Posted on

Ziyu Li’s Status Report for Feb 24th, 2024

This week I spent a lot of time in CAD software designing our new actuator.

Since we need to rapidly fabricate and test these actuators in different configurations (slider slope, material, lubricate method, form factor of actuator), great care is taken account to parameterize the design (which is both time consuming and rewording for me as a first timer).

One additional thing to emphasize in this report is the original source of this clever mechanism. During this week’s design presentation, I cited the original video from Ulmas Zoirov in the presenter’s note, but not on the slide itself, and this created unintentional confusion about the source of the idea. I apologize for this major oversight, and wanted to emphasize that this is Ulmas Zoirov’s idea, and we mainly want to iterate on this and engineer his vision in real life (since no physical device of this design is ever made, and we could not find further information on the future of his project).

For next week, I will be fabricating these CAD parts using resin 3D printers and experiment with the actuation by hand, to provide an initial feasibility analysis. I will also work on a much more formal and much more in depth design document.

Posted on

Team Status Report for Feb 24th, 2024

What are the most significant risks that could jeopardize the success of the project?

Since we have switched to a slider based actuator, the biggest worries are 1. the durability of the actuator, which despite optimization in the design iteration, might still be limited by the nature of the slider mechanic. 2. How do we recover consistently from a slider jam?

How are these risks being managed? What contingency plans are ready?

For our existing slider actuator, we will rapidly iterate over the course of next two weeks to try out different motors, slider slope, material, lubricate method, form factor of actuator, sliding speed, etc., to try and find the best combination that can result in the fastest and most consistent actuation of the braille dot patterns. We are cautiously optimistic that this plan will work, but if not, we have back up plans where a group of push-pull solenoid will activate individual ball-pen-like latches.

Were any changes made to the existing design of the system? Why was this change necessary, what costs does the change incur, and how will these costs be mitigated going forward?

As reference in our design presentation slide, we significantly changed our block diagram to accommodate for the new actuator design. This change is motivated by our quest to find the cheapest and easiest way of actuate a large amount of bi-directional dots.

There are no scheduling changes. For an updated visualization of the actuator, please refer to Ziyu’s status report for this week.

Posted on

Yujun’s Status Report for Feb 24th, 2024

This week, I mainly dealt with our change in design for the braille printer. I began coding the braille translation in python and is able to change each braille pattern into a 6 bit data encoding.

Furthermore, I researched more into brailles and found that grade 2 brailles are used commonly for experienced braille readers and it is normally the grade of braille used in the public. There are 26 new patterns that have to be incorporated for grade 2 braille and they serve as abbreviations for commonly used sequence of letters. While my plan is to implement grade 2 to our braille learning tool, it could be against the purpose of the project which is to start with basic braille and allow the students to have a easy jump into the braille language.

In order to stay on schedule, I am to start learning how to convert the python logic into one that is applicable to the arduino used for our hardware.

Next week, I am planning to discuss the use of grade 2 braille with my teammates and decide on whether to implement it to our code or not. Furthermore, it is our plan to fully decide on how to decode these braille encodings back into patterns for the sliders to read and display (most likely through the uses of multiplexers and decoders).  In other words, we are to have a concrete idea on the functionality of the programs needed for the hardware as the software next week, and finish purchasing the hardware components needed for the project. Personally, I have to come up with a way to decode the encoding into a readable format for the hardware.

 

What is Braille? [Your Guide to Braille] - Braille Works

Posted on

Team Status Report for Feb 17th, 2024

What are the most significant risks that could jeopardize the success of theproject? How are these risks being managed? What contingency plans are ready?

The most significant risks are the components we are able to find and afford in terms of size and power. Our main issue is the small spacing of each braille cell from each other. However, we have found at least two backup plans of actuators we can assemble ourselves in case the sliders don’t work.

• Were any changes made to the existing design of the system (requirements,block diagram, system spec, etc)? Why was this change necessary, what costsdoes the change incur, and how will these costs be mitigated going forward?

There were changes made to the block design and implementation approach as referenced above. We have shifted to a more elegant and simpler design approach which address our power and size concerns for now. The 3D printed sliders will have engravings that at different positions engage each unique combination of 3 pins per each braille column. This eliminates the need for small actuators for every single pins.

• Provide an updated schedule if changes have occurred

There have been no changes to the schedule so far, since we shifted and caught up this week. We will observe our progress this following week and adjust the schedule then, if necessary.

Posted on

Samay’s Status Report for Feb 17th, 2024

This week, I spent a significant amount of time on refining our implementation plan as we approach our design review this upcoming week. In particular, our team had many concerns about both the size and power issues of our initial plan to use an array of actuators that each control each braille pin. In terms of size, there were no affordable actuators that were realistically small enough for our requirements. We also considered the power usage of the available solenoids, which require a current always to keep a pin up.

As a result, my progress was also behind for this week since we got caught in these technical issues. However, I made significant progress during a meeting on Friday with our group. I suggested we find inspiration on the internet for other methods of actuating an array of pins. This led to great team progress with a newer idea (sliders for every column that have an encoding that cycles through all combinations of pins per column).

I also contributed to the design review presentation and document by addressing the implementation plan and researching which components exactly we need. I started by looking into the types of small motors we could use to precisely control the sliders. For example, I compared stepper motors to servo motors in terms of precision, speed, power, and size. I found that there were similar size characteristics but stepper motors require less power.

Next week, I hope to first finalize an initial parts list based on our current implementation plan. I aim to also order parts to begin testing as well as begin on CAD models for the device.

Posted on

Ziyu Li’s Status Report for Feb 17th

This week I mainly focused on researching different braille pattern actuation patterns, and coming up with a viable solution that is both cheap and compact. We research three main solution: 1. Electromagnetic actuation, like push-pull solenoid 2. Stepper motor paired with more intricate mechanical design, and 3. A slider solution that is able to enumerate a three-dot pattern, and use two of the same slider config to constitute each braille character. The final solution is what we settled on, as it is a. extremely cheap to implement, b. low fabrication difficulty, and c. is able to provide a close to standard braille pattern size. I am currently working on a full 3D model of this system in CAD, but for reference people can check out this video: https://www.youtube.com/watch?v=rTzhWKBfiuk

Posted on

Yujun’s Status Report for Feb 17th, 2024

This week, I mainly worked on researching the hardware side of the project despite being in charge of the software due to the fact that the hardware implementation of the braille grid was more complex than we assumed.

We were behind the schedule in the beginning of the week, yet we caught up by having an extra meeting on Friday morning where we researched together and finalized our design. The only issue is that we  couldn’t order any components we thought of last week as our hardware design changed significantly.

The original design which used solenoids to push brailles turned out to be too costly in terms of power input. The amount of power it needed to hold all of the solenoids could also generate a lot of heat in the process. Thus, I presented an idea I found on the web which used a  a stepper motor which would slide a long block that contained all the braille push patterns on it.  Thus, we now only need two motors per braille cell.

In terms of the software, I pseudocode of the translation was made which takes a braille to alphabet data and translates each alphabet to 2 numbers. For each column, there are 6 braille patterns possible and for each one of them a number was assigned.

By next week, I need to finalize the translation part of the code which is only possible when we as a team finalize whether we are going to use a raspberry pi or an arduino based on the complexity of our implementation.

Posted on

Team Status Report for Feb 10th, 2024

As we are approaching the start of the designing phase of our project, we realized there are some significant risks to consider. To begin with, the minuscule gap between dots in a braille might pose some difficulties in designing the grid with the balls and require extremely high precisions when it comes to actuating them into readable brailles. As a counter measure we have a plan B being planned currently that deals with 3D printing the grid instead of looking for pre-existing hardware components.

In terms of the software aspect, it is to be noted that braille dictionary data requires a lot of memory due to the fact that the braille patterns are stored in matrix like data structure. Thus, we are planning to do the translation on the web application and then to transfer only the necessary data into the braille pad and find ways to store the data in binary structure instead of a matrix with 1’s representing the dots.

As we have not completely finalized on the components needed for the product, it is inevitable that we are prone to changes to the design. By next week we are to be fully decided on which hardware components to order as well as an analysis on the cost and scale of the order. Currently we have begun to list all the possible components that could be viable. We are going to have a finalized list by early next week and make orders by the end.  This is the initial schedule that we have proposed so far

Posted on

Yujun Lee’s Status Report for Feb 10, 2024

This week I was able to talk to the CMU librarian about existing support for the visually impaired. Coupled with additional research done on the braille language, I was able to become familiar with the general structure and the standards for braille and also realized that our product is indeed needed for the blind population.

The progress of myself as well as the team is on track and to make sure we are on schedule in the future we are going to meet at least once outside of the class time provided to us every week. We also have been communicating regularly over slack and messages to ensure we are on track.

By next week I plan to have the braille database ready to use for the software, and find ways to encode the braille patterns into a matrix or find a more data-efficient way of storing the patterns to reduce memory usage.

Posted on

Ziyu Li’s Status Report for Feb 10th

This week I put most of my effort into learning PCB design online. Since our project require us to layout linear actuators in a compact way, this would definitely be needed further down the road. No one on the team have any practical experience with this field, so I had to learn from scratch, which was a fun experience. Although our proof of concept will likely not involve any PCB, I would still like to place my one first order within next week, so that we can be sure this won’t be a challenge in the future.

Another thing I worked on is I researched the different mini electromagnetic actuator components that are readily available on the market right now, and locked on a 6mm one that seems to be promising. The idea is we would like to place the order for this component in small amount next week, and test its capabilities. Ideally we can fit some kind of already-existing solutions into our system.