| 1. |
- Alam, Assad, et al.
(författare)
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Look-Ahead Cruise Control for Heavy Duty Vehicle Platooning
- 2013
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Ingår i: Proceedings of the 16th International IEEE Annual Conference onIntelligent Transportation Systems (ITSC 2013). - : IEEE conference proceedings. - 9781479929146 ; , s. 928-935
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Konferensbidrag (refereegranskat)abstract
- Vehicle platooning has become important for thevehicle industry. Yet conclusive results with respect to thefuel reduction possibilities of platooning remain unclear, inparticular when considering constraints imposed by the topography.The focus of this study is to establish whether itis more fuel-efficient to maintain or to split a platoon that isfacing steep uphill and downhill segments. Two commercialcontrollers, an adaptive cruise controller and a look-aheadcruise controller, are evaluated and alternative novel controlstrategies are proposed. The results show that an improvedfuel-efficiency can be obtained by maintaining the platoonthroughout a hill. Hence, a cooperative control strategy basedon preview information is presented, which initiates the changein velocity at a specific point in the road for all vehiclesrather than simultaneously changing the velocity to maintainthe spacing. A fuel reduction of up to 14% can be obtainedover a steep downhill segment and a more subtle benefit of0.7% improvement over an uphill segment with the proposedcontroller, compared to the combination of the commerciallyavailable cruise controller and adaptive cruise controller thatcould be used for platooning. The findings show that it isboth fuel-efficient and desirable in practice to consider previewinformation of the topography in the control strategy.
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| 2. |
- Begum, Shahina
(författare)
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Intelligent Driver Monitoring Systems Based on Physiological Sensor Signals : A Review
- 2013
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Ingår i: IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC. - 9781479929146 ; , s. 282-289
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Konferensbidrag (refereegranskat)abstract
- Drowsiness, stress and lack of concentration caused by a variety of different factors is a serious problem in traffic. Many traffic accidents are due to these risky behaviors of the drivers. 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 physiological sensor signals such as Electrocardiogram (ECG), Elektro-okulogram (EOG), Electroencephalogram (EEG) and Pulse Oximeter (Oxygen saturation measurements) enable clinician to determine psychological and behavioral state with high accuracy. There are researchers working on developing intelligent systems help to monitor potential risky behaviors of drivers using sensor signals. Thus, this paper provides an overview and analysis of driver monitoring/alerting systems developments and implementations which are based on physiological sensor signals. Summarizing published research works and systems this review provides a resource for researchers, scholars and developers working in the area.
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| 3. |
- Cats, Oded, et al.
(författare)
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Real-Time Bus Arrival Information System : An Empirical Evaluation
- 2013
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Ingår i: IEEE Conference on Intelligent Transportation Systems. - : IEEE conference proceedings. - 9781479929146 ; , s. 1310-1315
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Konferensbidrag (refereegranskat)abstract
- Waiting time uncertainty is one of the main determinants of public transport reliability and overall level-of-service. The dissemination of real-time information concerning vehicle arrivals is often considered an important measure to reduce unreliability. Moreover, the prediction of downstream vehicle trajectories could also benefit real-time control strategies. In order to adequately analyze the performance of real-time bus arrival information system, the generated predictions have to be compared against empirical bus arrival data. A conventional real-world bus arrival prediction scheme is formulated and applied on the trunk lines network in Stockholm. This scheme was found to systematically underestimate the remaining waiting time by 6.2% on average. Prediction error accuracy and reliability varies considerably over time periods, along the route and as a function of the prognosis horizon. The difference between passengers' waiting time expectations derived from the timetable and real-time information is equivalent to 30% of the average waiting time.
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| 4. |
- Forsgren, Malin, et al.
(författare)
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Towards shorter lead times in railway timetabling in Sweden
- 2013
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Ingår i: IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC. - 9781479929146 ; , s. 1053-1058
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Konferensbidrag (refereegranskat)abstract
- Railway timetabling in Sweden has traditionally been associated with long lead times. In order for the railway sector to be able to compete with other transport modes, the infrastructure manager must become better at meeting the demand for railway services whose need for infrastructure capacity is not well-defined 6-18 months in advance. Research at SICS is changing the Swedish timetabling process so that it will accommodate late capacity requests in a significantly better way than before. This paper describes the principle behind the new method, briefly describes the optimization model that has been developed to support the new process, and presents examples that show how optimization tools can support the new process.
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| 5. |
- Gundlegård, David, 1978-, et al.
(författare)
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The Smartphone As Enabler for Road Traffic Information Based on Cellular Network Signalling
- 2013
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Ingår i: Intelligent Transportation Systems (ITSC), 2013. - : IEEE. - 9781479929146 ; , s. 2106-2112
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Konferensbidrag (refereegranskat)abstract
- The higher penetration rate of GPS-enabled smartphones together with their improved processing power and battery life makes them suitable for a number of participatory sensing applications. The purpose of this paper is to analyse how GPS-enabled smartphones can be used in a participatory sensing context to build a radio map for RSS-based positioning, with a special focus on road traffic information based on cellular network signalling. The CEP-67 location accuracy achieved is 75 meters for both GSM and UMTS using Bayesian classification. For this test site, the accuracy is similar for GSM and UMTS, with slightly better results for UMTS in the CEP-95 error metric. The location accuracy achieved is good enough to avoid large errors in travel time estimation for highway environments, especially considering the possibility to filter out estimates with low accuracy using for example the posterior bin probability in Bayesian classification. For urban environments more research is required to determine how the location accuracy will affect the path inference problem in a dense road network. The location accuracy achieved in this paper is also sufficient for other traffic information types, for example origin-destination estimation based on location area updates.
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| 6. |
- Larson, Jeffrey, et al.
(författare)
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Coordinated route optimization for heavy-duty vehicle platoons
- 2013
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Ingår i: IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC. - : IEEE conference proceedings. - 9781479929146 ; , s. 1196-1202
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Konferensbidrag (refereegranskat)abstract
- Heavy-duty vehicles traveling in platoons consume fuel at a reduced rate. In this paper, we attempt to maximize this benefit by introducing local controllers throughout a road network to facilitate platoon formations with minimal information. By knowing a vehicle's position, speed, and destination, the local controller can quickly decide how its speed should be possibly adjusted to platoon with others in the near future. We solve this optimal control and routing problem exactly for small numbers of vehicles, and present a fast heuristic algorithm for real-time use. We then implement such a distributed control system through a large-scale simulation of the German autobahn road network containing thousands of vehicles. The simulation shows fuel savings from 1-9%, with savings exceeding 5% when only a few thousand vehicles participate in the system. We assume no vehicles will travel more than the time required for their shortest paths for the majority of the paper. We conclude the results by analyzing how a relaxation of this assumption can further reduce fuel use.
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| 7. |
- Nilsson, Julia, 1986, et al.
(författare)
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Predictive manoeuvre generation for automated driving
- 2013
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Ingår i: 16th International IEEE Annual Conference on Intelligent Transportation Systems. - 9781479929146 ; , s. 418-423
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Konferensbidrag (refereegranskat)abstract
- This paper focuses on the problem of trajectoryplanning in an autonomous guidance application for one-way,two-lane roads. The problem is formulated in a recedinghorizon framework, as the minimization of the deviation from a desired velocity subject to a set of constraints introduced to avoid collision with surrounding vehicles, and to stay within the lane boundaries. As well known, this formulation can result in planning algorithms with prohibitive computational complexity, thus preventing real-time implementation. To avoid this limitation, the paper shows how the structured environment of one-way roads, can be exploited in order to formulate a low complexity receding horizon problem that can be efficientlysolved in real-time. The proposed algorithm is demonstrated in simulations considering overtake manoeuvres.
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| 8. |
- Rodrigues de Campos, Gabriel, 1986, et al.
(författare)
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Autonomous cooperative driving: a velocity-based negotiation approach for intersection crossing
- 2013
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Ingår i: 16th International IEEE Conference on Intelligent Transportation Systems. - 9781479929146 ; , s. 1456-1461
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Konferensbidrag (refereegranskat)abstract
- In this article, a scenario where several vehicles have to coordinate among them in order to cross a traffic intersection is considered. In this case, the control problem relies on the optimization of a cost function while guaranteeing collision avoidance and the satisfaction of local constraints. A decentralized solution is proposed where vehicles sequentially solve local optimization problems allowing them to cross, in a safe way, the intersection. This approach pays a special attention to how the degrees of freedom that each vehicle disposes to avoid a potential collision can be quantified and led to an adequate formalism to the considered problem. In the proposed strategy, collision avoidance is enforced through localstate constraints at given time instants and agents are assumed to only communicate the available time to react and the time stamps at which they expect to be within the intersection. Simulations results on the efficiency and performance of the proposed approach are also presented.
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| 9. |
- Sundbom, Malin, 1985, et al.
(författare)
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Online driver behavior classification using probabilistic ARX models
- 2013
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Ingår i: 16th International IEEE Conference on Intelligent Transportation Systems, October 2013, The Hague, The Netherlands. - 9781479929146 ; , s. 1107-1112
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Konferensbidrag (refereegranskat)abstract
- This paper shows how a probabilistic ARX model can be usedto predict the driver's steering behavior and classify the current driving style, based on measurements from the vehicle sensors. An algorithm, online classifying the driving style and predicting the steering behavior, is designed and validated on data recorded on a test track. The algorithm is designed to distinguish between two driving styles corresponding to normal and aggressive driving.
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| 10. |
- Turri, Valerio, 1987-, et al.
(författare)
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Linear model predictive control for lane keeping and obstacle avoidance on low curvature roads
- 2013
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Ingår i: IEEE Conference on Intelligent Transportation Systems, Proceedings, ITSC. - : IEEE conference proceedings. - 9781479929146 ; , s. 378-383
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Konferensbidrag (refereegranskat)abstract
- This paper presents a control architecture based on a linear MPC formulation that addresses the lane keeping and obstacle avoidance problems for a passenger car driving on low curvature roads. The proposed control design decouples the longitudinal and lateral dynamics in two successive stages. First, plausible braking or throttle profiles are defined over the prediction horizon. Then, based on these profiles, linear time-varying models of the vehicle lateral dynamics are derived and used to formulate the associated linear MPC problems. The solutions of the optimization problems are used to determine for every time step, the optimal braking or throttle command and the corresponding steering angle command. Simulations show the ability of the controller to overcome multiple obstacles and keep the lane. Experimental results on an autonomous passenger vehicle driving on slippery roads show the effectiveness of the approach.
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| 11. |
- Wahlstedt, Johan
(författare)
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Evaluation of the two self-optimising traffic signal systems Utopia/Spot and ImFlow, and comparison with existing signal control in Stockholm, Sweden
- 2013
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Ingår i: 2013 16th International IEEE Conference on Intelligent Transportation Systems - (ITSC). - : IEEE conference proceedings. - 9781479929146 ; , s. 1541-1546
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Konferensbidrag (refereegranskat)abstract
- The city of Stockholm has adopted the 'Urban mobility strategy' stating that the more surface efficient modes public transport (PT), cycling and walk should be prioritised over cars. This has led to an interest to extend the signal priority for PT beyond its present level. Self-optimising signal control systems can keep the impacts on other traffic at a controlled level when introducing extensive PT priority, and they may reduce the cycle time causing less waiting time for pedestrians and cyclists. In this paper two self-optimising systems are tested and compared with each other and with the existing signal control using microscopic simulation. VISSIM was connected to PC versions of the self-optimising systems Utopia/Spot and ImFlow and to signal controller simulators including PRIBUSS. Both self-optimising systems reduced the average delay per person compared to existing signal control. ImFlow performed better than Utopia/Spot in the evaluation.
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