| 1. |
- Begum, Shahina, et al.
(författare)
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Classification of physiological signals for wheel loader operators using Multi-scale Entropy analysis and case-based reasoning
- 2014
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Ingår i: Expert systems with applications. - : Elsevier BV. - 0957-4174 .- 1873-6793. ; 41:2, s. 295-305
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Tidskriftsartikel (refereegranskat)abstract
- Sensor signal fusion is becoming increasingly important in many areas including medical diagnosis and classification. Today, clinicians/experts often do the diagnosis of stress, sleepiness and tiredness on the basis of information collected from several physiological sensor signals. Since there are large individual variations when analyzing the sensor measurements and systems with single sensor, they could easily be vulnerable to uncertain noises/interferences in such domain; multiple sensors could provide more robust and reliable decision. Therefore, this paper presents a classification approach i.e. Multivariate Multiscale Entropy Analysis-Case-Based Reasoning (MMSE-CBR) that classifies physiological parameters of wheel loader operators by combining CBR approach with a data level fusion method named Multivariate Multiscale Entropy (MMSE). The MMSE algorithm supports complexity analysis of multivariate biological recordings by aggregating several sensor measurements e.g., Inter-beat-Interval (IBI) and Heart Rate (HR) from Electrocardiogram (ECG), Finger Temperature (FT), Skin Conductance (SC) and Respiration Rate (RR). Here, MMSE has been applied to extract features to formulate a case by fusing a number of physiological signals and the CBR approach is applied to classify the cases by retrieving most similar cases from the case library. Finally, the proposed approach i.e. MMSE-CBR has been evaluated with the data from professional drivers at Volvo Construction Equipment, Sweden. The results demonstrate that the proposed system that fuses information at data level could classify 'stressed' and 'healthy' subjects 83.33% correctly compare to an expert's classification. Furthermore, with another data set the achieved accuracy (83.3%) indicates that it could also classify two different conditions 'adapt' (training) and 'sharp' (real-life driving) for the wheel loader operators. Thus, the new approach of MMSE-CBR could support in classification of operators and may be of interest to researchers developing systems based on information collected from different sensor sources.
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| 2. |
- Begum, Shahina, et al.
(författare)
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Driver's Mental State Monitoring System Using CBR Based on Heart Rate Variability Analysis
- 2012
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Ingår i:
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Konferensbidrag (refereegranskat)abstract
- The consequences of tiredness, drowsiness, stress and lack of concentration caused by a variety of different factors such as illness, sleep depletion, drugs and alcohol is a serious problem in traffic and when operating industrial equipment. This is especially important for professional drivers since both expensive equipment and lives may be at stake, e.g. in mining, construction and personal transportation, reduced concentration, stress or tiredness are known to be the cause of many accidents. A system which recognizes the state of the driver and e.g. suggests breaks when stress level is too high or driver is too tired would enable large savings and reduces accident. Today different sensors enable clinician to determine a driver’s status with high accuracy. The aim of the paper is to develop an intelligent system that can monitor drivers’ stress depending on psychological and behavioral conditions/status using heart rate variability. An experienced clinician is able to diagnose a person’s stress level based on sensor readings. Here, we propose a solution using case-based reasoning to diagnose individual driver’s stress. During calibration a number of individual parameters are established. The system also considers the feedback from the driver’s on how well the test was performed The validation of the approach is based on close collaboration with experts and measurements from 18 driver’s from Volvo Construction Equipment are used as reference.
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| 3. |
- Begum, Shahina, et al.
(författare)
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Mental State Monitoring System for the Professional Drivers Based on Heart Rate Variability Analysis and Case-based Reasoning
- 2012
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Ingår i: 2012 FEDERATED CONFERENCE ON COMPUTER SCIENCE AND INFORMATION SYSTEMS (FEDCSIS). - NEW YORK : IEEE. - 9788360810484 ; , s. 35-42
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Konferensbidrag (refereegranskat)abstract
- The consequences of tiredness, drowsiness, stress and lack of concentration caused by a variety of different factors such as illness, sleep depletion, drugs and alcohol is a serious problem in traffic and when operating industrial equipment. A system that recognizes the state of the driver and e. g. suggests breaks when stress level is too high or driver is too tired would enable large savings and reduces accident. So, the aim of the project is to develop an intelligent system that can monitor drivers' stress depending on psychological and behavioral conditions/status using Heart Rate Variability (HRV). Here, we have proposed a solution using Case-Based Reasoning (CBR) to diagnose individual driver's level of stress. The system also considers feedback from the driver's on how well the test was performed. The validation of the approach is based on close collaboration with experts and measurements from 18 drivers from Volvo Construction Equipment (Volvo CE) are used as reference.
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| 4. |
- Filla, Reno, et al.
(författare)
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A Case Study on Quantifying the Workload of Working Machine Operators by Means of Psychophysiological Measurements
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 5. |
- Filla, Reno, et al.
(författare)
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A Case Study on Quantifying the Workload of Working Machine Operators by Means of Psychophysiological Measurements
- 2013
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Konferensbidrag (refereegranskat)abstract
- 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 easily used to assess operator workload in sufficient detail to use it as a complement to traditional subjective evaluations in machine testing, either of real machines or in a human-in-the-loop simulator. In a longer perspective, such measurements are expected to play a role in a workload-adaptive operator assistance system.However, the findings do not give support for this vision. Instead they indicate that other types of measurements than what have been used in our study should be employed if ease of use for practitioners such as test engineers is in focus, but also that other factors than just machine operability must be considered to have a great influence on the operator workload.
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| 6. |
- Filla, Reno, 1973-
(författare)
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A Methodology for Modeling the Influence of Construction Machinery Operators on Productivity and Fuel Consumption
- 2009
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Ingår i: Proceedings from the Human-Computer Interaction HCI International 2009, San Diego (CA), USA. - Berlin / Heidelberg : Springer. - 9783642028083 ; , s. 614-623
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Konferensbidrag (refereegranskat)abstract
- 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.
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| 7. |
- Filla, Reno, 1973-
(författare)
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Alternative system solutions for wheel loaders and other construction equipment
- 2008
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 8. |
- Filla, Reno, 1973-
(författare)
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An Event-driven Operator Model for Dynamic Simulation of Construction Machinery
- 2005
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Ingår i: Proceedings form the Ninth Scandinavian International Conference on Fluid Power, Linköping, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 9. |
- Filla, Reno, 1973-
(författare)
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Anläggningsmaskiner: Hydrauliksystem i multidomäna miljöer
- 2003
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 10. |
- Filla, Reno, 1973-, et al.
(författare)
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Dynamic Simulation of Construction Machinery : Towards an Operator Model
- 2005
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Ingår i: Proceedings from the IFPE 2005 Technical Conference. ; , s. 429-438
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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