There are few industries where the demands for material testing and quality assurance are more challenging than in the aerospace industry. Ensuring the safety of all human passengers, crew, and cargo with fully inspected materials and components is no simple task.
Genesis Systems Group is a full-service robotic systems integrator, supporting the manufacturing, transportation, and aerospace markets. The company offers 24/7 support from its world headquarters in Davenport, IA and additional branches in Japan and Mexico. For the aerospace market, Genesis specializes in robotic non-destructive inspection systems (NDIs).
The NSpect™ line of NDI solutions from Genesis is designed to reliably inspect large surface areas as quickly as possible in aerospace applications. High-tolerance inspections are required to determine whether materials are manufactured with acceptable quality and do not have any flaws or indications greater than a specified size. The NSpect systems also work to minimize the risks associated with traditional testing processes for all kinds of aerospace components, including those for large and small aircraft, satellites, and even full-sized rockets.
To inspect aerospace components and materials with high accuracy, Genesis integrates robots with ultrasonic process equipment that conducts thorough transmission ultrasound with a sender and a receiver. Common ultrasound test types include pulse echo, phased array, and shearography. NDI systems from Genesis can also conduct water-based and air-coupled ultrasound, eddy current, gauss meter, emergent, and non-emergent testing types. The range of materials that can be inspected is vast, but most commonly involve steel, aluminum, and composite materials.
Robotic Systems Designed for the Ultimate Test
The NSpect systems combine ultrasonic inspection data with robot positional information and present it as A-Scan, B-Scan, and C-Scan images. This eliminates the need for manual inspections of large components that have very high tolerance requirements. “Preventing fatigue and identifying defects in components without affecting material integrity is challenging, even for experienced professionals,” said Whitney Moon, Director of the Aerospace Division at Genesis Systems Group.
An important component in these systems is a 6-axis articulated robot paired with a virtual encoder called the Genesis Blitz Module. Through extensive C++ programming, the Blitz Module can take all robot positions and create a virtual encoder with six degrees of freedom in about 200 microseconds. This is intended for grid sizes that are measured in increments of 1 mm or less. “In the inspection world, this is called pulse-on-position,” explained Ryan Steckel, Automation Systems Engineer at Genesis Systems Group.
“The Blitz Module takes the inspection data from the material under test and correlates the data with the position of the instrument or sensor. The faster the pulses can be sent, the faster the robot can run and the more productive the NDI systems are as a result,” said Steckel. The recognized standard to send these pulses is 10 ms, while the Blitz Module can send pulses in just 1 ms.
Another new development from Genesis is called the RoboPogo, a part-holding system with multiple articulated robots for components undergoing NSpect NDI testing. A single RoboPogo system can handle complex parts with multiple geometries.
“In 2017, Genesis took on a project that required the fixturing of especially large parts for NDI. Doing this with traditional hard tooling or manually adapted fixtures would be very cumbersome and expensive,” Moon explained. When holding parts that are between 10 and 110 feet long, a robotic solution makes sense because it can twist and rotate measurement devices around multiple geometries with a single system. Robots have advantages over gantry positioners because they are more flexible to accommodate varied processes and can better handle automatic tool changers for on-the-fly adjustments.
PC-Based Control Simplifies Integration
“The applications we address with solutions like the RoboPogo are very complex, so we need automation systems that simplify our designs,” Moon said. “This is why we incorporate advanced PC-based control systems from Beckhoff. In our experience, automation solutions that rely on standalone devices for specific processes only complicate designs. Our approach is to streamline automation, and PC-based controllers are attractive in this context because we can put all tasks under one roof.” Genesis Systems integrates all functions into one Beck-hoff embedded PC that can run the PLC, safety PLC, HMI software, Windows OS, and essentially any inspection software used by Genesis.
Today, Genesis Systems Group typically uses the Beckhoff CX2030 embedded PC equipped with a 1.5 GHz Intel® Core™ i7 dual-core processor. This device provides enough processor performance for most of the company's applications. “We use the CX2030 embedded PC networked over EtherCAT on our systems with 20 robots, and we still only use about 25 percent of the CPU capacity,” explained Steckel. “Gathering all the NDI data and maintaining communication with 20 different KUKA robots within a millisecond is impressive — a testament to the value of PC-based control and EtherCAT.”
For the most complex NDI systems, Genesis uses the CX2040 embedded PC, which increases the performance with a 2.1 GHz Intel® Core™ i7 quad-core processor. The different CPU cores are assigned specific tasks, such as end-of-arm tool collision sensing, position monitoring, and more. For simpler applications that employ a single robot, Genesis Systems usually opts for the CX9020 embedded PC with an ARM Cortex™ processor.
System programming and runtime is handled using TwinCAT 3 software from Beckhoff. This makes it possible for Genesis Systems to run PLC, motion control, safety logic, inspection software, HMI, and Windows OS all on one embedded PC. “The engineering environment accommodates Structured Text and object-oriented programming, which helps us grow the RoboPogo concept, as some systems have four robots, some have as many as 20,” Moon said. “We can expand or reduce this dynamically with minimal programming changes that we might otherwise have to work through with Ladder Logic, for example. With the TwinCAT software suite, Genesis engineers are also able to create entire programs on their PCs and easily update or troubleshoot applications remotely, rather than having to physically travel to our customer locations all over the world.”
Object-oriented programming (OOP) also introduced significant time savings for Genesis Systems Group. With OOP, it's easier for Genesis to take existing code libraries that have already been developed and implement them in entirely new systems. “With OOP, we no longer spend substantial amounts of time redoing large portions of code to address new processes for a different configuration,” Steckel explained. “To start up a new system, it's much easier to just set basic parameters rather than rewriting every line of code. For example, when setting up a system with shearography on one system and switching to ultrasonic on the next, I do not spend time searching through many files to locate shearography-specific controls. I simply replace my instance of shearography with the ultrasonic function block.”
EtherCAT Cuts Cabling and Boosts Robot Safety
On the networking side, RoboPogo and other NDI systems from Genesis are based on EtherCAT, which is widely accepted by major robot manufacturers around the world. EtherCAT promotes extremely accurate measurements and highly precise system synchronization, which is critical for test and measurement applications. Genesis was also an early adopter of EtherCAT P and One Cable Automation technology, which combine power and data transmission on one industrial Ethernet cable. “As Genesis Systems began to work with more commercial airplanes and spacecraft, many applications extended for hundreds of feet,” Moon said. “Having to run the numerous cables involved back to enclosures is especially time-consuming and expensive in these cases. That's why Genesis Systems Group uses EtherCAT P technology to route the power and EtherCAT network around entire fixtures without running lines way back to a main enclosure from each stand.”
To drastically reduce these cable runs, a large percentage of the I/O devices deployed by Genesis Systems are Ether-CAT P Box and EtherCAT Box modules with IP 67 protection. These can be mounted directly on machinery and robot arms for the direct connection to sensors, actuators, and other field devices much closer to the process. This cuts down the required cabling and reduces the size of electrical cabinets or eliminates them completely. “Because our NSpect systems often require water to carry ultrasonic inspection signals, IP ratings are very important,” Steckel explained. “Accordingly, our I/O system must be highly resistant to moisture in testing environments.”
Integrated safety technology in the EtherCAT I/O system takes the form of TwinSAFE, which provides additional benefits for robotic systems. “Implementing safety with industrial Ethernet and distributed I/O helps us increase the level of safety functionality in our designs and minimize our reliance on traditional safety relays,” Moon said. “Using TwinSAFE, we've reduced our required number of traditional safety relays by 90 percent. EtherCAT diagnostics also help boost the safety in our systems with built-in tools that can identify the exact location of any error from a device connected to the network.”
Another important I/O technology for Genesis is the EL6695 EtherCAT bridge terminal, which enables real-time data exchange between EtherCAT I/O sections with different masters. “While the EL6695 is not itself a TwinSAFE device, it gives us increased ability to reliably connect more safety zones via the EtherCAT system,” Steckel explained. “It also allows our safety zones to be reconfigurable on the fly. For example, we can have one established safety zone, then an operator can close a gate, resulting in two different zones. Safe loading can happen in one zone, but the system continues running in the other. This was previously not possible with other PLCs and safety interfaces we worked with.”
EtherCAT also extends to the motion control platforms designed by Genesis. Beckhoff AX5000 Servo Drives with integrated safe torque off (STO) are used to raise and level testing platforms. Some platforms are transported on wheels and when they reach parts for inspection, the AX5000 and connected AM8000 servomotors raise up the platform, stabilize it, and level it. This is used for headstock and tailstock positioners and any other type of motion system used. “We also integrate One Cable Technology (OCT) connections between our Beckhoff servomotors and drives, leading to additional cabling and installation savings comparable to what we experience with EtherCAT P,” Moon said.
Upon Closer Inspection, Significant Savings Observed
Once evaluation began in earnest, PC-based control technology was rapidly accepted by Genesis, resulting in a swift implementation. “The Genesis engineering team was quick to realize significant benefits from PC-based control for these industry-specific applications,” said Dennis Sowada, Regional Sales Engineer at Beckhoff Automation. “This team's deep technical expertise, combined with strategic planning, rapidly produced a comprehensive control platform that also includes advanced EtherCAT P networking.”
Hardware, software, cabling, and networking in the PC-based control platform have combined to promote significant savings observed by Genesis. This has made the company more flexible to cost-effectively develop NDI systems like RoboPogo that tackle some of the most complex testing applications imaginable. “By adding One Cable Automation, Genesis Systems can reduce NDI system cabling by up to 50 percent for drives, motors, sensors, actuators, and pneumatic valves,” Steckel said. “As we plan future developments, we know EtherCAT P can also be applied toward larger devices, such as entire electrical cabinets and eventually robots.”
“Through the combined use of PC-based control technologies and EtherCAT, Genesis Systems also reduced cabling and installation time of all electronic components by 50 percent,” Moon added. “Additionally, we reduced the space needed in our electrical cabinets and enclosures by 20 percent.”
This article was contributed by Beckhoff Automation, Savage, MN. For more information, visit here.