Technology inside: Bacon slicer motion control

The Delta motion controller is programmed to do closed-loop position control using encoder feedback from the servo drive that moves the bacon slab into the cutting blade. The RMC sends a +/- 10 V analog output to the servo drive that moves the bacon slab.

10/29/2012


Figure 2. The RMC75E motion controller from Delta Computer Systems controls up to two motion axes simultaneously. Courtesy: Delta Computer SystemsTo improve the performance of the bacon slicer, Titan Slicer executives called in an experienced control system integrator, Tui Technology of Rotorua and Whangarei, New Zealand. Tui’s engineer, Malcolm Jones, had worked with motion controllers made by Delta Computer Systems Inc. of Battle Ground, Wash., in the past and came up with a new control system design for the bacon slicing machine using a Delta RMC75 motion controller. A PLC was still used in the new design, but for less time-critical functions, such as issuing on/off controls for the blade motor.

The Delta motion controller is programmed to do closed-loop position control using encoder feedback from the servo drive that moves the bacon slab into the cutting blade. The RMC sends a +/- 10 V analog output to the servo drive that moves the bacon slab.

The RMC’s fast cycle time allows the cutting operation to produce repeatable results. At 1600 rpm, there is a 38 ms time window in which to decide whether the bacon slab is to be moved forward to set up for the next cut or backward to clear the blade. The 1 ms loop time in the RMC running the Advanced Gear Move instruction enables repeatable and accurate slice thickness.

The Advanced Gear Move is just one of a number of gearing functions supported by the RMC 75. Whereas simple linear relationships can be set up between master and slave (using the RMC’s Gear Absolute function), an Advanced Gear Move operation lets the user program a nonlinear relationship between master and slave. For example, Figure 4 shows an Advanced Gear Move operation where the motion of the slave is dictated using a fifth-order polynomial equation. Most of the RMC’s simpler gearing commands allow the designer to choose the exact gear ratio to be used by specifying a numerator and denominator when the motion step is programmed.

Malcolm Jones said, “Where the RMC pays for itself is in the control of the first slice to meet our critical design goal.”

To program and tune the motion, Malcolm Jones used Delta Computer Systems’ RMCTools software, which includes a Plot Manager that displays trend or capture plots for key motion parameters versus time. Figure 4 is a plot that was produced by the Plot Manager that shows the operation of the advanced gear move instruction. RMCTools software also includes a Tuning Wizard, which enables quick and easy setting of control loop parameter gains for optimizing motion. “Using the Delta tools, I was able to prove that the system had enough timing margin to handle the higher cutting speeds,” said Jones.

www.deltamotion.com 

- Brad Smith is regional applications specialist, Delta Computer Systems Inc. Edited by Mark T. Hoske, content manager CFE Media, Control Engineering and Plant Engineering, mhoske@cfemedia.com.



No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 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...
2016 Product of the Year; Diagnose bearing failures; Asset performance management; Testing dust collector performance measures
Safety for 18 years, warehouse maintenance tips, Ethernet and the IIoT, GAMS 2016 recap
2016 Engineering Leaders Under 40; Future vision: Where is manufacturing headed?; Electrical distribution, redefined
SCADA at the junction, Managing risk through maintenance, Moving at the speed of data
Safety at every angle, Big Data's impact on operations, bridging the skills gap
The digital oilfield: Utilizing Big Data can yield big savings; Virtualization a real solution; Tracking SIS performance
Applying network redundancy; Overcoming loop tuning challenges; PID control and networks
Driving motor efficiency; Preventing arc flash in mission critical facilities; Integrating alternative power and existing electrical systems
Package boilers; Natural gas infrared heating; Thermal treasure; Standby generation; Natural gas supports green efforts

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

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.
This article collection contains several articles on the vital role of plant safety and offers advice on best practices.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me