Week19

Project Presentation

José J. Lazarte R.

Project Files

Assignment
   Document a final project that integrates the range of units covered, answering:
For developing my project I divided it in two parts, in the first part  I couldn´t get my initial goals, that is why I had to modify the base concept. In the second part, with the expience of the first I solved the problems  and got my goals.

         what does it do?
The name of my project in "ECO-Energy Generator Walking". It should give the possibility to generate energy in an ecological way whitout any conventional source.
Due that energy in our universe is not created nor destroyed, the goal of my project is to transform energy. The transformed energy is obtained from the movement of the human body.
         who's done what beforehand?
I made a research about the State of the Art of the topic and I  found the following relevant projects:
References:
1. The Japanese company NTT is developing a prototype of shoes that will be able to generate electricity as you walk wearing them.

2. Baha al-Hasnawi, a 30 years old Irakian inventor, created a device in his house at the city of Karbala (Iraq), using a little engine from a toy of his child.

3. Four mechanical engineering students at Rice University in Houston, Carlos Armada, Julian Castro, David Morel and Tyler West, created the PediPower shoes for their graduation project.

4. The mechanical engineers Tom Krupenkin and Ashley Taylor of the University of Wisconsin in Madison used power generation produced by a footprint shoe on the ground through vibrational energy, for creating a shoe that generates energy.

5. The researchers at the Georgia Institute of Technology (Atlanta), Zhong Lin Wang and his team, including graduate student Long Lin, who submitted the job, were working on a miniature generator based on a phenomenon of energy called the piezoelectric effect, which is the result of pressure.

         what did you design?
In my case I designed all parts. The project has:
1. Mechanical Components.
        - The plataform's structure
        - The lever, gear, and other mechanical parts.
2. Electrical and Electronic Components.
        - The structure for the energy transformer.
        -  The Electrical circuit
        - The electronics circuit.
        - The microcontroller circuit and program.
3. The foot holder.
        - The Base for the plataform.
        - The structure for the foot holder

         what materials and components were used?
According to designed parts the material used are:
1. Mechanical Components.
        - The platform's structure                         15mm thickness plywood.
        - The lever, gear, and other mechanics parts.       Acrylico of 10mm thickness acrylic, iron wire diameter 7mm,                                                                                       steel spring of 5cm.
2. Electric and Electronic Components.
        - The energy transformer structure.                    DC Generator, magnets, relays
        -  The Electric circuit                                          Switch, copper wire 1mm in diameter
        - The electronics circuit.                                      Diodes, LEDs, Resistors, copper sheets for                                                                                    printed circuits, push button, capacitor and                                                                                    electronic crystal.
        - The microcontroler circuit and program.             ATtiny 44, Arduino software.

3. The foot holder.
        - The Base for the plataform.                               MDF of 3mm
        - The structure of the foot holder                                    MDF of 3mm and glue.  
         where did they come from?
All materials came from the FabLAb inventory, with escepción of relays, DC generator and switch which were purchased from the local market.
         how much did they cost?
Prices are listed then:

1. Mechanical Components.                                                                    Prices:
15mm thickness plywood. (24" x 13")................................................................. $2.00
10 mm thickness Acrylic (8"x20").................................................................................. $1.00
Iron wire diameter 7mm (1´).............................................................................. $0.78
Steel spring of 5cm.(1 unit).................................................................................$0.30

2. Electric and Electronic Components.
DC Generator, ......................................................................................................... $0.30
Magnets:
              MAGNET 1-4"DIA X 30....................................................................... $8.78
              MAGNET 1-2"DIA X 24....................................................................... $23.40
Relays (x12 - C/U $0.35)...................................................................................... $4.2
Switch........................................................................................................................ $0.83
Copper wire of 1mm of diameter(3´)................................................................. $0.20
Diodes, (rectifier bridge)..................................................................................... $3.46
LEDs, (x4 , 1A and 400V).......................................................................................$1.80
Resistors, (x6)..........................................................................................................$0.02
Single side circuit board stock,............................................................................$0.18
Push button, ..............................................................................................................$0.73
Capacitor(x5).............................................................................................................$0.65
Electronic crystal(x2).............................................................................................$0.98
ATtiny 44. (x2).........................................................................................................$2.35
Battery (x1)...............................................................................................................$4.50

3. The foot holder.
3mm thickness MDF(2´x2´).......................................................................................$1.50
3M #214 masking tape 6"x60 yds (2´)...............................................................$1.91
Glue..............................................................................................................................$0.50
Total : .........................................................................................................................$60.37

         what parts and systems were made?
As I explained at the begining, my project has two parts. For the first part my concept for generating energy was to use  a generator, which should be moved using a lever and a gear over a plataform. For that  purpose I designed and constructed each of the components, as I explain here.

platform's lengths sketch	Generator position sketch
lever's length sketch	gear size

For the development of this work I used Rhinoceros&nbsp.
Design in 2D:
Design in 3D:
Animation:

Animation of  lever	Animation of  gear	Animation of  lever and gear

Then I made the design of the support lever which consists of a platform that will be mounted with the other two mechanical parts and both will support the entire structure. I has been thought to implement it in three parts.

In the image shown is the template from which the data were taken ...	...to draw the template model using Rhinoceros software.
		Bottom where the lever shaft, generator and lever slot will fit...	Top that will contain support for the foot

The third part is similar to the second but completely hollow.
Then the design of the gear lever was held for a number of teeth  and  initially consider it too big and in the size of these was too small. The difficulty of this, is in the process of which the laser cutter didn't has the precision for acrylic (I used a 1 mm. thickness) this is shown in the following figures.
For that reason the size of the gear teeth decreased, which improved torque but  the angle of rotation decreases. Then for do so, I had to modify the shape of the gear lever and resizing, this is shown in the following figures.
With that I already have structured the mechanics that will allow me to install the generator.

Using the software Rhinoceros I made the three parts an do after that I construct it using the ShopBot.


After this, I started to assembling the AC generator  on the platform, to do so, I had to cut a small  piece of metal for use it as an axis and hold it in the platform.

The result is that, now I can assemble not only the AC generator if not also the lever and the gear. I show this in the following image.

At this part I had the AC generator assembled, now I show how the first circuit transforms the AC signal in pulsed signal. Although the three components fit very well as is shown in the figure.

When I tested the level of energy generated, I noticed that the voltage generated by moving the lever just exceeded 1 volt. And  the problem was to reduce the number of gear teeth which reduced the length of travel of the lever.

The angle of rotation in the small gear was of 360° and in the bigger gear 120° as shown in the following figures.

That was a serius problem ..!!.
After meditating, I decided to change strategy on how to generate energy using the same platform.  Performing minor corrections on the plataform I could implement it in the following way.

Using the principles of electromagnestism, I used the electric current induced by magnetic fields.
To achieve this I used coils and magnets, coils from relays and  magnets from FabLab Inventory. The relay used and their characteristics are shown below.

Reference page for the relay made click over the picture

When I messure the inductance of the coil it was of 2.96H. I connected the coils in series in two rows of 6 units each.

The change made in the lever were with the order to accommodate in the whole body of it the greatest possible number of magnets.

Reference page for the magnets made click over the picture

But the firs result was failed, the structure collapsed when the magnets were placed.

So,  I redesigned the lever reducing the number of holes, I introduced 3 magnets in each hole and pasted them with glue the result of that is shown below.

edAfter assembly the spring and lever shaft  I could place it on the platform.
 
I tested to see if all this could generate more energy, I connected an oscilloscope and measured the signals generated by each coil group and identified the correct phase to connect the two groups in serial connection and increasing moreover the generated voltage.

According to the measurements of each group of coils when they pass between the magnets generate alternate pulses of about 5 volts of amplitude. After connecting the coil terminals of both groups the voltage generated, without any load connected, is shown below.

I could measure amplitude of pulses from 10 to 15 volts depending on how fast the magnets passed between the coils. Connecting the rectifier, resistor of 1.4 ohms, battery as load and in the way  as shown in the circuit, the measurements of voltage and current generated were.

From the mesurements:

Maximum amplitude of input voltage = 3.2 div x 2V/div = 6.4V.
Maximum current amplitude = (2.2div x 2mV/div )/1.4Ohms=3.14mA
Maximum power = 6.4V x 3.14mA = 20.096mW.

Now to verify the battery charge I connected the oscilloscope in the battery in the next video I  can see this slow but continual increase.

 

The  baterry and rectifier used are:

BATTERY,RECHARGABLE,NiMH,3.6V,40mAh
40mAh 3.6V Rechargeable Nickle metal hydride.

Rectifier: PIV=400 Volt@2 A.

The next part is the microcontroller's card construction and programming. First I made the programmer using the ATtiny44.
I started by downloading the model given in the academmy course In my case I used Andy Bardagjy's design. I read the enclosed information carefully and used PNG image, retouching and modifying the resolution size in order to have a suitable image for the Modela.
Uploaded the file to perform the first milling test, the parameters used are shown in the image

We place a board on the Modela machine and made ​​the first milling, I did not realize that the regions should be fully copper free, were not marked so when I send it, only the outline was milled.

Parameters were modified and a second milling was done. I observed that by varying the parameters I was able to get the required copper free regions.
It was possible to obtain the required free copper areas  but I realized that the machine cut too much from the edges  of the tracks, which thinned them too much. The further modifications to the milling parameters were performed as shown in picture
The results of the milling and all three tests are shown in following picture

After cutting the outlines for the three tests, I proceeded to solder the components to begin implementation.

I made the connection and test programming using an additional programmer as shown in Figure

The programming procedure  is described in the transcript shown.

I made the microcontroller card to use a LED and a button. Considering the pin description for the ATiny44, shown in the figure, we decided to use the terminals 11 and 10, which correspond to pins 2 and 3 respectively.

The images of the initial and the modified scheme below in which I  added two resistors, an LED and Button.

With the file in png format I proceeded to mill the tracks on the card. Obtaining the result shown. imperfections are observed at the edges but the routing went very well. With the experience gained in the assigment 4, the assembly of the card was made.

Where we ncan see the button, the LED and current limiting resistors.
The design rules are for basic components so additional characteristics to consider voltage and current limits.
Whereas the level of supply voltage is 5 volts for the case of the diode led.
According to the datasheet it has a LED test current of 10mA. In our case  to reduce the power consumption in the device I considered that the main current for the diode led is 5mA.
Using Kirchoff's laws we can calculate the value of resistance needed to obtain the required current in the LED.

V= IxR => R= V/I : R = 5v/5mA = 1KOhm

An for the button i used a pull down resitor.  Both connections are shown in the following image.

To check the funcionality of the implemented circuit:

For  program the ATtiny44 on a windows environment I used the USBcard constructed before and the appropriate drivers.
We loaded the Arduino program and he configured the Card used, the port and programmer type.

The following figure shows how to connect the programmer to the ATtiny44 card.

The programs used to test the card is obtained from those who are in the examples in the Arduino program, modifying the terminals used to interact with the LED and button using the ATtiny44. Below is the code of the demo programs and video shows.

Video

I used the microcontroller card to monitor the level of charge, because due to its low power consumption can be connected to the battery directly and through managed by the microcontroller LED flashing, the brightness LED will indicate the level of load. Then three LEDs as additional lighting were added.

This assembly is shown in the following figures.

Next videos show the operation.

Video 1 - Video 2 - Video 3 - Video 4

Finally, the last part was to develop the foot support, for this i prepared a template on paper then the mold was scanned and processed in coreldraw. The design of the foot support was performed, footbed and templates bottom of the platform.

Then proceed to assemble it and the result is:

         what processes were used?
I used:
- Mechanical Design in 2D and 3D
- Computer-aided design
- Computer-controlled cutting
- Electronics production
- Electronics design
- Embedded programming
- Mechanical design, machine design

         what questions were answered?
The questions that were answered are:
- How to generate more energy?
- How much energy can be generated?
- How to modify the mechanical structure for the new method of power generation
- How to make the shoes more confortable for the user?
- What materials will be used?
- What shape will it have?
- How the design of electronics parts will be?
         how was it evaluated?
The project performance will be evaluated through the ability to power one luminaire of leds and the ability to charge the battery using the mechanism designed during walking.
         what are the implications?
The implications that the project can generate are:
- Demonstrate the ability to generate energy with the movement of the human body.
- Demonstrate that magnetic energy can be used to convert it into electrical energy.
- With better design we could get a best performance of the implemented system.
- The system is open to be used as a tool that facilitates the ecological use of natural resources.

      projects can be separate or joint, but need to show individual mastery of all of the skills
      where possible, you should make rather than buy the parts of your project
   present your final project, weekly assignments, and tutorials?

Project Files