Method and apparatus for starter motor diagnosis and prognosis using parameter estimation algorithm

A method for determining the state of health of a starter motor in a vehicle, said method comprising:

• using a current sensor to determine a starter motor current of the starter motor;
• using a voltage sensor to determine a starter motor voltage of the starter motor;
• providing an engine speed of an engine of the vehicle;
• identifying a starter motor resistance that is a combination of a starter motor armature resistance and a starter motor brush resistance;
• identifying a starter motor armature inductance;
• identifying a back EMF motor constant;
• identifying a time model of the starter motor using the starter motor voltage, the starter motor current, the engine speed, the starter motor resistance, the starter motor armature inductance and the back EMF motor constant;
• defining model parameters from the time model;
• providing a regression model based on the time model;
• using a controller to determine motor parameters Rm, Km and Lm as
• R
• m
• =
• p
• 1
• -
• 1
• p
• 2
• ,
• K
• m
• =
• p
• 3
• p
• 2
• ⁢
• ⁢
• and
• ⁢
• ⁢
• L
• m
• =
• p
• 2
• Δ
• ⁢
• ⁢
• t
• based on the regression model, where p1, p2 and p3 are the model parameters, Rm is a resistance motor parameter, Km is a back EMF constant motor parameter and Lm is an inductance motor parameter;
• using the controller to determine an error using the motor parameters;
• and
• using the controller to compare the error to an error threshold to determine the state of the health of the starter motor.

A method for determining the state of health of a starter motor in a vehicle, said method comprising:

• using sensors to determine a starter motor voltage and a starter motor current of the starter motor;
• identifying a time model of the starter motor using a the starter motor voltage, a the starter motor current, an engine speed, a starter motor resistance, a starter motor armature inductance and a back EMF motor constant;
• defining model parameters from the time model;
• and
• using the model parameters in a controller to determine an error that is used to determine the state of health of the starter motor.

A method for determining the state of health of a starter motor in a vehicle, said method comprising:

• using a current sensor to determine a starter motor current of the starter motor;
• using a voltage sensor to determine a starter motor voltage of the starter motor;
• providing an engine speed of an engine of the vehicle;
• identifying starter motor values that will be used to determine the state of health of the starter motor;
• identifying a time model of the starter motor using the starter motor voltage, the starter motor current, the engine speed and the starter motor values;
• defining model parameters from the time model;
• providing a regression model based on the time model;
• using a controller to determine motor parameters based on the regression model, wherein the motor parameters are stored as a temperature in a look-up table;
• using the controller to determine an error using the motor parameters;
• and
• using the controller to compare the error to an error threshold to determine the state of health of the starter motor.