Centrifugal fertiliser spreading: velocity and mass flow distribution measurement by image processing

This paper investigates the use of a new imaging system to measure the velocity and the mass flow distribution of fertiliser granules spread by a centrifugal device. The new acquisition system consists of a digital camera placed above the disc so that its view axis corresponds to the disc axle. This provides useful geometrical properties to develop a simple and efficient image processing. The technique provides a global estimation of the spreading characteristics for the whole fertiliser flow using a global analysis of an image rather than identifying individually each trajectory in the image. The new technique is compared to a previously assessed imaging method. Concerning the mass flow distribution, results deduced from both imaging methods are also compared to those deduced from a compartmented collection ring.