Ways to make packaging machine design more flexible
Cover story: Control system flexibility, a need across all industries, includes the ability for users to easily re-use code from one controller to the next and scale from a simple two-axis machine to a high-axis coordinated motion system that runs on the same software, reducing hardware costs, training time, and troubleshooting.
In the packaging industry, companies need flexibility to meet the evolving demands of the market-different product looks, quantities, and sizes.
This translates to a range of machine speeds to produce different product sizes and shapes at the same level of quality. It also introduces the need for automatic changeover procedures to accommodate different packaging material or fill product types.
These attributes have to be clearly communicated between the end user and the original equipment manufacturer (OEM) or machine builder to create a machine that will meet the end user's changing needs for years to come.
Some of the most important elements in control system flexibility include software and controller hardware. A scalable solution is needed for the hardware with common software used across the differently scaled solutions. The users should be able to easily re-use code from one controller to the next.
This is a common need across all industries: having a low-cost solution for a simple two-axis machine and an economical solution for a machine with a high-axis coordinated motion system that runs on the same software, is important to keeping costs down. The ability to scale along a product line of controllers reduces hardware costs, training time, and troubleshooting efforts.
Another need is finding pre-made tools for their industry requirements. It is difficult to design a system for a packaging machine with a controller that's designed for the process industry. The OEM needs solutions from providers who understand their industry, know the needs of the machine, and have software tools pre-built to accommodate those needs.
The design of the control cabinet also is important in flexible design. Using an integrated motor and servo drive system, with the drives mounted out of the cabinet and on the frame of the machine, addresses this need. If an OEM wants to design a control system for low axis count but use that same control cabinet for a system with dozens of axes, adding more drives to the control cabinet for additional motion axes means more cabinet space, more parts, and more time to build, along with multiple design iterations.
With some systems, it also means adding unnecessary components like back-planes and extra slots that may or may not be used, to add flexibility to the design, but at a much higher cost. An integrated motor and drive system allows for additional servos without changing the design of the control cabinet. Additional servo drives can be added to the system by modifying the existing chain of servos already on the machine. This also allows for the same control cabinet across multiple families of machines and frees the cabinet design from the needs of the machine itself.
There are packaging OEMs that manufacture four or five lines of packaging equipment, and each one of those product lines have multiple machine sizes. By using a cabinet-free servo drive solution, they are able to standardize the control cabinet across all machines. Each control cabinet is the same size, and the components are largely the same, even across the different product lines. This reduces costs significantly because the bill of materials is roughly the same for all machines.
Design flexibility also reduces the need to maintain inventory of parts. When assembly and field technicians are accustomed to building and working with the same system, assembly time is less and errors are fewer. Familiarity also helps field service technicians to quickly find problems if they arise.
- Allen Tubbs is product manager, electric drives and controls, Bosch Rexroth Corp. Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering, firstname.lastname@example.org.
- Machine designs can be simplified with control system flexibility.
- Scalable software and hardware and reusable code help.
- Compatible automation components also ease machine design time and maintenance.
When designing a machine and considering controls, are scalability needs considered, beyond one machine?
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