Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (374)

Search Parameters:
Keywords = pumping control range

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
20 pages, 14676 KB  
Article
Optimal and Model Predictive Control of Single Phase Natural Circulation in a Rectangular Closed Loop
by Aitazaz Hassan, Guilherme Ozorio Cassol, Syed Abuzar Bacha and Stevan Dubljevic
Sustainability 2025, 17(19), 8807; https://doi.org/10.3390/su17198807 - 1 Oct 2025
Abstract
Pipeline systems are essential across various industries for transporting fluids over various ranges of distances. A notable application is natural circulation through thermo-syphoning, driven by temperature-induced density variations that generate fluid flow in closed loops. This passive mechanism is widely employed in sectors [...] Read more.
Pipeline systems are essential across various industries for transporting fluids over various ranges of distances. A notable application is natural circulation through thermo-syphoning, driven by temperature-induced density variations that generate fluid flow in closed loops. This passive mechanism is widely employed in sectors such as process engineering, oil and gas, geothermal energy, solar water heaters, fertilizers, etc. Natural Circulation Loops eliminate the need for mechanical pumps. While this passive mechanism reduces energy consumption and maintenance costs, maintaining stability and efficiency under varying operating conditions remains a challenge. This study investigates thermo-syphoning in a rectangular closed-loop system and develops optimal control strategies like using a Linear Quadratic Regulator (LQR) and Model Predictive Control (MPC) to ensure stable and efficient heat removal while explicitly addressing physical constraints. The results demonstrate that MPC improves system stability and reduces energy usage through optimized control actions by nearly one-third in the initial energy requirement. Compared to the LQR and unconstrained MPC, MPC with active constraints effectively manages input limitations, ensuring safer and more practical operation. With its predictive capability and adaptability, the proposed MPC framework offers a robust, scalable solution for real-time industrial applications, supporting the development of sustainable and adaptive natural circulation pipeline systems. Full article
Show Figures

Figure 1

21 pages, 6171 KB  
Article
Detailed Transient Study of a Transcritical CO2 Heat Pump for Low-Carbon Building Heating
by Jierong Liang and Tingxun Li
Buildings 2025, 15(19), 3489; https://doi.org/10.3390/buildings15193489 - 26 Sep 2025
Abstract
This study presents the development and experimental validation of a dynamic simulation model for a transcritical CO2 heat pump system coupled with a stratified water tank, with particular focus on strong transient behavior and detailed heat exchanger characteristics. Due to the unique [...] Read more.
This study presents the development and experimental validation of a dynamic simulation model for a transcritical CO2 heat pump system coupled with a stratified water tank, with particular focus on strong transient behavior and detailed heat exchanger characteristics. Due to the unique thermophysical properties of CO2 under transcritical conditions, conventional modeling approaches are insufficient. The model was validated against experimental results under a range of operating conditions. It accurately predicted outlet water temperatures within ±3.2 °C and system COP within ±6.8% deviation from measurements. In contrast to previous models, this approach offers improved accuracy in capturing dynamic system responses, including startup transients, and demonstrates high adaptability across varying ambient temperatures and load profiles. Importantly, the model also considers the vertical installation layout of components, enabling analysis of gravitational effects on system dynamics and offering insights into optimal configuration strategies. The validated model serves as a powerful tool for system optimization and advanced control design in residential CO2 heat pump applications. Full article
(This article belongs to the Section Building Energy, Physics, Environment, and Systems)
Show Figures

Figure 1

13 pages, 563 KB  
Review
Treatment of Type 1 Diabetes Mellitus During Pregnancy Using an Insulin Pump with an Advanced Hybrid Closed-Loop System: A Narrative Review
by Ingrid Dravecká
Reprod. Med. 2025, 6(4), 26; https://doi.org/10.3390/reprodmed6040026 - 25 Sep 2025
Abstract
Pregnancy in women with type 1 diabetes mellitus (T1DM) is associated with a high risk of maternal and perinatal complications, and achieving optimal glycaemic control remains a clinical challenge. This article presents a narrative review of the evidence on advanced hybrid closed loop [...] Read more.
Pregnancy in women with type 1 diabetes mellitus (T1DM) is associated with a high risk of maternal and perinatal complications, and achieving optimal glycaemic control remains a clinical challenge. This article presents a narrative review of the evidence on advanced hybrid closed loop (AHCL) insulin delivery systems in pregnancy, with a focus on maternal glycaemic outcomes, neonatal outcomes, and psychosocial aspects. The relevant literature was identified through a structured search of PubMed, Scopus, and Web of Science (2010–2025), supplemented by guideline documents and reference screening. Eligible studies included randomised controlled trials, observational studies, and qualitative investigations. Data were synthesised thematically. Findings from key trials, including CONCEPTT, AiDAPT, and CRISTAL, demonstrate that AHCL systems improve time in range, lower mean glucose, and reduce hyperglycaemia without increasing hypoglycaemia. Some evidence also suggests improved neonatal outcomes, though statistical significance varies. Qualitative studies highlight reduced anxiety, improved sleep, and enhanced quality of life for women using AHCL during pregnancy. In conclusion, AHCL systems show strong promise in optimising maternal glycaemic control and potentially improving perinatal outcomes. However, larger, unbiased studies and real-world evaluations are needed to confirm their benefits and support broader clinical implementation. Full article
Show Figures

Figure 1

14 pages, 505 KB  
Article
Experimental Setup for the Validation of Photoplethysmography Devices for the Evaluation of Arteriovenous Fistulas
by Simone Chiorboli, Adriano Brugnoli and Vincenzo Piemonte
Bioengineering 2025, 12(9), 990; https://doi.org/10.3390/bioengineering12090990 - 18 Sep 2025
Viewed by 267
Abstract
This study describes the design and validation of an experimental setup for testing photoplethysmographic (PPG) devices intended for the non-invasive monitoring of vascular accesses in hemodialysis patients. Continuous assessment of arteriovenous fistulas is essential to detect pathological conditions such as stenosis, which can [...] Read more.
This study describes the design and validation of an experimental setup for testing photoplethysmographic (PPG) devices intended for the non-invasive monitoring of vascular accesses in hemodialysis patients. Continuous assessment of arteriovenous fistulas is essential to detect pathological conditions such as stenosis, which can compromise patient safety and dialysis efficacy. While PPG-based sensors are capable of detecting such anomalies, their clinical applicability must be supported by controlled in vitro validation. The developed system replicates the anatomical, mechanical, optical, and hemodynamic features of vascular accesses. A 3D fistula model was designed and fabricated via 3D printing and silicone casting. The hydraulic circuit used red India ink and a PWM-controlled pump to simulate physiological blood flow, including stenotic conditions. Quantitative validation confirmed anatomical accuracy within 0.1 mm tolerance. The phantom exhibited an average Shore A hardness of 20.3 ± 1.1, a Young’s modulus of 10.4 ± 0.9 MPa, and a compression modulus of 105 MPa—values consistent with soft tissue behavior. Burst pressure exceeded 2000 mmHg, meeting ISO 7198:2016 standards. Flow rates (400–700 mL/min) showed <1% error. Compliance was 2.4 ± 0.2, and simulated blood viscosity was 3.9 ± 0.3 mPa·s. Systolic and diastolic pressures fell within physiological ranges. Photoplethysmographic signals acquired using a MAX30102 sensor (Analog devices Inc., Wilmington, MA, USA) reproduced key components of in vivo waveforms, confirming the system’s suitability for device testing. Full article
(This article belongs to the Section Biomedical Engineering and Biomaterials)
Show Figures

Figure 1

18 pages, 6260 KB  
Article
Operational Mechanisms and Energy Analysis of Variable-Speed Pumping Stations
by Yan Li, Jilong Lin, Yonggang Lu, Zhiwang Liu, Litao Qu, Fanxiao Jiao, Zhengwei Wang and Qingchang Meng
Water 2025, 17(17), 2620; https://doi.org/10.3390/w17172620 - 4 Sep 2025
Viewed by 879
Abstract
The spatiotemporal uneven distribution of water resources conflicts sharply with human demands, with pumping stations facing efficiency decline due to aging infrastructure and complex hydraulic interactions. This study employs numerical simulation to investigate operational mechanisms in a parallel pump system at the Yanhuanding [...] Read more.
The spatiotemporal uneven distribution of water resources conflicts sharply with human demands, with pumping stations facing efficiency decline due to aging infrastructure and complex hydraulic interactions. This study employs numerical simulation to investigate operational mechanisms in a parallel pump system at the Yanhuanding Yanghuang Cascade Pumping Station. Using ANSYS Fluent 2024 R1 and the SST k-ω turbulence model, we demonstrate that variable-speed control expands the adjustable flow range to 1.17–1.26 m3/s while maintaining system efficiency at 83–84% under head differences of 77.8–79.8 m. Critically, energy losses (δH) at the 90° outlet pipe junction escalate from 3.8% to 18.2% of total energy with increasing flow, while Q-criterion vortex analysis reveals a 63% vortex area reduction at lower speeds. Furthermore, a dual-mode energy dissipation mechanism was identified: at 0.90n0 speed, turbulent kinetic energy surges by 115% with minimal dissipation change, indicating large-scale vortex dominance, whereas at 0.80n0, turbulent dissipation rate increases drastically by 39%, signifying a shift to small-scale viscous dissipation. The novelty of this work lies in the first systematic quantification of junction energy losses and the revelation of turbulent energy transformation mechanisms in parallel pump systems. These findings provide a physics-based foundation for optimizing energy efficiency in high-lift cascade pumping stations. Full article
(This article belongs to the Section Hydraulics and Hydrodynamics)
Show Figures

Figure 1

16 pages, 7655 KB  
Article
A Low-Jitter Delay Synchronization System Applied to Ti:sapphire Femtosecond Laser Amplifier
by Mengyao Wu, Guodong Liu, Meixuan He, Wenjun Shu, Yunpeng Jiao, Haojie Li, Weilai Yao and Xindong Liang
Appl. Sci. 2025, 15(17), 9424; https://doi.org/10.3390/app15179424 - 28 Aug 2025
Viewed by 540
Abstract
Femtosecond lasers have evolved continuously over the past three decades, enabling the transition of research from fundamental studies in atomic and molecular physics to the realm of practical applications. In femtosecond laser amplifiers, to ensure strict synchronization between the seed laser pulse and [...] Read more.
Femtosecond lasers have evolved continuously over the past three decades, enabling the transition of research from fundamental studies in atomic and molecular physics to the realm of practical applications. In femtosecond laser amplifiers, to ensure strict synchronization between the seed laser pulse and the pump laser, enabling their precise overlap during the amplification process and avoiding a decline in pulse amplification efficiency and the generation of undesired phase noise, this study designed a synchronous timing signal generation system based on the combination of FPGA and analog delay. This system was investigated from three aspects: delay pulse width adjustment within a certain range, precise delay resolution, and external trigger jitter compensation. By using a FPGA digital counter to achieve coarse-delay control over a wide range and combining it with the method of passive precise fine delay, the system can generate synchronous delay signals with a large delay range, high precision, and multiple channels. Regarding the problem of asynchronous phase between the external trigger and the internal clock, a jitter compensation circuit was proposed, consisting of an active gated integrator and an output comparator, which compensates for the uncertainty of trigger timing through analog delay. The verification of this study shows that the system operates stably under an external trigger with a repetition frequency of 80 MHz. The output delay range is from 10 ns to 100 μs, the coarse-delay resolution is 10 ns, the fine-delay adjustment step is 1.25 ns, and the pulse jitter is reduced from a maximum of 10 ns to the hundred-picosecond level. This meets the requirements of femtosecond laser amplifiers for synchronous trigger signals and offers essential technical support and fundamental assurance for the high-power and high-efficiency amplification of Ti:sapphire ultrashort laser pulses. Full article
Show Figures

Figure 1

9 pages, 1015 KB  
Article
Semiconductor Laser with Electrically Modulated Frequency
by Boris Laikhtman, Gregory Belenky and Sergey Suchalkin
Photonics 2025, 12(9), 860; https://doi.org/10.3390/photonics12090860 - 27 Aug 2025
Viewed by 471
Abstract
We propose a novel method for controlling the frequency of semiconductor lasers. This technique facilitates the production of devices with fast frequency tuning and intrinsic linearization of laser frequency sweeps. The electrical contact layer positioned between the lower undoped cladding and the waveguide, [...] Read more.
We propose a novel method for controlling the frequency of semiconductor lasers. This technique facilitates the production of devices with fast frequency tuning and intrinsic linearization of laser frequency sweeps. The electrical contact layer positioned between the lower undoped cladding and the waveguide, along with the upper laser contact, is used for the optical gain pumping. Since the laser pumping current does not pass through the lower cladding, changes in carrier concentration within the cladding affect the laser frequency while minimally impacting the device’s output power. Control of the free carrier concentration in the lower cladding is achieved using the space-charge-limited current (SCLC) technique. This novel approach establishes a linear relationship between the laser frequency shift (∆f) and voltage (V) applied to the cladding—an essential feature for light detection and ranging (LIDAR) system development. The proposed technique is applicable to all semiconductor lasers. As an example, we present the calculated characteristics of a quantum cascade laser (QCL) operating at a 10 µm wavelength. Full article
(This article belongs to the Special Issue Photonics: 10th Anniversary)
Show Figures

Figure 1

20 pages, 8470 KB  
Article
Experimental Investigation of Fracture Behavior in Coal-Seam Hard Roofs Using Different Fracturing Fluids
by Maolin Yang, Shuai Lv, Sicheng Wang, Xing Wang, Yu Meng and Yongjiang Luo
Appl. Sci. 2025, 15(17), 9321; https://doi.org/10.3390/app15179321 - 25 Aug 2025
Viewed by 572
Abstract
In fully mechanized mining faces with large mining heights, thick and hard roofs present significant challenges, including extensive overhang areas, difficult roof control, and frequent roof failures. Hydraulic fracturing is a crucial technique for roof weakening and mine pressure control, and the performance [...] Read more.
In fully mechanized mining faces with large mining heights, thick and hard roofs present significant challenges, including extensive overhang areas, difficult roof control, and frequent roof failures. Hydraulic fracturing is a crucial technique for roof weakening and mine pressure control, and the performance of fracturing fluids directly determines the effectiveness of pressure relief. This study conducted true triaxial hydraulic fracturing experiments using three media: clear water and low-viscosity and high-viscosity fracturing fluids. Fracture propagation patterns under varying media and roof strength conditions were systematically investigated through acoustic emission (AE) monitoring, pump pressure analysis, and rock strain measurements. The results show that both fracturing fluid properties and roof compressive strength significantly influence hydraulic fracture initiation, AE characteristics, and ultimate fracture morphology. Compared to conventional clear water, high-viscosity fracturing fluid exhibits superior performance in fracture initiation efficiency (34% higher peak pressure), propagation intensity (3.7 times more AE energy), and influence range (34% greater fracture length). These advantages make it particularly suitable for hard roof conditions requiring precise fracture management. The results provide a theoretical foundation for optimizing hydraulic fracturing parameters in hard roof control engineering applications. Full article
Show Figures

Figure 1

27 pages, 16089 KB  
Article
Broadband Sound Insulation Enhancement Using Multi-Layer Thin-Foil Acoustic Membranes: Design and Experimental Validation
by Chun Gong, Faisal Rafique and Fengpeng Yang
Appl. Sci. 2025, 15(17), 9279; https://doi.org/10.3390/app15179279 - 23 Aug 2025
Viewed by 747
Abstract
This study presents an acoustic membrane design utilizing a thin foil sound resonance mechanism to enhance sound absorption and insulation performance. The membranes incorporate single-layer and double-layer structures featuring parallel foil square wedge-shaped coffers and a flat bottom panel, separated by air cavities. [...] Read more.
This study presents an acoustic membrane design utilizing a thin foil sound resonance mechanism to enhance sound absorption and insulation performance. The membranes incorporate single-layer and double-layer structures featuring parallel foil square wedge-shaped coffers and a flat bottom panel, separated by air cavities. The enclosed air cavity significantly improves the sound insulation capability of the acoustic membrane. Parametric studies were conducted to investigate key factors affecting the sound transmission loss (STL) of the proposed acoustic membrane. The analysis examined the influence of foil thickness, substrate thickness, and back cavity depth on acoustic performance. Results demonstrate that the membrane structure enriches vibration modes in the 500–6000 Hz frequency range, exhibiting multiple acoustic attenuation peaks and broader noise reduction bandwidth (average STL of 40–55 dB across the researched frequency range) compared to conventional resonant cavities and membrane-type acoustic metamaterials. The STL characteristics can be tuned across different frequency bands by adjusting the back cavity depth, foil thickness, and substrate thickness. Experimental validation was performed through noise reduction tests on an air compressor pump. Comparative acoustic measurements confirmed the superior noise attenuation performance and practical applicability of the proposed membrane over conventional acoustic treatments. Compared to uniform foil resonators, the combination of plastic and steel materials with single-layer and double-layer membranes reduced the overall sound level (OA) by an additional 2–3 dB, thereby offering exceptional STL performance in the low- to medium-frequency range. These lightweight, easy-to-manufacture membranes exhibit considerable potential for noise control applications in household appliances and industrial settings. Full article
(This article belongs to the Section Acoustics and Vibrations)
Show Figures

Figure 1

50 pages, 2391 KB  
Review
A Comprehensive Review of Heat Transfer Fluids and Their Velocity Effects on Ground Heat Exchanger Efficiency in Geothermal Heat Pump Systems
by Khaled Salhein, Abdulgani Albagul and C. J. Kobus
Energies 2025, 18(17), 4487; https://doi.org/10.3390/en18174487 - 23 Aug 2025
Viewed by 773
Abstract
This study reviews heat transfer fluids (HTFs) and their velocity effects on the thermal behavior of ground heat exchangers (GHEs) within geothermal heat pump (GHP) applications. It examines the classification, thermophysical properties, and operational behavior of standard working fluids, including water–glycol mixtures, as [...] Read more.
This study reviews heat transfer fluids (HTFs) and their velocity effects on the thermal behavior of ground heat exchangers (GHEs) within geothermal heat pump (GHP) applications. It examines the classification, thermophysical properties, and operational behavior of standard working fluids, including water–glycol mixtures, as well as emerging nanofluids. Fundamental heat exchange mechanisms are discussed, with emphasis on how conductivity, viscosity, and heat capacity interact with fluid velocity to influence energy transfer performance, hydraulic resistance, and system reliability. Special attention is given to nanofluids, whose enhanced thermal behavior depends on nanoparticle type, concentration, dispersion stability, and flow conditions. The review analyzes stabilization strategies, including surfactants, functionalization, and pH control, for maintaining long-term performance. It also highlights the role of velocity optimization in balancing convective benefits with pumping energy demands, providing velocity ranges suited to different GHE configurations. Drawing from recent experimental and numerical studies, the review offers practical guidelines for integrating nanofluid formulation with engineered operating conditions to maximize energy efficiency and extend system lifespan. Full article
Show Figures

Figure 1

10 pages, 240 KB  
Article
Differences in Metabolic Control Between Different Insulin Use Patterns in Pediatric Patients with Type 1 Diabetes Through Intermittent Glucose Monitoring
by Rocio Porcel-Chacón, Leopoldo Tapia-Ceballos, Ana-Belen Ariza-Jimenez, Ana Gómez-Perea, José Manuel Jiménez-Hinojosa, Juan-Pedro López-Siguero and Isabel Leiva-Gea
Diseases 2025, 13(8), 254; https://doi.org/10.3390/diseases13080254 - 9 Aug 2025
Viewed by 391
Abstract
Introduction: In healthcare centers with limited resources, or for patients who prefer to make continuous changes in their treatment themselves and do not want to rely solely on technology, intermittent glucose monitoring (isCGM) with an insulin pump is a viable option that warrants [...] Read more.
Introduction: In healthcare centers with limited resources, or for patients who prefer to make continuous changes in their treatment themselves and do not want to rely solely on technology, intermittent glucose monitoring (isCGM) with an insulin pump is a viable option that warrants further study. Material and methods: prospective single-center study that collected data at 3 months and after isCGM implantation in pediatric patients with Type 1 diabetes, categorized according to their insulin regimen. Results: We found statistically significant differences in the time in range (TIR) between 70 and 180 mg/dl at 3 months after using the sensor (p = 0.017), although these differences were not maintained at 1 year (p = 0.064). When stricter TIRs (70–140 mg/dl) were analyzed, statistically significant differences were observed at 3 months (p = 0.01) and at 1 year (p = 0.018) in favor of patients using CSII. While 75% of the patients in the CSII group had good control with HbA1c < 7% after one year of sensor use, only 34.6% in the MDI group achieved these values. However, the CSII group presented a higher coefficient of variation (62.31% at 3 months and 43.08% at 1 year) (p = 0.02), and a higher number of hypoglycemic episodes (7.38% and 7.32%, respectively) (p = 0.016). The CSII group also had a higher number of capillary blood glucose measurements at the beginning of the study (8.32/day) (p = 0.249), but this number became similar between both groups after one year. Conclusions: We found statistically significant differences in favor of CSII over MDI in terms of metabolic control after one year of isCGM use. However, the TIR values were still below the range considered to be indicative of good control. These findings lead us to question whether CSII should be initially considered in specific cases where HCL is not possible, or if it would be more effective to wait until the patient is ready, or the necessary resources are available to start directly CSII integrated in a closed loop system. Full article
22 pages, 13716 KB  
Article
In Silico Identification of Six Mushroom-Derived Sterol and Triterpenoid Compounds as Potential P-Glycoprotein Modulators in Multidrug Resistance
by Jéssica Fonseca, Carlos S. H. Shiraishi, Rui M. V. Abreu, Sara Ricardo and Josiana A. Vaz
Appl. Sci. 2025, 15(16), 8772; https://doi.org/10.3390/app15168772 - 8 Aug 2025
Viewed by 409
Abstract
The overexpression of P-glycoprotein (P-gp) is often directly related to multidrug resistance (MDR), one of the greatest challenges in cancer treatment. This transmembrane efflux pump decreases the intracellular concentrations of chemotherapy drugs, reducing their effectiveness and resulting in treatment failure. This work used [...] Read more.
The overexpression of P-glycoprotein (P-gp) is often directly related to multidrug resistance (MDR), one of the greatest challenges in cancer treatment. This transmembrane efflux pump decreases the intracellular concentrations of chemotherapy drugs, reducing their effectiveness and resulting in treatment failure. This work used in silico methods to assess the potential of bioactive chemicals produced from mushrooms as P-gp modulators. A database comprising 211 bioactive compounds from mushrooms was investigated using molecular docking and virtual screening techniques against the P-gp structure. The compounds ergosta-4,6,8(14),22-tetraen-3-one, lucidumol A, (22E,24S)-ergosta-4,22-dien-3-one, antcin K, 3,11-dioxolanosta-8,24(Z)-diene-26-oic acid, and (22E)-19-norergosta-5,7,9,22-tetraen-3β-ol were identified as the six best candidates from our database of mushroom compounds based on their binding affinities, toxicity predictions, and pharmacological properties assessed through ADME analyses (absorption, distributions, metabolism, and excretion). These six compounds exhibited strong binding affinities, with binding energies ranging from −12.31 kcal/mol to −10.93 kcal/mol, all showing higher affinities than the control, tariquidar, which had a binding energy of −10.78 kcal/mol. Toxicity predictions indicated favorable safety profiles for all six, while ADME analyses found that all six compounds had high oral bioavailability and a low probability of acting as P-gp substrates. These results position bioactive mushroom compounds, particularly these six, as promising P-gp modulators, suggesting positive outcomes in cancer treatment. Full article
(This article belongs to the Special Issue Anticancer Drugs: New Developments and Discoveries)
Show Figures

Figure 1

25 pages, 6272 KB  
Article
Research on Energy-Saving Control of Automotive PEMFC Thermal Management System Based on Optimal Operating Temperature Tracking
by Qi Jiang, Shusheng Xiong, Baoquan Sun, Ping Chen, Huipeng Chen and Shaopeng Zhu
Energies 2025, 18(15), 4100; https://doi.org/10.3390/en18154100 - 1 Aug 2025
Cited by 2 | Viewed by 526
Abstract
To further enhance the economic performance of fuel cell vehicles (FCVs), this study develops a model-adaptive model predictive control (MPC) strategy. This strategy leverages the dynamic relationship between proton exchange membrane fuel cell (PEMFC) output characteristics and temperature to track its optimal operating [...] Read more.
To further enhance the economic performance of fuel cell vehicles (FCVs), this study develops a model-adaptive model predictive control (MPC) strategy. This strategy leverages the dynamic relationship between proton exchange membrane fuel cell (PEMFC) output characteristics and temperature to track its optimal operating temperature (OOT), addressing challenges of temperature control accuracy and high energy consumption in the PEMFC thermal management system (TMS). First, PEMFC and TMS models were developed and experimentally validated. Subsequently, the PEMFC power–temperature coupling curve was experimentally determined under multiple operating conditions to serve as the reference trajectory for TMS multi-objective optimization. For MPC controller design, the TMS model was linearized and discretized, yielding a predictive model adaptable to different load demands for stack temperature across the full operating range. A multi-constrained quadratic cost function was formulated, aiming to minimize the deviation of the PEMFC operating temperature from the OOT while accounting for TMS parasitic power consumption. Finally, simulations under Worldwide Harmonized Light Vehicles Test Cycle (WLTC) conditions evaluated the OOT tracking performance of both PID and MPC control strategies, as well as their impact on stack efficiency and TMS energy consumption at different ambient temperatures. The results indicate that, compared to PID control, MPC reduces temperature tracking error by 33%, decreases fan and pump speed fluctuations by over 24%, and lowers TMS energy consumption by 10%. These improvements enhance PEMFC operational stability and improve FCV energy efficiency. Full article
Show Figures

Figure 1

15 pages, 2371 KB  
Article
Designing and Implementing a Ground-Based Robotic System to Support Spraying Drone Operations: A Step Toward Collaborative Robotics
by Marcelo Rodrigues Barbosa Júnior, Regimar Garcia dos Santos, Lucas de Azevedo Sales, João Victor da Silva Martins, João Gabriel de Almeida Santos and Luan Pereira de Oliveira
Actuators 2025, 14(8), 365; https://doi.org/10.3390/act14080365 - 23 Jul 2025
Cited by 1 | Viewed by 1019
Abstract
Robots are increasingly emerging as effective platforms to overcome a wide range of challenges in agriculture. Beyond functioning as standalone systems, agricultural robots are proving valuable as collaborative platforms, capable of supporting and integrating with humans and other technologies and agricultural activities. In [...] Read more.
Robots are increasingly emerging as effective platforms to overcome a wide range of challenges in agriculture. Beyond functioning as standalone systems, agricultural robots are proving valuable as collaborative platforms, capable of supporting and integrating with humans and other technologies and agricultural activities. In this study, we designed and implemented an automated system embedded in a ground-based robotic platform to support spraying drone operations. The system consists of a robotic platform that carries the spraying drone along with all necessary support devices, including a water tank, chemical reservoirs, a mixer, generators for drone battery charging, and a top landing pad. The system is controlled with a mobile app that calculates the total amount of water and chemicals required and sends commands to the platform to prepare the application mixture. The input information in the app includes the field area, application rate, and up to three chemical dosages simultaneously. Additionally, the platform allows the drone to take off from and land on it, enhancing both safety and operability. A set of pumps was used to deliver water and chemicals as specified in the mobile app. To automate pump control, we used Arduino technology, including both the microcontroller and a programming environment for coding and designing the mobile app. To validate the system’s effectiveness, we individually measured the amount of water and chemical delivered to the mixer tank and compared it with conventional manual methods for calculating chemical quantities and preparation time. The system demonstrated consistent results, achieving high precision and accuracy in delivering the correct amount. This study advances the field of agricultural robotics by highlighting the role of collaborative platforms. Particularly, the system presents a valuable and low-cost solution for small farms and experimental research. Full article
(This article belongs to the Special Issue Design and Control of Agricultural Robotics)
Show Figures

Figure 1

27 pages, 6704 KB  
Article
Dynamic Characteristics of a Digital Hydraulic Drive System for an Emergency Drainage Pump Under Alternating Loads
by Yong Zhu, Yinghao Liu, Qingyi Wu and Qiang Gao
Machines 2025, 13(8), 636; https://doi.org/10.3390/machines13080636 - 22 Jul 2025
Viewed by 417
Abstract
With the frequent occurrence of global floods, the demand for emergency rescue equipment has grown rapidly. The development and technological innovation of digital hydraulic drive systems (DHDSs) for emergency drainage pumps (EDPs) have become key to improving rescue efficiency. However, EDPs are prone [...] Read more.
With the frequent occurrence of global floods, the demand for emergency rescue equipment has grown rapidly. The development and technological innovation of digital hydraulic drive systems (DHDSs) for emergency drainage pumps (EDPs) have become key to improving rescue efficiency. However, EDPs are prone to being affected by random and uncertain loads during operation. To achieve intelligent and efficient rescue operations, a DHDS suitable for EDPs was proposed. Firstly, the configuration and operation mode of the DHDS for EDPs were analyzed. Based on this, a multi-field coupling dynamic simulation platform for the DHDS was constructed. Secondly, the output characteristics of the system under alternating loads were simulated and analyzed. Finally, a test platform for the EDP DHDS was established, and the dynamic characteristics of the system under alternating loads were explored. The results show that as the load torque of the alternating loads increases, the amplitude of the pressure of the motor also increases, the output flow of the hydraulic-controlled proportional reversing valve (HCPRV) changes slightly, and the fluctuation range of the rotational speed of the motor increases. The fluctuation range of the pressure and the rotational speed of the motor are basically not affected by the frequency of alternating loads, but the fluctuation amplitude of the output flow of the HCPRV reduces with the increase in the frequency of alternating loads. This system can respond to changes in load relatively quickly under alternating loads and can return to a stable state in a short time. It has laudable anti-interference ability and output stability. Full article
(This article belongs to the Section Electrical Machines and Drives)
Show Figures

Figure 1

Back to TopTop