Diagnostic Test Set Minimization and Full-Response Fault Dictionary

Abstract

We minimize a given test set without loss of diagnostic resolution in full-response fault dictionary. An integer linear program (ILP), formulated from fault simulation data, provides ultimate reduction of test vectors while preserving fault coverage and pairwise distinguishability of faults. The complexity of the ILP is made manageable by two innovations. First, we define a generalized independence relation between pairs of faults to reduce the number of fault pairs that need to be distinguished. This significantly reduces the number of ILP constraints. Second, we propose a two-phase ILP approach. In the first phase, using an existing procedure, we select a minimal detection test set. In the second phase, additional tests are selected for the undiagnosed faults using a newly formulated diagnostic ILP. The overall minimized test set may be only slightly longer than a one-step ILP optimization, but has advantages of reducing the minimization problem complexity and the test time required by the minimized tests. Benchmark results show potential for significantly smaller diagnostic test sets.

A Novel Fault Diagnostic Method Based on Node-Voltage Vector Ambiguity Sets

“…Manuscript SBT establishes the relationship between the circuit characteristics and failure components in advance via simulations, and then refers to actual measured characteristics to determine faulty components. Fault dictionary technology is an important branch of this approach [2]- [5]. To develop a fault dictionary, numerous technologies have been applied, including stimulus selection, test node optimization, fault characteristic extraction, and decision algorithm design.…”

“…To develop a fault dictionary, numerous technologies have been applied, including stimulus selection, test node optimization, fault characteristic extraction, and decision algorithm design. These technologies were reviewed in [5] and [6]. References [7]- [10] have added several new methods, which have been applied successfully to numerous projects [11].…”

“…References [7]- [10] have added several new methods, which have been applied successfully to numerous projects [11]. The concept of fault ambiguity sets is widely used in engineering, particularly in test node optimization, because it can easily program auto-test systems [3]- [5], [13].…”

“…According to [2]- [5], a corresponding table for failure components and node-voltages can be established using dc 5 V as a stimulus, by allowing circuit parameters to change randomly within the vicinity of the nominal value, and by considering only a single hard fault, as shown in Table I.…”