Mounting System Design for Drive Trains of Hybrid Electric Vehicles
Typ
Examensarbete för masterexamen
Master Thesis
Master Thesis
Program
Publicerad
2006
Författare
Kataria, Amit
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Although individual mobility represents a general desire of today s society, the role of passenger cars within actual traffic systems is discussed more and more controversially. One main reason is the carbon dioxide content of the exhaust gas emissions which is considered to contribute to global warming. This situation led to a renewed interest in hybrid vehicles which combine at least two types of propulsion systems. Generally an Electrical Motor (EM) is integrated between Internal Combustion Engine (ICE) and Gear Box (GB). The resulting Hybrid Electric Drive Train (HEDT) differs from the original one with respect to mass distribution, inertia moments and cg position, for example, thus requiring an adaptation of the mounting system in order to maintain a low vibration and noise level inside the passenger cabin. A powertrain mounting system has a significant effect in the noise, vibration and harshness (NVH) as well as ride and handling characteristics of a vehicle. Lighter vehicles and increasing customer demands for a vehicle refinement and dynamics are placing a greater emphasis on the optimization of the position, stiffness and damping characteristics of the mounts. A modeling approach is described, using the multibody dynamic simulation package ADAMS/ Engine, which allows the compromises between conflicting design requirements to be assessed rapidly and an optimum specification reached. The use of time domain non-linear approach allows the motion of the powertrain and mounts deflection to be assessed under normal and extreme driving conditions. Model of the major engine components allow the forced response of the powertrain, to low frequency engine excitation, to be predicted in order that idle shake and, via the use of transfer functions, interior vibration may be assessed. In addition the rigid body modes of the powertrain can be predicted and separated from known vehicle and powertrain forcing frequencies for good vehicle dynamics and NVH. Finally, Active Vibration Compensation methods are investigated and a piezo active controller is designed and tested in laboratory. This thesis deals with the development of a controller that receives inputs from a sensor and accordingly generates a response which in turn is fed to the piezo actuators. Since the road conditions vary continuously, it is necessary for the controller to generate a very quick response. Besides reduction in the weight and volume, this "Active Method" offers a high reduction in vibrations in the low frequency range.
Beskrivning
Ämne/nyckelord
Farkostteknik , Vehicle Engineering