Exponential degradation model for estimating remaining useful life

Use `exponentialDegradationModel`

to model an exponential
degradation process for estimating the remaining useful life (RUL) of a component.
Degradation models estimate the RUL by predicting when a monitored signal will cross a
predefined threshold. Exponential degradation models are useful when the component
experiences cumulative degradation. For more information on the degradation model, see
Exponential Degradation Model.

To configure an `exponentialDegradationModel`

object for a specific
type of component, you can:

Estimate the model parameters using historical data regarding the health of an ensemble of similar components, such as multiple machines manufactured to the same specifications. To do so, use

`fit`

.Specify the model parameters when you create the model based on your knowledge of the component degradation process.

Once you configure the parameters of your degradation model, you can then predict the
remaining useful life of similar components using `predictRUL`

. For a basic example illustrating RUL prediction with a
degradation model, see
Update RUL Prediction as Data Arrives.

For general information on predicting remaining useful life, see Models for Predicting Remaining Useful Life.

creates an exponential degradation model for estimating RUL and initializes the
model with default settings.`mdl`

= exponentialDegradationModel

specifies user-settable model properties using name-value pairs. For example,
`mdl`

= exponentialDegradationModel(`Name,Value`

)`exponentialDegradationModel('NoiseVariance',0.5)`

creates
an exponential degradation model with a model noise variance of
`0.5`

. You can specify multiple name-value pairs. Enclose
each property name in quotes.

`fit` | Estimate parameters of remaining useful life model using historical data |

`predictRUL` | Estimate remaining useful life for a test component |

`update` | Update posterior parameter distribution of degradation remaining useful life model |

`restart` | Reset remaining useful life degradation model |

[1] Gebraeel, Nagi.
"Sensory-Updated Residual Life Distributions for Components with Exponential Degradation
Patterns." *IEEE Transactions on Automation Science and
Engineering*. Vol. 3, Number 4, 2006, pp. 382–393.