| This report documents the design and development of a high-bandwidth, hydrostatic, transient engine dynamometer system designed specifically for studying transient dynamics of internal combustion engines as they interact with the vehicle powertrain system. The primary component of this system, the hydrostatic dynamometer, is a design unique to the Powertrain Control Research Laboratory (PCRL) at the University of Wisconsin-Madison and its development constitutes the majority of this report. The notable characteristic of this design is exceptionally low inertia that results in a very high system bandwidth.; The bandwidth of this dynamometer is exploited by combining it with high fidelity powertrain models that run in real time to calculate the instantaneous loading an engine would experience if it were actually being used in a vehicle. This Hardware-In-the-Loop (HIL) configuration reproduces the effects that various powertrain hardware modifications would have on engine transients, and therefore control and diagnostic algorithms.; Specifically, this dissertation contains the following information: (1) a description of the mechanical, hydraulic, electronic and computer hardware that is used to construct the dynamometer, (2) an overview of the additional test hardware used with the transient test system, (3) the development and results of simulation models used to model the dynamometer hardware, the engine, and the entire hardware-in-the-loop vehicle model, (4) the creation of a library for these models for simulating subsystems or the entire test system, (5) the development and results of analysis routines used to help better understand the dynamics of the dynamometer system, (6) the development of the signal processing routines used to filter the feedback signals, (7) the development of control algorithms used to control the dynamometer, and (8) test results for the dynamometer operating in torque control and with the hardware-in-the-loop models. |
