SiDAC Architactures in hydrostatic transmission control

Hydrostatic transmissions are often used in locomotion power trains of off-road machinery and their advantages are widely recognized. A number of commercial applications exist, however the choice of combined controls for pump and motor are not as frequent as their advantages would suggest. This becomes particularly evident where the desired comer ratio of the transmission approaches the break-even point between fixed and variable displacement motors. Previous works stressed the importance of a flexible and simple tool for evaluation and comparison of various control strategies, all belonging to the SiDAC (Single Directive Automatic Controls) class, on a reference system used for Hydrostatic Transmission (HT) simulation. This paper tries to go into deeper detail by introducing a simulation environment as close as possible to an operating circuit, and trying to identify critical parameters and guidelines suitable for: (i) better evaluation of existing products; (ii) schemes for control systems evaluation and synthesis; (iii)case studies collection for teaching and lecturing purposes.