Approach | Advantage | Disadvantage | Application |
---|---|---|---|
Simple and easy to analyze; | Too much accumulated experience data required; | The initial design estimation; | |
Few parameters required and easy to get; | Only a general estimation without regard to the specific cases of working loads and failure; | Less important, small-sized, mass-produced components and parts. | |
Able to obtain confidence limits. | Inaccuracy prediction in terms of the individual. | Â | |
Simple to model, methods mature, and widely used. | Unable to be used for long-term prediction; | Suitable for linear-time, invariant systems when the performance of its characteristics are smoothly changing. | |
No need for historical data or fully understanding the fault mechanism; | Unable to synthesize prior knowledge; | Â | |
High efficiency in computing and allowed to be used online. | Sensitive to noise and the initial state; poor effects on the dynamic process of non-stationary. | Â | |
Life prediction based on Logistic Regression (LR) [84,85,86] | No need to set the critical threshold; | Not feasible unless normal feature domain description and unpredictable behavior are both available; | Service performance evaluation for degradation failure equipment like machine tools. |
Able to obtain the time dynamic characteristics without making too much assumptions for equipment failure process and the distribution function. | Unable to do real-time prediction with offline data. | Â | |
Variety of status information are integrated into account; | Complex computation of parameter estimation involving numerical integration; | Risk analysis of the joint characteristic variables; | |
The characteristic index able to change with time. | Assumption that risks change with variables proportionally. | Analysis of data distribution, residual distribution unknown or censored data. | |
No need for fault history data; | Â | Â | |
Life prediction based on Neural Network [32] | Strong self-learning ability, non-linear fitting ability and good robustness; | No standard method to determine the structure of the neural network; | Pattern recognition or some certain signal processing. |
Excellent memory ability and nonlinear mapping skill. | Sufficient sample data required for the parameter calibration; | Â | |
 | Uncertainty of structure and weight. |  | |
Able to deal with uncertain problems. | Unable to model the unknown fault; | Used to solve uncertainty and relevance fault of complex equipment; | |
Able to avoid data over-fitting. | Difficulty in computing for the unknown network; | Widely used in the intelligent systems of computer intelligence science, industrial control, medical diagnostics and other fields. | |
Effective multi-source information fusion and expression; | Relies on reliability of the prior knowledge; | Â | |
Able to visualize the dependency links among each pair of variables. | Results are sensitive to the selection of prior distribution. | Â | |
Life prediction based on Support Vector Machine (SVM) [50, 91] | Concrete realization of the structural risk minimization criterion | Not suitable for large-scale data processing; | Small sample, nonlinear and high dimensional mode recognition, such as predicting porosity and clay content in oil well logging. |
Simple structure, good promotion performance and fast learning; | Theoretical defects in Kernel function for nonlinear classification problems; | Â | |
Only one minimal in optimization solution. | Slow solution speed. | Â | |
Life prediction based on Markov Model /Hidden Markov Model (HMM) [60, 61, 92, 93] | Able to model different stages of degradation; | Unable to model the unknown fault; | Unable to directly observe the state, but able to observe the vector sequence; |
No need for prior knowledge of fault mechanism, able to process incomplete data; | Complex hidden semi-Markov model is required if the fault time is not exponentially distributed; | Widely used in pattern recognition, speech recognition, behavior recognition, character recognition and fault diagnosis and other fields. | |
Predictions with confidence intervals. | The model calculation increases with the number of states. | Â | |
Able to do the linear unbiased minimum mean square error estimation; | State equation and measurement equation need to be defined; | Real-time online prediction for linear Gaussian system. | |
Prediction accuracy does not change with the prediction time interval; good robustness; | Noise level could influence the performance and stability of the algorithm; | Â | |
Able to estimate the current state and also predict the future state. | Only works with linear system and Gaussian noise. | Â | |
State-space prediction based on particle filter [93, 96,97,98] | By finding a random sample to carry out the approximate calculation for the probability density function to obtain the state minimum variance distribution; | Large amount of sampling are required to avoid degradation; | Real-time online prediction of strong-nonlinear, non-Gaussian noise system, such as radar tracking and robot localization. |
High accuracy. | Computation is more complex than Kalman filtering; | Â | |
 | High-dimensional system and increasing particles complex computation. |  |