A Fault Diagnosis Method for Non-linear Analog Circuits

For diagnosing faults in non-linear analog circuits,a fault diagnosis method is proposed based on the principle of linear relativity of node-voltage increments.By piecewise linear-modeling of non-linear elements,the changes in node-voltages caused by faults are shown to be piecewise linearly related.Broken lines in the node-voltage plane are taken as fault character to construct a fault dictionary,and the distance from the test result point to each broken line is calculated to measure the accordance of the circuit status to the fault character.In this way both soft and hard faults in non-linear circuits can be diagnosed.Experimental results indicated that the proposed method is practical to be implemented in computer.