Global ETD Search

21	Predictive Energy Management of Long-Haul Hybrid Trucks : Using Quadratic Programming and Branch-and-Bound Jonsson Holm, Erik January 2021 (has links) This thesis presents a predictive energy management controller for long-haul hybrid trucks. In a receding horizon control framework, the vehicle speed reference, battery energy reference, and engine on/off decision are optimized over a prediction horizon. A mixed-integer quadratic program (MIQP) is formulated by performing modelling approximations and by including the binary engine on/off decision in the optimal control problem. The branch-and-bound algorithm is applied to solve this problem. Simulation results show fuel consumption reductions between 10-15%, depending on driving cycle, compared to a conventional truck. The hybrid truck without the predictive control saves significantly less. Fuel consumption is reduced by 3-8% in this case. A sensitivity analysis studies the effects on branch-and-bound iterations and fuel consumption when varying parameters related to the binary engine on/off decision. In addition, it is shown that the control strategy can maintain a safe time gap to a leading vehicle. Also, the introduction of the battery temperature state makes it possible to approximately model the dynamic battery power limitations over the prediction horizon. The main contributions of the thesis are the MIQP control problem formulation, the strategy to solve this with the branch-and-bound method, and the sensitivity analysis. Predictive energy management quadratic programming branch-and-bound mixed-integer quadratic programming energy optimization look-ahead control model predictive control receding horizon control optimal control convex optimization heavy-duty vehicle long-haul truck hybrid electric vehicle Control Engineering Reglerteknik
22	Aircraft Fuel Consumption - Estimation and Visualization Burzlaff, Marcus January 2017 (has links) (PDF) In order to uncover the best kept secret in today's commercial aviation, this project deals with the calculation of fuel consumption of aircraft. With only the reference of the aircraft manufacturer's information, given within the airport planning documents, a method is established that allows computing values for the fuel consumption of every aircraft in question. The aircraft's fuel consumption per passenger and 100 flown kilometers decreases rapidly with range, until a near constant level is reached around the aircraft's average range. At longer range, where payload reduction becomes necessary, fuel consumption increases significantly. Numerical results are visualized, explained, and discussed. With regard to today's increasing number of long-haul flights, the results are investigated in terms of efficiency and viability. The environmental impact of burning fuel is not considered in this report. The presented method allows calculating aircraft type specific fuel consumption based on publicly available information. In this way, the fuel consumption of every aircraft can be investigated and can be discussed openly. ddc:620 info:eu-repo/classification/ddc/629.13 Luftfahrt Luftfahrzeug Flugmechanik Flugtriebwerk Aeronautics Airplanes Airplanes--Performance Airplanes--Fuel consumption aviation commercial aircraft passenger flight mechanics flight mechanics Breguet equation fuel consumption fuel consumption fuel burn payload range airport planning document long-haul environment saving

Search results

Predictive Energy Management of Long-Haul Hybrid Trucks : Using Quadratic Programming and Branch-and-Bound

Aircraft Fuel Consumption - Estimation and Visualization