Off-line programming trims time and cost of routing application

Citation

(2004), "Off-line programming trims time and cost of routing application", Industrial Robot, Vol. 31 No. 1. https://doi.org/10.1108/ir.2004.04931aaf.002

Off-line programming trims time and cost of routing application

Off-line programming trims time and cost of routing application

Keywords: Fanuc, Off-line programming, Automotive, Robots

In today's overtly fashion conscious automotive world, manufacturers ultimately rely on the consumer to apply the final judgment to their products. Focus groups exposed to a product before its launch can provide confirmation that the design team got it right – although more often than not, and the main reason for these pre-launch viewings, aesthetic and functional shortcomings are identified.

To any manufacturer, the implications of product modifications are extensive and in particular in the automotive world the chain of supply affected has costly time repercussions along its length. Concurrent build of automation systems to a commissioned state is not always possible without a “final design” component being available. This causes a time delay in component availability which inevitably compounds down the chain.

A partnership of three companies Intier Automotive, Fanuc Robotics and B4 (Lichfield) Limited, has addressed one related problem area that enables “time to market” to be reduced dramatically. Off-line programming (OLP) of robotic systems is nothing new when moving from point to point – spot welding robots on framing lines have been OLPed for many years – however, OLP of contour following applications, accurately following a precise path, has rarely moved out of the research world.

Intier Automotive is a world leader in the integration of complete vehicle interiors. A first tier supplier to manufacturers including Jaguar, Rover, Ford and BMW, Intier's product is arguably the most visible to the critical eye of the end user. “The company has always been an “early adopter” of automation systems; we understand the essential part it plays to ensure consistently high quality,” commented Roger Larcombe, Intier's Engineering Projects Manager.

Faced with ever shortening lead time demands from customers, Intier invested in its first robotic machining systems, 12 months back. The first two systems, engineered by Fanuc Robotics, were designed to trim the foam-injected instrument panel mouldings of the new Range Rover, code named L30. This installation was a radical change from previous trimming techniques which used relatively expensive and inflexible punching dies or water jet cutting equipment. The new robotic cells allowed flexibility to re-programme, accommodating design changes (Plate 2).

Plate 2 Trimming the door interiors

“The cycle times using a robot cell are longer than using a punch press but we're easily able to justify the new approach in the luxury car market. Volumes are relatively low and also we accommodate multiple derivatives without the need for additional high cost tooling,” explained Larcombe.

The opportunity to implement OLP came when Jaguar Cars nominated Intier as supplier for door interiors for its new “flagship” model, code name X350. Following an extensive feasibility study Intier drove Jaguar to consider the OLP approach and its potential benefits in the traditionally “high level of change” product environment.

Figure 1 The robot cells comprising a FANUC M-710i and fixtures were modelled using IGRIP

Intier took the decision to invest in more robot cells, but needed to identify a shorter route to the system commissioning stage. Larcombe explains, “Even though we have the cost and flexibility benefits with the robotic system, the down side is programming the part profiles which could not be started, using conventional techniques, until an approved component became available. This can be many weeks while tooling is being manufactured and several days of robot programming when mouldings finally become available”.

“Our first decision, after going out to tender, was to stay with Fanuc Robotics as system integrators. Our requirements had specified OLP and initial research had demonstrated the absolute performance characteristics of Fanuc's machines. We felt particularly comfortable with Fanuc's technical support and its effectively “buying in” to the risks – as calculated as they were.”

At this stage, Fanuc introduced B4 (Lichfield) Ltd, an industrial simulation specialist, to the project. As users of Delmia's IGRIP and the UK representative for Krypton metrology products, B4 had previously provided consultancy services to both Fanuc and Intier.

Both robot cells, comprising a FANUC M-710i robot, the fixtures, routing tools and guards, were modelled using IGRIP (Figure 1). The CAD data of the door panels were then translated in IGRIP and the models generated were superimposed in their nominal positions in the cell.

After defining the cell sequence and programme commands in IGRIP, the profiles of the panel were recorded together with the robot arm positioning mode at specific points. Simulation of the cell followed this stage and unlike conventional system build methods, the robot arm was driven around the cell, for the first time, in its virtual world. Any unreachable locations and collision points identified at this time were safely corrected by altering the programme without hardware cost involved.

Julian Cashman, Fanuc's Project Manager, explains “As the programme was created to the many CAD drawings relating to components in the “virtual cell”, compensation for the cell in the “real world” was necessary. To enable this, B4 used its Krypton metrology system to measure the robot and its environment, finding the nominal car reference frames in the real world referenced to the real robot”.

“As the simulated robot programmes were developed from the same reference system, all that was needed on the shop floor was to update the reference frames in the robot controller from the nominal to the measured frames. This process successfully aligned the robot programmes from the perfect CAD world to the real installation on the shop floor.”

The system build and programming ran concurrently with tool manufacture and the first panel to be cut on the system was well within tolerance at all points, effectively removing the need to programme locations manually.

Intier and its partners have risen to the challenge of OLP and in doing so they have illustrated that time to market can be dramatically reduced, in this case by several weeks, with high resultant cost savings and project programme benefits. When future modification requests are made, the cells will save more time as new punch tools will not be required and OLP will be utilised immediately and new CAD data become available.

Driven by increasing confidence in the new approach, Intier is considering to implement further cells.

As maturing growth markets inevitably become more competitive and customers demand greater choice, manufacturers can expect “time to market” demands to increase – OLP of robotic systems will no doubt become another every day “must have” tool to ensure any opportunity for making profit.

For further information, contact:

Maurice Hanley, National Sales and Marketing Manager, FANUC Robotics (UK) Limited. Tel: 024 7663 9669; E-mail: sales.fruk@fanucrobotics.co.uk; Web site: www.fanucrobotics.co. uk;

Further reference sites: www.b4qroup.com; www.intier.com