Nonlinear Controller for Automotive Thermal
Management Systems

Problem Motivation

The traditional automotive cooling system components include a wax based thermostat valve and crankshaft driven water pump.This thermostat does not readily adapt to different engine loads and operating conditions. The Wax pellet thermostat cannot provide a narrow temperature control range. It has other limitations like Limited diagnostics on the common thermostat valve and the crank driven water pump contributes to engine parasitic losses.

However,a servo-motor valve and pump can better regulate the coolant fluid flow in the engine to realize fuel economy gains and emission reductions. Advanced thermal system technologies can provide 1%-3% fuel economy improvements through lower parasitic losses, higher operating temperatures, reduced component temperature fluctuations, lowered emissions, and alternative engine block monitoring temperatures.

Research Objectives and Goals

  Redesign the current engine thermal management system for improved economy and reduced
emissions.

  Replace wax pellet thermostat with electro-mechanical valve actuator.

  Replace current belt-driven coolant pump with a variable speed electric pump.

  Mathematically model cooling system and components.

  Design control strategy for synchronous operation of the smart thermostat and electric water pump.

  Validate concept numerically and experimentally in laboratory.

System Description

Simplified System Model

Simulation Results

Fig. 1 Actual and Desired Engine Temperatures.

Fig. 2 Engine Temperature Tracking Error.

Fig. 3 Engine and Radiator Temperatures.

Fig. 4 Coolant flow rate through Radiator.

Fig. 5 Heater input.

Fig. 6 Rotational speed of Radiator Fan.

References
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