Technologies for filtering mechanical resonance with intelligent servo drives

Control machine resonance—the “white noise” generated by machine motion—in servo-driven printing and converting machines. Bosch Rexroth intelligent servo drives provide advanced programming tools, diagnostic features, and integrated filtering capabilities to combat mechanical resonance.


Figure 2 - White noise test identifies resonant frequency. Using Rexroth’s Drive-Integrated Command Value Generator, apply a noise signal to the torque command input of the motor. Courtesy: Bosch RexrothWith Rexroth IndraDrive intelligent servo drives, the effects of resonance can be overcome without compromising performance or investing additional resources. To illustrate the implementation and benefits of this solution, the Rexroth IndraDrive converter drive can be used to control a synchronous ac motor.

The first step is to identify the resonant frequency by doing a “white noise” test. Using Rexroth’s Drive-Integrated Command Value Generator (Figure 2), a noise signal can be applied to the torque command input of the motor.

While the motor is vibrating, capture one second’s worth of data and upload results to the oscilloscope window in Rexroth’s IndraWorks engineering suite and displayed as a function of time.

In addition to a smoothing time constant (low-pass filter), the IndraDrive offers a host of additional filtering options.

For more about this tutorial, and for Figures 1, 3, 4, 6 and 7, see: Use intelligent servo drives to filter mechanical resonance - linked at the bottom of this article.

Figure 5 - Based on the results from the white noise test, apply the filter with a center frequency of 1075 Hz and a bandwidth of 100 Hz. The default value of 100 Hz usually works well. As soon as the filter is activated, the audible humming is greatly re- Brian Schmidt is senior applications engineer, food, packaging and printing industry sector, Bosch Rexroth Corp. Edited by Mark T. Hoske, content manager CFE Media, Control Engineering and Plant Engineering


No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2013 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
A cool solution: Collaboration, chemistry leads to foundry coat product development; See the 2015 Product of the Year Finalists
Raising the standard: What's new with NFPA 70E; A global view of manufacturing; Maintenance data; Fit bearings properly
Sister act: Building on their father's legacy, a new generation moves Bales Metal Surface Solutions forward; Meet the 2015 Engineering Leaders Under 40
Cyber security cost-efficient for industrial control systems; Extracting full value from operational data; Managing cyber security risks
Drilling for Big Data: Managing the flow of information; Big data drilldown series: Challenge and opportunity; OT to IT: Creating a circle of improvement; Industry loses best workers, again
Pipeline vulnerabilities? Securing hydrocarbon transit; Predictive analytics hit the mainstream; Dirty pipelines decrease flow, production—pig your line; Ensuring pipeline physical and cyber security
Upgrading secondary control systems; Keeping enclosures conditioned; Diagnostics increase equipment uptime; Mechatronics simplifies machine design
Designing positive-energy buildings; Ensuring power quality; Complying with NFPA 110; Minimizing arc flash hazards
Building high availability into industrial computers; Of key metrics and myth busting; The truth about five common VFD myths

Annual Salary Survey

After almost a decade of uncertainty, the confidence of plant floor managers is soaring. Even with a number of challenges and while implementing new technologies, there is a renewed sense of optimism among plant managers about their business and their future.

The respondents to the 2014 Plant Engineering Salary Survey come from throughout the U.S. and serve a variety of industries, but they are uniform in their optimism about manufacturing. This year’s survey found 79% consider manufacturing a secure career. That’s up from 75% in 2013 and significantly higher than the 63% figure when Plant Engineering first started asking that question a decade ago.

Read more: 2014 Salary Survey: Confidence rises amid the challenges

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.