Technology: New sensor views objects in 3D

In May 2009, ifm efector will launch a new 3D image sensor that the company calls a breakthrough in 3D technology. Industrial, automotive applications will be first.

By Control Engineering Staff April 9, 2009

In May 2009, ifm efector will launch a new 3D image sensor that the company calls a breakthrough in 3D technology. The sensor uses a combination of time-of -flight distance measurement, photonic mixing device technology, and an integrated smart pixel array to view objects in three dimensions.

Based on Phontonic Mixer Device (PMD) technology, the sensors capture a complete three-dimensional image in real time. Time-of-flight measures the time it takes a pulse from an active light source to return to the receiver. A pixel array collects all active light and each pixel divides the photons into two sections for evaluation. imf and PMD Tech partnered in 2002 to develop the technology, which was patented in 1996.

Future applications include a range of automotive systems, including pre-crash sensing, blind-spot detection, passenger out-of-position detection and more. More-imminent industrial applications include palletizing/de-palletizing and other packaging applications.

The PMD 3D image sensor from ifm efector can evaluate the entire layer of a pallet to determine if product is out of place.

In a typical palletizing application, a robotic arm removes bulk material from a conveyor or storage location and stacks it on a pallet. The new sensor could be used to detect when a layer of product is complete or incomplete. Today, multiple ultrasonic and distance sensors are mounted to a palletizer to detect the edges of a skid. The sensors are used to determine if a layer of product is askew, or if extra product has been added. The sensors measure only certain points of the skid and can miss the presence of a single box.

In the ifm solution, a PMD 3D sensor is mounted to the top of the palletizer. The sensor’s 64×48 pixel array projects 3,072 data points of reference onto the pallet. The PMD 3D image sensor evaluates the entire layer of a pallet and sends an image back to the main control indicating the highest and lowest point. The sensor can determine the average distance to each object, and a three-dimensional picture of the stored pallet is then identified. Using the 3D data, pallets can be removed without the risk of damage to other pallets.

ifm exhibits at Hannover Messe April 20 – 24, 2009 in stand D36, Hall 9. More information on its other sensor innovations can be found there, or through its website:

Renee Robbins , senior editor
Control Engineering News Desk

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