Modeling, Control Design, and Experimental Validation of an Overactuated Thermal Management System for Engine Dynamometer Applications

Effective engine mapping and calibration are contingent upon tight control of the environment in which the mapping and calibration are performed. Among the most important variables to be controlled are the temperatures of coolant and oil that circulate through the engine block. Because of the large time constants associated with thermodynamic systems, controlling these variables often represents a bottleneck in the engine mapping and calibration processes. In this paper, we examine a particular layout for a thermal management unit, which is currently being used in practice. By developing and analyzing a thermodynamic model of the system, we are able to gain insight into the system dynamics and explore special features to optimize the temperature response. In particular, we will show how the overactuation in the system may be leveraged in the presence of hard saturation constraints and different dynamic actuator authorities. We present design and validation results (both simulation and experimental) for the proposed controller, and compare the performance to the baseline controller in order to quantify improvements.