Mechatronics is really nothing new. Combining mechanical and electrical engineering methods, tools, designs and components has been done for several decades at least. Automation, control and software elements have been mixed into mechatronics projects for many years. So what else is new?
Well, even though mechatronics has been around for a while, few users had the funding and computing power needed to gather and analyze enough data to make mechatronics practical at their design and build stages. And, even if they had enough resources, most mechatronic modeling tools didn't include enough physical, dynamic data to produce useful representations that could help design engineers and builders make better decisions. Many builders argue it's still better to build and test physical prototypes because eventually they will have to do it anyway.
What's happening lately is that mechatronics is getting simpler, easier, affordable and practical for everyone. However, it still requires users to make some significant mental shifts, such as truly cooperating with other engineering disciplines and considering how their specialties affect overall systems.
"Mechatronics can be as simple as an automatic urinal flusher or garage door opener, or it can be as complex as the Mars rovers or the Cassini probe, which are really just giant mechatronics platforms," says Kris Jentzsch, project engineer at Pacific Gas & Electric's Diablo Canyon Power Plant (DCPP), who has B.S. and M.S. degrees in mechatronics. "In the U.S. Navy and nuclear industry, we refer to mechatronics as instrumentation and control."
The Bigger Picture
Apparently, where and how the word "mechatronics" is used isn't as important as how much collaboration it can achieve. For instance, Jentzsch reports that he's been working with students at Cal Poly to build a training skid with two tanks, one heater, transfer lines, valves, sensors and other components. However, their initial proposals were written separately, and didn't include many of the interdisciplinary bits and pieces the skid was going to need, such as drain valves for low-flow areas, load calculations for breakers, chemicals needed to control corrosion, and other basic issues.
"This happens because the mechanical side says it doesn't do electronics, and the electrical side says it doesn't do mechanics," Jentzsch explains. "So the mechanical side doesn't consider the temperature sensors the skid will need, while the electrical side buys the RTDs, but doesn't consider how to mount them. However, mechatronics means working together more, putting in different components, and seeing what they do to the whole system. We're still trying to get the skid built, but we haven't resolved all these issues yet."
John Pritchard, global marketing manager for motion control and design at Rockwell Automation, adds, "Our litmus test for mechatronics asks: When mechanical designers are deciding what to do and specify, are they really considering the impact on the electronics and controls, and vice versa?"
Profiles Add Dynamic Motion
No doubt the biggest advance in mechatronics recently is the addition of sophisticated and dynamic motion data to its formerly static CAD/CAE designs and performance profiles, which better reflect the reality of how machines operate.
For example, engineers at Kliklok-Woodman in the U.S. and U.K. recently needed to design and add a more durable flap kicker to their company's high-speed Celox end-load cartoner and sealer (Figure 1). The kicker deflects open the flaps of each carton, so packaged foods can be smoothly loaded into the cartons. However, the kicker, driven by pneumatic cylinders, tended to wear down more quickly at high speeds, and one food manufacturer needed to run at a very fast 325 cartons per minute. So Kliklok's engineers began working on a servo-driven kicker, and used Rockwell Automation's Motion Analyzer modeling and simulation software to identify and digitally test motion solutions with the right speed and throughput. Motion Analyzer recently was tied to Dassault Systèmes' SolidWorks 3D mechanical CAD software via an application programming interface (API) that provides a live link between them.
"It made complete sense to use Motion Analyzer to do the initial motor sizing because the motion of the flap kicker is solely dependent on size of the particular carton and its flaps," says Florin Bruda, Kliklok's mechanical engineer. "I could plug in the specific end-user requirements, quickly test different servo motor sizes to find the right one, and avoid testing each option on a physical prototype."
To do this, the engineers created motion profiles of the servo-driven kicker in Motion Analyzer, and transferred them to SolidWorks to visualize the machine's movement. Next, SolidWorks calculated the torque and force required to move the load through its profile, and Motion Analyzer used the results to size and select the right motors and drives. The engineers estimate they reduced design time by about a third by using Motion Analyzer and SolidWorks together.
National Instruments has worked with Dassault for several years to integrate NI's motion control design tools based on its LabView and SoftMotion software with SolidWorks' mechanical simulation capabilities.
Common Language and Culture
One of the surest ways to combine mechanical, electrical and controls engineering more easily and more affordably for more users is to push them to use the same language and software, which then drives understanding and cooperation.