Although energy efficiency of an Open Center System (OC-System), used widely for excavators, has been improved from the perspective of hydraulic efficiency, total efficiency including the engine has not been taken into account sufficiently. Meanwhile, a Constant Pressure System (CP-System) enabling the engine to be driven optimally is developed but is not accepted in the industry due to complexity of components. Thus in this research, a hybrid system combining an OC-System with a CP-System is proposed enhancing total efficiency. This system is designed for simulation based on the basic theory and the analysis of measurement data. The simulation shows it consumes 30 % less fuel than the conventional OC-System.

Hydraulic load-sensing systems have become state-of-the-art technology for tractors. They combine high energy
efficiency with ease of use and functionality. However, current systems are suitable for comprehensive
machinery management only to a limited degree, particularly if there is a wide variety of different implements.
With electronic load-sensing (e-LS) machine manufacturers are able to individually, actively and dynamically
optimize the hydraulic system in response to various requirements relating to the implement and work process.
Improved productivity and efficiency increase the economic benefit of the machine and new functions allow
automated and monitored workflows for a simplified machine operation.

In the last decades, simulation tools and virtual prototypes were vastly promoted to speed up development
processes. But for complex systems, the modelling and model validation effort is very high, and always some
modelling inaccuracies have to remain due to account for effective cost and computational effort for the
simulations and validation tests. To contribute to the discussion from another point of view, this paper will
present a new approach to speed up development by extreme reduction of hardware iteration time to test changes
of main valve spool geometry according to operator feedback.

Hybridization is frequently applied in order to increase the energy efficiency of off-road and construction
machinery. One such novel energy saving method was proposed for working hydraulics, based on an established
zonal concept for airplanes. The introduced method supplied the power on demand to the actuators, utilising
direct-driven hydraulics in machinery. However, component selection plays a significant role in order to achieve
high efficiency. Therefore, the primary goal is to evaluate the energy efficiency of selected components for the
front hoe of the micro excavator under the digging and levelling cycles. The efficiency of the zonal hydraulic
pre-selected components was evaluated utilising a developed Matlab/Simulink model and energy efficiency
maps.