Commit 775d8c65 authored by Jake Read's avatar Jake Read

compare data

parent 7b560b17
......@@ -6,8 +6,6 @@ DEX is a small materials testing machine that should be capable of running tensi
| --- | --- |
| ![dex](images/2019-10-17_dex-01.jpg) | ![dex](images/2019-10-17_dex-03.jpg) |
... better image of dex, with loacell, and controller
## Usage
DEX runs a [squidworks](https://gitlab.cba.mit.edu/squidworks/squidworks) controller. To run, use the 'dex' branches of [cuttlefish](https://gitlab.cba.mit.edu/squidworks/cuttlefish) and [ponyo](https://gitlab.cba.mit.edu/squidworks/ponyo)
......@@ -17,27 +15,38 @@ DEX runs a [squidworks](https://gitlab.cba.mit.edu/squidworks/squidworks) contro
## Comparison to Instron 4411
... incoming
To see how we do against a real instron, I tested identical samples on the DEX as well as on an Instron '4411' with a 5kN load cell. In the plot below (I'm using cuttlefish to plot the .csv that I saved from Bluehill, the Instron software), the leftmost plot is taken on the 4411, and the lazier slope belongs to the DEX.
## TODO
While the samples fail around the same load, the difference in elongation is ~ 1.5mm wide: this is almost surely the machine's own deflection, stretch in the belts, etc.
![dex-compare](images/2019-10-17_data-compare.png)
- run tests on 4411
- write chart / data manipulation tools for cuttlefish, overlay graphs
This obviously warrants correction. One way to do this is to build a stiffer machine, however, we will be chasing up the cost and complexity if we do this. Rather, we should throw some more control at it. To start, we can circle back to our attempts at [subpixel tracking](https://gitlab.cba.mit.edu/calischs/subpixel_tracking), or attach a small linear stage directly to our fixturing elements. For this, I am imagining something like the [AMS5311](https://ams.com/as5311), which should do some 12 bits inside of a 2mm throw (for 0.4um resolution). Either can be added to existing systems, given network controllers / modular browser code. Since I want to integrate it elsewhere, it's likely that the camera option comes first.
## TODO
```
- encapsulate branches for ponyo, cuttlefish.
- bs ?
- put rpi setup back on desk with dex, branch, close
- revisit with cameras, rate control
```
#### Controller TODOs:
- server config for bootstrap entire system ! (/url-to-program-location)
```
- extension rate is important, include this
- assign meaning to charts and graphs (date / location / etc)
- this should be generic json-object making, yeah?
- save tests as .json objects (optionally) develop program for reading
- overlay multiples, save images
- read-in csv as well
- save images of tests (genpurp canvas save tool?)
```
#### Circuit TODO:
- draw / fab temp and humidity sensor (looks like Bosch BME280 828-1063-1-ND)
- better implementation of load cell amplifier ? filippos' part number ? nice unit to have.
```
- draw / fab temp and humidity sensor (looks like Bosch BME280 828-1063-1-ND)
- better implementation of load cell amplifier ? filippos' part number ? nice unit to have.
```
## Building a Displacement Exercise
......
B<?xml version="1.0" encoding="UTF-16"?>
B<?xml version="1.0" encoding="UTF-16"?>
Export Raw Data : Export raw data,True
Export Raw Data : Format,Comma Separated Values (.CSV)
B<?xml version="1.0" encoding="UTF-16"?>
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