Observation des modes d'un laser de puissance. Validation de la méthode

Measurement of the motion of fertilizer particles leaving a centrifugal spreader using a fast imaging system

International audience; Although mechanically simple, centrifugal spreaders used for meneral fertilization involve complex physics that cannot be fully characterized at the present time. We are developing sensors to evaluate the spatial distribution of the fertilizer on the ground based on the measurement of initial flight conditions of fertilizer granules after their ejection by the spreading disk. The techniques developed are based on the analysis of images of the area around the disk showing the granule ejection. A high resolution - low cost imaging system for the analysis of high speed particle projection developed for this specific purpose is presented in this paper. The system, based …

Design of an image processing integrated circuit for real time edge detection

Presents the design of a real time image processing micro-system to detect defects on manufacturing products. The analysis method is based on an edge detection algorithm (differential operators) to select the information related to the structure of the objects present in the image. The edge calculation function has been integrated in a standard cell circuit using a CMOS 1.5 mu m process. The ASIC has been implemented and tested in an image processing microsystem with a CCD camera. Results show an improvement of performances (speed, noise, size reduction system characterization, etc. . .) in comparison with the first prototypes (software implementation and printed board with standard compone…

Variable rate fertilisation: Measurement of fertilizer granules motion on a centrifugal spreader by image analysis

Although mechanically simple, centrifugal spreaders used for mineral fertilization involve complexphysics that cannot be fully characterized at the present time. We are developing sensors to evaluatethe spatial distribution of the fertilizer on the ground based on the measurement of initial flightconditions of fertilizer granules after their ejection by the spreading disk. The techniques developedare based on the analysis of images of the area around the disk showing the granule ejection. A fastimaging technique developed for this specific purpose is presented in this paper. It allows toautomatically compute the direction of ejection and velocity of each granule observed in the image.

Centrifugal spreading : motion blurred images to determine the three components of fertiliser outlet velocity

In the optical control of centrifugal spreading, the use of a single CCD camera to measure the outlet velocity is not limited to flat discs and 2D motion estimation. Combining the kinetic study of the fertiliser motion on the vane and the geometric analysis of image acquisition, the 3D components of the outlet velocity can be deduced from motion blurred images in the case of a traditional concave disc. The estimation of the horizontal and vertical outlet velocities is useful to predict spread patterns using ballistic flight models. This opens up the possibility to implement simple spreader test tools for quality diagnoses or sensors for feedback loop adjustments.

Nouvelle tomographie Compton

International audience