This work aims to analyse a complete hydraulic system of a medium size agricultural tractor, in order to perform an energy dissipation analysis and to test possible alternative configurations and solutions. The fuel consumption and energy dissipation in off-road vehicles have infact become a key feature, given the great attention devoted to the need of reducing pollutant emissions, in order to satisfy the future emission limits. Standard and alternative architecture configurations are modelled and compared on the basis of the power consumption to perform the same duty cycle. Among the results, it is worth highlighting that a relevant percentage of energy may be saved with simple modifications in the hydraulic power generation group.

In the modern world continually grows ecological consciousness of societies. We are looking for new and develop the already known methods of energy generation from renewable sources. Designing of simulation models using newest software (i.e. Simulation X) of existing system and on their base building new allow in an easy and fast way to demonstrate their advantages but also find areas that need to be improve. Based on previous experiences and virtual tests [12] finally was managed to create model of Francis turbine control system using water hydraulic elements. This article presents of the system consisting of three connected and interacting subsystems: hydraulic model of the guide apparatus control system, three-dimensional model of guide apparatus and model of water flow through the system of guide apparatus - turbine.

Hardware-in-the-loop (HIL) setups are widely used in research, since they allow us fast and accurate testing under realistic conditions and easy repeatability. In this paper a HIL-setup is used to emulate the behavior of a hydraulic pump with an electric motor/generator. The setup contained a real-time simulator (RTS), two electric motors and two frequency converters. A real-time simulator was used for simulating the hydraulic and mechanical parts of the hydraulic machine. In previous study, it was shown that a virtual model of a hydraulic machine in a HIL setup can be used for testing by emulating the hydraulic pump with an electric motor. As the built setup did not fulfill requirements, new components for this kind of HIL setup are needed to be chosen carefully: optimized for data transfer speed, low latency and suitable refresh rates. In this research an attempt to find the optimum electric motor parameters, for the emulation purpose of a hydraulic pump was made. The parameters should be chosen based on refresh rate of the motor and initial analysis to narrow down the choices.

This study focuses on the global energy flow analysis along the three main energy lines of an off-highway vehicle used on port areas called a reach stacker. In order to characterize the energy consumption of the power train and the actuation system, a model of the machine has been established using the bond graph methodology. This language is suitable for representing multi domains energy transfers and allows the determination of the needed energy for an actuator to perform a given task. The simulation results are then compared with measurements carried out on a real reach stacker. Those data help to identify several parameters like friction coefficients and efficiencies. The energy flow analysis also gives detailed information on the main energy losses sources which prefigures coming evolutions.