| 1. |
- Altaf, Faisal, 1982, et al.
(författare)
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Feasibility Issues of using Three-Phase Multilevel Converter based Cell Balancer in Battery Management System for xEVs
- 2013
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823434 ; 46, s. 390-397
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Konferensbidrag (refereegranskat)abstract
- The use of a three-phase multilevel converter (MLC) as an integrated cell balancer and motor driver is investigated for three-phase AC applications in EVs/HEVs/PHEVs. The paper analyzed an issue of additional battery losses caused by the flow of reactive and/or harmonic power from each power cell of the three-phase MLC battery system. The paper also investigates the size of shunt capacitor required for compensation of the losses to acceptable level. This study concludes that the size of the required capacitor is too big for the vehicle application unless some other active compensation is used as well. Another practical way to employ the MLC as a cell balancer is to use it in a cascaded connection with the conventional three-phase two-level voltage source inverter however it may not be a cost-effective solution either due to high component count.
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| 2. |
- Grahn, Markus, 1978, et al.
(författare)
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A Diesel Engine Management System Strategy for Transient Engine Operation
- 2013
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823434 ; 7:1, s. 1-6
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Konferensbidrag (refereegranskat)abstract
- A strategy for diesel engine management systems has been introduced and evaluated. The strategy calculates set points for engine management system controllable quantities with an aim to minimize fuel consumption for a given engine speed and requested torque profile, while keeping accumulated emissions below given limits. The strategy is based on existing methodology for steady-state engine operation, but extended to handle transient effects in the engine caused by dynamics in the air system. The strategy has been evaluated using a simulation model of a diesel engine system. The model estimates fuel consumption together with NOX and soot emissions for a transient simulation cycle depending on set points in the engine management system for boost pressure, oxygen fraction in the intake manifold, and injection timing. For the transient simulation scenario used in this paper and with given limits on accumulated emissions, the strategy has been shown to decrease fuel consumption with up to 0.7% compared to a strategy that is based only on steady-state engine operation.
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| 3. |
- Johannesson, Lars, 1979, et al.
(författare)
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Including a battery state of health model in the hev component sizing and optimal control problem
- 2013
-
Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823434 ; , s. 398-403
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Konferensbidrag (refereegranskat)abstract
- This paper studies convex optimization and modelling for component sizing and optimal energy management control of hybrid electric vehicles. The novelty in the paper is the modeling steps required to include a battery wear model into the convex optimization problem. The convex modeling steps are described for the example of battery sizing and simultaneous optimal control of a series hybrid electric bus driving along a perfectly known bus line. Using the proposed convex optimization method and battery wear model, the city bus example is used to study a relevant question: is it better to choose one large battery that is sized to survive the entire lifespan of the bus, or is it beneficial with several smaller replaceable batteries which could be operated at higher c-rates?
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| 4. |
- Kianfar, Roozbeh, 1984, et al.
(författare)
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A Distributed Model Predictive Control Approach to Active Steering Control of String Stable Cooperative Vehicle Platoon
- 2013
-
Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823434 ; 7:1, s. 750-755
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Konferensbidrag (refereegranskat)abstract
- A distributed receding horizon approach is adopted for active steering control of acooperative vehicle platoon in the lateral direction. String stability is enforced by translatingthe classical definition of string stability from frequency domain into time domain constraint.Each vehicle locally computes its own control action and broadcasts its intention to its follower.Any deviation from the intention of each vehicle from the predicted states is penalized andconstrained in the optimization problem which is solved locally by the vehicles. The stringstability condition is robust against uncertainty in the intent trajectory. The effectiveness ofproposed approach is verified by simulation in a double lane change scenario.
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| 5. |
- Larsson, Viktor, 1984, et al.
(författare)
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Comparing two approaches to precompute discharge strategies for plug-in hybrid electric vehicles
- 2013
-
Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823434 ; , s. 121-126
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Konferensbidrag (refereegranskat)abstract
- This paper investigates two alternative approaches to precompute a discharge strategy for the main commuter route of a plug-in hybrid electric vehicle. The first approach is based on the idea of computing a state of charge reference trajectory by solving a convex program; while the second approach utilizes dynamic programming to determine an optimal cost-to-go function. During real-time operation the torque split is decided by an equivalent consumption minimization strategy where the main difference between the two approaches is how the equivalence factor is determined. With the first approach it is adapted to track the state of charge reference trajectory and in the second approach it is given by the partial derivative of the cost-to-go function with respect to state of charge. To evaluate the two approaches a simulation study is performed in the dynamic vehicle modelling software Autonomie using logged commuter driving data. The simulation results indicate no clear difference between the two approaches in terms of fuel economy and battery usage. Both approaches are, however, significantly better than a charge depleting charge sustaining discharge strategy.
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| 6. |
- Pourabdollah, Mitra, 1984, et al.
(författare)
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Effect of Driving patterns on Components sizing of a Series PHEV
- 2013
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. - 9783902823434 ; 7:1, s. 17-22
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Konferensbidrag (refereegranskat)abstract
- In the past decade, it has been demonstrated that Plug-in Hybrid Electric Vehicles (PHEVs)can significantly reduce petroleum consumptions. However, the extend to which these vehicles canreduce the petroleum consumption highly depends on components size and driving patterns. In otherwords, PHEVs show the best benefits if the components are dimensioned to match the driver’s drivingbehavior. In this paper, the effect of different driving patterns on the optimal sizing of three majorcomponents of series PHEVs, i.e., battery, electric motor, and engine generator unit is studied. Differentdriving cycles are generated stochastically from real driving data using Markov chains, to representlife-time driving patterns of different drivers.To find the optimal size of the components, the problem is formulated as a convex optimization problem.The optimization variables (the variables of component size and energy management) are obtained byminimizing a cost function which is the sum of the operational and component costs.
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| 7. |
- Hang, Chang C., et al.
(författare)
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Practical Aspects of PID Auto-Tuners Based on Relay Feedback
- 1988
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Ingår i: 2nd International IFAC Symposium on Adaptive Control of Chemical Processes 1988 (ADCHEM '88), Lyngby, Copenhagen, Denmark, 17-19 August. - 1474-6670. ; 21:7, s. 153-158
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Konferensbidrag (refereegranskat)
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| 8. |
- Johansson, Rolf
(författare)
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Lyapunov Design for Adaptive Control of Robots
- 1989
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - 1474-6670. ; 22:3
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents algorithms for continuous-time direct adaptive control of robot manipulators. Lyapunov theory is used for controller design and stability investigation. Algorithms for rapid continuous-time adaptive control are presented.
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| 9. |
- Källström, Claes, et al.
(författare)
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Adaptive Autopilots for Large Tankers
- 1978
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Ingår i: 7th Triennial World Congress of the IFAC : A Link Between Science and Applications of Automatic Control, Helsinki, Finland, 12-16 June - A Link Between Science and Applications of Automatic Control, Helsinki, Finland, 12-16 June. - 1474-6670. ; 11:1, s. 477-484
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Konferensbidrag (refereegranskat)abstract
- The adaptive autopilots are based on velocity scheduling, a self-tuning regulator for steady state course keeping, a high gain turning regulator with variable structure, and a Kalman filter. Results from simulations and full-scale experiments on three different tankers are presented. The autopilots are shown to work excellently under different loads, speed and weather conditions.
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| 10. |
- Olsson, Gustaf, et al.
(författare)
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Estimation and Control of Biological Activity in the Activated Sludge Process Using Dissolved Oxygen Measurements
- 1977
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Ingår i: IFAC Symposium on Environmental Systems Planning, Design and Control, Kyoto, Japan, 1-5 August. - 1474-6670. ; 10:7, s. 745-755
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Konferensbidrag (refereegranskat)abstract
- The control of an activated sludge process is considered. It is discussed how the organism activity is a crucial information for the control. It is shown, how the concentration profile of dissolved oxygen (DO) in the biological reactor is related to the sludge activity. As a result the DO profile is a useful measurement information for control purposes
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