-
Notifications
You must be signed in to change notification settings - Fork 1
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
47 changed files
with
1,403 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,179 @@ | ||
# Availability Modelling | ||
|
||
# Introduction | ||
|
||
sdvsv | ||
|
||
# Model Parameters | ||
|
||
## Performance Time ($$t_p$$) | ||
|
||
The average time a T-Stick performance lasts given in hours. | ||
|
||
## Performer Intensity ($$j_p$$) | ||
|
||
The intensity of the performance, rough indicator of the impact of a performance on the reliability of certain components. | ||
|
||
## Simulation Parameters | ||
|
||
These additional parameters may be used for simulation, when wanting to take into account technician availability. It is not used for PIR calculations for the T-Stick evaluation though. | ||
|
||
### Performance Frequency ($$p_f$$) | ||
|
||
The average amount of performances per month. It can be used along side ***maintenance time between performance***, and ***technician availability*** to compute the ***interruption percentage*.** | ||
|
||
### Technician Availability ($$A_{tech}$$) | ||
|
||
The average amount of hours a technician/luthier is available to fix any issues an artist can’t fix with their instrument per month. | ||
|
||
### Technician Turnaround ($$t_{tech}$$) | ||
|
||
The average amount of business days it takes for the technician/luthier to return the instrument to the artist/musician. | ||
|
||
## Model Inputs | ||
|
||
### Maintenance Time between performances ($$t_m$$) | ||
|
||
The amount of time an artist/musician spends maintaining the T-Stick in between performances, given in hours. | ||
|
||
### Mean time to repair for T-Stick Components ($$MTTR_c$$) | ||
|
||
Mean time to repair/replace for T-Stick components in hours | ||
|
||
### Mean time between failure for T-Stick Components ($$MTBF_c$$) | ||
|
||
Mean time between failure of T-Stick components in hours | ||
|
||
### Maintenance actions between performance | ||
|
||
The actions the artist/musicians take when maintaining their instrument. | ||
|
||
### Available tools (T) | ||
|
||
The available equipment an artist has on hand for maintaining and fixing their instrument. | ||
|
||
# Compute Practice Interruption Rate (PIR) | ||
|
||
## 1. Computing MTBF and failure rate of T-Stick | ||
|
||
To compute the Practice interruption rate we must first compute the failure rate of the T-Stick ($$ \lambda_{tstick}$$). We do this by adding the failure rate of each component. | ||
|
||
$$$ | ||
\begin{equation} | ||
\lambda_{tstick} = \lambda_{esp32} + \lambda_{fsr}+\lambda_{imu}+\lambda_{button}+\lambda_{capsense}+\lambda_{resistor}+\lambda_{touchsensor}+\lambda_{battery}+\lambda_{connectors} | ||
\end{equation} | ||
$$$ | ||
|
||
where $$\lambda_i$$ is the failure rate of component *i*. | ||
|
||
The failure rates for several components such as: | ||
|
||
* FSR | ||
* Resistor | ||
* IMU | ||
* Capsense Board | ||
* ESP32 Board | ||
* Battery | ||
|
||
can be estimated using a combination of the [FIDES reliability prediction too](https://www.fides-reliability.org/)l, the [MIL-217F Handbook](https://drive.google.com/file/d/1QNUiTOAwJebwC-bk0FJWB0jD3I6XFxFi/view?usp=drive_link), and the [NPRD-91](https://drive.google.com/file/d/1QPMqClW2nHY4U9tmMO5Lzc11RDF2Oeoc/view?usp=sharing). The MTBF of the connectors is taken from the performance model. | ||
|
||
We compute the MTBF of the t stick by taking the reciprocal of the failure rate. | ||
|
||
$$$ | ||
\begin{equation} | ||
MTBF_{tstick} = \frac{1}{\lambda_{tstick}} | ||
\end{equation} | ||
$$$ | ||
|
||
## 3. Compute Mean Performances between failure (MPBF) | ||
|
||
We can then compute the mean performances between failure ($$MTBF_{tstick}$$) by dividing the $$MTBF_{tstick}$$ by the **performance time (**$$t_P$$) | ||
|
||
$$$ | ||
\begin{equation} | ||
MPBF = \frac{MTBF_{tstick}}{t_p} | ||
\end{equation} | ||
$$$ | ||
|
||
## 4. Compute PIR | ||
|
||
We calculate the practice interruption rate by taking the reciprocal of $$MPBF$$. | ||
|
||
$$$ | ||
\begin{equation} | ||
PIR = \frac{1}{MPBF} | ||
\end{equation} | ||
$$$ | ||
|
||
Using Eq.5, Eq.6 and Eq.7 we can simplify the PIR expression. | ||
|
||
$$$ | ||
\begin{align*} | ||
PIR &= t_p(\frac{1}{MTBF_{tstick}}) \tag{Using Eq.3}\\ | ||
&= t_p(\lambda_{tstick}) \tag{Using Eq.6} \\ | ||
\end{align*} | ||
$$$ | ||
|
||
Hence an alternative expression for the Practice Interruption rate is: | ||
|
||
$$$ | ||
\begin{equation} | ||
PIR = t_p(\lambda_{tstick}) | ||
\end{equation} | ||
$$$ | ||
|
||
In simple words the **Practice Interruption Rate** is the: | ||
|
||
$$$ | ||
\text{average performance time} \times \text{failure rate of the t-stick} | ||
$$$ | ||
|
||
# Compute Performance/Maintenance Ratio (PMR) | ||
|
||
Computing the Performance/Maintenance Ratio (PMR) is a matter of taking the $$MTBF_{tstick}$$ computed in the PIR model and dividing that by the average maintenance time. | ||
|
||
## Computing Average Maintenance time ($$T_m$$) | ||
|
||
To compute average maintenance time we consider the mean time to repair ($$MTTR_c$$) of each component and the failure rate of each component ($$\lambda_c$$). We can then take a weighted average of all the repair by taking into account each components contribution to the total failure rate. | ||
|
||
$$$ | ||
\begin{equation} | ||
T_m = \sum_{c=0}^n \frac{\lambda_c}{\lambda_{tstick}}(MTTR_c) | ||
\end{equation} | ||
$$$ | ||
|
||
## Compute PMR | ||
|
||
To compute PMR we divide the $$MTBF_{tstick}$$ by the average maintenance time ($$T_m$$). | ||
|
||
$$$ | ||
\begin{equation} | ||
PMR = \frac{MTBF_{tstick}}{T_m} | ||
\end{equation} | ||
$$$ | ||
|
||
# Compute Direct Maintenance Costs (DMC) | ||
|
||
We can also look at the direct maintenance cost of the T-Stick which we define as the dollars spent on maintaining the T-Stick per performance hour. | ||
|
||
## Compute Mean Repair Cost of the T Stick | ||
|
||
The mean repair cost of the T-Stick ($$MRC_{tstick}$$) is computed the same way the average maintenance time, by using a weighted average of the mean repair cost of each component. | ||
|
||
$$$ | ||
\begin{equation} | ||
MRC_{tstick} = \sum_{c=0}^n \frac{\lambda_c}{\lambda_{tstick}}(MRC_c) | ||
\end{equation} | ||
$$$ | ||
|
||
## Compute DMC | ||
|
||
To compute DMC we divide the mean repair cost by the mean time between failure of the T-Stick ($$MTBF_{tstick}$$) | ||
|
||
$$$ | ||
\begin{equation} | ||
DMC = \frac{MRC_{tstick}}{MTBF_{tstick}} | ||
\end{equation} | ||
$$$ | ||
|
||
|
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,5 @@ | ||
# Gesture Algorithms | ||
|
||
# Introduction | ||
|
||
Many different gesture algorithms have been used in the T-Stick. This section will list links to documentation for these algorithms. Check the [T-Stick Designs](./T-Stick%20Designs.md) to find out which algorithm is compatible with which T-Stick version. |
Oops, something went wrong.