3D measurement systems

3D-Measurement Systems

3D-measurement systems are also part of insensiv’s product portfolio. Depending on the task the methods used are based on either stereo camera systems or laser sectioning, which uses the triangulation method and a unit composed of a camera and a laser. In addition, insensiv also offers a pattern generator process and the time-of-flight method.

The stereo method is used when only a snapshot is possible for an online evaluation, when the color information is relevant, or if the object is partially transparent, as for example in the measurement of crates of bottles.

Laser sectioning is preferably used when a continuous speed of the object to be measured or the measurement system is given.

insensiv also integrates complete 3D-sensors which offer a projection pattern process.

Aside from making 3D-data available, insensiv‘s systems also offer an internal evaluation of this data and corresponding control of actuators. Especially the stereo systems are customer specific solutions, where the cameras, lighting, and casing make up one cohesive unit. The resolution of the image sensors as well as the computing power are scaled according to your specific task, and we offer 3D-systems with color and grayscale sensors. These can be designed for both indoor and outdoor use.

See our flyer for further information.

Stereo method

The stereo method is used when only a snapshot is possible for an online evaluation, when the color information is relevant, or if the object is partially transparent, especially outdoors.

Three-dimensional objects can be measured with 3D stereo image processing. The object is captured by two lightly displaced cameras and because of the perspective imaging and the offset of the cameras (these take slightly different images). The closer the object is to the camera, the greater the deviation of its position will be in the two images. Based on this offset the height information can be obtained. Also, because the 3D-information is taken from complete images and not line-by-line, as with laser sectioning, the object does not have to be moving in relation to the cameras, although of course it can be.

The measurement accuracy depends on the distance between the cameras, their order, the camera‘s resolution, and the object‘s size and distance to the camera. With increasing distance the measurement accuracy is decreased quadratically. 3D-stereo image processing works especially well with stationary objects or those objects whose movements are not easily influenced, since a moving object is not required using this method.

A specific product using this method is the measurement of bottle crates in reverse vending machines with a simultaneous recognition of bottles. Further fields of application can be found in agriculture or industrial quality and production control.

See our flyer for further information.

This product requires customer specific development. Contact us for further information.

single-chip 3 D-camera

The single-chip 3 D-camera is a stereo camera that only needs one sensor. Using a special mirroring technique the image is split; images of two virtual cameras are displayed in the left or right half of the sensor accordingly. Because of this mirroring the cameras are oriented so that their fields of view overlap, which maximizes the relevant image data used for the stereo processing.

The advantages of this system result from using only one sensor since deviations in brightness that can result from using two real cameras can be avoided. In addition no communication between the cameras is necessary since the stereo image is directly available for processing after recording has begun. Also, because of the mirror system no synchronization of the cameras is needed when recording moving objects.

In using an embedded camera with a powerful processor the 3D-analysis can take place directly on the camera, so that no additional PC is needed. Only the required 3D-data sent to the responsible control unit via Ethernet or RS232. This makes it possible to build cost-optimized 3D-systems for an online 3D-analysis.

Areas of use include lane guidance systems in agriculture or the measurement of moving objects or persons. The single-chip 3D-camera is generally scalable, and with right choice of the camera and adjustment of its lens it can be used for many applications.

For further information see our flyer.

Laser sectioning

Laser sectioning is preferably used when a continuous speed of the object to be measured or the measurement system is given.

The laser sectioning method is a light sectioning method, with which object surfaces are measured three-dimensionally. To gather the 3D-data the object is moved relative to a laser line and simultaneously viewed with a camera that is positioned outside of the laser‘s plane. The camera records an offset laser line because of the object‘s differences in height, and based on this offset height information can be calculated.

In contrast to the stereo method the laser sectioning method only needs one camera, which is used to gather 3D-information line-by-line. The measurement accuracy depends on the size of the laser line, the resolution and distance of the camera, and the reflective properties of the examined surface.

Because the object to be analysed needs to moving relative to the camera, the laser sectioning method may be used, for example, to control the quality of value goods on conveyor belts. In this process „unknown“ objects could also be measured.

A specific example of an application is the measurement of packages in combination with a scale to determine the postage automatically.

See our flyer for further information.

This product requires customer specific development.

Multi-line laser sectioning

The laser sectioning method can also process more than one line per image. Depending on the number of lines the resolution can thereby be increased in the direction of the object movement. If the measured object moves more than 10 mm between two recorded images, a laser pattern with 9 lines can be used even though a distance of 1 mm is needed between two height profiles. 

With this process unmoved objects may be measured if the number of necessary height profiles can be reproduced by a line projector.

 

Light barriers

Single or multi laser lines only produce parallel height profiles in discrete distances. If height profiles with deviating directions are additionally needed, laser grids or more complex patterns are used.

Pattern methods

The correct identification of single lines becomes increasingly difficult the higher the number of laser lines used. If the pattern is varied across the surface it is easier to determine which part of the pattern the camera „sees“ in a specific area. This increases the spatial distance between two measurements because a specific area of the pattern is evaluated, however, this makes the measurement of extremely complex object forms possible.

This product requires customer specific development.

Time-of-flight

The time-of-flight process determines the difference in time between sending a light impulse and the reception of the reflected signal. Because the speed of light is known this can be used to determine the distance to given objects. A second camera can additionally determine the color of the 3D-points, if infrared lighting is used.

This product requires customer specific development. Contact us for further information!