Volume 1 – Symposium: Tuesday, March 8

Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Components:Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Component

Volume 2 – Conference: Wednesday, March 9

10. Internationales Fluidtechnisches Kolloquium:Group 1 | 2: Novel System Structures Group 3 | 5: Pumps Group 4: Thermal Behaviour Group 6: Industrial Hydraulic

Volume 3 – Conference

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group 8: Pneumatics Group 9 | 11: Mobile applications Group 10: Special domains Group 12: Novel system architectures Group 13 | 15: Actuators & sensors Group 14: Safety & reliabilit

Volume 2 – Conference

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group 1 | 2: Digital systems Group 3: Novel displacement machines Group 4: Industrial applications Group 5: Components Group 6: Predictive maintenance Group 7: Electro-hydraulic actuatorsDer Download des Gesamtbandes wird erst nach der Konferenz ab 15. Oktober 2020 möglich sein.:Group 1 | 2: Digital systems Group 3: Novel displacement machines Group 4: Industrial applications Group 5: Components Group 6: Predictive maintenance Group 7: Electro-hydraulic actuator

Evaluation of steady flow torques and pressure losses in a rotary flow control valve by means of computational fluid dynamics.

In this paper, a novel design of a rotary hydraulic flow control valve has been presented for high flow rate fluid power systems. High flow rates in these systems account for substantial flow forces acting on the throttling elements of the valves and cause the application of mechanically sophisticated multi-staged servo valves for flow regulation. The suggested design enables utilisation of single-stage valves in power hydraulics operating at high flow rates regimes. A spool driver and auxiliary mechanisms of the proposed valve design were discussed and selection criteria were suggested. Analytical expressions for metering characteristics as well as steady flow torques have been derived. Computational fluid dynamics (CFD) analysis of steady state flow regimes was conducted to evaluate the hydraulic behaviour of the proposed valve. This study represents a special case of an independent metering concept applied to the design of power hydraulic systems with direct proportional valve control operating at flow rates above 150 litres per minute. The result gained using parametric CFD simulations predicted the induced torque and the pressure drops due to a steady flow. Magnitudes of these values prove that by minimising the number of spool’s mobile metering surfaces it is possible to reduce the flow-generated forces in the new generation of hydraulic valves proposed in this study. Calculation of the flow jet angles was analytically verified by measuring the deflection of the velocity vector using flow velocity field distribution, obtained during visualisation of the results of CFD simulations. The derived calculation formulas can predict metering characteristics, values of steady flow torques and jet angles for the specified design and geometry of the suggested valve. The proposed novel structure of the flow control valve promises to attain improved controllability, reliability and efficiency of the hydraulic control units of heavy mobile machinery operating at high flow rates regimes

Challenges with Respect to Control of Digital Displacement Hydraulic Units

This paper investigates the many complications arising when controlling a digital displacement hydraulic machine with non-smooth dynamical behavior. The digital hydraulic machine has a modular construction with numerous independently controlled pressure chambers. For proper control of dynamical systems, a model representation of the systems fundamental dynamics is required for transient analysis and controller design. Since the input is binary (active or inactive) and it may only be updated discretely, the machine comprises both continuous and discrete dynamics and therefore belongs to the class of hybrid dynamical systems. The study shows that the dynamical system behavior and control complexity are greatly dependent on the configuration of the machine, the operation strategy, and in which application it is used. Although the system has non-smooth dynamics, the findings show that simple continuous and discrete approximations may be applicable for control development in certain situations, whereas more advanced hybrid control theory is necessary to cover a broader range of situations

Methods and Tools to Ease the Electrification of Off-Highway Vehicles and Machinery Produced by Small and Medium-Sized Companies

Sostenibilità ambientale, emissione di gas serra, e inquinamento atmosferico sono tra i grandi driver dell’elettrificazione dei trasporti. Da questo punto di vista, l’elettrificazione dei consumi è evidente nel automotive, ma lo stesso è iniziato anche per l’industria Off-Highway. Questo passaggio è importante per lo sviluppo di nuove tecnologie, ma comporta nuove sfide. Per esempio, facilita l’insorgere di architetture e lo sviluppo di tecnologie evolutive e rivoluzionarie, favorendo la nascita di nuovi macchinari e aziende. A tal proposito, sia il mondo industriale che quello accademico hanno iniziato lo sviluppo di soluzioni elettrificate, ma con alti costi. Per le aziende medio-piccole, più sensibili al cambiamento, le risorse richieste da questo processo possono essere molto sfidanti. Molte lavorano come integratori di sistemi, cioè comprano dai fornitori componenti e sistemi stock. Al contrario, le aziende leader del mercato possono puntare su prodotti ottimizzati basati su componenti custom, rientrando dell’investimento iniziale grazie all’economia di scala. Modellistica e simulazione possono aiutare molto la progettazione a livello sistemico, ma lo sviluppo di un modello matematico non è banale. Questo processo può tuttavia essere semplificato da software di modellistica indirizzati all’ambiente industriale, specialmente per i produttori più piccoli. Modellistica e simulazione consentono il passaggio dall’approccio steady-state a transient-state, fondamentale per studiare i vantaggi dell’elettrificazione: nuove strategie di controllo, minori consumi energetici, maggior produttività, ecc. Dopo un’iniziale presentazione dell’industria, della sua storia, e delle sfide, sono presentati i componenti e le architetture principali. Sono anche mostrati i macchinari più interessanti per capire le tendenze di industria e ambiente accademico. Per esempio, si capisce che il retrofitting dei macchinari è importante per questa fase di transizione, seppur vero che possono essere applicate diverse migliorie. Per investigare quanto un software di modellistica di tipo industry-oriented sia in grado di aiutare le piccole-medie aziende del settore, un sollevatore idraulico elettrificato è creato usando Simscape. È mostrata la modellizzazione dei quattro sottosistemi principali, e i movimenti principali della macchina comparati con i dati sperimentali. Se ci si concentra sul focus di questo lavoro, simulazione e prove reali sono abbastanza vicini. Infatti, pur riconoscendo che modelli più dettagliati siano necessari per analisi più accurate, è evidente che questa tipologia di software può già essere usata per modellare sistemi complessi e prendere confidenza con alcuni risultati. Infine, due diversi approcci sono analizzati simulando il modello su un ciclo di lavoro. Innanzitutto, senza alcun cambiamento al sistema di controllo, viene proposto un valore di velocità che bilanci consumo di energia e produttività della macchina. A questo proposito, lo storico e le osservazioni empiriche del costruttore confermano tale risultato, evidenziando la buona applicabilità del modello. In secondo luogo, è implementata e simulata una nuova strategia per il controllo della velocità del motore elettrico, e i risultati mostrano una diminuzione del consumo energetico. Tuttavia, per migliorare l’accuratezza della previsione e diminuire di più i consumi, è necessario approfondire ulteriormente alcune componenti. I risultati ottenuti testimoniano quanto il sistema attuale possa essere migliorato senza cambiare alcun componente, basandosi solamente su un design di tipo transient-state, e sfruttando i vantaggi dell’elettrificazione. Inoltre, è dimostrato quanto un software di modellistica industry-oriented possa essere utile ai produttori più piccoli per affrontare meglio questa importante transizione.Environmental sustainability, greenhouse emissions, and air pollution reduction are among the major drivers for the electrification of the transport and mobility sector. Indeed, the electrification of the consumptions for the automotive industry is in broad daylight, but the same process has just started for the off-highway industry. This process enables new technologies, but it comes also with new challenges and objectives. For instance, it facilitates new off-highway architectures and the development of both incremental and disruptive technology, enabling the emergence of completely new machinery and companies too. In this regard, industry and academia have already started developing electrified solutions, but they come with high development costs. Small and medium-sized companies can be particularly sensitive to changes, and the expertise, cost, and timeframe related to this process can be extremely challenging. Many of these companies usually work as system integrators, relying on the integration and tuning of off-the-shelf components and systems. On the contrary, leading off-highway manufacturers can design more optimized machinery thanks to custom-made products, relying on the economy of scale to return on investments. Modeling and simulation can greatly help system-level design but building the mathematical model of an entire machinery is not trivial. In this regard, using industry-oriented modeling software like Simscape can simplify it, especially for small manufacturers. Indeed, modeling and simulation shift the design from steady-state design to dynamic and transient-state design, which is an essential step to investigate the potential of electrification: new control strategies, lower energy consumption, higher productivity, better forecast of the machinery hour rate, etc. After an overview of the industry, its history, and the new challenges, the main components and architectures typical of the electrification process are presented. The most interesting electrified machinery are also shown to understand the general trends of both industry and academia. In fact, this analysis shows how much retrofitting can be important for this transition to more electrified machinery, but also how many improvements can be applied. To investigate how much an industry-oriented modeling software can help small and medium-sized companies, an electrified material handler is modeled using Simscape. The modeling of the main four subsystems is presented (energy storage, electric motor, mechanics, and hydraulics), and the most important movements are compared with experimental data. While focusing on the real objectives of this work, simulation and real-world testing show a good match. Indeed, even if the modeling of other subsystems is needed for more in-depth and accurate analysis, it is shown how industry-oriented software can be used to model complex subsystems and to get sensible results. Lastly, two different approaches are analyzed by simulating the model over a personalized and realistic duty cycle. First, without changing anything of the current control strategy of the machinery, one reference velocity is proposed to balance energy consumption and productivity. The empirical results of the manufacturer of the hydraulic material handler confirm this trend, highlighting the good applicability of the model. Second, a new strategy based on the control of the electric motor speed is proposed and simulated. The results show the possibility of reducing energy consumption, but some components need to be modeled more in-depth to reach better accuracy and even lower results. Nonetheless, it proves how much the system can be improved without changing any component, by relying on transient-state design and using the additional control variables enabled by electrification. Furthermore, it is shown how much an industry-oriented modeling software can help SMEs during this important phase