Sensor technologies enhance factory operations


Technical Insights' sensor technology alert

Palo Alto, Calif. March 16, 2004 A new-age simulation engine that remotely controls factory processes in real time using data from sensors is likely to be the next big thing in assembly line operation management.

The engine's unique visualization tool helps cut out interferences from human errors, inadequate materials, or logistic planning gone awry by virtually representing the manufacturing facility for itemized monitoring.

The sensors read the changes on the factory floor and convert it into data for a configuration event analyzer that converts it into 3-D animation events. To facilitate system improvements, the engine's Singapore-based inventors have even built a new visualization device, which enables even novice users to operate the machine.

For the system to be fully effective, discrepancies in the visualizers' predictions and the data relayed by the engine will have to be sorted out. Interaction techniques are vital because the modifications made on the simulated model will be carried out on the actual factory floor.

"Scientists are working on new techniques that will display confirmed, predicted, and corrected states in a single cyber model," states Technical Insights Analyst Anand Subramanian.

Meanwhile in Europe, a new class of sensors called contactless capacitive angular-position sensors with accuracy of up to 0.03 degrees variation over a full-circle range has given industrial precision applications a shot in the arm. These sensors can detect angular positions for any application and even measure linear positions by combining linear movement and angular sensing.

With capacitive sensors using superior dielectric rotors, researchers are considering them as an alternative to the more prevalent optical encoders in select applications. The easy design of the electronic interface also permits uncomplicated production, as it can be assembled using off-the-shelf components.

While difficult angles are being taken care of, scientists in France are developing systems for accurate measurement of flat surfaces' dimensions. The success of optical techniques such as holographic interferometry and shearography is limited to small objects. For larger ones, a relatively inexpensive 3D, non-contact system with uniformly high resolution is being created.

The sensor system operates on a customized, motorized gantry, where every axis is controlled using a separate cable. The optics comprises a laser diode with anamorphic beam-conditioning optics and a charge-coupled device chip to capture the beams.

However, this protracted setup enables only isolated measurements. A fringe projection-based all-optical configuration that can profile objects of any size is in the pipeline.

High-resolution fiber optic sensors are also being used as displacement sensors for sub-micron measurement, especially as touch probes inside grooves. Since traditional shank-based systems involve pretravel that can increase unreliability, scientists in Japan are considering using fiber optic sensors for its greater thermal stability, resolution, and directionality.

"The system, consisting of three displacement sensors and a tip ball that is the only source of mass, provides faster measurements because of its higher frequency," notes Subramanian.

Apart from use in coordinate measuring machines for dimensional metrology, 3D control, and manufacturing processes, the system finds application in profile and orientation measurement and depth mapping.

These advances in sensor technology are expected to supplement developments in micro-fabrication techniques and factory processes, creating more accurate and reliable operations and devices.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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