A generalized fault diagnosis method in dynamic analogue circuits

Abstract

SUMMARYFault diagnosis of analogue circuits is essential for analogue and mixed-signal systems testing and maintenance. A new method is proposed in this paper for multiple fault diagnosis of linear analogue circuits in frequency domain. The Woodbury formula is applied to the modiÿed nodal equation to construct the fault diagnosis equation, which relates the limited measured circuit responses with the multiple faults inside the circuit in a linear way. A recently developed ambiguity group locating technique is modiÿed here to identify the faulty parameters directly. Computation cost is reduced compared to combinatorial search in traditional fault veriÿcation methods. Only one node is needed for voltage measurement, but multiple excitations on accessible nodes are required for fault identiÿcation. Parameter evaluation can provide the exact solution to the deviated values of faulty parameters. The faulty parameter deviations can have any ÿnite values. Example circuits are provided to illustrate the proposed method. Two other methods for multiple analogue fault diagnosis sharing the same mechanism as the method proposed in this paper are also brie y described. The proposed method is extremely e ective for the circuit with very limited accessible nodes and is also computationally e cient.

A method for fast simulation of multiple catastrophic faults in analogue circuits

“…According to the above discussion we enlarge the cluster step by step, every time creating the structure of the first or the second type and simultaneously form its node impedance matrix, using Equation (7) or (8). Also some branches connecting the nodes of the enlarged cluster are added and the node impedance matrix is modified with the help of the equation like (3).…”

“…Let us consider the active filter [7,8,17] shown in Figure 4 containing eight operational amplifiers, characterized by the model used in Example 1, shown in Figure 2(b). The circuit parameters are as follows: C 2 = C 12 = C 18 = C 29 = 10 nF, R gen = 50 , R 1 = 182 , R 10 = 11.1k, To find the node impedance matrix Z of this circuit we first create two clusters N A and N B by removing the branches numbered 26 and 27.…”

Multiple Soft Fault Diagnosis of Nonlinear DC Circuits Considering Component Tolerances

“…Less papers have been devoted to multiple faults, e.g. [8,11,13,[17][18]26]. To perform soft fault diagnosis a diagnostic test is arranged leading to diagnostic equations including circuit parameters as variables.…”

Multiple Soft Fault Diagnosis of Nonlinear Circuits Using the Continuation Method

“…Several papers have been focused on the multiple fault diagnosis, e.g. [11,14,16,17,19,20]. Although many achievements in this field have been made, the problem is still open and no fully automatic method is available for analog circuits.…”

“…During the last several years, many methods devoted to soft fault diagnosis of analog circuits have been developed [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Appropriate tools for soft-fault diagnosis are SAT methods.…”