Specifying Quantization Characteristics for Required Lifetime Prognostic Performance

The accuracy of lifetime prediction is significantly influenced by the quality of condition monitoring (CM) data, and both forward and reversed problems related to this issue have been extensively investigated thus far. The quality of CM data is inevitably affected by quantization errors resulting from analog-to-digital conversion (ADC) in practical scenarios; however, it has received relatively less attention compared to measurement error (ME). To clarify the usability of the CM data for predicting the lifetime, a reversed problem “the specification of both quantization and ME range to achieve a desirable lifetime prediction performance” is considered in this article. To address this problem, guidelines for formulating specification limits related to distribution-based quantization and ME characteristics are developed. By referring to a widely employed degradation model based on the Wiener process, permissible values for both ME and quantization parameters under a specified lifetime prediction requirement are derived. It means that the desirable performance for lifetime prediction cannot be achieved if these permissible values are not met. In addition, several special scenarios are further considered, and the analytical results of permissible values are obtained. Finally, numerical examples and case study of control moment gyroscopes are provided to illustrate the implementation procedure and usefulness of theoretical results.