Optimization of a fertilizer spreading process

An optimization method for accurate fertilizer application by centrifugal spreader is described. The cost functional is a distance between a prescribed dose and the distributed dose. The distributed dose is computed using a simplified spread pattern and the unknowns of the problem are three time-dependent parameters of the spreader: the average (distribution) center, the average (distribution) angle and the mass flow rate. In order to take into account the mechanical limits of the device, constraints are introduced in the form of bounds on the parameter functions and their time derivatives. Numerical experiments show that application errors can be significantly reduced for parallel tracks within a main field body.