bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Design of a General-Purpose In-Situ Tribology Test Chamber for Fluid Power Applications
Authors: Masia Antonio , Caponeri Giulio , Cetra Stefano , Shang Lizhi 
Published: November 2023

Abstract
The efficiency and reliability of hydrostatic pumps and motors are significantly affected by their tribological interfaces, which function as both a seal and a bearing. The performance of tribological interfaces is heavily influenced by their design parameters, including clearance, roughness, material, surface finishing, and thermal treatment, as well as the operating conditions, such as speed, load, temperature, and fluid characteristics. Experimental tribological tests of isolated lubricating interfaces for various designs and operating conditions can greatly assist pump and motor designers in addressing the increasing demand for highly efficient hydrostatic machines. The challenge of designing the experiment for the abovementioned purpose is to keep the isolated lubricating interface operating in a well-representative operating condition. This paper introduces and describes a novel general-purpose in-situ tribology test chamber for fluid power applications with the goal of conducting tribological tests of individual lubricating interfaces of different types of hydraulic units. The novel design of the test chamber is co-designed by Purdue researchers and Test Industry S.r.l. Its core element is the test chamber, which allows for testing the sample fully submerged in hydraulic oil. It provides the sample with the environmental condition necessary to replicate realistic operating conditions, such as load, pressure, rotation speed, and fluid temperature. This paper describes the definition of the test rig specifications, the test rig’s design architecture, hydraulic circuit, hydraulic system capability, and mechanical driveline. The general capabilities of the test rig, as well as its ability to investigate a wide range of lubricating interfaces by measuring the main tribological parameters such as friction, leakage, pressure/temperature distribution, and loading capability of hydrostatic machine tribological interfaces, are also described. The first experimental investigation will be conducted on a piston pump machine design to investigate the friction and leakage from each of its interfaces — piston/cylinder, block/valveplate, and slipper/swashplate separately at various operating conditions, including the speed at around zero rpm. The sensor parameters, sample design, and test results in terms of the overall frictional torque of the selected sample will be discussed.
Counteracting Centrifugal Forces on the Cups in a Floating Cup Pump
Authors: Achten Sef , Mommers Robin , Achten Jasper , Potma Jeroen , Achten Peter 
Published: November 2023

Abstract
Within hydraulic axial piston machines, critical components experience centrifugal forces, which can limit the performance of the actual machine. Often, this results in tipping of the cylinder block or barrel, causing friction in the barrel-port plate interface and affecting the efficiency and durability of the machine. In a hydraulic machine based on the floating cup technology, such as pumps, motors, and hydraulic transformers, the centrifugal force experienced by the cups is counteracted by the fixed pistons. The combined reaction forces on the cups cause a tipping torque on the barrel plate. Although a hydrostatic trust bearing can be used to compensate for such tipping, the effectiveness of the bearing depends on the pressure within the system and is limited in the amount of torque it can compensate for. This solution is sufficient for machines up to a certain size and a maximal rotational speed. However, if the machine requirements exceed these limits, a different solution is needed.
Ideally, the centrifugal forces on the cups are counteracted by the barrel plate, since it rotates around the same axis as the cups. This can be realized by introducing an opposite force using counterweights connected to the barrel plate. The centrifugal force on the counterweight is redirected via a lever to counteract the centrifugal force on the cup, minimizing the interaction between the cup and piston. As a result, the barrel plate tipping torque is diminished, decreasing the friction between the barrel plate and the port plate, which in turn results in an increase in efficiency and durability of the machine. The new solution also creates the opportunity to further increase the maximum rotational speed. This is especially important for electro-hydraulic actuators and hydraulic transformers.
Optimal Design of Cartridge Check Valve Control Unit in a Multi-Pump Hydraulic System
Authors: Xi Xiangshuo , Wang Qingfeng , Wang Tao 
Published: November 2023

Abstract
Multi-pump hydraulic systems have a wide range of applications requiring large flowrate. As a highly integrated component, the cartridge check valve (CCV) control unit has an important influence on the overall performance of multi-pump large-flowrate systems. It is a critical issue to design its parameters properly, for mismatched parameters may lead to poor performance or even accidents. On the one hand, it is challenging to implement accurate theoretical analysis due to strong nonlinearity and complexity. On the other hand, the implementation of optimal design using a trial-and-error approach is time-consuming and expensive. To solve these problems simultaneously, this work develops an automatic method to design the parameters of the CCV control unit based on the combination of numerical simulations and the nondominated sorting genetic algorithm III. The parameter discretization method based on probability has been proposed to improve the performance of the optimization algorithm. Both subsequent simulations and experimental results confirm that the performance indicators of the optimized hydraulic system such as backflow and response time have been significantly ameliorated compared to the original hydraulic system. In general, this work develops a time-saving and convenient method for parameter optimization of the CCV control unit, which can also serve as a reference for component design and selection in similar hydraulic systems.
An Analysis of a Multi-Pump System for Actuator Operation in Electric Mobile Machinery
Authors: Tozzi C. Gama Artur , Heybroek Kim , Ericson Liselott 
Published: November 2023

Abstract
This paper presents an analysis of a multi-pump solution for a hydraulic cylinder for application in mobile machinery with electric prime movers. The flexibility provided by using electric motors instead of an internal combustion engine allows for the design of alternative hydraulic architectures that remove the need for a centralized pumping system and support more direct control of individual components. This allows them to operate at a higher efficiency region to improve overall vehicle efficiency, leading to smaller batteries and shorter or less frequent recharge periods. To evaluate the capabilities of this proposal, this paper focuses on a backward calculation analysis of a single actuator operating with multiple pump/motors connected to each chamber. A series of hydraulic machines with fixed displacement and identical sizes are connected to the actuator chambers through on/off directional valves. The system controls the flow by using the required pumps and selecting their optimal speeds to minimize energy consumption or maximize energy recovery. The results show how the number of pumps affects the system’s performance and provide insights regarding the selection of operating machines according to the actuator speed and force.
Control of Hydraulic Injection Moulding Machine With Electro-Hydraulic Variable-Speed Drive
Authors: Hertz Rasmus A. , Therkelsen Ole , Kristiansen Søren , Christensen Jesper K. , Hansson Frederik A. , Schmidt Lasse 
Published: November 2023

Abstract
In this work an industrial hydraulic injection moulding machine, is retrofitted with a electro-hydraulic variable-speed drive. The focus is placed on the injection cylinder, where the design of the hydraulic system is realized with standard components. The design is based on two permanent magnet synchronous motors connected to two fixed displacement pumps, allowing the control of the injection cylinder without the need for valves in the flow path, removing the dynamic influence of a valve and reducing throttle losses. The controller structure is designed from a model-based approach, where the electric motors and associated drives are operated in speed control modes. A sum and load pressure decoupling control structure is proposed, enabling the use of SISO control design for the pressure level and the load pressure separately. For the latter, a cascaded hydraulic drive controller structure is proposed, where the inner loop consists of a pressure controller, and the second and third loop consists of a velocity and position controller respectively. A method to smoothly switch from velocity to pressure control is furthermore proposed. Experimental results comparing injection cycles of an industrial injection moulding machine and the retrofitted injection drive and proposed control are presented.
Slipper Wear in Variable Operating Conditions
Authors: Merkel Philip Amos , Duensing Yannick , Schmitz Katharina 
Published: November 2023

Abstract
Electro-hydrostatic actuators (EHA) offer highperformance hydraulic control while featuring a range of advantages compared to classic valve-controlled actuation. They are highly efficient, modular, power-by-wire actuators thus enabling the design of efficient hydroelectric drives urgently needed for the electrification of hydraulic machinery. EHAs are therefore steadily replacing valve-controlled actuators in many applications. However, in some cases, the robustness of the existing EHA systems has proven to be insufficient for their respective applications. Especially pumps are known to limit the service life of EHAs. [1]
A very commonly used pump type here is the axial piston pump. The robustness of its hydrostatically partially balanced contacts has proven to be particularly challenging under the variable load conditions typically arising in EHA applications. [1], [12], [13]
This contribution aims at the description of the relevant wear effects on the slipper-swashplate contact under variable load conditions as well as the impact of the wear on the load-carrying capabilities of the slipper contact. For this, occurring wear is experimentally identified on component-level tests. A simulative elastohydrodynamic lubrication study of the slipper-swashplate contact allows the identification of the wear progress as well as a study of the influence of existing wear profiles on the slipper behavior.
Bandwidth Expansion and Resonance Suppression for High-Frequency Electro-Hydraulic Acceleration Control System by Three-Variable Control Method With Dynamic Pressure Feedback
Authors: Luo Guifu , Yang Tingming , Mu Ziyang , Zou Jun , Zhou Hua , Yang Huayong 
Published: November 2023

Abstract
Due to the characteristics of high-power density, the high-frequency electro-hydraulic acceleration control system (HFEHACS) has been an important component of vibration simulation equipment such as load simulators, and fatigue testing machines. However, the performance of the HFEHACS is strongly restricted by the inherent low bandwidth and low damping ratio of the electro-hydraulic subsystem. In general, these two shortcomings must be traded off to achieve the desired compromise performance. To expand the bandwidth and increase the damping ratio of the electro-hydraulic subsystem simultaneously, an improved control method that combines the three-variable control (TVC) method with dynamic pressure feedback was proposed in this work. First, the dynamic model of the high-frequency electro-hydraulic subsystem with an elastic base considered was established, and the influence of the elastic base on the HFEHACS was analyzed by simulation. Second, the basic TVC was designed to expand the bandwidth and suppress the resonance of the electro-hydraulic subsystem previously, after that, the dynamic pressure was estimated and added into the control method for increasing the damping ratio of the system and further suppressing the resonance of the system. Third, simulations and experiments were conducted to verify the effectiveness of the improved control method. Simulation results showed that the resonance of the HFEHACS caused by both the electro-hydraulic system and the elastic base could be suppressed well by the improved TVC. Experiments results showed that the bandwidth of the electro-hydraulic subsystem with the proportional controller could be expend to about 190Hz, and the bandwidth of the system with the traditional TVC method could be expanded to nearly 250Hz with relatively apparent resonance, while the bandwidth of the system with the proposed method was expanded to 250Hz with smaller resonance. Thus, the effectiveness of the proposed method in expanding the system bandwidth and reducing the system resonance simultaneously was demonstrated.
Flow Ripple Minimization in a Triplex Pump Through the Implementation of Various Linkage Mechanisms
Authors: Herrera-Perez Martin S. , Morse Kristen , Nahin Md Minal , Van de Ven James D. 
Published: November 2023

Abstract
A significant amount of research has been conducted to reduce the outlet flow ripple in pumps. The approach usually focuses on techniques to improve valve timing, but few attempts have been made to achieve this improvement from the piston trajectory itself. This paper investigates how the flow ripple in a triplex pump is influenced by the implementation of different linkage mechanisms that allow direct tuning of the piston trajectory. The model of a baseline pump with a displacement of 10 cc/rev and operating pressures that range from 5 to 50 MPa is built to account for the kinematics and pressure dynamics of three linkage configurations: (1) inline crank-slider, (2) offset crank-slider, (3) Watt-II crank-slider. The kinematics of the linkage configurations (2) and (3) are optimized to minimize output flow ripple. Flow ripple reductions of 10% and 25% are found for the offset crank-slider and Watt-II crank-slider respectively, compared with the inline crank-slider. Tradeoffs between kinematic and dynamic flow ripple are observed as the pump model is evaluated at various operating pressures. An optimum Watt-II linkage mechanism with a kinematic and dynamic flow ripple of 10.6% at 5 MPa is found and described in this paper along with its performance across a wide range of operating pressures.
Modelling of the Entire Aircraft Fuel System Through Simulink for Accurate Performance Evaluation
Authors: Sciatti Francesco , Tamburrano Paolo , Distaso Elia , Amirante Riccardo 
Published: November 2023

Abstract
As the primary fluid system in aircraft, the fuel system plays a vital role in storing, controlling, and continuously providing a clean flow of fuel to the engine throughout all flight phases. Considering that any fuel system malfunctions can lead to decreased engine performance and increased fuel consumption, it is crucial for the system to function efficiently to ensure aircraft safety and reliability. In gas turbine engines that utilize kerosene-based fuels, such as jet fuels, the fuel system comprises several components, including fuel tanks, fuel lines, centrifugal boost pumps, filters, main fuel pumps, fuel metering units (FMUs), and fuel injector nozzles. The FMU is of utmost importance since it regulates the fuel flow rate delivered to the combustion chamber and controls the angle position of the inlet guide vanes (IGVs). In light of the current dearth of comprehensive simulation models of aircraft fuel systems in the scientific literature, the goal of this paper is to create a highly accurate numerical code that reflects the entire fuel system of a gas turbine engine for aircraft. To ensure the accuracy of the proposed model, well established and referenced equations are used. Firstly, a layout for the fuel system is introduced, followed by an assessment of the computational model created using the software Simulink. Afterwards, the simulation results obtained via closed-loop control are presented and discussed.
Human-in-the-Loop Motion Control of a Two-DOF Hydraulic Backhoe Powered by the Hybrid Hydraulic Electric Architecture (HHEA)
Authors: Chatterjee Arpan , Li Perry Y. 
Published: November 2023

Abstract
The Hybrid Hydraulic-Electric Architecture (HHEA) combines the respective power density and control advantages of hydraulic and electric actuation to save energy for off-road vehicles. It uses a set of selectable common pressure rails to transmit the majority of power and electric actuation to modulate that power. As it is critical that off-road vehicles can perform tasks dexterously and exactly as commanded by the operator, the switchings between discrete pressure rails pose a potential challenge for smooth and precise motion. A control strategy consisting of a backstepping nominal control and least norm transition control has previously been developed to address this issue. It has been tested on 1 degree of freedom (DOF) testbeds where known trajectories were able to be tracked precisely. This paper presents the implementation of the HHEA motion control strategy on a 2-DOF backhoe operated by a human operator via a 2-DOF joystick. Unlike previous studies, the duty cycle is unknown beforehand and the decision to change pressure rails is taken in real-time. The efficacy of the motion control strategy has been validated experimentally. Several strategies to improve the user interface: control in workspace coordinates, pressure feedback, and velocity field-based task specification, have also been implemented and demonstrated to make operating the multiple DOF, HHEA actuated machine more intuitive to novice operators.
A Digital Hydraulic Full-Bridge Oscillation Transformer
Authors: Johansen Per , Hansen Anders Hedegaard 
Published: November 2023

Abstract
As emission standards around the world grow more stringent, construction equipment manufacturers are looking towards electrification. A variety of electrified machines are being brought to market, dramatically reducing emissions of carbon dioxide, nitrogen oxide and acoustic noise. However, electrification comes with challenges as the machine’s ability to perform a full day’s work on a single charge is imperative. OEMs must balance battery cost with the power and range requirements of the machine without creating price-prohibitive products. Adding extra battery power to enable longer runtime adds expense, and therefore in the pursuit to balance extended runtime, without excessive battery costs, the inefficiency of hydraulics is the prime target. In this paper we present a novel linear transformer based on the digital displacement technology. The transformer differs from other linear topologies in that the piston is free-floating and the chambers are operated similar to digital displacement unit chambers, where switching losses are minimized with timely operation of the low- and high-pressure manifold valves in relation to the compression and decompression of the displacement chamber. While exhibiting the disadvantage of a single piston machine in terms of vibrations, the mechanical construction of the transformer is simple compared to rotational piston-type displacement units, however the simplicity comes with the cost of complicated control. The research target is to develop a small, efficient, high-frequency transformer, which can replace the inefficient control valves in common-pressure-rail systems. A prototype designed for operation of the boom in an electrified wheel loader is presented.
An Analysis of a Digital Electro Hydrostatic Actuator for Application in Aircraft Flight Control Systems
Authors: Nostrani Marcos Paulo , Oliveira e Silva Dimitri , Simões Lopes Junior Rodrigo , Vigolo Vinícius , Krus Petter , De Negri Victor Juliano 
Published: November 2023

Abstract
With the global awareness of reducing greenhouse gas emissions, research into developing more energy efficient hydraulic systems has become important. The aeronautical industry has been looking for more efficient solutions for aircraft application, where the search for more efficient systems has increased considerably, bringing the concept called More Electric Aircraft. However, hydraulic actuators are unbeatable against other technologies, due to their high power/weight ratio and reliability, being the predominant technology in flight control surfaces. Nevertheless, the hydraulic systems have low energy efficiency. With the aim of improving the energy efficiency of hydraulic systems, digital hydraulics has become one of the main technologies under study. However, the use in aircraft is still new. Therefore, this paper presents a digital hydraulic actuator for aircraft flight control surfaces called Digital Electro Hydrostatic Actuator - DEHA. A mathematical model was elaborated and was validated in a test bench rig. The actuator was applied to control an aircraft in the Aero-Data Model in a Research Environment - ADMIRE model. Furthermore, a Servo Hydraulic Actuator - SHA model was developed for comparison. The results show that DEHA can fly the ADMIRE aircraft in the proposed missions, with an energy efficiency of 41.63% while the SHA reached an efficiency of 0.46%, considering the LOE. This represents an efficiency increasing of 90.5 times, which demonstrates that DEHA can be a promising solution for aeronautical application.
A Survey Study on ePump Design Architectures for Mobile Hydraulics
Authors: Sarode Shanmukh , Assaf Hassan , Tawarawala Parth , Vacca Andrea , Shang Lizhi , Sudhoff Scott 
Published: November 2023

Abstract
With the electrification trends affecting mobile hydraulics, there is a growing need for energy-efficient and compact hydraulic supply units driven by electric machines, also known as ePumps. This paper aims to compare various ePump designs that utilize different combinations of “best-in-class” commercially available hydraulic pumps and electric machines (EMs), to meet the requirements of a generic mobile hydraulic application.
The paper intends to discuss the effect of the design architecture of the combination of a permanent magnet synchronous machine (PMSM), with several hydraulic pumps, including axial piston machines, bent axis piston machines, external gear machines, vane pumps, and radial piston pumps. A large combination of ePump architectures exists, and for engineers, it can be challenging to assess the pros and cons of each option for an electrified application. To address this challenge, in this paper, different commercially available pumps and an EM are chosen to evaluate key performance and design parameters such as drive cycle efficiencies, mass, and volume. Qualitative cost and power density considerations are also investigated. The effect of variable displacement ePump operation on the drive cycle is demonstrated for two ePump cases. By providing a benchmarking based on a generalized utilization cycle, this study serves as a guideline for selecting appropriate ePump architectures in electrified mobile hydraulic applications.