Internal combustion engine thermal state model
AssigneeGeneral Motors Corporation
InventorPeter James Maloney
Life of this patent
Estimating the term…
Abstract
An internal combustion engine system is reticulated into an exhaustive network of interdependent temperature nodes and heat transfer branches for estimating thermal states at various nodes as required in engine control and diagnostic operations. All material heat transfer processes of each node of interest in engine control and diagnostics are modeled with additional nodes and their respective heat transfer processes added as necessary for a comprehensive analysis of all thermal dependencies, resulting in a precise, generic, portable thermal model for each relevant engine system temperature node.
Claims9
A method for estimating temperature in an internal combustion engine system, comprising the steps of:
- reticulating the engine system into a network of thermally interdependent temperature nodes;
- identifying, for at least one of the temperature nodes, all significant heat transfer branches into and out of the node;
- modeling heat transfer at the identified heat transfer branches;
- and
- estimating temperature at the at least one heat transfer node as a function of the modeled heat transfer at the identified heat transfer branches.
A thermal state estimation method for internal combustion engine system control, comprising the steps of:
- representing an engine system as a network of thermally coupled temperature nodes;
- establishing a temperature node at which accurate temperature estimation is required for engine control;
- identifying heat transfer processes that significantly affect the temperature at the established temperature node;
- identifying all additional temperature nodes with temperatures on which any of the identified heat transfer processes are substantially dependent;
- identifying additional heat transfer processes that significantly affect the temperature at the additional temperature nodes;
- modeling the heat transfer rate of the additional heat transfer processes;
- estimating temperature at the additional temperature nodes as a function of the modeled heat transfer rate of the additional heat transfer processes;
- modeling the heat transfer rate of the heat transfer processes that significantly affect the temperature at the established temperature node;
- estimating temperature at the established temperature node as a function of the modeled heat transfer rate of the heat transfer processes that significantly affect the temperature at the established temperature node;
- and
- controlling engine operation in accordance with the estimated temperature at the established temperature node.
A thermal state estimation method for internal combustion engine system diagnostics, comprising the steps of:
- representing a complete engine system as a network of thermally interdependent temperature nodes;
- establishing a temperature node at which accurate temperature estimation is required for engine diagnostics;
- identifying heat transfer processes that significantly affect the temperature at the established temperature node;
- identifying all additional temperature nodes with temperatures on which any of the identified heat transfer processes are substantially dependent;
- identifying additional heat transfer processes that significantly affect the temperature at the additional temperature nodes;
- modeling the heat transfer rate of the additional heat transfer processes;
- estimating temperature at the additional temperature nodes as a function of the modeled heat transfer rate of the additional heat transfer processes;
- modeling the heat transfer rate of the heat transfer processes that significantly affect the temperature at the established temperature node;
- estimating temperature at the established temperature node as a finction of the modeled heat transfer rate of the heat transfer processes that significantly affect the temperature at the established temperature node;
- providing a temperature range for the established temperature node associated with normal engine system operation;
- comparing the estimated temperature to the provided temperature range;
- and
- diagnosing a fault condition when the estimated temperature is outside the provided temperature range.
Dependencies are inferred from the claim text.