2012, Article in monograph or in proceedings ()During the previous HVTT conference in Melbourne, results have been presented of a project FORWARD, including eleven different trailer manufacturers, involving testing and modeling activities to establish a practical basis for realistic fatigue assessment as a step towards an improved light-weight trailer design. The present paper describes the next step as part of the follow-up project LIFE (LIfetime Fatique Enhancement), starting with the model-based assessment of a realistic loading history for a semi-trailer. Representative loading conditions in this history, being derived from three weeks of field testing, are then used in Finite Element analyses to estimate fatigue life at a critical high loaded welded connection in the aluminum
trailer chassis. Results are discussed with respect to the order of different loading cycles (Palmgren-Miner number, based on fatigue tests), 3D loading at the weld, the varying weld quality, and the impact of bonded connections in the trailer. These ‘lessons learned’ are interpreted, to result in improved general guidelines in light-weight trailer design.
2010, Article in monograph or in proceedings (Theoretical and Practical Issues in Transport, pp. 106-112)One way to reduce the fuel consumption to payload ratio of heavy vehicle combinations is to reduce the empty trailer weight. This requires an understanding of the vehicle structure, assembly techniques and production process, and of special materials (e.g. high strength steel) with emphasis on strength and fatigue. But in all cases, one needs to have realistic design loads available. This paper describes an approach to determine these loads as a first step in the process. For this purpose, tractor-semitrailer combinations have been tested under normal operational conditions, for a longer period, under monitoring of a large number of measurement data. These data have been transferred into dynamic loading data in terms of forces at each separate wheel and at the king-pin in vertical, lateral and longitudinal direction. The experience with several trailers has resulted in a cost-effective testing procedure, which also allows the assessment of representative loading cycles.
2019, Article in monograph or in proceedings (Shakshuki, Elhadi (ed.), The 10th International Conference on Ambient Systems, Networks and Technologies (ANT 2019))This research is an explorative study to look for the potential to predict traffic density from driver behaviour using signals collected from the Controller Area Network (CAN) bus. The hypothesis is that driver behaviour is influenced by traffic density in such a way that an approximation of the traffic density can be determined from changes in the driver behaviour. Machine learning will be employed to correlate a selection of commonly available sensors on cars to the traffic density. Challenges in the processing of the data for this purpose will be outlined. The data for this study is collected from five passenger cars and nineteen trucks driving on the A28 highway in Utrecht region in the Netherlands. This study is restricted to straight roads in order to isolate the steering behaviour attributable to the traffic state influences rather than following the curve in the road. The results are encouraging that the correlation between driver behaviour and traffic density can be established. An overall accuracy of over 95% is achieved with a precision of 92%. The recall rate however is low most likely caused by over-fitting due to the unbalanced data set. The results still look promising and more training data should improve the results. This research is part of the broader project VIA NOVA which aims to investigate the use of car-sensor data for traffic and road asset management.
2008, Article / Letter to editor (Onderwijsinnovatie, vol. 10, iss. 2, (2008), pp. 10-13)Met de komst van lecoraten zijn hogescholen zich ook gaan richten op ‘toegepast onderzoek’. Maar past dat wel in het hbo? En zo ja, hoe implementeer je dat? Dit artikel beschrijft hoe binnen de HAN de competentie ‘Onderzoek doen’ hogeschoolbreed is ingekaderd.
2019, Article / Letter to editor (Transportation Research Record : Journal of the Transportation Research Board, vol. 2673, iss. 2, (2019), pp. 60-70)Extreme winter weather conditions severely affect the transportation sector. Technologies such as Road Weather Information Systems provide live data on the road surface conditions to assist the road authorities in providing safe mobility. The main problem is, however, the limited number of such systems that have been deployed, resulting in fragmented informa- tion about road conditions. This paper addresses the problems associated with the limited quantity of information concerning slippery winter road conditions by presenting a proof-of-concept for a system that not only detects slippery winter road con- ditions, but also predicts the type of slippery surface (ice, snow and slush) via vehicle-based systems. The concept demon- strated in this paper makes use of commonly available variables, which are, longitudinal slip ratios, longitudinal acceleration and the ambient temperature to identify such situations. The developed system employs a Fuzzy Inference System that is not only capable of identifying slippery conditions but is also capable of classifying surfaces based on the extent of slipperiness. This provides the road authorities with several moving sensors (vehicles traveling on a particular road) compared with the few fixed sensors currently available. This could deliver a pool of information to assist the road authorities to efficiently han- dle their staff and equipment so that appropriate equipment reaches the right place at the right time.
2009, Part of book or chapter of book (, pp. 375-395)Extant literature on collaborative learning shows that this instructional approach is widely used. In this chapter, the authors discuss the lack of alignment between collaborative learning and assessment practices. They will argue that peer assessment is a form of collaborative learning and a mode of assessment that perfectly fits the purpose of collaborative learning. As such, the authors purposefully depart from the more traditional application of assessment as a summative tool and advocate the consideration of formative peer assessment in collaborative learning. This shift towards formative assessment they believe has the potential to enhance learning. Their goal in this chapter is to review both shortcomings of current peer assessment practice as well as its potential for collaborative learning. Interactivity is central to foster the alignment between assessment and collaborative learning and the authors present a set of guidelines derived from research for increasing interactivity through formative peer assessment among peers in collaborative learning contexts.
2012, Article / Letter to editor (Lastechniek : vakblad voor verbinden en snijden, vol. 2012, iss. 11, (2012), pp. 18-21)Tijdens de conferentie Trends in Welding Research van juni jl. in Chicago was een speciale sessie gewijd aan de microstructuurontwikkeling tijdens het lassen. Eén van de bijdragen was een presentatie van de onderzoeksresultaten van een M2i-onderzoek (Materials Innovation Institute), waarbij Tata Steel en TU Delft betrokken waren [1]. Het onderzoek had betrekking op de lasbaarheid van in ontwikkeling zijnde hogesterktestaalsoorten.
2012, Article / Letter to editor (Journal Vehicle System Dynamics, vol. 50, iss. 6, (2012), pp. 939-959)Path tracking driver models assume the observed path deviation ahead of the vehicle to be proportionally transferred to a corrective steering input. The most simple version of such a model includes three parameters, a single preview distance, a steering gain and a delay time, being examined in this paper, in dependency of vehicle properties, driver characteristics, velocity and path. It is shown that, for different and bounded preview lengths, a driver can follow any path with almost the same minimum path error, if the gain is adapted appropriately. The upper boundary is path-dependent but driver and path characteristics have only a minor effect on the resulting relationship between preview length and gain. Consequently, gain and preview length may well vary along some path. This has been examined, experimentally, for different drivers. A too small preview length conflicts with closed-loop stability, explicitly described in terms of vehicle parameters, vehicle speed and driver delay time. The results of this paper provide a basis for enhanced understanding of human driver behaviour.
2010, Article in monograph or in proceedings (11th Heavy Vehicle Transport Technology symposium, Melbourne)The paper discusses the derivation of test data for three tractor-semitrailer combinations, to be used for strength and durability analysis of semi-trailers with the ultimate goal to reduce the semitrailer mass. Mathematical relationships have been used to transfer these data to representative loading data for the semi-trailer, in terms of forces and moments in all directions at the axles and king-pin, being used to optimize weight without compromising the vehicle resistance to fatigue. These activities have been the starting point of a follow-up project FORWARD (Fuel Optimised trailer Referring to Well Assessed Realistic Design loads) including now eleven different trailer manufacturers, and the Dutch Chassis and Body work association FOCWA. FORWARD will extend the previous approach with the objective to lower the trailer weight in order to improve the ratio of payload to fuel consumption. FORWARD consists of the following steps (1) a testing program, the larger part of which corresponds to normal use for a representative period, (2) to apply these data to validate a vehicle model allowing the derivation of representative loading data, and exploration of the effect of design changes on these loading data, (3) to apply these loading data for further FEM analysis of the global chassis and of local critical points.