Hydrostatic Transmissions: the SIDAC Class of Controls

variable diqdacement pump, a fixed or variable displacement motor and a load unit, any conceivable control interface should handle the degrees of freedom ofboth engine and hydraulic units through proper pilot signals generated starting from the directives issued by a supervising 1eveL A special class of controls WDAC'I calls for a single directive and has additional aukomatic capabilities, which m&es them specially suited for the locomotion of wheeled vehicles. Two implementations are possible: primary controls (variable pump only) and secondary controls variable pump and motor). In the paper a number of candidate architectures of both are introduced and compared in respect of their steady state and dynamic performance.