Increases in size and quantity of its orders led Wisconsin-based auto parts manufacturer Felss Rotaform LLC (New Berlin, WI) to expand operations through a new dual-robot machine-tending cell. The company is a supplier of precision parts using its rotary swaging, axial forming and tube end-forming processes. To meet the continuous process improvement goals of the company, the new cell had to be safer, faster and more flexible than its previous manufacturing cells.
To address the complex nature of the automation, the company contacted Siemens and systems integrator IAS Inc. (New Berlin, WI) due to their track record in innovation and expertise in integrated robotics and control technologies. Six months later, Felss Rotaform found itself operating a digitalized, integrated manufacturing cell that was breaking the company’s productivity and profitability records.
While reviewing requirements for their next-generation robotics cell, Felss Rotaform had several goals. First, it wanted to boost productivity by deploying new high-speed PLCs to achieve shorter full-cycle turnaround times for each individual part.
Second, it wanted to explore a more advanced safety solution that assured better control of who was entering the cell. In the older cells, a machine could accidentally be turned on when a maintenance person was present in the cell, placing that individual at risk for injury. To avoid this, Felss Rotaform wanted an automated process to guarantee the cell was vacant once restarted.
Third, it wanted more flexibility for cell changeovers, which would allow the company to test and provide a more diverse product range for its customers. The older cells required the entire cell be reprogrammed each time a new process was performed, which could take days to execute.
Felss Rotaform’s initial goal was a 48-second full-cycle turnaround time for each part in the new cell (far faster than any of its older cells). The design and implementation of the solution sped the complete part production process up to 38 seconds, an efficiency improvement of 20%. Once the new cell was implemented, downtime went from days to hours for complex changeovers and, for typical scheduled changeovers, what used to take eight hours to perform now takes just 15 minutes, according to Chad Due, Felss Rotaform electrical controls engineer.
“This new cell can produce in two shifts what would previously take three to accomplish. This allows us to produce 600 additional parts over a 24-hour period. In addition, profitability for the cell has increased by 13%,” said Due.
Richard Parkhurst, Siemens account manager, knew IAS would be strongly positioned to accomplish Felss Rotaform’s goals. “Some integrators perform strictly software development and others are more skilled at building and assembling the hardware. IAS brought a combination of all of the necessary skills and expertise, including robotics and safety engineering capabilities,” he said.
IAS recognized that Siemens products would be critical in helping Felss Rotaform achieve its goals by providing the required speed, reliability, flexibility, and safety. For example, an Ethernet-based Siemens PROFIsafe digitalized communications backbone was designed into the cell to control machine and perimeter safety. Safe communication is provided between the various PLCs and robots. PROFIsafe relays status information from the devices inside of the cell to the main PLC and provides
a big advantage over older technology because both standard and safe communication take place via a single bus system.
All sensors and actuators within the PROFIsafe solution can be freely programmed within the distributed safety concept, regardless of their I/O station. This flexibility allows operators to switch off actuators selectively. Other advantages include fail-safe communications, advanced diagnostics and hot swapping capabilities, which help to reduce downtime.
Siemens Simatic S7-1500 PLCs with built-in Profinet interface also played a major role in increasing operational speeds. The high-speed backplane bus, with its high baud rate and efficient transmission protocol, yields a crucial performance advantage for fast signal processing.
According to Simon Vancina, the IAS applications engineer and main robotics and PLC programmer, “The S7-1513F PLC was a great choice for this project because of its speed, range of available
I/O expansion cards, programmable safety controller functionality, relatively compact form factor and low cost.”
Siemens’ TIA Portal played a critical role in saving time and engineering resources when programming all of the PLCs and HMIs. The use of the TIA Portal shortens time to market by means of simulation tools, programmer productivity tools, and additional diagnostics.
“TIA Portal lets me write code the way I want to write it and switch from one programming language to another whenever I need to,” said Vancina. “For instance, with TIA Portal I could choose Ladder Logic to make simple logical sections easier to read, and then in the next line of code switch to something like Structured Text to implement more complex process controls or calculations. Nearly all PLCs allow the use of the various IEC 61131-3 programming languages, but TIA Portal lets you combine them in a unique and effective way. This is a very convenient feature that allows us to reduce our code development time and enabled us to get this system online much faster.”
With the project implemented, Felss Rotaform immediately saw benefits beyond its core goals. Big automotive manufacturers are always looking to test new products. They count on their suppliers to assist them in the testing process. The most responsive suppliers in the testing phase are often rewarded with new business.
The new manufacturing cell at Felss Rotaform was designed with product testing in mind. It can run six different new part numbers in a week, which takes an entire month on another cell.
The new cell is also much more advanced in its ability to detect defective parts. For manufacturers like Felss Rotaform, traceability plays a key role in reducing operating costs. The cell can help prevent defective parts from being shipped by detecting defective parts and placing them in a separate bin, even stopping the cell and alerting the operator if defects happen too frequently. If a defective part is shipped and found by the customer, it could mean the return of an entire shipment, costing the supplier hundreds of thousands of dollars.
IAS and Siemens are currently testing two similar robot cells that will be implemented in 2018 and include better maintenance tracking for more advanced digital manufacturing. The new system tracks how long a machine has been running and indicates when key critical parts are nearing their projected cycle time thresholds.
One solution being explored is MindSphere, a cloud-based open Internet of Things (IoT) operating system that serves as a connected platform with apps that provide a range of functions, such as reducing security risks and improving the availability of connected machines and plants.
In addition, the new system will incorporate predictive analytics to send an alert about potential issues to a cell’s master control. “The new system tells you what needs to be replaced and what type of part the system needs. You scan the part before you install it and it tells you whether it is the right part for that machine,” said Vancina.