liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Quantifying Operability of Working Machines
Linköping University, Department of Management and Engineering, Fluid and Mechatronic Systems. Linköping University, The Institute of Technology.
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. , 99 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1390
Keyword [en]
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: urn:nbn:se:liu:diva-70394ISBN: 978-91-7393-087-1 (print)OAI: oai:DiVA.org:liu-70394DiVA: diva2:438934
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
List of papers
1. Using Dynamic Simulation in the Development of Construction Machinery
Open this publication in new window or tab >>Using Dynamic Simulation in the Development of Construction Machinery
2003 (English)In: Proceedings from the Eighth Scandinavian International Conference on Fluid Power, Tampere, Finland, Vol. 1, May 7–9, 2003, 651-667 p.Conference paper, Published paper (Other academic)
Abstract [en]

As in the car industry for quite some time, dynamic simulation of complete vehicles is being practiced more and more in the development of off-road machinery. However, specific questions arise due not only to company structure and size, but especially to the type of product. Tightly coupled, non-linear subsystems of different domains make prediction and optimisation of the complete system's dynamic behaviour a challenge. Furthermore, the demand for versatile machines leads to sometimes contradictory target requirements and can turn the design process into a hunt for the least painful compromise. This can be avoided by profound system knowledge, assisted by simulation-driven product development. This paper gives an overview of joint research into this issue by Volvo Wheel Loaders and Linkoping University on that matter, lists the results of a related literature review and introduces the term "operateability". Rather than giving detailed answers, the problem space for ongoing and future research is examined and possible solutions are sketched.

Keyword
simulation, complex systems, integrated product development
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-13368 (URN)
Conference
The Eighth Scandinavian International Conference on Fluid Power, May 7-9, Tampere, Finland
Available from: 2005-09-26 Created: 2005-09-26 Last updated: 2011-09-06Bibliographically approved
2. Dynamic Simulation of Construction Machinery: Towards an Operator Model
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, 429-438 p.Conference 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.

Keyword
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
3. An Event-driven Operator Model for Dynamic Simulation of Construction Machinery
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.

Keyword
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
4. A Methodology for Modeling the Influence of Construction Machinery Operators on Productivity and Fuel Consumption
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, 614-623 p.Conference 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 (Print) 1611-3349 (Online) ; 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: 2011-09-06Bibliographically approved
5. Hybrid Power Systems for Construction Machinery: Aspects of System Design and Operability of Wheel Loaders
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, 611-620 p.Conference 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
6. Study of a method for assessing operability of working machines in physical and virtual testing
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, 209-234 p.Article 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
Keyword
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
7. A Case Study on Quantifying the Workload of Working Machine Operators by Means of Psychophysiological Measurements
Open this publication in new window or tab >>A Case Study on Quantifying the Workload of Working Machine Operators by Means of Psychophysiological Measurements
(English)Manuscript (preprint) (Other academic)
Abstract [en]

In this study of eighteen wheel loader operators, test-driving a machine in three different traction force settings, we examine if a workload index derived from psychophysiological measurements of heart rate, finger temperature, skin conductance, respiration rate and end-tidal CO2-concentration in exhaled air can be used to assess operator workload in sufficient detail to use it as a complement to traditional subjective evaluations, and also to use such measurements in a workload-adaptive operator assistance system in a longer perspective.

Keyword
Operator, working machines, mental workload, physical workload, operability, human-machine interaction
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-70393 (URN)
Available from: 2011-09-06 Created: 2011-09-06 Last updated: 2011-09-06Bibliographically approved

Open Access in DiVA

Quantifying Operability of Working Machines(4167 kB)1532 downloads
File information
File name FULLTEXT02.pdfFile size 4167 kBChecksum SHA-512
d92c0154e1cca65a51641795b051dbc660ac3f1170958287ffaa10ccc67f9b0b037aace9df7645c06ce42ba745573568c68a78b03bc91d582daa7337f055bac0
Type fulltextMimetype application/pdf
omslag(241 kB)88 downloads
File information
File name COVER01.pdfFile size 241 kBChecksum SHA-512
e52943d38135f00285a7556182b20162be60d02e349f57406920a43035934a1f40737a101a3f2f634ee3cf5fc1b88b4fe28f8530f4837d60a24b5df70a1997d2
Type coverMimetype application/pdf

Authority records BETA

Filla, Reno

Search in DiVA

By author/editor
Filla, Reno
By organisation
Fluid and Mechatronic SystemsThe Institute of Technology
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 1540 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 2578 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf