The elusive consequences of slow engine response on drive cycle fuel efficiency

Nazari, Shima; Middleton, Richard H.; Martz, Jason; Stefanopoulou, Anna G.

doi:10.23919/acc.2017.7963791

Cited by 5 publications

(2 citation statements)

References 12 publications

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“…15 Other parameters such as reduced exhaust gases specific enthalpy due to decreased exhaust temperature also contribute to the increased response time. This enlarged turbo-lag can create driveability problems or even reduce the fuel economy gain of EGR 22 if not compensated with a system like the PSS. The smaller plots on the right show intake manifold pressure (top left), boost pressure (top right), and compressor inlet pressure (p ci , left middle).…”

Section: Baseline Controllermentioning

confidence: 99%

Control of hybrid boosting in highly diluted internal combustion engines

Nazari

Siegel

Stefanopoulou

2020

International Journal of Engine Research

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A novel hybrid system enabling both flexible supercharging and limited torque assist is studied to mitigate transient response challenges of a turbocharged spark ignition engine equipped with low pressure exhaust gas recirculation. The hybrid system, called a power split supercharger (SC), is configured with a planetary gear set that splits the supercharging power between a small low-voltage electric motor and the engine crankshaft. The air path controller relies on the coordination of four actuators on the engine side and three low-level actuators on the hybrid boosting device. A decentralized control scheme is used in this work, in which the master–slave structure of the boost pressure controller decreases the turbo-lag associated with exhaust gas recirculation, while minimizing the SC operation for fuel economy. A vector reference governor is used to prevent compressor surge during engine tip-outs. In addition, the desired intake manifold pressure is modified to provide time for evacuating the exhaust gas recirculation and avoiding misfires when transitioning to low load, while the hybrid capability of the power split SC is used to recuperate the unwanted generated power. All controllers are validated on both a mean value engine model and a high-fidelity engine model. Practical challenges of implementing the vector reference governor to the highly nonlinear engine air path with pressure pulsations originating from the engine reciprocation are discussed and some solutions are proposed.

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Section: Baseline Controllermentioning

confidence: 99%

Control of hybrid boosting in highly diluted internal combustion engines

Nazari

Siegel

Stefanopoulou

2020

International Journal of Engine Research

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“…Among which the use of hybrid energy storage devices in autonomous power supply systems to coordinate fluctuations in electricity generation and consumption [6,7], [8,9]; taking into account the nonlinearity of the control object in the synthesis of the ACS controller to reduce power consumption from the power source and increase the life of an autonomous object [10,11]; taking into consideration friction forces and aerodynamic resistance of air for specific energy savings depending on motion parameters [12,13]. The importance of matching the control strategy to the driving style is determined by [14]. It is necessary to note the works that determine the seriousness of the issue of working out the mechanical units of the vehicle [15,16], in order to improve safety and controllability.…”

Section: Inroductionmentioning

confidence: 99%

Computer Simulation of Electric Vehicle Acceleration Processes With Different Positions of the Mass Center

Nazarova,

Osadchyy,

Brylystyi

2020

AAIT

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Due to the electrification of modern vehicles the role of the electric drive is growing as the main mover. In conditions of increasing requirements for the safety controllability and energy efficiency of a vehicle on electric traction,it is actual to take into account the dynamic properties of a vehicle in various driving modes when developing an automatic control system. In the work it is investigated the influence of the mass center position on the redistribution of forces during acceleration on a straight-line section. Taking into consideration the position of the mass center in the control system allows redistributing the desired moment to the wheels with better adhesion to the surface, which increases the safety and controllability of the vehicle, as well as minimizes energy costs on wheels with the worst adhesion. The aim of the work is to investigate the influence of the mass center position on the dynamics of a vehicle with full, rear and front wheel drive using computer simulation. The mathematical description includes analytical expressions for the redistribution of the support reactions for each of the wheels, which makes it possible, on their basis, to carry out computer simulation of the electric vehicle acceleration on a straight-line section. For the indicated types of vehicle drives, a computer model has been developed that includes, in the automatic control system for torque redistribution, the coordinates of the mass center position, which are converted on the basis of analytical expressions into the physical parameters of the system.Computer simulation of acceleration from zero to one hundred km/h with full pressing of the accelerator pedal for nine different positions of the mass center and three types of drive was carried out. Data were obtained on the change in accelerations, support reactions and torque of wheels during acceleration at various mass center positions. Based on the results obtained, the most preferable coordinates of the mass center for each type of drive from the point of view of the acceleration dynamics on a straight section were determined. The developed computer model can be used to study the dynamics of an electric vehicle when cornering, as well as to study energy indicators in all dynamic driving modes.

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