Load drive controlling device

A load drive controlling device for controlling a drive of an inductive load comprising:

• a switch driven at a preset duty which controls an electric current flowing in the inductive load;
• an actual electric current value detector detecting an actual electric current value flowing in the inductive load;
• a dulling controller (i) setting a first electric current value for a dulling adjustment operation based on a change trend between a previous value and a current moment value of a target electric current of the inductive load, and (ii) setting the current moment value of the target electric current as a guard value;
• a dulling adjuster (i) performing the dulling adjustment operation on the first electric current value, and (ii) limiting a dulled value based on the guard value;
• a PI controller (i) performing a Proportional Integral control based on a deviation between the dulled value that is output from the dulling adjuster and the actual electric current value, and (ii) setting the preset duty, wherein
• when the change trend of the target electric current value is increasing, (i) the dulling controller sets a value greater than the current moment value of the target electric current as the first electric current value, which allows an increase of the first electric current value to increase to a maximum electric current value that is a 100% duty target electric current value, and (ii) the dulling controller sets the guard value as an upper limit value of the dulled value, and
• when the change trend of the target electric current value is decreasing, (i) the dulling controller sets a value smaller than the current moment value of the target electric current as the first electric current value, which allows a decrease of the first electric current value to decrease to a minimum electric current value that is a 0% duty target electric current value, and (ii) the dulling controller sets the guard value as a lower limit value of the dulled value.