Extended Analysis of a Valve-Controlled System with Multi-Chamber Actuator

2021 ◽  
Author(s):  
Henrique Raduenz ◽  
Liselott Ericson ◽  
Kim Heybroek ◽  
Victor J. De. Negri ◽  
Petter Krus
Keyword(s):  
Energy Losses ◽  
System Efficiency ◽  
Proportional Valve ◽  
Controlled System ◽  
Load Sensing ◽  
Controlled Systems ◽  
Compensation Factor ◽  
State Behaviour ◽  
Extended Analysis

This paper outlines an extended analysis on how multi-chamber actuators can improve the efficiency of valve-controlled systems. Resistive control is a major source of energy losses in valve-controlled systems that share the same pump to drive multiple loads. By combining different chambers, the load on multi-chamber actuators can be transformed into different pressure and flow rate levels. This allows the adaptation of its load to the loads on other actuators. This can lead to a reduction of resistive control energy losses that occur between pump and actuators when driven simultaneously. As a case study to highlight how the system efficiency can be improved, a load sensing system with a conventional and a multi-chamber actuator is analysed. The equations that describe the system steady state behaviour are presented to evaluate the effect of the load transformations on the system efficiency. A disadvantage of such architecture is the fact that load transformations result in different actuator speeds. To reduce this effect, a compensation factor for the command signal to the proportional valve is presented. The highlight from this paper is the potential for efficiency improvement enabled by the adoption of multi-chamber actuators in a valve-controlled architecture. Further research is required for the selection of number of chambers and their areas since they directly affect the system efficiency.

scholarly journals Analysis of energy losses in a hydraulic load sensing proportional valve

2021 ◽  
Vol 868 (1) ◽  
pp. 012038
Author(s):  
S M Mirzaliev ◽  
M K Sultonov ◽  
G Lucci ◽  
A K Igamberdiyev ◽  
N А Kholikova
Keyword(s):  
Energy Losses ◽  
Proportional Valve ◽  
Load Sensing ◽  
Hydraulic Load

Reliability of nonlinear stochastic controlled systems considering the dynamics of sensors and actuators

2021 ◽  
pp. 107754632110037
Author(s):  
Sun Jiaojiao ◽  
Xia Lei ◽  
Ying Zuguang ◽  
Huan Ronghua ◽  
Zhu Weiqiu
Keyword(s):  
Closed Loop ◽  
First Passage Time ◽  
Hamiltonian Function ◽  
Small Time ◽  
Kolmogorov Equation ◽  
Sensors And Actuators ◽  
First Passage ◽  
Controlled System ◽  
Main Structure ◽  
Controlled Systems

A closed-loop controlled system usually consists of the main structure, sensors, and actuators. The dynamics of sensors and actuators may influence the motion of the main structure. This article presents an analytical study on the first-passage reliability of a nonlinear stochastic controlled system under the consideration of the dynamics of sensors and actuators. The coupled dynamic equations of the controlled systems with sensors and actuators are first given, which are further integrated into a controlled, randomly excited, dissipated Hamiltonian system. By applying the stochastic averaging method for quasi-Hamiltonian systems, a one-dimensional averaged differential equation for the Hamiltonian function is obtained. The backward Kolmogorov equation associated with the averaged equation is then derived for the first-passage reliability analysis, from which the approximate reliability function and probability density of first-passage time are obtained. The accuracy of the proposed procedure is demonstrated by an example. A comparative analysis of the reliability of the system with/without sensors and actuators is carried out, which indicates that ignoring sensors and actuators will make underestimation of the reliability of the closed-loop system with small time. However, when time increases, there appears the opposite trend. Our findings provide a reference for control strategy design.

GLOSSING THE GLOSS: READING PETER LOMBARD’SCOLLECTANEAON THE PAULINE EPISTLES AS A HISTORICAL ACT

Traditio ◽  
2018 ◽  
Vol 73 ◽  
pp. 83-116
Author(s):  
PETER O'HAGAN
Keyword(s):  
Early Modern ◽  
Biblical Text ◽  
Classroom Activity ◽  
New Approach ◽  
Central Focus ◽  
Recent Scholarship ◽  
Pauline Epistles ◽  
History Of ◽  
Extended Analysis

Peter Lombard's influential commentary on the Pauline Epistles, theCollectanea in omnes divi Pauli epistolas,has received little extended analysis in scholarly literature, despite its recognized importance both in its own right and as key for the development of hisSentences.This article presents a new approach to studying theCollectaneaby analyzing how Lombard's commentary builds on theGlossa “Ordinaria”on the Pauline Epistles. The article argues for treating theCollectaneaas a “historical act,” focusing on how Lombard engages with the biblical text and with authoritative sources within which he encounters the same biblical text embedded. The article further argues for the necessity of turning to the manuscripts of both theCollectaneaand theGlossa,rather than continuing to rely on inadequate early modern printed editions or thePatrologia Latina.The article then uses Lombard's discussion of faith at Romans 1:17 as a case study, demonstrating the way in which Lombard begins from theGlossa,clarifies its ambiguities, and moves his analysis forward through his use of otherauctoritatesand theologicalquaestiones.A comparison with Lombard's treatment of faith in theSentenceshighlights the close links between Lombard's biblical lectures and this later work. The article concludes by arguing that scholastic biblical exegesis and theology should be treated as primarily a classroom activity, with the glossed Bible as the central focus. Discussion of Lombard's work should draw on much recent scholarship that has begun to uncover the layers of orality within the textual history of scholastic works.

Soft Switching Approach to Reducing Transition Losses in an On/Off Hydraulic Valve

2009 ◽  
Author(s):  
Michael B. Rannow ◽  
Perry Y. Li
Keyword(s):  
Hydraulic System ◽  
Check Valve ◽  
Fluid Flows ◽  
Soft Switching ◽  
Total System ◽  
System Efficiency ◽  
Hydraulic Systems ◽  
Controlled Systems ◽  
Flow Through ◽  
Hydraulic Valve

A method for significantly reducing the losses associated with an on/off controlled hydraulic system is proposed. There has been a growing interest in the use of on/off valves to control hydraulic systems as a means of improving system efficiency. While on/off valves are efficient when they are fully open or fully closed, a significant amount of energy can be lost in throttling as the valve transitions between the two states. A soft switching approach is proposed as a method of eliminating the majority of these transition losses. The operating principle of soft switching is that fluid can temporarily flow through a check valve or into a small chamber while valve orifices are partially closed. The fluid can then flow out of the chamber once the valve has fully transitioned. Thus, fluid flows through the valve only when it is in its most efficient fully open state. A model of the system is derived and simulated, with results indicating that the soft switching approach can reduce transition and compressibility losses by 79%, and total system losses by 66%. Design equations are also derived. The soft switching approach has the potential to improve the efficiency of on/off controlled systems and is particularly important as switching frequencies are increased. The soft switching approach will also facilitate the use of slower on/off valves for effective on/off control; in simulation, a valve with soft switching matched the efficiency an on/off valve that was 5 times faster.

scholarly journals Pneumatic Actuator Controlled by Proportional Valve. Experimental results

2021 ◽  
Vol 286 ◽  
pp. 04010
Author(s):  
Valentin Nicolae Cococi ◽  
Constantin Călinoiu ◽  
Carmen-Anca Safta
Keyword(s):  
Control Valve ◽  
Industrial Applications ◽  
Experimental Results ◽  
Pneumatic Actuator ◽  
Proportional Valve ◽  
Controlled Systems ◽  
Automation Systems ◽  
Simulation Results ◽  
The Mathematical Model ◽  
Fire Ignition

In nowadays the pneumatic controlled systems are widely used in industrial applications where valves must be operated, where there is a fire ignition risk, or in different automation systems where a positioning action is desired. The paper presents the experimental results of a pneumatic actuator controlled by a proportional control valve. The goal of the paper is to compare the experimental results with the numerical simulation results and to improve the mathematical model associated with the experiment.

Memory as State Behaviour

2021 ◽  
pp. 87-119
Author(s):  
Kathrin Bachleitner
Keyword(s):  
Qualitative Analysis ◽  
Collective Memory ◽  
West Germany ◽  
Ontological Security ◽  
Collective Memories ◽  
Yom Kippur War ◽  
State Behaviour ◽  
Emotional Trigger ◽  
Oil Crisis

This chapter shows how collective memory channels a country’s international behaviour. To that end, it first lays out the nexus between memory and state behaviour put forward by the temporal security concept. It then goes on to distinguish it from international relations’ classical realist and ontological security approaches and their predictions on state behaviour. To keep their temporal security intact, countries are assumed to enter into an ‘in-between-time’ conversation with their ‘significant historical others’. Through the emotional trigger of shame, policymakers avoid potential disconnects with their country’s ‘narrated self in the past’, thus bringing their courses of action in line with collective memory. To illustrate this process, the empirical case study looks at the reaction of West Germany and Austria to two wars in the Middle East. It contrasts their support for either of the warring parties during the Six Day War of 1967 and the Yom Kippur War and international oil crisis of 1973. The qualitative analysis demonstrates that West Germany and Austria’s different collective memories of the Nazi legacy channelled their behaviour along diverse reasonings to support either the Israeli or the Arab side.

Computational Fluid Dynamics Modelling of a Load Sensing Proportional Valve

2019 ◽  
Author(s):  
Alessandro Corvaglia ◽  
Giorgio Altare ◽  
Roberto Finesso ◽  
Massimo Rundo
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steady State ◽  
Complex Geometry ◽  
Ansys Fluent ◽  
Proportional Valve ◽  
Fluid Forces ◽  
Load Sensing ◽  
Cfd Models ◽  
Dynamics Modelling

Abstract In this paper, two 3D CFD models of a load sensing proportional valve are contrasted. The models were developed with two different software, Simerics PumpLinx® and ANSYS Fluent®. In both cases the mesh was dynamically modified based on the fluid forces acting on the local compensator. In the former, a specific template for valves was used, in the latter a user-defined function was implemented. The models were validated in terms of flow rate and pressure drop for different positions of the main spool by means of specific tests. Two configurations were tested: with the local compensator blocked and free to regulate. The study has brought to evidence the reliability of the CFD models in evaluating the steady-state characteristics of valves with complex geometry.

Raging Bull’s Stylistic Dissonance

2017 ◽  
Author(s):  
Todd Berliner
Keyword(s):  
Illustrative Case ◽  
Avant Garde ◽  
Extended Analysis ◽  
Illustrative Case Study ◽  
Classical Hollywood ◽  
Made In

Illustrating some of the points made in chapter 5, chapter 6 offers an extended analysis of some complex tendencies in Raging Bull’s cinematography, editing, and sound devices. The film tests the limits of the classical Hollywood style and sometimes crosses over into avant-garde practice. Raging Bull offers an illustrative case study of the boundaries of Hollywood’s stylistic systems.

Exploration of the Development of Schemes to Achieve a District-Aggregate Energy-Intensity Goal - Taking the 12th Five-Year Period Energy Intensity Goal of Daxing District, Beijing as a Study Case

2014 ◽  
Vol 962-965 ◽  
pp. 1455-1460
Author(s):  
Xiang Qian Li ◽  
Li Juan Yang ◽  
Ling Ling Chen
Keyword(s):  
Energy Consumption ◽  
Gross Domestic Product ◽  
Energy Intensity ◽  
Industrial Structure ◽  
Energy Losses ◽  
Residential Energy ◽  
Initial Value ◽  
Study Case ◽  
Per Capita

The paper explored how to develop schemes to achieve a district’s energy consumption per gross domestic product (ECPGDP) target. It first analysed the available measures regarding the reduction of ECPGDP. These measures include optimising the industrial structure, reducing the energy intensity of different industries, reducing the per capita residential energy consumption, and reducing the energy losses. Next, the procedure and methods of developing schemes to achieve the target ECPGDP were proposed. The procedure contains five steps: determine the target ECPGDP, predicting the initial value of the ECPGDP, analysing the availability of different measures of reducing the ECPGDP, forming the schemes of achieving the target, and summarising the proposed schemes. Finally, the paper considered the 12th Five-Year period ECPGDP target of Daxing District, Beijing as a study case. In the case study, four quantitative schemes to achieve the target ECPGDP were considered.

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