Test pulse width calculation device, control device, test pulse width calculation method, and program

A control device comprising:

• a processor;
• an output circuit to output a test pulse for a failure diagnosis test;
• an input circuit to input the test pulse;
• a memory to store a threshold for detection of noise superposed on a signal to be input to the input circuit of the control deice;
• and
• an electrical measurement circuit to perform electrical measurement on an input path of the signal to be input to the input circuit, wherein
• the processor comprises
• a measurement value acquirer to acquire an electrical measurement value from the electrical measurement circuit,
• a test pulse width calculator to calculate, based on comparison between the electrical measurement value and the threshold, a reference noise width that is a reference for calculating a test pulse width and calculate the test pulse width that is larger than the calculated reference noise width, and
• a test pulse width setter to set the test pulse of the output circuit to the test pulse width calculated by the test pulse width calculator,
• the test pulse width calculator acquires, as a provisional noise width, a time width in which an absolute value of the electrical measurement value is consecutively over time not less than the threshold, and
• in a case where the provisional noise width is a plurality of provisional noise widths, when an interval between the plurality of provisional noise widths is smaller than a predetermined value, the test pulse width calculator calculates, as the reference noise width, a maximum value of a modified noise width obtained by summing the plurality of provisional noise widths and the interval between the plurality of provisional noise widths, and calculates the test pulse width that is larger than the calculated reference noise width.

A test pulse width calculation method for calculating a time width of a test pulse for use in a failure diagnosis test of a control device, the test pulse width calculation method comprising:

• acquiring an electrical measurement value in an input path of a signal to be input to an input circuit of the control device;
• and
• calculating, based on comparison between the electrical measurement value and a threshold for detection of noise superimposed on the signal to be input to the input circuit, a reference noise width that is a reference for calculating a test pulse width, and calculating the test pulse width that is larger than the calculated reference noise width, wherein
• the calculating includes acquiring, as a provisional noise width, a time width in which an absolute value of the electrical measurement value is consecutively over time not less than the threshold, and
• in a case where the provisional noise width is a plurality of provisional noise widths, when an interval between the plurality of provisional noise widths is smaller than a predetermined value, the calculating includes calculating, as the reference noise width, a maximum value of a modified noise width obtained by summing the plurality of provisional noise widths and the interval between the plurality of provisional noise widths, and calculating the test pulse width that is larger than the calculated reference noise width.