Abstract: In order to reduce the energy consumption, the noise and the pollution caused by waste oil disposal in hydraulic system, the most direct method is adopting the pump controlled technology without throttle loss. In pump controlled system, through changing the speed or the displacement of the pump, the pressure and volume flow will be completely matched with the need of loads. First the technical characteristics, state of the art and the existing problems about pump controlled cylinder are discussed, then according to the construction features of the double-acting vane pump (motor) and the axlial piston pump, two innovative flow distribution principles are put forward to balance the asymmetrical volume flow produced by unequal areas of the differential cylinder. By using new methods the movement differential cylinder can be closed-loop controlled with only one pump without using any auxiliary elements. So the new system solution has the advantages of high energy efficiency, compact structure and low cost. The two new flow distribution principles and the system integration schemes used to control the differential cylinder with these two new principles are analyzed. The research work will be of great theoretical and practical significance to realizing the green hydraulic control technology.

Key words: Differential cylinder, Electro-hydraulic control technology, Pump controlled cylinder, Fruit fly optimization algorithm, Mathematical morphology, Reliability prediction, Rolling bearing, Support vector regression