The reflectance indicates the percentage of luminous flux reflected by a surface. The brighter the surface, the higher the reflectance: A white wall reflects up to 85 percent of the light, bright wood panelling only up to 35 percent.

What are the advantages of time-of-flight measurement compared to conventional triangulation sensor technology?

The OGD sensor measures distances with PMD technology, a time-of-flight method that detects objects much more reliably than, for example, CMOS sensors. The sensor especially demonstrates its strength when detecting shiny surfaces or black surfaces with low reflectance. While the OGD can still detect the objects, an CMOS sensor will no longer provide a result. Even multi-coloured objects such as chipboard or pieces of meat are reliably detected thanks to the PMD technology. Background suppression and laser light make the OGD extremely reliable even if exposed to external interference such as movements and reflections. The sensor can detect objects even at extreme alignment angles, while a triangulation sensor must be aligned at an angle of 90° to the object.

What are the advantages of OGD sensors compared to standard sensors?

The OGD eliminates the duplicated effort of mounting and wiring both a transmitter and a receiver (or reflector) - the total cost of your solution can be significantly reduced. The window function, a user-definable object detection range, makes it possible to process objects of different sizes with a single device. Even with changing production lines, there is no need to reconfigure the sensors.

M18-Cube: The space saving ifm housing
OGD distance sensor

The new generation of OGD distance sensors

Faster, further, better

Thanks to innovative PMD technology (PMD: photonic mixer device), the OGD photoelectric distance sensor detects objects with extreme precision up to a range of 2 m.

With this powerful on-chip time-of-flight measurement system, you can detect the presence of objects or their correct installation with maximum accuracy. Typical applications include detection in rapid succession and at high speed, for example in the field of conveying or material handling. The excellent reflection resistance and background suppression of PMD technology, together with a high excess gain, enable reliable detection.

The PMD technology of the OGD sensors is vastly superior to conventional diffuse reflection laser sensors or red light sensors. As their range is angle and colour independent, even difficult objects such as shiny metallic surfaces can be detected.

The reflectivity is output in addition to the distance value. This not only allows identification of objects, but also conclusions about their material properties. Outputting the distance value and reflectivity simultaneously enables material differentiation while also increasing process reliability.

With its M18 thread, the compact laser sensor is easy to install. The setting is made directly on the device or alternatively via IO-Link, using convenient 3-button operation. Visualisation is achieved with the integrated 8-segment 2-colour display on the sensor.

The OGD photoelectric distance sensor in detail

Use cases

Two-stage conveyor belt stop function

Background suppression is yet another advantage the OGD provides. The feature comes in handy when implementing a stop function at the end of a conveyor belt. Reflections from the metallic rollers do not affect the sensor. The OGD also reliably detects objects of different colours. In this application, the first switch point triggers a speed reduction of the belt. When the object reaches the second switch point, the belt is stopped.

The advantage: By replacing the two devices which are typically required for a light barrier, the OGD helps to reduce the purchase, installation and wiring costs. In addition, it can be used in almost any mounting situation, as it can be aligned to the belt at an oblique angle.

Quality assurance during production

The OGD performs precise and reliable inline quality checks to monitor the correct position and orientation of small shiny components or those with low reflectance such as O-rings or toothed wheels.

Assembly errors such as missing O-rings of 5 mm thickness or more are detected. This error proofing process during production and before final quality checks minimises the risk of costly consequential damage such as plant downtimes or batch failures. At the same time, the inline quality check contributes to long-term and efficient quality assurance. The earlier errors are discovered, the lower the consequential costs are and the sooner improvements can be made.

With increasingly oblique angles, the reflected light diminishes, causing the reflectance value precision to deteriorate.

Object detection in product handling

The OGD reliably detects objects even in unfavourable lighting conditions. It even does not skip reflective materials or those with ragged surfaces such as foils, which often come in colourful or dark designs.

The sensor detects dirt on the lens through the reflectance value via IO-Link and alerts the operator about cleaning. This reduces faulty measurements and increases process reliability.

Other applications that have been solved with the OGD

RAP

Automation solutions from ifm for RAP Confectionery

Cimt

Sensor technology in dental milling machines

Technology

The ifm distance sensors of the OGD product series use pmd time-of-flight technology for precise, robust and long-range distance measurement. With time-of-flight technology, light waves emitted by the laser light source propagate. When the light bounces off the target, the phase pattern shifts and this shift is directly proportional to the distance.

Advantages of time-of-flight technology

Robust detection of small reflective, shiny or black objects
Even multi-coloured objects such as chipboard or pieces of meat are reliably detected thanks to the PMD technology
Background suppression and laser light make the OGD extremely reliable even if exposed to external interference such as movements, reflections and extraneous light
Fast installation thanks to colour and angle independence