Good vibrations helped make the Beach Boys famous, but in industrial environments, vibrations are anything but good. Minimizing unwanted motion can bring many benefits, improving production speed and reducing wear and tear on manufacturing equipment.
The Challenges of Unwanted Motion
Many problems can occur when there’s unwanted movement in automated machinery. Production times can be slower when processes must be slowed to accommodate vibration, such as when bottles are transferred from a production line into a case that’s moving along a conveyor belt. And over time, minor shaking can cause components to fail sooner than desired.
These problems are greatest in heavy equipment, such as gantries and fast-moving systems that handle materials.
For years, one of the most common techniques for reducing vibration has been to make moving components more rigid. The more rigid a moving arm is, the less it will shake. But this design technique has been not well suited to the primary goals of recent years: making machines that are smaller, lighter and less expensive to produce. OEMs recognize that when the size of moving parts is reduced, today’s machines can be moved with smaller motors. However, even though a smaller motor will trim the cost, weight and size of equipment, it won’t address the problem of unwanted mechanical deviations.
Suppression Options with Auto Tuning
The solution: vibration suppression. Vibration suppression techniques can be used for effective movement control while reducing unwanted shaking. With this approach to vibration control, equipment designers are able to give customers smaller, lighter and less expensive machines that run as fast or faster than their predecessors.
It’s relatively common to gain a 20% performance improvement when vibration suppression is added. It’s not uncommon to experience gains in the 50% range, notes Mitsubishi. Removing the vibration, reduces the tack, or settling time. Lowering the tack allows the machine to run faster while still maintaining extremely high accuracy.
However, it’s difficult to adjust all the motors in advanced equipment. As with the machines themselves, not all vibration suppression systems are created equal. Often, it’s difficult and time-consuming to calibrate all the motors and get the machines running smoothly, without much mechanical deviation.
If those vibrations aren’t well controlled, the entire machine will undergo unwanted movement, which can cause internal components to degrade at a faster pace. The heavier the loads, the more likely it is that vibrations will carry into the machine’s base.
The most efficient machines use automated tuning capabilities to adjust themselves. Auto tuning is far simpler than adjusting each motor in a complex machine. Also, auto tuning of these motors will dramatically reduce movements on the moving parts, so the body of the machine won’t have to endure mechanical deviation. It’s also easier to accommodate production flex. Auto tuning technology makes it easy to set up equipment and make adjustments when loads change, for example, when bottle sizes go from 12 to 16 ounces.
Tuning is a specialty at Mitsubishi. The company has honed its techniques, either letting operators make adjustments by pressing a single button (One Touch Tuning), or making use of Auto Tuning, where the amplifier continuously adjusts for optimal performance. Taking it one step further, tuning also allows the system to detect and remove unwanted vibration from the entire machine itself. This simple one button setup procedure is a boon for all users, but it’s especially helpful for those who often need to adjust equipment daily.
This simple setup step triggers a complex process that uses several filters to minimize unwanted motion. Many tuning technologies use only a couple filters. Mitsubishi systems employ five or more filters to maximize stability. Using more filters helps provide smooth operations in a wide range of conditions, making it easy for manufacturers to use the equipment for many different applications.
Such capabilities are an important factor in today’s fast-changing production environments, where smaller lot sizes are becoming more common. Benefits also are seen with long production runs, since using a number of filters ensures that vibration-free operations can be maintained for long periods.
Positioning for Profitability
When companies employ filtering technologies that have been well-tested in a host of real-world production facilities, they are likely to see solid improvements in productivity. At the same time, many plant managers will enjoy reductions in unplanned downtime caused by component failures in equipment that has excessive vibration.
Better vibration control presents a winning combination for any industrial automation facility: Reduced setup time, faster performance and fewer component failures can bring significant improvements to the operation’s bottom line.
See a demo of Mitsubishi's vibration supression approach here.
