| Summary: | Good comfort for the driver of a construction machine is crucial. Gearshift comfort is an important part of the total comfort. Volvo Construction Equipment Components has a simulation environment of the powertrain, SimPow, which is implemented in Matlab/Simulink. SimPow is mostly used for simulation of control strategies and performance. In order to be able to study gearshifting comfort, Volvo has an interest in developing new models for SimPow. The purpose of this thesis work is to build complementing models for SimPow, and evaluate what modifications are needed in order to be able to study gearshifting comfort. The work is limited to study only movement in the longitudinal direction and for one vehicle - the Wheel Loader L150E. The models are implemented in Simulink. The complementing models are of two kinds: – Models of the vehicle. The bodies, vehicle frame and cabin are considered as rigid bodies. Elements consisting of springs and dampers, insulators, are connecting frame and cabin. Driving forces from the wheels results in acceleration (longitudinal, vertical and rotational) and jerk for the center of gravity of the vehicle frame. The acceleration of the frame gives rise to forces in the insulators, connecting frame and cabin. These forces accelerates the cabin and the driver. – Longitudinal models of the wheels. Torque from the powertrain gives rise to a longitudinal force, driving force, in the contact patch between ground and tire. The conclusion from the evaluation shows that a longitudinal model of the wheels is needed. Further, it is considered sufficient to study and measure the longitudinal acceleration of the frame. Therefore, the models of the vehicle are not needed.
|
|---|
