A modelling procedure for linearized motions of tree structured multibodies .2. Design of an active spray boom suspension on a spraying-machine

In part 1 of the paper, the linearized equations of motion of a multibody system have been established. In this part, the method is used to compute the equations of motion of a spraying-machine consisting of 10 bodies. Tyres are represented by the tyre model of Crolla. The contact length tyre-ground which determines the low-pass filtering quality for the tyres, is also taken into account. Through a smaller nominal model that has been derived directly from the multibody model, an active spray boom suspension is designed with the aid of the linear quadratic Gaussian method with loop transfer recovery. A hydraulic actuator counteracts undesired rolling of the tractor by rotating the spray boom in the opposite direction, such that the distance between the spray nozzles and the held crops remains within an acceptable range. In the simulations, compensated and uncompensated spray boom motions are generated by driving the machine over some incompressible standardized tracks and corresponding spray deposit distributions are generated.