Method for estimating and correcting bias errors in a software air meter
AssigneeGeneral Motors Corporation
InventorsKenneth P. Dudek, Ronald A. Davis
Life of this patent
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Abstract
A method for estimating and correcting bias errors in a vehicle system which implements iterative prediction and estimation to determine a measure of at least one determinable vehicle engine parameter determines if the vehicle engine is in a substantially steady state condition, determines a measure of error between the predicted and measured values of a control parameter while the vehicle is in the steady state condition, estimates a system bias in response to the determined error, and offsets the system bias in subsequent predictions, thereby reducing the error between the predicted and measured values of the control parameter and increasing the accuracy of the estimations of the determinable vehicle parameter.
Claims25
In an engine control system in which the value of an unmeasured engine parameter is determined through measurement of the values of other parameters including a control parameter and the iterative prediction and estimation of the values of the control parameter and the unmeasured parameter based upon the other measured parameter values and a system model, the improvement comprising the steps of:
- comparing the estimated value of the control parameter with the measured value of the control parameter during steady state operation to derive a quantitative indication of system bias;
- and
- employing the quantitative indication of system bias in the iterative prediction of the control parameter and the unmeasured parameter thereby improving the accuracy of the unmeasured parameter value estimation.
In an engine control system in which the value of an unmeasured engine parameter is determined through measurement of the values of other parameters including a control parameter and the iterative prediction and estimation of the values of the control parameter and the unmeasured parameter based upon the other measured parameter values and a system model, the improvement comprising the steps of:
- comparing the predicted value of the control parameter with the measured value of the control parameter during steady state operation to derive a quantitative indication of system bias;
- and
- employing the quantitative indication of system bias in the iterative prediction of the control parameter and the unmeasured parameter thereby improving the accuracy of the unmeasured parameter value estimation.
In an engine control system in which future values of at least one engine state is predicted through iterative prediction and estimation responsive to measures of various engine parameters, including a measure of the one engine state, the improvement comprising the steps of:
- comparing the predicted value of the one engine state with the measured value of the one engine state during steady state operation to derive a quantitative indication of system bias;
- and
- employing the quantitative indication of system bias in the iterative prediction of the one system state thereby improving the accuracy of the predicted future values of the one engine state.
A method for estimating and correcting bias errors in a vehicle system which implements iterative prediction and estimation to predict a measure of at least one vehicle engine parameter in response to a set of model parameters and various measured engine parameters, comprising the steps of:
- determining a measure of error between the predicted and measured values of the one engine parameter while the vehicle is in a steady state condition;
- estimating a system bias in response to the determined error;
- and
- offsetting the system bias in subsequent predictions, thereby reducing the error between the predicted and measured values of the one engine parameter.
A method for estimating and correcting bias errors in a vehicle system which implements iterative prediction and estimation to determine a measure of at least one determinable vehicle engine parameter and predicts at least one control parameter, which is also separately measured, in response to a set of model parameters and various measured engine parameters, comprising the steps of:
- determining a measure of error between the predicted and measured values of the control parameter while the vehicle is in a steady state condition;
- estimating a system bias in response to the determined error;
- and
- offsetting the system bias in subsequent predictions, thereby reducing the error between the predicted and measured values of the control parameter and increasing the accuracy of the estimations of the determinable vehicle parameter.
A method for estimating and correcting bias errors in a vehicle system which implements iterative prediction and estimation to determine a measure of at least one determinable vehicle engine parameter and estimates at least one control parameter, which is also separately measured, in response to a set of model parameters and various measured engine parameters, comprising the steps of:
- determining a measure of error between the estimated and measured values of the control parameter while the vehicle is in a steady state condition;
- estimating a system bias in response to the determined error;
- and
- offsetting the system bias in subsequent predictions, thereby reducing the error between the estimated and measured values of the control parameter and increasing the accuracy of the estimations of the determinable vehicle parameter.
Dependencies are inferred from the claim text.