplier, that’s fine too because Hexagon can incorporate that via the software.
Practically everything used in the cell in terms of hardware comprises tried and trusted industry standards: the robot, sliders/tracks, drives and controls, PLC equipment inside the cabinet, and safety systems – it’s all easily available, reliable and easily maintained. The only exclusively Hexagon hardware ingredient is the measurement tech: – AT960 absolute laser tracker and AS1 absolute scanner on the end of the robot.
For the standard cell, Hexagon says it will always have at least one in stock ready to ship, and because they’re supplied in flatpack format, customers can be up and running quickly. Bespoke configurations, understandably, will take a little longer.
On the software side, aside from HxGN Robotic Automation, the only other vital part of the cellular equation that remains is what to do with the inspection data itself after measurement? Fortunately, Hexagon has that covered too with its technically advanced but simple to use PC-DMIS and Inspire metrology software packages which take care of inspection data collection, reporting and analysis.
Much of Hexagon’s promotional literature shows the standard automation cell measuring a car door and this is exactly the type of part that is perfect for this type of measurement.
“The AS1 is ideal for measuring relatively large parts quickly and efficiently,” Mr Kimber advises. “By design it’s accurate to 50µm up to a distance of 30m from the tracker so it’s ideal for measuring things like car panels, vehicle doors, wings, sills, frames, composite structures, sheetmetal parts and moulds with lengths upwards of 3-4m.
“One scenario is when manufacturing large batches of components as the cell can be used effectively to prove parts are in spec at the beginning of a production run. Typically, companies will use the cell offline to prove a first-off, and then take subsequent samples mid- and end-batch to ensure conformity and consistency throughout the entire run. Essentially, the cell is a shopfloor rapid validation system that’s robustly built to be used under shopfloor conditions. And it is fast – typical inspection times for a car door – around 1.5 to five minutes depending on coverage and feature count.
“A different example could be with a company making small quantities of composite aerospace parts. Here, rather than using sample inspection methods, you’re likely to want to conduct 100% inspection because of the application. The cell is absolutely perfect for these types of applications as well.
“Like all technology however, laser scanners have their limitations,” he says. “If you’re measuring engine blocks for example with cylinder bores with 3-4µm tolerances, one of our CMMs is a far better option. Horses for courses.”
New laser scanner enhances versatility
Key to the effectiveness and versatility of the new cell – and indeed a whole host of other Hexagon technology including CMMs, arms and trackers – is its new latest and greatest AS1 blue line laser scanner. Jon Kimber is in no doubt that the AS1 is one of the most important Hexagon developments in recent times as it makes the standard automation cell in particular so effective on a variety of different components in virtually any material – metals, plastics, carbon fibre, foams, Perspex, even glass – you name it.
“In the past with less versatile technology, laser scanners tended to be only suitable for measuring heavily profiled components, but now, because of the accuracy of the AS1 and the fact that it’ll scan just about any surface – light, dark, shiny or matt – it’s equally good on features as well as profiles. It could be used on a perfectly flat section of sheet metal for example containing various stamped or punched features or alternatively on a pressed, curved part.”
The AS1 scanner really does represent the pinnacle of laser line technology for portable metrology systems. The introduction of functions such as dynamic exposure settings and automatic noise elimination have facilitated significant improvements in scanning usability and data quality.
The Absolute Scanner AS1 uses a set of optical algorithms known as SHINE (Systematic High-Intelligence Noise Elimination) technology which empowers scanning on challenging materials such as chrome, shiny black or multi-colour surfaces by filtering scan data outliers without compromising scanner performance and accuracy.
These technology advances expand the scope of use dramatically. We’ve mentioned the measurement of large scale composite parts and automotive body and interior panels, but other applications include the inspection of reworked turbine blades in gas or steam turbine maintenance, repair and overhaul (MRO) situations.
Hexagon
www.hexagon.com
