Page 268 of catalogue Position sensors and object detection systems of ifm Electronic GmbH

Object recognition

Image sensors

System description

Introduction In assembly and handling technology, object recognition systems are an integral part in assembly monitoring. The 100 % testing before, during or after the individual assembly steps prevents complex and cost-intensive reworking or rejection of material or workpieces. Image sensor The efector dualis image sensor solves tasks like monitoring of presence, completeness and position, quality control as well as sorting tasks. With its dimensions of only 60 x 42 x 53 mm it sets new standards and is thus suitable for use in applications with very limited mounting space. Furthermore, the industrially compatible mounting and wiring technology enables easy and quick process connection even in demanding applications. Direct object detection The direct object detection functions like a photo comparison. If triggered by an internal or external trigger pulse, the efector dualis image sensor captures an image of the object. Following the settings defined by the user the sensor recognises certain structures and contours by the grey shades in the image. These structures and contours generate a geometric shape which the image sensor compares to the shapes that the user has taught before by means of the original workpiece. If the detected geometric shape lies within the determined tolerances (contour, orientation and match), the result is considered positive. The realisation of a geometric shape using the image data allows quick and flexible object recognition. Here, it is now also possible to compare the detected shape with various taught shapes. In addition, the image can also be divided into individual shapes which are then separately checked for presence. This allows recognition if part of an object is missing during completeness monitoring. Via a freely definable process interface these useful information can be made available to the user for process optimisation. The backlighting method The workpiece moves between the image sensor and lighting element. Just when the workpiece is in the image zone of the image sensor a trigger produces a flash signal and the lighting element flashes briefly. The image sensor captures the silhouette of the workpiece and compares the contour of the captured silhouette with the geometric shape stored in the unit. If a deviation from the stored reference contour is detected, the image sensor transmits a switching signal for example to the external controller to reject the faulty workpiece. The efector dualis image sensor can operate with any type of light (e.g. white light, red light, infra-red light). ifm electronic offers also suitable lighting elements either with visible red light or with invisible infra-red light.
Image sensor efector dualis.

The efector dualis image sensor reliably detects the fixing hole on the joint flange by means of a backlight.

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