AutoFair2017-Day1-Article1
AutoFair2017-Day1-Article1
AutoFair2017-Day1-Article1
AutoFair2017-Day1-Article1
AutoFair2017-Day1-Article1

Get to the core of safety and productivity

Nov. 15, 2017
Proper safety system methods, tools, design and analysis address the risk while providing the value in productivity
Safety solutions from Rockwell Automation are about making machines safer and more productive at the same time. There are two parts to safety productivity. One part includes the tools used during the risk assessment, design and validation phases. The other part is on the actual operations side of things, with smart safety, and there are analytics for that.

“People will pay money to reduce risk, but the payoff is always on the productivity side, which is where the value is," said Patrick Barry, business development manager at Rockwell Automation during a Safety Solutions booth tour at Automation Fair in Houston. "Rockwell Automation's safety solution is focused on making a smart machine more productive, more reliable and easier to repair."

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One of the most important things when you start safeguarding a machine is understanding the human interaction, continued Barry. "If you don't understand what operators are doing with the machine, you risk choosing the wrong safety products or using the wrong safeguard," he said. "If you don't pick the right safeguard, the risk is it will be used, but the machine productivity will suffer or someone may choose to defeat it."

This is one of the reasons why Rockwell Automation is pushing the assessment stage of the safeguard process—the first step of the Functional Safety Lifecycle. "This risk assessment needs to be done very early in the design process," said Steven Ludwig, commercial program manager at Rockwell Automation. "It's better to design risks out of the machine and create a productive design than to build a machine and then make it safe. The key is to make the machine as productive as possible while still keeping workers safe."

Safety tools

Regardless of the safety standard, they all basically use the methodology in the Rockwell Automation Functional Safety Lifecycle, said Ludwig. "To help keep customers from getting stuck in the safety process, Rockwell combines its expertise in safety with hardware and tools," he explained.

The first step of the Functional Safety Lifecycle is the risk or safety assessment, for which Rockwell Automation has a software product called Risk Assessment Software Win (RASWin). The RASWin product assists management with the safety process and gives the user consistent documentation at completion. It helps the user to perform a risk assessment on a machine, develop a functional requirements specification and perform safety system validation.

Safety documentation at the completion of a project is also important. "Instead of having homegrown safety documentation, the RASWin tool provides a standard method," said Ludwig. "If an injury does occur, it can provide due-process documentation. This documentation can also be used as a sales tool, helping the customer to understand the included safety functionality in OEM and custom equipment, a common best-in-class feature. It also helps to make an OEM more self-sufficient in safety, and safety is a driver for operational excellence."

Following proper safety methods can make a machine more productive, and there are tools to improve design productivity, as well. "These tools reduce the time it takes to design a safety system," said Barry. "It's not just the engineer's time, it's ensuring that the calculations and safety function are done and implemented properly. It ensures a safety compliant system."

The RASWin tool works with some other free tools from Rockwell Automation for design, such as Safety Automation Builder, which is used to simplify machine safety design. These tools guide the user though safety-system layout, hardware selection and safety-level analysis.

With the safety system designed, the tools point the way to the company’s pre-engineered safety functions for machines. This includes drawings for use in schematics, product configuration and ladder-logic examples and HMI faceplates. These tools and examples reduce development time and costs.

Safety analytics

"On the operation side, Rockwell Automation's safety solution also includes analytics that can help to reduce mean time to repair (MTTR) issues, for example, and track uptime on a machine making it more productive," said Ludwig.

Safety is part of The Connected Enterprise. "From a safety prospective, you have to understand what the expected operation of the machine is, as a first step, and that is done with the risk assessment," said Ludwig. "With that understood, analytics create usable data, allowing you to compare the actual operation with the expected operation to understand compliance, worker behavior and related activity."

For example, during risk assessment and design, an assumption for how often a safety door will be opened may be made. "With analytics, we can now determine if the assumption was correct," said Barry. "More use than expected can reduce product life and may affect the overall reliability of a safety system. With analytics, all safety functions identified during the risk assessment are compared to real-world data. If a safety guard isn't opening when it should be several times a shift, it could indicate that the safety function is being bypassed. If it is being used too much, there may be other issues."

Productive machine safety

"There are alternative measures to lock-out, tag-out procedures," continued Barry. An example of this was on an automated machine in the Rockwell Automation Safety Solutions booth. The machine included two coordinated Fanuc robots with part handling and assembly tooling and is used as a training tool by universities and manufacturers.

"The safety features on the machine were designed to keep the machine both safe and productive," said Barry. "The design allows operators to interact with the robots in a more productive manner. It demonstrates safe speed and position methods using a Allen-Bradley GuardLogix controller, SafeZone safety laser scanner and GuardShield safety light curtain on a machine to keep it up and running. The safety laser scanner detects the approach of an operator into a warning area.”

When the operator enters the area, the robots slow down and a warning signal is activated, but the machine remains productive. If the operator continues to approach the machine, interrupting the light curtain, the machine stops.