PROJECT Development

Welcome to the very last week of my blog ! Today I will be sharing about my group's chemical device! We have spent a lot of time and effort into making this device work and we tried our best to fixed certain issues like programming.

 1. Our team Chemical Device

The objective of our product is to prevent drunk driving accidents by preventing drunk people from driving. With the help of our chemical device, this will greatly reduce the number of car accidents that is related to alcohol. 


Cars are common in the 21st century, as the number of vehicles increases, accidents related to cars also increases.  A lot of these accidents occurred due to irresponsible driving behavior, like drinking while driving, which is one of the biggest causes of car accidents.  

 

Our device is a breathanalyzer that is installed onto the steering wheel. The device can detect alcohol from the driver’s breath and once a certain alcohol level is detected, our device will alert the driver that he is not suitable to drive through the use of LED lights, alarm, system that prevents driver from starting the vehicle and LCD screen that shows the Breath Alcohol Content (BAC) and that alcohol is detected. This is how the LCD works when the driver is in: 


  • - Proper condition for driving: LCD shows “SAFE TO DRIVE”  

  • - Drunk state: LCD showsBAC = xxx mg/L and “ALCOHOL DETECTED” 


As for the alarm, it will turn on once driver is unsafe for driving. The alarm will be activated together with the red LED lights once the driver is not fit for driving. If he/she is not under alcohol influence, the LED light will be green, and alarm is not activated. 


As for the system that prevents driver from starting the vehicle, when alcohol is detected before the driver starts the engine, this system will prevent driver from starting the engine. This prevents the chances of drunk driving as the driver is not allowed to drive when he is drunk. 

By using this chemical device, it will solve issues of the people from drinking while driving. When the alcohol sensor detects alcohol from the driver, the car engine will stop hence prevent the driver from driving. As such, this will reduce the number of accidents on the road. This chemical device promotes road safety. 


2. Team Planning, Allocation and execution

BOM (Bill of Materials)


Gantt Chart



3. Design and Build Process


Part 1, design and build of Breathanalzyer Frame (done by Kit and Steward)


I was in charge of the designing process while Steward is in charge of making the design into 3D using Fusion360

Link to Steward's blog:https://cp5070-2021-2b01-group5-stewardsoh.blogspot.com/p/project-development.html

Part 2. Design and Build of steering wheel (done by kit & Nander) Link to Kit’s Blog 

After planning out and designing the chemical device, which is the breathalyzer, our group feel that it would be better if we could create a steering wheel for our device to be put on. By making the steering wheel, we felt that it would be easier to visualize how it works and easier representation of how our chemical device works in an actual scenario.  

The problem that we had is that the steering wheel could not be printed using the 3D printer as it is too big, and it would take a long time to be printed. Thus, we came up with an idea to use a laser cutting machine to cut out 5 parts of steering wheel and stack it on top of one another to make it look 3 dimensional. 

1. The first step is to create a sketch, then choose a plane for the sketch to be drawn on 


2. After choosing a plane, we then set Parametric for each of the desired radius and thickness of our steering wheel. 


3. After setting all the desired parametric, draw out a circle and choose the set parametric accordingly

4. To create the curve part of the wheel on bottom left and right of the wheel, use the arc function and mirror it and it should look like the picture as shown below. By using mirror function, this ensures both curves are symmetrical. 

5. After drawing out and setting up all the parameters, create another 2 more of the same shape with a smaller outer diameter. Hence, we would be getting smaller and smaller wheel size so that it could be stacked and look 3 dimensional. 


6. After creating all the sketches, we decided to make some holes for a connecter to go into each of the layers. Since each layer is around 3.5mm, we have a total of 5 layers, where the biggest layer is in the middle while the smaller layer is the outermost layer. Thus, length of the connecter would be around 3.5mm x 5 = 17mm

 

7. The picture below is what we had in mind, where the holes will be used as connector parts. Each layer is stacked on top of the other to make it look 3 dimensional. 

Part 3. Arduino Programming (done by Steward& Nander). Link it to Nander blog
Link to Nander's blog:

Part 4. Integration of all parts and electronics (done by everyone)
Embed the finalized fusion 360 design files. 

 

 Insert his html: <iframe src="https://ichat2234.autodesk360.com/shares/public/SH9285eQTcf875d3c53976e117db2d5d67be?mode=embed" width="800" height="600" allowfullscreen="true" webkitallowfullscreen="true" mozallowfullscreen="true"  frameborder="0"></iframe> 


 Insert this html: <iframe src="https://ichat2234.autodesk360.com/shares/public/SH9285eQTcf875d3c5391e239b298b30bbb3?mode=embed" width="800" height="600" allowfullscreen="true" webkitallowfullscreen="true" mozallowfullscreen="true"  frameborder="0"></iframe> 


Documentation for integration. 

For the integration of our components, we first used Fusion360 to ensure that our printed breathanalyzer frame is well thought out in terms of dimensions. After using Fusion360 to position all the components inside the frame, we assured that the frame can fit the components well. And we planned to integrate the components just like the one shown below. 





During the integration process, we used sticky tape to ensure that the breadboard and MAKER UNO is placed firmly on the back part of the frame. After that we connected the wire and placed the MQ-3 sensor and LCD to the corresponding holes that are located on the front part of the frame. The holes are designed specifically for them so that they can fit there perfectly. We also used paper tape to help us ensure that the wires were well connected for the LEDs. This is because the wire is quite loose and short so paper tape is used to join the wires firmly. After which, we closed the frame after integrating all the components. Continuous servo is not included in the frame because it is just a representation of the car engine. Below is the photo of our product. 




  1. 4. Problems and solutions  

Problems 

Solutions 

Planning of chemical device 

Getting components that are not available in school was part of the issue, we searched online for extra parts. We needed to contact the supplier from overseas in order to obtain parts like the filter. 

 

Steering wheel model  

During the discussion, we wanted to 3D print the steering wheel, but the time taken to bring the model of the life size steering wheel would take way too long. We had come up with a solution, we decided to use laser cutting as an alternative to 3D printing. Since laser cutting is only a 2D shaped object and it does not look 3D, we agreed on making multiple layers of the steering wheel of different sizes so that the steering wheel looks 3D. Moreover, we had also used a pin to hold the layers together instead of using superglue/hot glue. 

 

Arduino programming  

The key problem with the Arduino programming is that one the programmable button is pressed, the sensor does not measure alcohol content anymore, due to our lack of knowledge in Arduino, we were not able to figure out what was wrong. 
After doing our research, the solution is to use the “while” function. While the servo is rotating we programme the sensor to continue reading alcohol level. 

 

Fusion360 design 

We used the hinge that we learnt from our 3D printing sessions to allow us open our chemical device. Moreover, we also design the snap fit to allow each of our chemical device parts to fit onto one another like lego parts, hence we do not need to use super glue/hot glue. Of course, if our snap fit does not work, we are still open to using glue as an alternative solution. 

 

Due to the long duration of printing, we decided to increase the print speed and adjusted other print settings to shorten the duration. However, the trade-off is that the print quality was really bad, so the snap fit that was designed earlier did not fit at all. So, we had to improvise, and we decided to use hot glue to join the parts together. 

 

3D printing time/Cura 

After designing, we realized that the time taken for the printing of our chemical product is around 25 hours and the maximum time that we can book the 3D printer for is 4h.  

 

We changed the entire device design and made some tweaks to it. We change the length and height slightly, making it slightly different from our original design. Moreover, we also changed the infill percentage to 10%, to ensure that the 3D printer takes lesser time to print.  

 

Apart from changing the designs, we split our chemical device into 3 main parts. Hence instead of spending 25h to print our chemical device, we can use 2 or more 3D printers to print each part of our chemical device and each respective parts would take significantly lesser time to print, about 3-5h per parts. 

 

  

  1. 5. Project Design Files as downloadable files  

https://drive.google.com/drive/folders/16y1UlO99ExiB388gULxJICAROKm0-nkl?usp=sharing 



Reflection

During the entire process of making this chemical device, i would say it's a rather tiring process. We have met with so many difficulties, especially the arduino programming part. We did not know what was wrong and it took us a really long time for us to solve it. Apart from the arduino, we also had problems using the laser cutting machine. During the designing process, when we used the cura to estimate the time that would take for us to print our product, it turned out to be 25h long and we spent so much time and effort in trying to reduce that number by redesigning our entire chemical device. All in all, i would say that this module is really draining, however i did learn new skills like 3D printing, designing using Fusion360 and handtooling. Lastly, learning not to give up plays a huge part in making our chemical device come alive.


For this project, we did a lot of things such as designing prototype using CAD Fusion360 and printing it out using 3D printer and laser cutting the steering wheel. Not only that, but we also used what we have learnt from Arduino Programming tutorials and applied it in this project. Basically, this project tests us on all the technical skills we have learnt from ICPD and CPDD. We would say it is not easy to build a breathanalyzer in a short semester because it is our first time building a smart device and we feel puzzled from time to time as things did not work out the way we wanted. 

 

Nonetheless, what we could do to tackle the challenges is to go back to the lecture notes, practices, and blogs where we have documented everything we have gone through. For example, during laser cutting, we forgot what the setting is for cutting and engraving so we referred to our blog and managed to do it smoothly. As for the Arduino programming, what we learnt in tutorial is not sufficient to meet our objective so what we did was to do a lot of research and find resources and videos that could potentially help us to make our breathanalyzer works. We tried the codes on our circuit and see if it works, if not we improvise the codes so that it meets the objective. We only managed to make our Arduino Programming work after the fourth time of trying it. What we learned from this experience is that it is important to have growth mindset and perseverance because we would not have come this far without that mindset. When met with challenges, instead of giving up, we always try again and encourage one another that it can work.

 

When doing this project, we always try to do it face to face with minimal online meeting as we find doing face to face more efficient. As we know that the school curriculum is very tight, we treasure the time where we met in school for CPDD and practical session as this is the only time where we can really make big progress with all the facilities available. For every class or practical session, we always set a goal to finish by the end of the day so that things are going according to our plan.

 

In conclusion, even though we learned a lot of technical skills, we also learned a lot of soft skills such as communication. Communication is key and, in our team, we respect and listen to one another opinion so that no one is left out. During the process, we also find out about the working style of each member, so we know the strength and weakness of one another. Thus, we always try to help with one another weaknesses. For example, steward is better at programming, so he takes in charge of programming. Kit is better at designing and sketching so he did the drawings and I help out with researching and editing videos. We are confident that our skills will help us go through the final year capstone project.

 

 




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