blockSmooth
First-order exponential smooth
Extends from Interfaces.PartialConverters.SmoothSISO (Smooth-like converter).
Information
This information is part of the Business Simulation Library (BSL). Please support this work and ► donate.
A smooth is a first-order exponential information delay. It is typically used to model time lags in forming an expectation or in perceiving some information.
Inside the converter there actually is a stock x that stores the perceived or expected value of the information input u. The output y is derived immediately from x as can be seen from these equations where τ denotes the delayTime:
Notes
- The
delayTimegiven (either as constant parameter or continuous signal) will be clipped to a minimum value ofmodelSettings.dt, which denotes the smallest possible process time anywhere in the model. The time of delay for the process of information perception or expectation formation can thus never be zero or negative.
- In the system dynamics community a smooth is an information delay (as opposed to a material delay) [1, Appendices E and H]. Information delays model the process of updating information to the actual value. Since the technical procedure is called exponential smoothing, the name smooth has prevailed.
- The parameter
initin the Advanced tab allows to select →InitializationOptions:
- FixedValue (default) will use the parameter
initialValueto determine the initial output y. - SteadyState will set the initial output y equal to the initial input u.
- Free there will be no initial equation and thus the solver is free to find an initial output using
initialValueas an initial guess.
- FixedValue (default) will use the parameter
See also
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Time | delayTime | 1 | Constant delay time (optional) |
| OutputType | initialValue | 0 | Output at startTime |
| Advanced | |||
| InitializationOptions | init | modelSettings.init | Provide InitializationOptions (Free, FixedValue, SteadyState) |
| Structural Parameters | |||
| Boolean | hasConstantDelayTime | true | = true, if delayTime is given by the parameter instead of the input |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Connectors.RealInput | u (from SmoothSISO) | Input | |
| Interfaces.Connectors.RealInput | u_delayTime | Delay time |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| RealOutput | y (from SmoothSISO) | ||
| ModelSettings | modelSettings |