Difference between revisions of "Zoidberg II, powering robot fish"

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{{Project
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|title=Zoidberg II, powering robot fish
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|image=ZoidbergLogo.png
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|short_descr=This project is aimed at designing, constructing and improving autonomous robot fish, starting from the ZOIDBERG project. It will be able to swim deeply in the water, to communicate and to orient in a free space thanks to several sensors mounted on-board.
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|coordinator=GiuseppinaGini
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|tutor=PaoloBelluco;
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|students=AndreaParolina;DarioSimontacchi;MarcoPerri
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|resarea=Robotics
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|restopic=Bio Robotics
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|start=2008/11/01
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|end=2009/12/24
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|status=Closed
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|level=Ms
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|type=Thesis
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}}
 
== '''Part 1: project profile''' ==
 
== '''Part 1: project profile''' ==
  
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=== State of the art ===
 
=== State of the art ===
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Zoidberg II was initially thought to be the successor of Zoidberg I, the robot fish made by F. Milli, A. Nava, M. Mercurio. After studing several documents on smart materials, we decided to change the actuator from IPMC to Shape Memory Alloy and do a new robot fish, completely different Zoidberg I.
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The work that mostly influenced the design of our robot is a lower-scale automaton realized by Z. Wang, G. Hang, J. Li, Y. Wang and K. Xiao, which is actuated with the same type of SMA that we used.
 
The work that mostly influenced the design of our robot is a lower-scale automaton realized by Z. Wang, G. Hang, J. Li, Y. Wang and K. Xiao, which is actuated with the same type of SMA that we used.
  
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The design of the body has evolved into the current shape through many development steps, in response to the varying specifications of the on-board electronics, to changes in the manufacturing process of the hull, and for a better approach to the hydrostatic balance problem.
 
The design of the body has evolved into the current shape through many development steps, in response to the varying specifications of the on-board electronics, to changes in the manufacturing process of the hull, and for a better approach to the hydrostatic balance problem.
  
The first two images below represents the early proposed mostly flat design, and a step of the manufacturing of a "master" hull component in a modeling clay. The third image shows a simple prototype made of polyurethane foam, tethered to the tank for power supply. It can be noted the original configuration of the tail components, which were mounted in a horizontal fin arrangement with two parallel actuators.
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The first image below represents the model designed with CATIA software; it's shown inside the position and the shape of every component used. In the second there is the prototype realized with the high density polyurethane; it represents the left and the right part of the robot fish disposed on horizontal plane. In the last image we can see the external skin in plastic, made with the thermoshaping technic.
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<gallery>
 
<gallery>
Image:Forma_CATIA.jpg|First test body shape
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Image:Forma_CATIA.jpg|CATIA model
Image:Modello_Poliuretano.jpg|Developed test body
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Image:Modello_Poliuretano.jpg|Prototype in polyurethane
Image:Modello_Plastica.jpg|Propulsion test
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Image:Modello_Plastica.jpg|External skin in plastic
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</gallery>
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In next images there are tools and machinery that we used to realize the structure of the robot fish.
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<gallery>
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Image:Termoformante.jpg|Thermoshaping machine
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Image:Fresa.jpg|Milling cutter
 
</gallery>
 
</gallery>
  
 
==== Electronics ====
 
==== Electronics ====
  
The first version of the on-board electronics was a two-boards arrangement. Due to problems and delays with the company responsible of the manufacturing of said boards, there are no working exemplars of this solution. In the meantime the circuit has been redesigned and simplified to fit a single board, and we put together a very simple intermittent circuit to carry the first autonomous tests (without the robot being tethered to the tank).
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We have several boards: the main board control every functionality of the fish and contains a microcontroller unit (PIC18F4431), un Inertial Measurement Unit (ADIS16360), a thermometer sensor for internal temperature (ADT7301), a circuit to detect battery status and all connectors to the other boards.
  
Below are shown, in order: the original schematics of the two boards, the schematic of the oscillator used for the first tests, based on a 555 chip, and the intermittent circuit assembled on a prototype board.
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The pressure board include an SCP-1000 SPI sensor to check pressure informations and external temperature.
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In the proximity board there are the Sharp GD2P120 Ultrared sensor to control the distance between robot and obstacles and four photoresistor to detect the position of light coming externally.
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Final board is the actuator board used to control fin movements and check fin's current. This value is send to microcontroller which decides autonomously if this current should be increased or decreased.
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Below are shown all the schematics and first test circuit, based on a 555 chip.
  
 
<gallery>
 
<gallery>
Image:Schema_1.png|First board schematic
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Image:Main_Board.png|Main Board
Image:Schema_2.png|Second board schematic
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Image:Power_Board.png|Power Board
Image:BasicOscillator.svg|Test circuit (simplified) schematic
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Image:Pressure_Board.png|Pressure Board
Image:Test_circuit.jpg|Test circuit
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Image:Proximity_Board.png|Proximity Board
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Image:Actuator_Board.png|Actuator Board
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Image:Basetta_Astabile.jpg|Test circuit
 
</gallery>
 
</gallery>
  
 
==== Videos of the actuator tests ====
 
==== Videos of the actuator tests ====
  
Here are some clips, filmed during the first experiments trying to have a working actuator. The polymer and the electrodes are held in place by rough adhesive, and the power is supplied by an external generator. we are manually changing the polarity of the current going through the actuator.
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Here are some clips, filmed during the first experiments trying to have a working actuator. It's the first prototype, handly realized in wood.
 
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In the videos we can see the two principal movements of the robot: in the first we have straight swimming and in the latter we have turning move.
{{#ev:youtube|kDF3zGa5b-c}}
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*[http://it.youtube.com/watch?v=kDF3zGa5b-c External link]
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{{#ev:youtube|xNAmuwDQzKU}}
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*[http://it.youtube.com/watch?v=xNAmuwDQzKU External link]
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=== Final design ===
 
=== Final design ===
(todo)
 
<gallery>
 
Image:FishBoard.svg|Final review board schematic
 
Image:Zoidberg_interno.jpg|The hull open, exposing the wiring
 
Image:Zoidberg_incapsulamento.jpg|Internal arrangement of the structure
 
</gallery>
 
<gallery>
 
Image:PesceUpWeb.png|Complete robot, top view
 
Image:PesceSideWeb.png|Complete robot, side view
 
</gallery>
 
  
 
=== Tests and results ===
 
=== Tests and results ===
(todo)
 
  
 
==== Videos of the robot in action ====
 
==== Videos of the robot in action ====
  
{{#ev:youtube|_L9oLe1OXiU}}
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{{#ev:youtube|LYQ8wcNxqik}}
*[http://it.youtube.com/watch?v=_L9oLe1OXiU External link]
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*[http://www.youtube.com/watch?v=LYQ8wcNxqik External link]
 
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{{#ev:youtube|ptSdlPzTORw}}
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*[http://it.youtube.com/watch?v=ptSdlPzTORw External link]
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Latest revision as of 12:28, 3 October 2011

Zoidberg II, powering robot fish
Image of the project Zoidberg II, powering robot fish
Short Description: This project is aimed at designing, constructing and improving autonomous robot fish, starting from the ZOIDBERG project. It will be able to swim deeply in the water, to communicate and to orient in a free space thanks to several sensors mounted on-board.
Coordinator: GiuseppinaGini (gini@elet.polimi.it)
Tutor: PaoloBelluco (belluco@elet.polimi.it)
Collaborator:
Students: AndreaParolina (), DarioSimontacchi (), MarcoPerri ()
Research Area: Robotics
Research Topic: Bio Robotics
Start: 2008/11/01
End: 2009/12/24
Status: Closed
Level: Ms
Type: Thesis

Part 1: project profile

Project name

Zoidberg II, powering robot fish

Project short description

This project is aimed at designing, constructing and improving autonomous robot fish, starting from the ZOIDBERG project. It will be able to swim deeply in the water, to communicate and to orient in a free space thanks to several sensors mounted on-board.

Dates

Start date: 2008/11/01

End date: 2009/12/23

People involved

Project head(s)

Prof. Gini Giuseppina - User:GiuseppinaGini

Other Politecnico di Milano people

Ing. Paolo Belluco - User:PaoloBelluco

Students currently working on the project

Andrea Parolina - User:AndreaParolina

Dario Simontacchi - User:DarioSimontacchi

Marco Perri - User:MarcoPerri

Students who worked on the project in the past

Francesco Milli - User:FrancescoMilli

Maurizio Mercurio - User:MaurizioMercurio

Alessandro Nava - User:AlessandroNava

Laboratory work and risk analysis

Laboratory work for this project will be mainly performed at AIRLab/Lambrate. It will include significant amounts of mechanical work as well as of electrical and electronic activity. Potentially risky activities are the following:

Use of mechanical tools. Standard safety measures described in Safety norms will be followed. Use of soldering iron. Standard safety measures described in Safety norms will be followed. Use of high-voltage circuits. Special gloves and a current limiter will be used. Robot testing. Standard safety measures described in Safety norms will be followed.

Part 2: project description

The project is composed by:

  • State of the art;
  • Preliminary studies and sketches;
  • Design notes and guidelines;
  • Description and results of experiments;


State of the art

Zoidberg II was initially thought to be the successor of Zoidberg I, the robot fish made by F. Milli, A. Nava, M. Mercurio. After studing several documents on smart materials, we decided to change the actuator from IPMC to Shape Memory Alloy and do a new robot fish, completely different Zoidberg I.

The work that mostly influenced the design of our robot is a lower-scale automaton realized by Z. Wang, G. Hang, J. Li, Y. Wang and K. Xiao, which is actuated with the same type of SMA that we used.

It is discussed in: A micro-robot fish with embedded SMA wire actuated flexible biomimetic fin

Preliminary part design

Mechanical structure

The design of the body has evolved into the current shape through many development steps, in response to the varying specifications of the on-board electronics, to changes in the manufacturing process of the hull, and for a better approach to the hydrostatic balance problem.

The first image below represents the model designed with CATIA software; it's shown inside the position and the shape of every component used. In the second there is the prototype realized with the high density polyurethane; it represents the left and the right part of the robot fish disposed on horizontal plane. In the last image we can see the external skin in plastic, made with the thermoshaping technic.


In next images there are tools and machinery that we used to realize the structure of the robot fish.

Electronics

We have several boards: the main board control every functionality of the fish and contains a microcontroller unit (PIC18F4431), un Inertial Measurement Unit (ADIS16360), a thermometer sensor for internal temperature (ADT7301), a circuit to detect battery status and all connectors to the other boards.

The pressure board include an SCP-1000 SPI sensor to check pressure informations and external temperature. In the proximity board there are the Sharp GD2P120 Ultrared sensor to control the distance between robot and obstacles and four photoresistor to detect the position of light coming externally. Final board is the actuator board used to control fin movements and check fin's current. This value is send to microcontroller which decides autonomously if this current should be increased or decreased.

Below are shown all the schematics and first test circuit, based on a 555 chip.

Videos of the actuator tests

Here are some clips, filmed during the first experiments trying to have a working actuator. It's the first prototype, handly realized in wood. In the videos we can see the two principal movements of the robot: in the first we have straight swimming and in the latter we have turning move.

Final design

Tests and results

Videos of the robot in action