Project Update - Concept Report

Hello again, it's been a while without any posts, but that's because we've been hard at work.

After considering feedback we received after releasing our Ideation Report, we decided to make some improvements to our design.

Recap

Project Statement

Often images  of structures, wildlife and seabed are required for monitoring and exploration. Divers have limited amount of oxygen in their tanks to get these pictures as well as it is often not safe to dive due to current and pollution. 

Image have to be correctly oriented to be used and a remotely operated vehicle has to be positioned using a control system to attain this orientation.

Can we design and build a remotely operated vehicle that can take pictures at 1.5 meters depth?

In brief

The vehicle will be controlled by a remote control joystick, as well as an external display, that displays visual data sent from the rover's camera.

Detailed concept

This is an ROV that aims to facilitate underwater exploration at approximately 1.5 metres below the water surface.

It will be controlled remotely from a surface point, which the rover is tethered to by its power and data transmission cable. The controller will use a joystick to control the movement of the rover in all three axes, and will use a physical terminal to observe images sent from the rover.

Function analysis

Figure 1: Overall function analysis

Detailed Function Analysis

Figure 2: Detailed Function Analysis

Electronics parts

Figure 3: Camera Arduino

1) VC0706 Camera Arduino

    -take images in JPEG format

    -relay images to a PC or separate monitor

    

Figure 4: Motor Shield

2) Motor Shield

    -easily to control motor direction and speed, for motors providing forward and backwards movement beneath the water.

    -able to power a motor with a separate power supply of up to 12V

Figure 5: Joystick

3) Joystick
    - control motion along the X-axis and Y-axis
    -control the direction of the vehicle

    

Figure 6: LED

4) LED

    -provide vision so that arduino camera can take picture clearly

Figure 7: H-bridge motor controller chip

5) L298 H-bridge motor controller chip
  The L298 motor controller IC is a fully-featured IC chip that can allow us to control both the speed and direction of a motor. One L298 is already integrated within the Arduino motor shield, however we need a second one to control another group of motors that will be used to surface and submerge the rover.

Flowchart

Figure 8: Flowchart

Wiring diagram

Figure 9: Arduino connection

Figure 10: H-bridge connection

Materials

The primary material for the robot structure will be aluminium. There will be a PVC canister to store the electronics. Figures 11 and 12 list down the materials that will be needed to make this robot.

Figure 11: Material list

Figure 12: Detailed material list

Predicted total weight of robot = 3.2864 x 9.81 = 32.2396 N 

Safety Factor (SF) is set at 1.5,

SF = Buoyancy Force (BF) ÷ Weight

BF = 1.5 x 32.2396 = 48.3594 N

Total Volume = BF ÷ (Gravitational force x density of water)

Total Volume = 48.3594 ÷ (9.81 x 1000) = 0.0049296 cubic-meter

3D Model

Figure 13: 3D model of robot

The rover is designed to be lightweight, durable, and be easily expandable if the need arises. All electronics components will be stored within the cylindrical container in the middle of the rover, while the motors will be mounted to the sides. To prevent any obstacles from interfering with smooth operation of the motors, there is an acrylic panel acting as a sort of crash barrier.

That's all for now, please stay tuned for updates on our prototyping stages!

References

Ezy Strut (2016) Pipe Diameter Charts Available at: http://www.ezystrut.com.au/design/pipe-diameters/ (Assessed 16^th December 2016)

CEP (2016) Weight Calculator Available at: http://www.engineeringcivil.com/weight-calculator.html (Assessed 17th December 2016)

SI Metric (2016) specific gravity of metals Available at: https://www.simetric.co.uk/si_metals.htm (Assessed 17th December 2016)

Reference (2016) How do I calculate the weight of aluminium? Available at: https://www.reference.com/science/calculate-weight-aluminum-4340089a015bd6ec (Assessed 17th December 2016)

Lucas

Pei Yong

Joel

Gabriel

Keith

Week 6 - Transmission of wireless signals

For Week 6, our final activity before work really gets underway on our project, we are transmitting signals. Sounds fun huh? It is fun! We got to play around with some Wireless Sensor Network (WSN).

What is WSN?

WSN are spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sound, pressure, etc. and to cooperatively pass their data through the network to a main location.

We used 2 Xbee units, which are being connected to 2 separate computers to send the signals.

Figure 1: Xbee units

Figure 2: Connecting Xbee to Arduino

Task 1: Establishing a connection

We are required to set up a connection. In order to do this, there must be a receiver and an transmitter. The Xbee that has the USB port can be connected directly to the computer port. This setup will be the transmitter. The other Xbee that has no port will be connected to and Arduino. The Arduino is being connected to a second computer. This setup will be the receiver.

Figure 3: Connection of Xbee with Arduino

A code will be uploaded into the Arduino in order for the Xbee unit to receive and process the signal. After uploading the code, we have to set up the destination address. This is to ensure that we send the signal to the right receiver.

After setting up the destination address, our transmitter sends out a signal and it is being picked up by the receiver.

Task 2: Ring or get ring

The next task is to allow another group to ring our team's buzzer. For this task, we are working with team 7, where they are the transmitter and we are the receiver.

We will first have to connect the buzzer to the Arduino and set up a code.

Figure 2: Connection of buzzer

After that, we set up the destination address with group 7. From there, they send a signal to us to ring our buzzer.

Task 3: Connecting Week 1 pH sensor to lecturer's connection

The last activity is to establish a connection with our lecturer and send the data we collected from our pH sensor to her. So, this is how it works:

1) We set up the code and the destination address
2) We use our pH sensor to measure the pH of a unknown liquid.
3) The data is detected by the Arduino
4) Xbee unit send this data to our lecturer
5) Data is displayed on lecturer's computer screen


Here are some photos of us in action:

Figure 4

Figure 5

Figure 6

Figure 7

As most of the action for the activities involve only programming and connecting small electronics, we are mostly seated while doing the activities. Not much walking and usage of big machinery this week. Stay tune for the following weeks if you want to see us in action with the big machinery.

Some of the problem we faced while carrying out the activities include:

• Program error
• Wrong destination address being set up with group 7
• Arduino and Xbee software being unable to detect the components, even when connected to the computer

Should such situation arise again, we have the following measures to solve the problems:

Program error - Solve by troubleshooting and debugging errors in the code used. In some cases, the Arduino had been configured incorrectly, and in some other cases, the code provided by the lecturer had a non-obvious bug.

Wrong destination address - To solve this problem, one way is effective communication with others. This will allow each other to understand the problem and work together to solve it. In the case of the activities, we set up the wrong destination address with group 7. We communicated with them and through this interaction, we realised we set up the wrong address. We managed to correct the address and sound the buzzer.

Computer unable to detect Xbee or Arduino - This issue was quite unpredictable. To solve this, we may need more than 1 computer installed with the Xbee or Arduino software. If it cannot be detected, we will use the next computer. We usually face this problem when using Keith's or Joel's laptop. Only Lucas's or Pei Yong's laptop can detect the components. 

Reflection

From this activity, we can see that the Xbee unit is simple to use and it is quite effective in data transmission. However, as we plan to use a wire for data transmission for our robot project, so this is not as relevant to us as it is to other groups.

Underwater signals have to be strong enough to pass through the water. Unfortunately for us, the Xbee wireless data transmission system is not strong enough to do so.. A cable will be able to transmit the signal directly to the robot, which is more effective and efficient. 

Stay tuned to this blog for updates on our robot.



Lucas

Keith

Weeks 4 and 5 - Boat design and calculations

For week 4 and 5, we are required to build a boat and test the buoyancy of the boat as well as to find the force exerted by the motors. 

There is also limit as to how big our boat can be:

• Length < 30 cm
• Width < 20 cm
• Height < 20 cm
• Operating water depth < 15 cm

Constructing the boat over this limit can be done, however, marks will be deducted in doing so.

Here are some photos of our boat design on paper:

Figure 1

Figure 2

Figure 3 

Figure 4

Our team designed a boat with 2 frames on the side while the middle is empty, as seen in figure 5. This type of design are known as catamarans. Only metal rings are used to link the 2 frames, as well as to hold 2 cans as required. Polystyrene, also known as Styrofoam, is being used as the base to allow the boat to float.

Figure 5 (GPS World, 2016)

The dimensions for our boat:

• Length = 29 cm
• Breathe = 19 cm
• Height = 19 cm
• Operating depth of motor = about 5 cm

Our team used the following materials to construct the boat:

• 1x protractor.
• 4x 9V  toy propellers
• Half a sheet of polystyrene foam 
• Some steel wiring
• Some perforated steel bands
• Some ice-cream sticks
• Screws and nuts and cable ties as needed.  

The machinery used to construct the boat:

• Scroll saw

Figure 6: Scroll saw

The tools used to construct boat:

Hot glue gun  

Digital weighing scale (digital)

File

Ruler

Styrofoam cutter

Figure 7: Hot Glue Gun

Figure 8: File

After spending about 2 weeks to build the boat, we are finally able to test it. Some of the photos taken during the prototyping process:

Figure 9

Figure 10

Figure 11: Complete Product 

The bottom of the twin-hull design, which features a streamlined bottom, allows the boat to move faster. Both hulls are joined together by lightweight ice-cream sticks, as well as metal bands to carry the load of the boat between both hulls, thus spreading the weight equally between both hulls.

Now, let's test it!

Test 1: Buoyancy

Firstly, with the 2 cans on the boat, we deliberately add as many marbles on the boat until the boat capsizes. This is to determine the maximum angle of longitudinal and lateral roll that the boat can sustain.

Photos of the tests:

Figure 12

Figure 13: Boat on the verge of capsizing

Buoyancy Calculation:

Formula for buoyancy calculation= p x V x g

Relevant weights (In Grams) :

Motor (x4) :108

Steel Band (x4):40

Cable Tie (x8) :8

Satay Stick (x2) :2

Marbl :6

Ice Cream Stick (x3) :6

Can of soft drinks (x2) :330

Buoyancy of boat with cans:

Total Mass with cans: 830g

Since W=mg

W=0.830kg x 9.8

   = 8.134N

Buoyancy force  =Weight 

For safety factor = BF x2

                           = 8.134N x 2

                           =16.268N

Volume of boat (Including cans):

Volume= BF/Gravitational force x density of water

Volume=16.268/9.8x1000

Volume=0.00166m^3

Volume=1660cm^3

During the ideation and brainstorming of the boat design we also took into account the drag that would be experienced by our boat. After much pondering and consideration we concluded that we would utilize a cone shaped head for our boat.The cone shaped head although does not posses the lowest drag coefficient was ideal for our boat as the shape was relatively easier to create and was more suited towards our design.

Below is the drag force experienced by our creation.

Drag Force=0.5 x C x p x A x V^2

where, 

C = drag coefficient,

p = density of water,

A = front surface area of the boat

V = the volume of the boat

Drag Force= 0.5 x 0.5 x 1000 x (0.00166)^2

                  =0.6889 x 10^-3Nm

The maximum angle is 35 degrees, about 50 marbles, before the boat capsized.

Figure 14: Angle measurements

Force for the boat to capsize=

Test 2: Propulsion

We are required to measure the thrust (in kg) with respect to the voltage supplied to the motors.

Figure 15: Results for force measured

We also use Excel to show the best-fit trend line of the data recorded and we can see that many data are apply the line of best fit.

Figure 16: Graph of force with respect to voltage

That's all for these 2 weeks folks. Stay tune for week 6 activity as well as our prototyping of our robot that can take pictures at 1.5 meters depth.

References

• GPS World (2016) Researchers to Test Water Drone for Bridge Inspections  Available at: http://gpsworld.com/researchers-to-test-water-drone-for-bridge-inspections/  (Assessed 19th November 2016)

Joel

Keith

Project Update - Ideation and Specification Report

Project Statement

 

Often images  of structures, wildlife and seabed are required for monitoring and exploration. Divers have limited amount of oxygen in their tanks to get these pictures as well as it is often not safe to dive due to current and pollution. 

Image have to be correctly oriented to be used and a remotely operated vehicle has to be positioned using a control system to attain this orientation.

Can we design and build a remotely operated vehicle that can take pictures at 1.5 meters depth?

Considerations

1. Pressure of the water at the depth of 1.5 meters
2. how to move the vehicle efficiently to the following
3. which method of data transfer would be most provide minimal interference but at the same time most convenience. 
4. recovery in case of a failure.

Concept Consideration

Taking some of the above point this are the key component we decide to further brainstorm.

Therefore, we have shortlisted a few key component.

• Data Transmission
• Propulsion
• Housing
• Power Source

Ideas

After deciding on which component we would most likely be using we came up with two design.

Design 1 

Design 1 has side motor that rotate which will provide the vertical and some of the horizontal propulsion. The side motor will rotate with the use of servo motors and thus helping in the vertical movement. However, this may cause the ROV to out of control due to the in balance of the propulsion may not be balance.   

  Design 2

For design 2 we plan to fix the motors in place, thus making it more balanced, however it may be heavier. But it will allow for a simpler and conventional design.

Turning would be achieved by varying the thrust produced by the two horizontal thrust motors, while vertical movement would be achieved by spinning the vertical thrust motors in the needed direction.

Function analysis

The diagram below is our detailed function analysis:

Electronics

Even the dumbest of rovers needs some form of command and control in order to move. In this post, I will detail the choices made for electrical and electronic design of our team's unmanned rover.

The brains

For the CPU of the unmanned vehicle, we've decided to use a programmable Arduino microprocessor. This microprocessor will be responsible for collecting information from the camera and sending it back to the controller, as well as receiving information from the controller to control the motors.

Power

The rover will be fed by 2 power sources:

• 9V power supply for motors
• 5V power supply for Arduino microprocessor and camera

Communications

A single cable will be used to relay both power and serial communications to and from the rover.

Motive force

We'll be using at least 4 different motors - 2 to move the rover up and down, and 2 to propel the rover forward. By varying the rotational speeds of the forward-propelling motors, we can also have the rover move left and right.

"Eyes"

It would be difficult to control the rover without being able to see where it's going. As such, there is a need for an onboard camera to show what the rover is "seeing".

// todo with camera

Lists of sensor and electronics

1)Ultra bright LED - provide vision so that arduino camera can take picture clearly

2)Arduino Camera - take picture under the water

3)Arduino Uno - to control the electronic components
4)Motors - used for propellers to control the direction of vehicle 

Lists of building materials

1. PVC pipes - main body
2. Acrylic - housing for the camera
3. Aluminium extrusion - for the support of the ROV frame
4. Foam - to make the ROV less dense
5. 3D printed part (ABS/PLA) -motor housing and propeller
6. Ethernet cable

Week 3 Activity - Filtration

Our task for Week 3 was to build a rapid water filter in order to filter dirty water collected earlier on.

We were also tasked to evaluate the effectiveness of our rapid water filter as compared to other groups.

To start off, we were asked to formulate some hypotheses about our rapid water filter:

• If the dirty water passed through 6cm charcoal filtration system then the conductivity of the filtered water will increase, because the pH of the filtered water decreased.
• If the dirty water passed through 6cm charcoal filtration system then the dissolved oxygen of the filtered-water will decrease, because carbon will react with oxygen to become carbon dioxide.
• If the dirty water passed through 6cm charcoal filtration system then the pH of the filtered water will decrease because charcoal will acidify the pH of the water.

After that, it was time to get to work! First, we had to prepare the water filter, which consisted of a 6cm filter bed made of charcoal chips,

Figure 1: Preparing the water filter.

then after that we had to take readings of the water before filtering it,

Figure 2: Filtering the dirty water

and then we had to again take readings of the filtered water.

Figure 3: Measured readings.

From these readings, we derived the following conclusions to our hypotheses:

• Hypothesis 1: On the contrary, there was an increase of pH across the board, meaning that after we ran the water through the charcoal filter, it became more alkaline, instead of becoming more acidic as we thought. Why is this so? Did some element in the charcoal filter make the water acidic?
• Hypothesis 2: Since the amount of dissolved oxygen in the dirty water decreased in 2 out of 3 tries, we can safely assume this is true.
• Hypothesis 3: As seen in hypothesis 1, this is true as the conductivity of all three filtered water samples decreased in tandem with the increase of pH.

Next, we then had to compare our water filter against other groups', in order to see how effective ours was against theirs.

We chose 2 groups:

• Group 1, whose filterbed only consists of sand measuring 6cm deep, as the only difference between our filter and theirs is that they have a different material in their otherwise identical filter.
• Group 6, whose filterbed consists of only charcoal measuring 7cm deep, as the only difference between our filterbed and theirs is that their filter is thicker by 1cm.

Against both groups, we found that the pH change was higher than with our own filter.

In conclusion, this week we learnt that it was necessary to work together to divide the workload for the project. As taking the readings for the filtered and unfiltered water samples took plenty of time, we could not afford to have every group member stand and wait for the readings to stabilize. Hence, we decided to split into 2 groups and prepare a second water filter, so that we could do more at the same time.

Also, we learnt that, as the charcoal was dirty and covered in soot at first, we were required to clean the charcoal filter with clear running water. This was because that there was a potential for the soot to affect the experimental readings.

Written by Lucas

Week 2 Activity 2 - Hypothesis Testing

HYPOTHESIS TESTING

Test Run	pH of Water Samples
	October 2015 (No algal blooms)	November 2015 (With algal blooms)
1	7.25	5.65
2	7.40	5.41#
3	7.61	5.82
4	6.69*	6.01
5	6.77	5.49
6	6.30	6.41#
7	7.55	5.45
8	7.69	6.08

Null Hypothesis: Given or claim made

Alternative Hypothesis: When evidence proves null is wrong alternative hypothesis is right

During the second week of Engineering and Design we were taught a very sophisticated method of probability , which is the use of probability to test a hypothesis.

This can be done by 2 methods single tailed or two tailed tests.

 For our assignment we were supposed to validate whether or not a statement on algae blooms and pH of water is affected ,as seen in the picture and table above. This method was rather challenging initially but interesting nonetheless and can and will be applied no doubt in our future projects or assignments. My hypothesis on this skill is that it will be very useful in future projects.

See what else we did in week 2!

Written by Joel

Week 2 Activity 1 - Water environment

In the Week 2 activity, we were tasked to characterize physical and chemical properties of water (pH, conductivity and dissolved O₂ ). 
Materials needed:

1.       Around 150 mL of water each taken from

a.       Bio Stream flowing in front of SPCC, T12 and T11A.                     

b.       EcOasis pond between FC 2 and T1

c.       SP swimming pool near FC 5

2.       Four 500 mL plastic glasses

3.        Plastic pipette

We were instructed to observe and take pictures of the ecosystem of the 3 locations (Bio stream, SP swimming pool and EcOasis).
Here are the pictures we took from the 3 locations:
Bio stream

EcOasis

SP swimming pool

Then, we were poured around 150 ml of each water samples into 3 different plastic glasses and measure and record the followings water quality using the pH meter, conductivity meter, dissolved O2 meter .

 1.       For pH: Record when the value is stabilized for around 30 seconds.

2.       For conductivity: Record when the value is stabilized for around 30 seconds.

3.       For dissolved O₂: Record when the value is stabilized for around 30 seconds.

Here is the results we have:

Through the experiment last week, we learnt how to use those sensors to obtain experimental results, in order to learn about the physical and chemical properties of different water samples.

We then followed this activity up with a hypothesis testing activity, where we determined whether the pH level of a water body changed across a month.

It was an interesting and fun experience for all of us and we look forward to the next activity in week 3. 

Post written by Pei Yong and Lucas