Electronic control apparatus

1. An electronic control apparatus that controls actuation of an inductive load, comprising:

a current detector that detects current flowing through the inductive load and outputs a current detection signal according to a value of the detected current, the current detection signal being an analog signal;

an analog-digital converter that takes in the current detection signal from the current detector at a predetermined fetch timing, and converts the current detection signal into a digital current detection value; and

a controller that calculates a current arithmetic value by executing a predetermined arithmetic processing for the digital current detection value, and controls the current flowing through the inductive load based on the current arithmetic value, the controller including a learning portion that learns the fetch timing of the current detection signal,

wherein:

the learning portion, by obtaining the current arithmetic value while changing the fetch timing, obtains a sample data value of the current arithmetic value for each of a plurality of fetch timings; and

the learning portion calculates a deflection between an ideal value of the current arithmetic value and the sample data value of the current arithmetic value for each of the plurality of fetch timings, and learns the fetch timing of the analog-digital converter, causing the deflection with the ideal value of the current arithmetic value to be minimized.

2. The electronic control apparatus according to claim 1 , wherein:

a fetch start timing represents timing of actuation period of the inductive load; and

the fetch timing is set so as to be shifted by a predetermined sampling period from the fetch start timing.

3. The electronic control apparatus according to claim 2 , wherein:

the predetermined sampling period includes a first sampling period and a second sampling period which is longer than the first sampling period;

when the ideal value of the current arithmetic value is calculated, the controller adopts the first sampling period as the predetermined sampling period of the current detector; and

when the sample data values of the current arithmetic value is calculated, or when the current arithmetic value for current control of the inductive load is calculated, the controller adopts the second sampling period as the predetermined sampling period of the current detector.

4. The electronic control apparatus according to claim 1 , wherein:

the ideal value is equal to a target current value which is a target value of the current flowing through the inductive load.

5. The electronic control apparatus according to claim 1 , wherein:

before the controller executes current control of the inductive load, the controller learns the fetch start timing of the analog-digital converter.

6. The electronic control apparatus according to claim 1 , wherein:

the controller calculates an average value of current detection values as the arithmetic processing.

7. The electronic control apparatus according to claim 1 , wherein:

the controller calculates a duty ratio by execution of a current feedback control that causes the current arithmetic value to follow a target current value;

the controller generates a pulse-width modulation drive signal based on the duty ratio;

the controller executes a pulse-width modulation control for the current flowing through the inductive load by controlling actuation of a switching element based on the pulse-width modulation drive signal; and

the fetch timing of the analog-digital converter is set to a plurality of areas which are set to the duty ratio.