Efficiency Improvement for Engine Driven Hydrostatic Transmission

This paper describes a comprehensive investigation into improving the efficiency of engine driven hydrostatic transmission by suitable selection of the engine and transmission operating points. In order to investigate the feasibility of optimization an experimental study was performed on a fully instrumented test rig. This involved the use of a minicomputer with on-line control and data acquisition facilities programmed to search for the maximum overall efficiency. Two practical implementations were then investigated, both involving scheduling of the optimum operating conditions. One was a digital controller based on a micro-computer and the other an electrical analogue controller. Results of all these studies are presented and their relative merits are discussed