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Filla, Reno
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Filla, R. (2012). Study of a method for assessing operability of working machines in physical and virtual testing. International Journal of Vehicle Systems Modelling and Testing, 7(3), 209-234
Open this publication in new window or tab >>Study of a method for assessing operability of working machines in physical and virtual testing
2012 (English)In: International Journal of Vehicle Systems Modelling and Testing, ISSN 1745-6436, Vol. 7, no 3, p. 209-234Article in journal (Refereed) Published
Abstract [en]

In this study of eighteen wheel loader operators, test-driving a machine in three different traction force settings, we found strong support for the hypothesis that the operator’s control commands can be used to assess the machine’s operability, at least in form of ease of bucket filling.

The methods chosen to derive the control effort worked well and were computationally efficient.

Place, publisher, year, edition, pages
InderScience Publishers, 2012
Keywords
Mental workload, machine operability, human–machine interaction, operator modelling, vehicle simulation, virtual testing, working machines, wheel loaders, operators, control commands, control effort, vehicle testin
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-70392 (URN)10.1504/IJVSMT.2012.048939 (DOI)
Available from: 2011-09-06 Created: 2011-09-06 Last updated: 2012-09-20Bibliographically approved
Filla, R. (2011). Quantifying Operability of Working Machines. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Quantifying Operability of Working Machines
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In working machines the human operator is essential for the performance of the total system. Productivity and energy efficiency are both dependent not only on inherent machine properties and working place conditions, but also on how the operator manoeuvres the machine. In order to operate energy-efficient the operator has to experience the machine as harmonic. This is important to consider during the development of such working machines.

It is necessary to quantify operability and to include this interaction between the human operator and the machine in both the later stages of a development project (where physical prototypes are evaluated by professional test operators) as well as in the earlier stages like concept design (where only virtual prototypes are available).

The influence of the human operator is an aspect that is traditionally neglected in dynamic simulations conducted in concept design, because the modelling needs to be extended beyond the technical system. The research presented in this thesis shows two approaches to rule-based simulation models of a wheel loader operator. Both operator models interact with the machine model just as a human operator does with the actual machine. It is demonstrated that both operator models are able to adapt to basic variations in workplace setup and machine capability. A “human element” can thus be introduced into dynamic simulations of working machines, providing more relevant answers with respect to operator-influenced complete-machine properties such as productivity and energy efficiency.

While the influence of the human operator is traditionally ignored when evaluating machine properties in the early stages of the product development process, later stages are very reliant on professional test operators using physical prototypes. The presented research demonstrates how the traditional subjective evaluation of a machine’s operability can be complemented by a calculated measure for the operator’s control effort, derived from the recorded control commands of the machine operator. This control effort measure can also be calculated from the control commands of an operator model in a simulation, such as those presented in this thesis. It thus also allows for an assessment of operability already in the concept design phase.

In addition, the results of a study of quantifying operator workload by means of measuring psycho-physiological data such as heart rate variability and respiration rate are presented as the first step towards realising workload-adaptive operator assistance functions. Once fully developed, the method itself can also be used as another complement to the traditional subjective evaluations of operability. This approach can then be applied not only in testing of physical prototypes, but also earlier in the product development process in studies on human-in-the-loop simulators.

Abstract [sv]

I arbetsmaskiner spelar föraren en avgörande roll för maskinens prestanda. Såväl produktivitet som energieffektivitet beror inte enbart av maskinens egenskaper och arbetsomgivningen, utan beror också av sättet på vilket föraren manövrerar maskinen. För att främja ett bränslesnålt körsätt ska maskinerna upplevas som harmoniska och det är viktigt att beakta detta vid utvecklingen.

Det är nödvändigt att kvantifiera maskinharmonin och att ta hänsyn till interaktionen mellan föraren och maskinen i alla steg av ett utvecklingsprojekt. Detta gäller såväl sena faser, när fysiska prototyper redan har tagits fram och utvärderas av professionella provförare, såväl som tidiga faser som konceptutveckling, när endast virtuella prototyper finns tillgängliga.

Förarens inflytande beaktas traditionellt inte i prestandasimuleringar i konceptfasen, eftersom detta innebär att mer än enbart det tekniska systemet måste modelleras. I den forskningen som presenteras här visas två olika regelbaserade modeller av hjullastarförare. Båda förarmodellerna använder maskinmodellen på samma sätt som en verklig förare använder en verklig maskin. Det visas att båda förarmodellerna kan anpassa sig till förändringar både i arbetsomgivningen och i maskinens egenskaper. I och med detta kan man utöka dynamiska simuleringar av arbetsmaskiner med ”ett mänskligt element”. Detta ger bättre resultat vad gäller produktivitet, energieffektivitet och liknande egenskaper som föraren påverkar i kompletta maskiner.

Medan man i tidiga faser av produktutvecklingsprocessen traditionellt bortser från förarens inflytande, så är man i senare faser mycket beroende av att professionella provförare testar fysiska prototyper. Den här presenterade forskningen visar hur den traditionella subjektiva förarbedömningen av en maskins körbarhet kan kompletteras med ett mått på förarens ”spakarbete”, som beräknas utifrån en mätning på hur föraren använder sina kontroller för att styra maskinen. Detta mått på ”spakarbete” kan också beräknas utifrån de spaksignaler som genereras av förarmodellerna i en simulering. I och med detta kan en maskins körbarhet undersökas redan under konceptutvecklingen.

I avhandlingen redovisas också resultaten från en studie som gjorts i syfte att kvantifiera förarens arbetsbelastning genom att mäta psykofysiologiska mått som variationer i hjärtfrekvens och andningsfrekvens. Studien är ett första steg mot att förverkliga en vision av stödfunktioner i arbetsmaskiner vilka anpassar sig efter förarens momentana arbetsbelastning. En sådan metod att mäta förarens arbetsbelastning kan också användas som ett komplement till den traditionella subjektiva förarbedömningen av en maskins körbarhet. Metoden kan inte bara användas vid provning av fysiska prototyper utan också tidigare i produktutvecklingsprocessen vid studier i avancerade körsimulatorer.

Abstract [de]

IN ARBETSMASCHINEN spielt der Fahrer eine entscheidende Rolle für die Leistung des gesamten Systems. Produktivität und Energieeffizienz sind nicht nur abhängig von den Grundeigenschaften der Maschine und den Bedingungen am Einsatzort, sondern auch von der Art und Weise wie der Fahrer die Maschine manövreriert. Für eine kraftstoffsparende Fahrweise muss der Fahrer die Maschine als harmonisch erleben. Dies muss bei der Entwicklung beachtet werden.

Das Erfassen der Fahrbarkeit und die Berücksichtigung des Zusammenspiels zwischen Fahrer und Maschine ist in allen Phasen der Entwicklung notwendig, sowohl in den späteren Phasen, wenn Prototypen von Erprobungsfahrern ausgewertet werden, als auch in den frühen Phasen wie dem Konzeptentwurf, wenn nur virtuelle Prototypen vorhanden sind.

Der Fahrereinfluss wird traditionell in den dynamischen Simulationen während des Konzeptentwurfs vernachlässigt, denn er erfordert die Ausweitung der Modellierung über das technische System hinaus. In dieser Dissertation werden zwei Herangehensweisen zur Erstellung regelbasierter Modelle eines Radladerfahrers aufgezeigt. Beide Fahrermodelle interagieren mit dem Maschinenmodell gleich einem menschlichen Fahrer mit einer realen Maschine. Es wird gezeigt, dass beide Fahrermodelle in der Lage sind, sich auf Änderungen des Einsatzortes und der Maschineneigenschaften anzupassen. Somit kann „ein menschliches Element“ in die dynamische Simulation von Arbeitsmaschinen eingeführt werden, was zu qualitativ besseren Resultaten bezüglich Produktivität, Energieeffizienz und ähnlicher fahrerbeeinflusster Eigenschaften führt.

Während man in den frühen Phasen der Produktentwicklung traditionell vom Fahrereinfluss absieht, ist man später sehr auf die Erprobung physischer Prototypmaschinen durch professionelle Testfahrer angewiesen. In dieser Dissertation wird aufgezeigt, wie die traditionell subjektive Bewertung der Fahrbarkeit einer Maschine mit einem Maß der „Steuerungsarbeit“ komplettiert werden kann, berechnet aus der gemessenen Betätigung der dem Fahrer zur Verfügung stehenden Bedienelemente. Dieses Maß der „Steuerungsarbeit“ kann auch aus den Signalen der von uns vorgestellten Fahrermodelle in einer Simulation berechnet werden. Damit kann man die Fahrbarkeit bereits in der Konzeptentwicklung abschätzen.

Weiterhin werden die Resultate einer Studie zur Quantifizierung der Fahrerbelastung mithilfe psychophysiologischer Daten wie Veränderungen der Herzfrequenz und Atmungsfrequenz vorgestellt. Diese Studie ist ein erster Schritt zur Entwicklung eines Assistenzsystemes, dass sich an die aktuelle Fahrerbelastung anpasst. Eine solche Messmethode der Fahrerbelastung kan auch zusätzlich zur traditionellen subjektiven Fahrbarkeitseinschätzung angewendet werden – nicht nur bei der Erprobung physischer Prototpyen, sondern auch schon frühzeitig bei Studien auf Fahrsimulatoren.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2011. p. 99
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1390
Keywords
Operability, machine harmony, operator workload, control effort, simulation, operator model, human operator, working machines, construction equipment, wheel loaders
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-70394 (URN)978-91-7393-087-1 (ISBN)
Public defence
2011-11-11, C3, Hus C, Campus Valla, Linköpings universitet, Linköping, 10:00 (English)
Supervisors
Available from: 2011-09-06 Created: 2011-09-06 Last updated: 2011-09-07Bibliographically approved
Filla, R. (2009). A Methodology for Modeling the Influence of Construction Machinery Operators on Productivity and Fuel Consumption. In: Proceedings from the Human-Computer Interaction HCI International 2009, San Diego (CA), USA: Digital Human Modeling. Paper presented at Human-Computer Interaction HCI International 2009, San Diego (CA), USA, July 19-24 (pp. 614-623). Berlin / Heidelberg: Springer
Open this publication in new window or tab >>A Methodology for Modeling the Influence of Construction Machinery Operators on Productivity and Fuel Consumption
2009 (English)In: Proceedings from the Human-Computer Interaction HCI International 2009, San Diego (CA), USA: Digital Human Modeling, Berlin / Heidelberg: Springer , 2009, p. 614-623Conference paper, Published paper (Refereed)
Abstract [en]

This paper is concerned with modeling the actions of a human operator of construction machinery and integrating this operator model into a large, complex simulation model of the complete machine and its environment. Because human operators to a large degree affect how the machine is run, adaptive operator models are a necessity when the simulation goal is quantification and optimization of productivity and energy efficiency.

Interview studies and test series have been performed to determine how professionals operate wheel loaders. Two models using different approaches were realized and integrated into a multi-domain model for dynamic simulation. The results are satisfactory and the methodology is easily usable for other, similar situations.

Place, publisher, year, edition, pages
Berlin / Heidelberg: Springer, 2009
Series
Lecture Notes in Computer Science (LNCS), ISSN 0302-9743, E-ISSN 1611-3349 ; 5620
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-51998 (URN)10.1007/978-3-642-02809-0_65 (DOI)978-3-642-02808-3 (ISBN)
Conference
Human-Computer Interaction HCI International 2009, San Diego (CA), USA, July 19-24
Available from: 2009-11-27 Created: 2009-11-27 Last updated: 2018-01-25Bibliographically approved
Filla, R. (2009). Hybrid Power Systems for Construction Machinery: Aspects of System Design and Operability of Wheel Loaders. In: ASME 2009 International Mechanical Engineering Congress and Exposition: Volume 13: New Developments in Simulation Methods and Software for Engineering Applications; Safety Engineering, Risk Analysis and Reliability Methods; Transportation Systems. Paper presented at ASME 2009 International Mechanical Engineering Congress and Exposition (IMECE2009), Lake Buena Vista, Florida, USA, 13-19 November, (pp. 611-620). The American Society of Mechanical Engineers (ASME), 13
Open this publication in new window or tab >>Hybrid Power Systems for Construction Machinery: Aspects of System Design and Operability of Wheel Loaders
2009 (English)In: ASME 2009 International Mechanical Engineering Congress and Exposition: Volume 13: New Developments in Simulation Methods and Software for Engineering Applications; Safety Engineering, Risk Analysis and Reliability Methods; Transportation Systems, The American Society of Mechanical Engineers (ASME) , 2009, Vol. 13, p. 611-620Conference paper, Published paper (Refereed)
Abstract [en]

This paper will examine the wheel loader as a system with two parallel energy conversion systems that show a complex interaction with each other and with the power source. Using a systematic design approach, several principle design solutions for hybridization can be found.

Furthermore, the human operator with his/her control actions needs to be considered as part of the total system. This paper will therefore also connect to results from ongoing and previous research into operator workload and operability.

Place, publisher, year, edition, pages
The American Society of Mechanical Engineers (ASME), 2009
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:liu:diva-51999 (URN)10.1115/IMECE2009-10458 (DOI)000282197600069 ()978-0-7918-4386-4 (ISBN)
Conference
ASME 2009 International Mechanical Engineering Congress and Exposition (IMECE2009), Lake Buena Vista, Florida, USA, 13-19 November,
Available from: 2009-11-27 Created: 2009-11-27 Last updated: 2016-05-17Bibliographically approved
Filla, R. (2008). Alternative system solutions for wheel loaders and other construction equipment. In: : . Paper presented at 1st CTI Forum Alternative, Electric and Hybrid Drive Trains, 1 and 2 December 2008, Maritim Hotel Berlin, Germany. Berlin: CTI (CD)
Open this publication in new window or tab >>Alternative system solutions for wheel loaders and other construction equipment
2008 (English)Conference paper, Published paper (Other academic)
Abstract [en]

Within the Volvo Group there exist long-ranging experiences regarding hybrid propulsions systems for heavy commercial vehicles of the brands Volvo Trucks, Renalt Trucks, Mack Trucks, Nissan Diesel and Volvo Bus. For commercial vehicles like these, hybrid technology is to be regarded seriously and a business case is often given. The search for energy efficient solutions goes on also for construction equipment, and hybrids are everyone's topic. Within Volvo Construction Equipment there is a tradition of researching and developing energy efficient solutions, an example of which was the presentation of a first prototype of a hybrid wheel loader in the beginning of 2008. In this paper the wheel loader will be used as an example for other types of construction machinery. Using a systematic design approach, several more principle design solutions can be found. Reduced fuel consumption by 50% while keeping the performance and productivity at the same level is only possible by considering the complete machine as one system using a holistic approach. 

Place, publisher, year, edition, pages
Berlin: CTI (CD), 2008
Keywords
System solutions, wheel loaders, construction equipment
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-43948 (URN)75211 (Local ID)75211 (Archive number)75211 (OAI)
Conference
1st CTI Forum Alternative, Electric and Hybrid Drive Trains, 1 and 2 December 2008, Maritim Hotel Berlin, Germany
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2015-07-17Bibliographically approved
Filla, R. (2007). Effektivare hjullastare: Hybrider?. In: Hydraulikdagar 07,2007. Linköping: Linköpings universitet
Open this publication in new window or tab >>Effektivare hjullastare: Hybrider?
2007 (Swedish)In: Hydraulikdagar 07,2007, Linköping: Linköpings universitet , 2007Conference paper, Published paper (Other academic)
Abstract [sv]

Med allt högre bränslepriser och den tilltagande samhällsdebatten om växthusgaser och klimatförändringar förvånar det inte att även företag utanför personbilsbranschen undersöker alternativa systemlösningar för att minska avgasutsläppen och oljeberoendet. Detta föredrag presenterar Volvo CEs satsning på elhybrider med fokus på hjullastare.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet, 2007
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-41252 (URN)55402 (Local ID)55402 (Archive number)55402 (OAI)
Available from: 2009-12-10 Created: 2009-10-10 Last updated: 2009-12-10Bibliographically approved
Filla, R. (2005). An Event-driven Operator Model for Dynamic Simulation of Construction Machinery. In: Proceedings form the Ninth Scandinavian International Conference on Fluid Power, Linköping, Sweden. Paper presented at The Ninth Scandinavian International Conference on Fluid Power, Linköping, Sweden, June 1–3.
Open this publication in new window or tab >>An Event-driven Operator Model for Dynamic Simulation of Construction Machinery
2005 (English)In: Proceedings form the Ninth Scandinavian International Conference on Fluid Power, Linköping, Sweden, 2005Conference paper, Published paper (Other academic)
Abstract [en]

Prediction and optimisation of a wheel loader's dynamic behaviour is a challenge due to tightly coupled, non-linear subsystems of different technical domains. Furthermore, a simulation regarding performance, efficiency, and operability cannot be limited to the machine itself, but has to include operator, environment, and work task. This paper presents some results of our approach to an event-driven simulation model of a human operator. Describing the task and the operator model independently of the machine's technical parameters, gives the possibility to change whole sub-system characteristics without compromising the relevance and validity of the simulation.

Keywords
Discrete simulation, continuous simulation, complex systems, operator model, driver model
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-13370 (URN)
Conference
The Ninth Scandinavian International Conference on Fluid Power, Linköping, Sweden, June 1–3
Available from: 2005-09-26 Created: 2005-09-26 Last updated: 2011-09-06Bibliographically approved
Filla, R., Ericsson, A. & Palmberg, J.-O. (2005). Dynamic Simulation of Construction Machinery: Towards an Operator Model. In: Proceedings from the IFPE 2005 Technical Conference. Paper presented at International Fluid Power Exhibition 2005 Technical Conference, March 16-18, Las Vegas, USA (pp. 429-438).
Open this publication in new window or tab >>Dynamic Simulation of Construction Machinery: Towards an Operator Model
2005 (English)In: Proceedings from the IFPE 2005 Technical Conference, 2005, p. 429-438Conference paper, Published paper (Other academic)
Abstract [en]

In dynamic simulation of complete wheel loaders, one interesting aspect, specific for the working task, is the momentary power distribution between drive train and hydraulics, which is balanced by the operator. This paper presents the initial results to a simulation model of a human operator. Rather than letting the operator model follow a predefined path with control inputs at given points, it follows a collection of general rules that together describe the machine's working cycle in a generic way. The advantage of this is that the working task description and the operator model itself are independent of the machine's technical parameters. Complete sub-system characteristics can thus be changed without compromising the relevance and validity of the simulation. Ultimately, this can be used to assess a machine's total performance, fuel efficiency and operability already in the concept phase of the product development process.

Keywords
Simulation, construction machinery
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-13369 (URN)
Conference
International Fluid Power Exhibition 2005 Technical Conference, March 16-18, Las Vegas, USA
Available from: 2005-09-26 Created: 2005-09-26 Last updated: 2011-09-06Bibliographically approved
Filla, R. (2005). Operator and Machine Models for Dynamic Simulation of Construction Machinery. (Licentiate dissertation). : Institutionen för konstruktions- och produktionsteknik
Open this publication in new window or tab >>Operator and Machine Models for Dynamic Simulation of Construction Machinery
2005 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

VIRTUAL PROTOTYPING has been generally adopted in product development in order to minimise the traditional reliance on testing of physical prototypes. It thus constitutes a major step towards solving the conflict of actual increasing development cost and time due to increasing customer demands on one side, and the need to decrease development cost and time due to increasing competition on the other. Particularly challenging for the off-road equipment industry is that its products, working machines, are complex in architecture. Tightly coupled, non-linear sub-systems of different technical domains make prediction and optimisation of the complete system’s dynamic behaviour difficult.

Furthermore, in working machines the human operator is essential for the performance of the total system. Properties such as productivity, fuel efficiency, and operability are all not only dependent on inherent machine properties and working place conditions, but also on how the operator uses the machine. This is an aspect that is traditionally neglected in dynamic simulations, because the modelling needs to be extended beyond the technical system.

The research presented in this thesis focuses on wheel loaders, which are representative for working machines. The technical system and the influence of the human operator is analysed, and so-called short loading cycles are described in depth. Two approaches to rule-based simulation models of a wheel loader operator are presented and used in simulations. Both operator models control the machine model by means of engine throttle, lift and tilt lever, steering wheel, and brake only – just as a human operator does. Also, only signals that a human operator can sense are used in the models. It is demonstrated that both operator models are able to adapt to basic variations in workplace setup and machine capability. Thus, a “human element” can be introduced into dynamic simulation of working machines, giving more relevant answers with respect to operator-influenced complete-machine properties such as productivity, fuel efficiency, and operability already in the concept phase of the product development process.

Place, publisher, year, edition, pages
Institutionen för konstruktions- och produktionsteknik, 2005. p. 45
Series
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1189
Keywords
dynamic simulation, construction equipment, discrete simulation, continuous simulation, operator model, driver model, integrated product development
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-4092 (URN)91-85457-14-0 (ISBN)
Presentation
2005-09-16, C3, C-huset, Campus Valla, Linköping, 13:15 (English)
Opponent
Supervisors
Note
ISRN/Report code: LiU-Tek-Lic 2005:44Available from: 2005-09-26 Created: 2005-09-26
Filla, R. (2003). Anläggningsmaskiner: Hydrauliksystem i multidomäna miljöer. Paper presented at Hydraulikdagar 2003, Linköping, Sweden, June 3–4. Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Anläggningsmaskiner: Hydrauliksystem i multidomäna miljöer
2003 (English)Conference paper, Published paper (Other academic)
Abstract [sv]

I hjullastare och liknande maskiner konkurrerar arbetshydrauliken och drivlinan om dieselmotorns vridmoment. Balansen mellan dessa tre  system präglas av en hög dynamik, vilket är en avgörande skillnad mot vad som är fallet i person- och lastbilar. Bedömning av hur väl denna balans kan upprätthållas och kontrolleras är huvudpunkten i förarens subjektiva bedömning av en maskins körbarhet.

I artikeln diskuteras möjligheter till en objektiv kvantifiering av körbarhet. En mätmetod presenteras samt nya sätt att visualisera denna så viktiga balans mellan maskinens delsystem.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2003
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-13371 (URN)
Conference
Hydraulikdagar 2003, Linköping, Sweden, June 3–4
Available from: 2009-12-10 Created: 2009-02-11 Last updated: 2011-08-31Bibliographically approved
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