End Course Project 2: Breaking down the tasks

Date: 9. December 2010

Duration of activity: 6 hours

Group members participating : Michaël Ludmann, Guillaume Depoyant, Anders Dyhrberg, Michal Owsinski

I. Todays topic "Breaking down the tasks"

After a very positive start on the assignment last time distributing tasks to everybody. We realized that we maybe should apply a more systematic approach. We started by creating a system over view identifying all the required interfaces, to figure out their individual requirements, in order to get a total overview of the total complexity and give an estimate of the required tiem an effort we need to put in to this assignment to complete it in due time.

II. Goals for todays session

There are 2 main goals for today.

• a) Get a complete overview of the system, identify and specify all interface
• b) Identify and distribute the tasks required solved for next session.  

II.a System Overview

This is currently our expected overall system architeture

The following communication interfaces have been identified:

• I1.a "XBOX controller connection, protocol unknown between Player 1 and PC 1
• This interface is a wireless communication interface between the xbox controler and the PC. This is provided byt the vendoe and is not requiring any work form our part. But we are restricted to to use the dongles following the controllers since this is an non standard interface.

• I1.b "XBOX controller connection, protocol unknown between Player 2 and PC 2"
• Se description for I1.a

• I2.a "Wireless Ethernet between Terrorist Unit Android mobilephone and PC 1"
• This interface is a wireless Ethernet connection between the Android Mobile Phone and the pc. PC and the phone has to be on the same network on order to make this work as simple as possible. There must be a wireless access point for the Android phone to connect to. The Interface will for the moment only be used for the phone to stream images to the PC to enable the player to control the unit.
• OPTIONAL: One optional idea, we have but don't expect to have time for is to extend this interface to include the unit drive control information. We will  

• I2.b "Wireless Ethernet between Counter Terrorist Unit Android mobilephone and PC 2"
• Se description for I2.a

• I3.a "Bluetooth connection between Terrorist Unit NXT brick and PC 1"
• I3.b "Bluetooth connection between Counter Terrorist Unit NXT brick and PC 2"
• I4 "Bluetooth connection between Bomb Unit NXT brick and PC 1"
• I5 "Ethernet connection between PC 1 and PC 2"

Key Issues Identified in our last session:

• To deal with streaming the camera images to the computers while displaying informations about the sensors readings on players screens and allowing them to control the robots in real time. (Will require dedicated SW for the Android Phones)
• We need to implement a GamePad driver for the PC to control the units. (This is fairly easily achieved using key mapping on the PC. Mapping GamePad press to Keyboard Press)
• The mechanical release of the BOMB from the terrorist unit could turn out to be problematic. Same could the for the deactivation mechanized used by the CTU.
• We would have to experiment with the game play in order to keep it balanced, and fun for all players.
• We have to make a program for the PC side to show the Video Stream from the robots.
• We need to find/design a god play field for the game. We currently are expecting to use a city model available to us, used for tank strategy game[2].
• (Optional control feature) An obvious extension to the game would be to use the Wireless Ethernet on the camera phones to control the robot, by forward the instructions from to NXT using bluetooth, in order to extend the range from theoreticaly 10m to 100m.

II.b Graphical User Interface


The graphical user interface would be, according to our first drafts, split in several parts as the prototype we draw on the board shows in the picture below.

On the left would stand the two biggest frames containing the video stream coming from the phone attached to the robot we're controlling with the machine (terrorist or counter terrorist) and just below, a map of the field in order to have some hindsight and maybe elaborate few strategies. Thus, the left part is the visual part: it gives us all that we could see if we were actually on the filed trying to plant or defuse bombs.

The right part is a little bit smaller and is designed to display all the informations about the running game. The major things to display are:

• The time left for the game;
• The status of the bomb ("not yet planted", "planted", "defused")
• The goals of the current player

The other spaces are not yet defined because we have a lot of ideas and shouldn't put them all for clarity purpose. But we thought about a radar based on the ultrasonic sensor, a picture mapping the joypad to actions and even trying to implement some perks for each player and design a frame in order to visualize/use them.

II.c Bomb unit

So far, we have established what we think should be all the use cases for the bomb unit and its role and place in the communication protocol.

II.c Assignement for next session

Ludmann and Dyhrberg: Experiment with different pre built Android programs from Android to stream video from an android phone to the PC.

Ludmann: Continue working on the player Controlled Vehicle

Depoyant: Start working on the PC player interface, base on the framework Dyhrnberg made at an earlier lab session to test the Bluetooth logger

Owsinski: Start working on the bomb




III. Prototype and discussions


III.a. Mechanical prototype of one robot

For this session, a first prototype has been build. This one is about one of the robots played by a human player. At this time, we only have the very basis of such a robot, that is :

• a tracked vehicle :

• a way to mount a HTC desire phone in front of it. Only the part able to carry the phone has been (roughly) built :

We plan on using an Android HTC Desire phone lent by the university through the pervasive positioning course, on top of phones we already have.

The robot has been built so it keps things simple and efficient. It is indeed really sturdy and steady du to its low and balanced profile. Besides, tracks enable smooth and accurate movements, even on uneven surfaces. Basically, this robot should be able to handle crashes and impacts with the environnement and other robots, and it should run on every type of ground.

III.b. Ideas for the bomb

The bomb will be carried on some sort of waggon dragged by the terrorist vehicle. The bomb will consist on a infrared ball put on top of its own NXT brick which will be mounted on two free wheels (so the bomb won't move by itself, an other robotized unit will have to carry it).


In order to have the bomb follow the terrorist, we have thought about a claw mounted on and activated by the bomb unit itself, once the terrorist is placed in front of it (either detected with an proximity sensor -touch or ultrasound-, either when the terrorist player send a command to the bomb by bluetooth). So the claw will catch the back of the terrorist robot and the latter will be able to carry the bomb wherever its player will be willing to do so.


The releasing process is exactly the opposite (releasing made by the motorized claw controlled by the bomb unit).

Such a system would enable some new features in the game due to its greater flexibility. For instance, we thought of having many bomb units like the previously described one, so the terrorist unit would be able to plant more than one bomb by going back each time to its starting point (some kind of terrorist basecamp).

IV. References


[1] http://www.rezultat.dk/UNDERHOLDNING/BATTLESTATION/spiltyper.htm