Multitasking motion control software accelerates introduction of chocolate bar flow-wrappers

Citation

(2002), "Multitasking motion control software accelerates introduction of chocolate bar flow-wrappers", Assembly Automation, Vol. 22 No. 2. https://doi.org/10.1108/aa.2002.03322baf.005

Multitasking motion control software accelerates introduction of chocolate bar flow-wrappers

Keywords: Motion control, Food

Sweet success for advanced new motion control software

Baldor has supplied three multi-axis motion control systems to Premier Packaging. The systems are being used to upgrade three Cadbury chocolate bar wrapping/cartoning machines. The refurbished machines are destined for Canada, where Cadbury is introducing flow wrappers on its popular Dairy Milk bar, in place of the traditional foil wrapper and paper label. The project was extremely time sensitive, and Premier Packaging refurbished the machines in around four months, and imposed an even tighter schedule on its sub-contractors - which Baldor met by employing the multi- tasking features of the Mint motion control language.

Baldors role in this project was to provide a motion control subsystem to transfer and carton flow-wrapped chocolate bars. Three servo motor axes are employed for this. One controls a 'paddle' which sweeps bars through 90 degrees into a flighted conveyor. Two further axes collate bars into groups on a feedchain, and then actuate paddles which transfer the group into a 'lowerator' - simultaneously moving the lowerator on a step for depositing the group into a carton. The system is controlled by the Mint- compatible NextMove-BX, a standalone motion controller which comes with I/O, allowing it to also handle the various sensors in this application.

Development time was greatly reduced by means of Mint's multi-tasking capability. Baldor used this feature to divide the transfer and cartoning process into five separate tasks: start paddies, stop paddles (for rejects), feed feedchain, lower lowerator, and manage the man-machine interface. These software tasks were then worked on, in parallel, by several application engineers, allowing a software prototype to be written and trialed in less than a week. This design was then optimised and integrated with the hardware - including three BSM brushless AC servo motors, three Flex drives, a NextMove BX motion controller and various sensors - and delivered to Premier Packaging for commissioning (Plate 5).

Plate 5 The Baldor motion controller uses multi-tasking software to control three servo motor axes and the man-machine interface on this chocolate bar flow wrapping and cartoning machine. One of the tasks controlled by the Baldor motion controller: flow-wrapped chocolate bars are swept through 90 degrees by a 'paddle' into a flighted conveyor which takes them onto the cartoning process

"This project demonstrates that it's possible to refurbish older mechanically- based packaging machines easily," says Peter Broughton, Sales Engineer with Premier Packaging. "In this instance the machines were renovated with advanced electronic controls supporting software-based reconfiguration, for an outlay which is just a small fraction of the cost and time it would have cost to develop a new solution from scratch. For us, speed was an overriding objective, and Baldor's application engineering service played an important role in keeping the project on track". The three new machines are capable of flow wrapping and cartoning around 1000 bars per minute.

The availability of ready-to-use application examples played a key role in Baldor's rapid turnaround of the transfer and cartoning system. This was simplified by the high level 'keywords' in Mint, which offer a ready- programmed basis for many commonly required movements. Amongst the keywords used in this project was one of the FOLLOW group to control the sweep paddle; an electronically clutched gear ratio is implemented to allow a following task with ramped starts and stops via the FOLLOWMODE keyword. FLY is also used for control of the feedchain axis. This keyword provides a flying shear action which gives an idealised multi-segmented motion profile for controlling the action of the lugs that collate the bars into groups.

"Mint's multi-tasking trimmed several weeks development time off this project," adds Stuart Bratton, Project Engineer for Baldor. "The asynchronous aspects of the axes on this process would have made it quite a complex problem to deal with using traditional software techniques. This kind of software advance is key to reducing the time to market for complex projects, as OEMs build more and more features into their machinery."

He also noted that NextMove-BX's built in I/O and fieldbus capabilities allowed the motion controller to provide a complete solution, including the user interface and the inputs and outputs needed for the various sensing tasks. ln this instance, one of the controller's dual CAN ports is used to interface to a remote man-machine interface panel using the CANopen protocol.

For further information please contact: Eddie Palmer, Baldor, Mint Motion Centre, 6 Bristol Distribution Park, Hawkley Drive, Bristol, BS32 OBF, UK. Tel: +44 (0) 1454 850000; Fax: +44 (0) 1454 859001; E-mail: eddie.palmer@baldor.co.uk