PLCs Do Heavy Lifting For Better, Safer Cranes
Cranes do the heavy lifting in a broad range of applications, hefting anything from raw materials to finished goods. Unfortunately, their work doesn’t come without danger – accidents that cause deaths and serious damage remain too common.
Several years ago, the Georgia Institute of Technology set up a crane research program to devise technologies and techniques that reduce vibration, sway and other issues that make it difficult to control payloads as they’re moving. That effort led to a spinoff – three Georgia Tech associates formed CAMotion Cranes in 2008.
The startup proved to be a success story, highlighting the myriad benefits that come when professors, students and industry work together. Georgia Tech was among the companies that received hardware and software through the Siemens Cooperates with Education program to develop these solutions. Both GT students from the Mechanical Engineering program and the CAMotion team researched solutions leveraging Siemens SIMOTION, SINAMICS and SIMATIC technologies.
CAMotion Cranes products sold well, prompting an acquisition by PaR Systems Inc. in 2013. There’s no shortage of case studies that demonstrate the safety benefits of the company’s tools.
“An aluminum manufacturer had to move 50-ton ingots to several stations for different processes,” says Khalid Sorenson, senior fellow at PaR Systems Inc. “They had a manual operator on the crane, and there was a lot of load swing, where the ingots often slammed into equipment. The user approached us and we automated the process so there was much less damage to their infrastructure and their operators didn’t need to be so highly trained.”
He described another application at a site that assembled large earth moving equipment. Cabs and the chassis were built on different lines, and cranes were used to lift the cab and mate it with the chassis. The cab rotates during operation, so precision was important.
“It’s a very precise maneuver to get everything to mesh so the gears work,” Sorenson says. “If you did it manually and didn’t control the swing, the gear wheels could hit each other and cause damage. We use automated steps to make sure that doesn’t happen.”
PaR offers four principle technologies. The first is an anti-sway tool called Expert Operator. The second, Auto Move is a system that automates some tasks so operators don’t have to control every function. Crane Vision helps cranes avoid side loading and prevents adverse motion when problems such as snagged payload could cause problems. And finally, an anti-collision and collision prevention offering is called Safe Move.
Expert Operator has gained a lot of acceptance because it provides anti-sway controls without sensors. That’s important because the vast majority of the company’s business is from retrofits onto equipment in the field.
“We’re able to suppress vibrations on the crane whether it’s only moving an empty hook or carrying a heavy load,” Sorenson says.
He explained that there are a number of ways to control each different configuration of weight and size and move it without the vibrations that help cause sway. When the Georgia Tech associates looked at the solutions for a number of different configurations, they realized that some of them overlapped. They focused on these widely-applicable solutions when they developed Expert Operator.
“Our algorithm looks at all the solutions that overlap and picks the fastest one from that group of solutions,” Sorenson says. “We want to be able to move the crane without vibration in the most efficient manner. It’s easy to avoid sway if you move at an inch per hour, but that’s not very efficient.”
Programmable logic controllers are at the core of the four products. Siemens equipment was used from the outset of the research programs.
“We are part of the Siemens Cooperates with Education program, they gave us a lot of equipment,” says William Singhose, an associate professor at Georgia Tech and co-founder of CAMotion Cranes. “We started working with it and never had any issues that caused us to even consider changing.”
The unique capabilities of these PLCs help the company offer cost-effective systems. For example, the timing is easy to adjust, which helps PaR design a single platform that can be installed on many different cranes.
“The Siemens platform lets us dynamically change cycle times at run times,” Sorenson says. “We do this because our anti-sway algorithm is based on cycle time. To put it on different equipment, we have to alter the cycle time. Other PLC platforms restrict you to simplistic functions. Siemens provides a lot of power and control capabilities for programmers.”
The combination of Siemens hardware and the creativity of the founders has saved a diverse cross section of companies a lot of money, and possibly saved lives. Reducing the havoc that can occur when a crane’s empty hook swings wildly can be significant. When heavy payloads go out of control, the potential for major mayhem skyrockets.
The Georgia Tech associates and their partners at PaR are continuing to help ensure that crane operators can work with less stress. That’s helping these employees and their companies improve efficiency and safety. And it’s proving that innovation is still flourishing, especially when it’s abetted by corporations that give ambitious students the tools they need to create new solutions.Have an Inquiry for Siemens about this article? Click Here >>