Future more electric aircraft (MEA) architectures require a new generation of power-by-wire actuators, e.g. Electro Hydrostatic Actuators (EHA). These units have to be capable of frontline operation of safety critical flight control surfaces over the entire aircraft life. Prove of robustness becomes a challenging objective. This paper illustrates the Liebherr-Aerospace EHA technology as well as methods for validation of robustness. It gives an insight regarding the design of a robust piston pump.

Vacuum handling is a widespread technology in automated production systems for gripping of workpieces. Unfortunately, this solution accounts for a considerable share of industrial energy consumption. This consumption is mainly due to the losses in the involved steps like air compression, distribution, vacuum generation and gripper suction. However, the energy efficiency of vacuum handling systems is still relatively unexplored. The consortium partners are working together in the BiVaS project, which is funded by the Federal Ministry for Economic Affairs and Energy (BMWi). In this project, the drawback of high energy consumption is approached by the development of an energyefficient ejector, a biomimetic suction gripper as well as on system integration and the development of energy-efficient operating strategies and their energetic balancing in order to reduce the consumption of compressed air by 20 %. This reduction will be quantified experimentally in a pilot plant benchmark, where a realistic handling process is developed and examined. This paper shows the state of the art focusing on energy consumption of vacuum handling technology and the behaviour of the involved components during different handling operations. Furthermore, first biomimetic concepts and an estimation of the increase of energy efficiency will be presented for the running project.

Within a production machine, various electromechanical and pneumatic structures can be used for drive tasks. As these drive technologies can often replace each other, the energy efficiency, performance and TCO of pneumatic drives must be permanently enhanced to remain competitive. There is a large number of known measures for the reducing their energy consumption, e.g. minimizing of filling volumes, energy saving circuits etc. However, these measures are mainly considered separately and the possible overall energy saving effect resulting from their combination is rarely taken into account. The main goal of this paper is therefore to explore the possible combinations of pneumatic energy saving measures and their cumulative saving effect. Due to the fact that some measures are mutually exclusive (e.g. a general pressure reduction in properly sized drive), each combination should be considered separately. To evaluate their efficiency plausibly, a comprehensive assessment is required that contains both the total cost of ownership analysis (TCO) and a mechanical properties assessment. The presented comprehensive approach of the task analysis can serve as example of how an optimal drive configuration for the specific task can be found, thus creating a basis for solving constructive challenges in designing of pneumatic automation systems.

In this paper, the energy efficiency and dynamic performance of servopneumatic drivers are studied aiming at the correct sizing of the system components. The study is carried out through a non-linear dynamic model of a servopneumatic system. The simulation data are used along with the operating point method in order to understand the effect of loading conditions in the system performance, which is then used as a tool for component sizing. The results show the effects that the piston area has on the energy efficiency and dynamic behavior of the system. Moreover, the dependency of the servovalve size on the piston area is elucidated. A procedure to design an effective combination of piston area and sonic conductance of the servovalve is presented. A practical case where a servopneumatic system is being designed for the speed governor of a hydraulic turbine is described, evidencing the suitability of the proposed method for servopneumatic systems.

Economic utilization of geothermal networks under agricultural surfaces needs large agricultural areas. In order to exploit the cultivated land more effectively, this paper proposes a novel locally vibrating plough system that employs a hydraulic actuator direct on the plough blade instead of the state of the art external vibration units. Starting with a description of geothermal networks under agricultural surfaces and the construction technology in details, the contribution shows different concepts, the development and test of the most promising solution for imprinting local vibrations at the cutting edge with the goal of traction force reduction. A virtual demonstrator, the test rig set-up and the control concepts are described. Both of the closed-loop simulation and experimental position control of the entire vibration system demonstrate that the novel design has impressive performance improvement. Finally, the integration of the vibration system into a prototype tool is shown and the reduction of the traction force is proven by experiments carried out with a tractor on a testing field.

The correct classification of a logs assortment is crucial for the economic output within a fully mechanized timber harvest. This task is especially for unexperienced but also for professional machine operators mentally demanding. This paper presents a method towards an assistance system for machine operators for an automated log quality and assortment estimation. Therefore, machine vision methods for object detection are combined with machine learning approaches for estimating the logs weight based on a Convolutional Neural Network (CNN). Based on the dimensions oft he object ´log, a first categorisation into a specific assortment is done. By comparing the theoretical weight of a healthy log of such dimensions to the real weight estimated by the CNN-based crane scale, quality reducing properties such as beetle infestation or red rod can be detected. In such cases, the assistance system displays a visual warning to the operator to check the loaded log.

This paper shows an electrohydraulic control system to stabilize the chassis of a mobile machine driving across an off-road ground profile. The active hydraulic suspension system is based on new electronics, SW- and control architectures and the use of state of the art industrial components. The paper shows, that the static and dynamic performance of the system is dominated by the servo valve, which represents the central component of the system.

The following article describes the development, validation and series introduction of a novel highly integrated smart electrohydraulic 4-quadrant displacement machine. Starting in 2012, an unique unit consisting of a hydraulic internal gear machine combined with a newly developed electric machine with integrated electronic unit was created. The developed unit aims at the application in fully active automotive chassis in combination with hydraulic shock absorbers. The very special requirements of this application resulted in a new development with numerous detailed solutions which are described below. Parallel and interacting with the product development, all new series assembly and testing devices tailored to this product was developed.

Truck drivers spend all day moving goods. They are exposed to vibrations every time they drive. Modern cabin suspension and an air-suspended seat already offer a high level of comfort. This, however, is designed for vertical dynamics and you can observe the cab of a truck performs large pitching vibrations during acceleration. These are examined here. A pitch model of the cabin is set up for this purpose. On the basis of this model it is examined which reduction of the vibration can be achieved by the use of a hydraulically translated vibration absorber. The advantage of this absorber is the use of the hydraulic transmission to reduce the heavy mass at high absorber inertia. 4 kg of fluid mass act as 131 kg absorber mass reducing vibrations by more than 10%. The conventional vibration absorber is inacceptable due to the additional load. The investigation based on VDI 2057 Part 1 shows that driving comfort can be increased.

The UAE Pavilion will be a major attraction at Expo 2020 in Dubai. The roof of the building consists of 28 operable wings made of carbon and glass fiber, having masses ranging from 5 to 18 tons and total lengths in the range of 30 to 65 m that have to be actuated by a dedicated mechanism. In this paper we present the turn-key project for the design, manufacturing, installation, test and commissioning of the Roof Wing Opening System, which represents a unique system world-wide for operating the wings. It consists of one Hydraulic Power Unit with approximately 1 MW of installed power, 2 km of piping working at the nominal pressure of 210 bar, 46 hydraulic cylinders with 1.5 tons of mass each and the complete automation and control subsystem that includes 9 separate PLCs, dedicated software, 2.000 sensors and control points, and over 20 km of harness. One major challenge is the control of the wings. Part of them, due to their huge dimensions and masses, are actuated using two or three hydraulic cylinders that have to be properly synchronized during the movement, preventing unwanted displacements in order to avoid stresses on the wing mechanical structure and ultimately permanent damages. Due to the nature of the project, a final validation of the control algorithms can be done only at system level during the commissioning phase. Therefore, particular care has to be devoted to the verification strategy, anticipating the behavior of the system in the early validation stages and following a V-model approach, in order to identify critical situations and reduce the overall risk. After a brief system description, we will explain how the verification has been approached by using system level simulations and dedicated testing activities on specific subsystems. In particular, we will detail the verification of the control algorithms that has been performed on a dedicated Hardware-Inthe- Loop system first, followed then by dedicated tests on a reduced wing mock-up, allowing the study of the system behavior under the most critical conditions. These include the application of external forces with specified profiles. Finally, we will provide the actual status of the system installation, testing and commissioning activities that have been running in Dubai since January 2019.