New sensor for difficult tracking applications

Citation

(2004), "New sensor for difficult tracking applications", Sensor Review, Vol. 24 No. 1. https://doi.org/10.1108/sr.2004.08724aaf.001

New sensor for difficult tracking applications

New sensor for difficult tracking applications

Keywords: Laser scanning, Welding, Seam tracking

Weld seam tracking sensor manufacturer, Oxford-based Meta Vision Systems, has until now supplied equipment based on the projection of a laser stripe onto the surface of a fabrication. However, for about 10 per cent of applications, the technique suffers from reflectivity problems when fillet welding on shiny surfaces such as aluminium, for example, or when dealing with edges pre-machined for V-groove or multi-pass narrow gap welding. This precludes Meta sensors from being used in these types of application, many of which are complex, such as automated welding of pressure vessels, oil rig legs and off-road vehicles.

Now, for the first time, the company has introduced a product that works by scanning a high intensity laser spot across the joint, allowing seam tracking on shiny surfaces. Called A700, the sensor looks slightly ahead of the weld torch while an on-board linear camera, scanned in sync, captures a 3D cross section of the joint which the system software uses to determine its exact position before and during welding (Plate 1).

Plate 1 Meta has introduced a new laser scanning sensor, A700, whose forte is weld seam tracking in difficult applications

The sensor can be used with Meta's Laser Pilot MTR for robot applications and with the VistaWeld system on automated welding machines. Of particular note is that the image intensity is adjustable in real time and the frequency and scan width are both programmable, giving the user extensive control over the operating parameters for optimum results.

Benefits claimed as a result of fitting such a system include improved weld quality by eliminating human variability and error, set-up time and cost reductions as fixtures are not needed, increased productivity, less scrap and negligible requirement for rework. Depending on the application and shift patterns, payback time for investment in weld seam tracking can be as short as 6 months, as reported by some of Meta's customers which operate a combined total of 700 laser tracking systems – the largest worldwide installed base.

Most welding processes including GMAW, GTAW, sub-arc, plasma and laser are suitable for A700 tracking. The system can be optimised and programmed for a variety of joint profiles, depths and sizes, allowing it to tackle almost any application irrespective of the sensor stand off requirements, profile or surface type.

As with all Meta sensors, the A700 may be effectively applied in post weld situations such as tracking ultrasonic and X-ray inspection on flat and curved surfaces as well as other inspection and measurement applications where shape and profile need to be monitored. In combination with the VistaWeld system, additional functions performed include closed loop control, adaptive fill control, parameter measurement such as step height and gap, data logging and process history information.

For further information, contact: Meta Vision Systems Ltd, Oakfield House, Oakfield, Industrial Estate, Eynsham, Oxfordshire OX29 4TH. Tel: 01865 887900; Fax: 01865 887901; E-mail: sales@meta-mvs.com