bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Method for Preliminary Design of Variable Geometry Vaned Diffuser for Centrifugal Compressor
Authors: Tamaki Hideaki , Yamaguchi Satoshi 
Published: November 2023

Abstract
Centrifugal compressors require a wide operating range as well as high efficiency. Typical active control forms to enhance the operating range are suction throttling with a valve in a suction line, discharge throttling with a ring installed in a vaneless diffuser, variable inlet guide vanes, and variable geometry vaned diffuser (VVD). This study focuses on the design of a VVD whose vane rotates around a pivot to adjust its opening and proposes a method to estimate the main parameters of the VVD at the preliminary design stage. The design method here is based on matching the diffuser vane inlet angles with the flow angles at the diffuser inlet. If the designed VVD can maintain low incidence at the diffuser vane leading edge over the whole movable range of the vane is evaluated. A graph, which indicates the relation between the diffuser vane inlet angles and the flow angles at the diffuser inlet at diffuser choking and diffuser stalling, makes the evaluation easy. The proposed procedures were applied to select the number of vanes of the VVD for a turbocharger compressor. Tests for the validation of the design procedures were conducted by using fixed vaned diffusers that simulated the VVDs installed on the turbocharger with an 85 mm-diameter impeller. The results showed the effectiveness of the proposed design procedures. This paper first presents examples of applications of the typical active methods extending centrifugal compressors’ operating range for real machines and then discusses the design of VVD.
Eco-Driving Control of Connected and Automated Vehicles Using Neural Network–Based Rollout
Authors: Paugh Jacob , Zhu Zhaoxuan , Gupta Shobhit , Canova Marcello , Stockar Stephanie 
Published: November 2023

Abstract
Connected and autonomous vehicles have the potential to minimize energy consumption by optimizing the vehicle velocity and powertrain dynamics with Vehicle-to-Everything info en route. Existing deterministic and stochastic methods created to solve the eco-driving problem generally suffer from high computational and memory requirements, which makes online implementation challenging. This work proposes a hierarchical multi-horizon optimization framework implemented via a neural network. The neural network learns a full-route value function to account for the variability in route information and is then used to approximate the terminal cost in a receding horizon optimization. Simulations over real-world routes demonstrate that the proposed approach achieves comparable performance to a stochastic optimization solution obtained via reinforcement learning, while requiring no sophisticated training paradigm and negligible on-board memory.
Semi-Physical Modeling of Soft Pneumatic Actuators With Stiffness Tuning
Authors: Fairchild Preston , Shephard Noah , Mei Yu , Tan Xiaobo 
Published: November 2023

Abstract
The inherent low stiffness in soft robots makes them preferable for working in close proximity to humans. However, having this low stiffness creates challenges when operating in terms of control and sensitivity to disturbances. To alleviate this issue, soft robots often have built-in stiffness tuning mechanisms that allow for controlled increases in stiffness. Additionally, redundant pneumatic manipulators can utilize antagonistic pressure to achieve identical positions under increased stiffness. In this paper, we develop a model to predict the stiffness and configuration of a pneumatic soft manipulator under different pressure inputs and external forces. The model is developed based on the physical characteristics of a soft manipulator while enabling efficient parameter estimation and computation. The efficacy of the modeling approach is supported via experimental results.
A Novel Liquid Cooling Battery Thermal Management System With a Cooling Plate Based on Biomimetic Fractal Channels
Authors: Tang Zhiguo , Xiang Yi , Li Man , Cheng Jianping 
Published: November 2023

Abstract
An effective battery thermal management system (BTMS) is necessary to quickly release the heat generated by power batteries under a high discharge rate and ensure the safe operation of electric vehicles. Inspired by the biomimetic structure in nature, a novel liquid cooling BTMS with a cooling plate based on biomimetic fractal structure was proposed. By developing the physical model of the BTMS, numerical calculations were conducted to analyze the impacts of the structural parameters of the cooling plate and the inlet velocity of the coolant on the thermal performance of the batteries. The results showed that the cooling plate can meet the heat dissipation requirements of high-temperature uniformity for the batteries under high discharge rates, especially under the extremely uniform channel distribution mode for the adjacent fractal branch at the same level. Moreover, the increase in the group number of fractal branches can improve the cooling capacity of the cooling plate and reduce the pressure drop of the coolant. The increase in the level number of channels, the length ratio, and the inlet velocity of the coolant can enhance the cooling capacity. However, these methods of enhancing heat transfer require more pump power consumption. When the group number of fractal branches is 4, the level number of channels is 3, the length ratio is 1, and the inlet velocity of the coolant is 0.5 m/s, the BTMS can control the maximum temperature and maximum temperature difference of the batteries under 4C-rate discharge within 31.68 °C and 4.15 °C, respectively. Finally, orthogonal test was conducted on four factors: the group number of fractal branches, the level number of channels, the length ratio, and the inlet velocity of the coolant. The results showed that the level number of branches is the most important structural parameter.
Control of an Asymmetric Cylinder With Two Individually Controlled Pump/Motors
Authors: Kärnell Samuel , Ericson Liselott 
Published: November 2023

Abstract
Pump-controlled asymmetric cylinders need some kind of compensation for the difference between the in- and outlet flow. This can be done by using valves or additional pump/motors. An advantage with using valves is that only one pump/motor is required, but problems with mode-switch oscillations are more likely to occur. On the other hand, cylinder areas should be well matched with the pump/motor displacements for pump/motor compensation if the pump/motors are fixed and connected to the same shaft. However, this problem is avoided if the pump/motors are individually controlled. Furthermore, with individually controlled pump/motors, it is possible to control the pressure in one of the cylinder chambers and the piston speed simultaneously. This paper is focusing on such architectures. There are several possible configurations for architectures and control strategies for individually controlled pump/motors, and some are compared here. Results show that one of the configurations is more efficient than the others, but that it is less efficient than valve-compensation (assuming large valves). A controller design where one pump/motor is used to control the speed and another to control the pressure is suggested. Results show that the controller should be adapted based on the mode of operation.
Improving Fluid Power System Simulation Through an AAS-Based Simulation Framework
Authors: Becker Malte , Heppner Sebastian , Alt Raphael , Kleinert Tobias , Schmitz Katharina 
Published: November 2023

Abstract
This contribution introduces a simulation framework to significantly improve the simulation-based engineering process based on the Asset Administration Shell (AAS). The current simulation-based engineering process is characterized by long development times, high error susceptibility, and low availability of suitable simulation models. These deficits are addressed by seamlessly linking component data and encapsulated simulation models. Seamless linking is realized based on the AAS, a concept for realizing virtual representations of an asset [1]. The encapsulation enables better availability of simulation models in the engineering process by allowing stakeholders to exchange simulation models domain- and tool-independently. For this purpose, the Functional Mock-up Interface (FMI) is used, and coupling mechanisms for a component-based encapsulation of fluid power simulation models are presented.
Based on the AAS, linking component data and encapsulated simulation models is realized to parameterize the simulation models and reduce the long development time and error susceptibility.
Therefore, three functionalities have been developed based on the AAS data model. The first functionality allows searching and finding components or component simulation models from repositories of relevant stakeholders. As a result, individual components can be requested from specific component manufacturers during the development process. The second functionality enables domain- and tool-independent integration of simulation models into a simulation environment by using automatic parameterization or direct integration of encapsulated simulation models. Automatic parameterization reduces the time required and possible susceptibility to errors during manual parameterization, a task requiring integrating many different parameter sources. Finally, the third functionality enables bidirectional synchronization between field devices and component simulation models. As a result, the machine manufacturer can offer simulation model-based error support to the operator or assist the operator during commissioning.
These functionalities result in a concept for a new AAS-based simulation framework, shown in this contribution. The concept is a solution for mentioned deficits in the simulation-based engineering process.
Reinforcement Learning-Based Control of a Hydraulic Press With Multiple Actuators
Authors: Makansi Faried , Huang Jingkai , Schmitz Katharina 
Published: November 2023

Abstract
Methods of reinforcement learning are finding great success in solving complex decision and control tasks across different domains and applications. In the frame of control tasks, these methods seek to produce optimized controllers by gathering experience through interaction with the target system. Such controllers, which are often referred to as agents, can be generated without the need for rigorous physical modeling, parameter identification, and detailed knowledge of the system. Moreover, these approaches potentially allow to actuate several actuators with heterogenous control signal types, such as proportional valves and switching valves. Together with the generic interaction-based training concept, these approaches are promising tools for the control of complex hydraulic applications. The general applicability of reinforcement learning-based controllers for hydraulic control tasks has been shown in literature. However, several design options are not clearly investigated, especially regarding the selection of algorithms and the simultaneous coordination of multiple actuators. Therefore, this paper presents a study on different concepts for the reinforcement learning-based control of multiple actuators in a hydraulic press. Furthermore, solutions using a stochastic on-policy actor-critic algorithm (PPO) and a deterministic off-policy actor-critic method (TD3) are compared in this context. The results show that a setup with individual agents for each valve slightly outperforms solutions where one agent is used to control multiple valves. Moreover, the TD3 algorithm appears to yield better results on the given task than PPO.
3D Printed Gerotor Pump Geometries for Soft-Robot Actuation
Authors: Gallentine James , Barth Eric J. 
Published: November 2023

Abstract
Often, fluidic soft robots are driven by large pneumatic or low-bandwidth hydraulic systems which struggle to meet performance objectives. This research presents the design of two morphologies of compact, positive displacement hydraulic pumps designed to act as power supplies for fluidic soft robots. These hydraulic pumps were designed to leverage additive manufacturing technology, creating cost-effective, yet volumetrically powerful units. The operational bandwidth of these pumps (&gt; 10Hz) was substantially higher than the natural frequency of most elastomer-based soft robots (1–5Hz), allowing high control authority.
These designs allow for highly scalable pumps, with performance documented in the paper. Due to the 3D printed nature of the pump components, manufacture cost is greatly reduced when compared to machined components. Each was tested driving various soft robotic actuators, demonstrating high-bandwidth, yet precise operation.
With their minimal size, these pumps are candidates for un-tethered mobile soft robots, and their low weight and low noise allows them to be carried on the body for robotic actuators used in mobility rehabilitation.
Erosion Wear Analysis and Biomimetic Optimization of Solid Particles on Relief Valve
Authors: Cao Hao , Xu He , Sun Feng , Fan Weiwang 
Published: November 2023

Abstract
Hydraulic valve is a widely used mechanical component in hydraulic system. Its characteristics have great influence on the performance of hydraulic system. The surface of the relief valve spool is eroded by the erosion of particle pollutants in the oil. Erosion wear will lead to valve safety, stability decline. In this paper, the discrete phase model (DPM) was used to simulate the solid-liquid two-phase flow and and the results were analyzed. According to the erosion wear condition, a bionic valve core is designed by using bionic method. The erosion wear conditions of different kinds and diameter particles on valve were compared. The results show that different types and diameters have different erosion wear conditions on the valve core, and the bionic valve core has better erosion wear resistance than the prototype valve core. This paper provides a reference for further research on erosion and anti-erosion wear ability of bionic spool of relief valve.
A Programmable Multi-Functional Pressure-Compensated Multi-Way Valve Based on Differential Pressure Active Regulation
Authors: Wang Bo , Quan Long , Li Yunwei , Zhao Xingyu , Hao Yunxiao , Ge Lei 
Published: November 2023

Abstract
The traditional pressure-compensated multi-way valve generally have the problems of low flow control accuracy, limited flow range, and difficult flow fine-tuning. Therefore, this paper designs the pressure-compensated multi-way valve with active differential pressure regulation (PMVPR). Two proportional reducing valves (PRV) are used to change the force balance of the compensator spool, to realize the realtime regulation of the main valve differential pressure Δpm. Next, the strategies of disturbance compensation, variable gain control, nonlinear flow correction are designed. And the prototype of PMVPR and the feasibility of the proposed control strategy are experimentally verified. The experiment results show that by continuously controlling the output pressure of the PRV, the differential pressure Δpm can decrease to a minimum of 0.2 MPa and increase to a maximum of 1.6 MPa, and the flow of PMVPR varies within 40% to 140% of the rated flow; compensating the flow and spring force, the flow control accuracy of the PMVPR is improved, and the flow deviation of PMVPR can be reduced to less than 5% with different openings under 0∼35 MPa steady-state load characteristics; adopting the nonlinear flow correction strategy, the flow can change with the expected target flow, which has a good consistency. The new principle has impressive performance improvement of the entire valve and would provide new ideas for the further development of intelligent proportional multi-way valve and system.
Mixed Reality Technology: A Virtual Training Tool in Fluid Power Engineering
Authors: Azzam Israa , Pate Keith , Breidi Farid 
Published: November 2023

Abstract
Fluid power systems can be expensive and difficult to access, making it challenging to provide hands-on training. This work discusses the incorporation of Mixed Reality (MR) technology in Fluid Power applications for providing a virtual training environment that simulates the behavior of fluid power systems, allowing users to receive immediate feedback on the system’s performance. Mixed reality is a digitized-based technology that integrates a virtual environment with our real world by utilizing real-world sensor data and computer models. This technology allows running simulations that examine the complexity of highly-coupled systems, producing new digital environments where physical and digital elements can interact in real-time. With all these features, MR technology can be a practical training tool for running virtual simulations that mimic real-life industry settings. It can extend the user with a virtual training environment, thus preparing the next generation of fluid power engineers and specialists. Throughout this work, we present the development and capabilities of a digitized virtual copy of a hydraulic excavator’s arm in an MR environment as a proof of concept. The MR arm module is developed and deployed using Microsoft’s Mixed Reality Tool Kit (MRTK) for Unity through HoloLens 2 MR headset. The MR development involves generating virtual copies of the mechanical and hydraulic subsystems, conducting the virtual assembly, and creating a user interface in the MR environment to visualize and interact with the model. The developed MR module enables visualizing the excavator’s internal structure, conducting the virtual assembly, and running virtual simulations, all of which assist in training future fluid power operators. It is an effective training tool that helps train junior engineers/technicians, cutting down on cost and time.
Application of the Hydraulic Transformer Concept to Reduce Throttling Loss in a Multiple-Function Load Sensing System
Authors: Lengacher Jacob , Stump Patrick , Vacca Andrea , Jenkins Ryan , Pintore Francesco , Fiorati Stefano 
Published: November 2023

Abstract
A common problem encountered in state-of-the-art load-sensing (LS) systems is that of throttling losses due to load imbalance among hydraulic functions. Several architectures exist which resolve this challenge using multiple pumps — or accumulator-stabilized pressure rails — with dynamic switching of connections to minimize throttling losses. These solutions can be expensive and complex to implement, and can thus be unsuitable in cases when only one function causes the load imbalance. This work presents a solution based on a hydraulic transformer used to isolate one high-load, low-power actuator from the rest of the system while maintaining single pump LS functionality with lower throttling losses. This is accomplished by connecting a hydraulic transformer to an existing rotary function to boost the supplied pressure of the system to the level required by the high-load user. This boosted pressure is stabilized using an accumulator. This allows the main LS pumps in the system to operate at a pressure level set by the other functions.
The reference case considered is an Agricultural Tractor / Planter with four functions at similar load pressures and one requiring much higher pressure and much lower flow, which negatively affect energy efficiency. The paper describes the sizing of the proposed architecture using commercially available components, estimates its saving potential, and validates this potential with field tests. Experimental tests demonstrated a reduction in pump power of 37% over the baseline system for the most common operating conditions, demonstrating its viability as a method for reducing throttling losses caused by a load imbalance in the planter actuators.
Simulation Analysis of Flow Characteristics of a Novel Flap Check Valve Based on CFD Method
Authors: Peng Chao , Tan Shuang , Jin Sibo , Liangbin Xu , Lijun Chen , Xiaoping Ouyang 
Published: November 2023

Abstract
The traditional check valves mainly include lift check valves and swing check valves, but the lift check valve has a larger fluid resistance, and the swing check valve has a longer opening/closing time and slow dynamic response. In this paper, a new type of flap check valve is proposed based on the inspiration of the heart valve. To study the dynamic response of the valve and the flow characteristics of the flow field in the valve, a three-dimensional analysis model of the valve is established based on the dynamic mesh theory using the computational fluid dynamics (CFD) method, and the CFD simulation of the flow characteristics of the valve is carried out by setting the boundary conditions and working parameters. The transient flow field characteristics and the force state of the valve disc are discussed and analyzed. The simulation results show that: the dynamic response of the flap check valve in the process of opening and closing is faster than that of the swing check valve, and the flow line of the valve is close to laminar flow, so it is not easy to have turbulent flow phenomenon similar to that in the lift check valve.
Analysis and Simulation of Dynamics and Control of a Hydrostatic Wind Turbine
Authors: Leinberger Mark , Stelson Kim A. 
Published: November 2023

Abstract
Kω2 control, also called torque control, is a popular tool for maximizing wind turbine power in region 2. For hydrostatic wind turbines, the Kω2 law relates pressure and rotor speed. This work considers implementing the Kω2 law as pressure-regulation or rotor speed-regulation. Dimensionless, linearized models of these two approaches are used to investigate dynamics and control. Analysis shows that the mechanical rotor dynamics are much slower than the hydraulic transmission dynamics and that frictional and leakage losses have a negligible effect on system dynamics. Root locus analysis shows how systems responses change with variation of PID controller gains. Both control approaches require derivative controller action to sufficiently damp their responses; both are also fundamentally limited in their speed of response by a slow stable pole regardless of their controller loop gains. Nonlinear system simulation shows that both control approaches track the maximum power point with nearly identical transient behavior and experience nearly identical power losses when using suboptimal values of the control law gain K.
Adaptive Sliding Mode Control Based on the Immersion and Invariance Principle for the Accurate Spool Control of Proportional Servo Valve
Authors: Qiu Zhi , Zhang Junhui , Su Qi , Li Haibin , Xu Bing , Wang Jiasheng 
Published: November 2023

Abstract
Due to the wide working range of the proportional servo valve (PSV), the flow force changes greatly with the load pressure drop, which significantly affects the precise control of the valve spool position of the PSV. An adaptive sliding mode control based on the immersion and invariance principle (ASMCII) is designed in this paper to solve this problem. The load pressure drop is adaptive to the pressure senseless PSV, and then the ASMCII is used to achieve high precision control. Firstly, the dynamic model of PSV system under unknown large flow force disturbances is established, and the sliding mode control strategy based on reaching law is designed and applied. Secondly, in the design of disturbance estimation error manifold, the immersion and invariance principle (I&I) are applied to ensure the estimation error of load pressure drop converges to 0, for the sake of the accurate estimation of flow force. Finally, the stability analysis and simulation of the system are carried out. The results show that under the simulation conditions of 0–35 MPa, ASMCII converges uncertain pressure drops quickly to compensate flow force completely, which promotes both static and dynamical performance significantly contrast to PID and the sliding mode control.