Friday, 24 July 2015

Spider Challenge - The Finished Product

Activity Details:
Task: Choose an animal and study its movements. Create and program a robot to demonstrate the behaviour of an animal e.g. a tail wagging puppy or a jaw snapping crocodile
Start date of task: May 20th 
End date of task: July 24th

    • FACTS ABOUT OUR ROBOT:
    • Sensors used: ultrasonic and light
    • Animal: Spider
    • He is called Kevin "Kev the Chev" Chevy
      • "Net-casting spiders have enormous, compound lenses that give a wide field of view and gather available light very efficiently. The lenses can concentrate available light more efficiently than a cat or an owl. Each night a large area of light sensitive membrane is manufactured within these eyes (and rapidly destroyed again at dawn)." - The LIGHT SENSOR on this robot is able to detect the amount of light in it's surroundings similarly to the way a spider is able too.
      • "However, most spiders that lurk on flowers, webs, and other fixed locations waiting for prey tend to have very poor eyesight; instead they possess an extreme sensitivity to vibrations, which aids in prey capture. Vibration sensitive spiders can sense vibrations from such various mediums as the water surface, the soil or their silk threads. Changes in the air pressure can also be detected in search of prey." - The ULTRASONIC SENSOR on the robot is able to pick up objects that are close by

      • Wikipedia, (2015). Spider anatomy. [online] Available at: https://en.wikipedia.org/wiki/Spider_anatomy#Eyes.2C_vision.2C_and_sense_organs [Accessed 24 Jul. 2015].




Spider Challenge - Animatronic - Building


Activity Details:
Task: Choose an animal and study its movements. Create and program a robot to demonstrate the behaviour of an animal e.g. a tail wagging puppy or a jaw snapping crocodile
Start date of task: May 20th 




LEGS AND ORIGINAL BODY:
LONG CURVED LEGO PARTS WERE USED TO MAKE THE 8 LEGS OF THE SPIDER. VERY LITTLE ABOUT THE STRUCTURE AND POSITIONING OF THE LEGS CHANGED.
THE LEGS OF THE SPIDER WERE NOT INTENDED TO MOVE THE SPIDER OR CONNECT TO A MOTOR TO MOVE SO THEY REMAINED FLAT.
LATER ON GEARS WERE ADDED ON THE SIDE TO ASSIST SLIDING AND MOVEMENT OF THE BOT









GEARS AND FRONT MOTOR:
 THE FRONT GAP BETWEEN THE TWO INNER SPIDER LEGS WAS NOT LARGE ENOUGH TO FIT TWO WHEELS TO MOVE THE ROBOT FORWARD. AS AN ALTERNATIVE A PATTERN OF INTERLOCKING GEARS WERE USED. 



 SECOND MOTOR:
THE SECOND MOTOR OF THE SPIDER WAS ADDED FOR TWO REASONS; FIRSTLY BECAUSE WE FELT LIKE THE SPIDER WAS BECOMING TOO HEAVY FOR IT TO MOVE WITH JUST THE ONE SET OF COGS PUSHING IT FORWARD AND SECONDLY, BECAUSE THEN IT WOULD BE MORE ROOM AND OPPORTUNITIES TO ATTACH THE SENSORS AND SPREAD OUT THE 8 SPIDER LEGS.





 SENSORS:
AFTER THE ADDITION OF THE SECOND MOTOR IT BECAME CLEAR WHERE THE SENSORS COULD BE ATTACHED.

SMALLER LEGO PIECES WERE USED TO FASTEN THREE SENSORS TO THE FRONT, TOP AND SIDE.

ORIGINALLY THE ROBOT HAD THREE SENSORS; ULTRASONIC, LIGHT AND SOUND.
BUT AFTER DIFFICULTY WITH THE SOUND SENSOR'S PROGRAMMING IT WAS NO LONGER INCLUDED IN THE FEATURES AND CHARACTERISTICS.











WHEELS (SPIDER):


THE AXLE OF THE WHEEL WAS ORIGINALLY PUT IN THE MOTOR BUT WHEN IT BECAME TOO COMPLICATED TO PROGRAM IT WAS PUT IN THE ROUND HOLE ON THE SIDE SO IT COULD TURN ITSELF AS IT MOVED.












WHEELS (BATTERY):


Large back wheels added to the back of the battery pack. The design changed from the smaller wheels starting at the back (left side) and no wheels on the front (right). It was changed to the photo above so that the spider could pull the battery along without the wires being held up.

Sunday, 21 June 2015

Spider Challenge - Animatronic - Programming

Activity Details:
Task: Choose an animal and study its movements. Create and program a robot to demonstrate the behaviour of an animal e.g. a tail wagging puppy or a jaw snapping crocodile
Start date of task: May 20th 

  • In the beginning of the task, choosing an animal was, not so much of a challenge, but we did change our minds a few times. We had initially decided to create an elephant but as we gave it greater thought we realised that it may be too much of challenge; we went between ideas until we settled on a tarantula/spider. 
  • We initially started with the power pack as the body but upon further discussion it came to our attention that using one of the motors as a body was a drastically better option.
TRIAL 1: 

PROBLEMS WITH TRIAL:
  • the robot gears were not level or touching the floor so it couldn't move forward
  • the reversing turn can only work with two motors and only one was being used




TRIAL 2:
PROBLEMS WITH TRIAL:
  • the newly added small blue lego pegs on the bottom of the back legs raised the back of the robot to be level with the ground but it also stops the robot from reversing properly


TRIAL 3:

PROBLEMS WITH TRIAL:

  • sound sensor could only be activated after the robot had completed 15 rotations when it was supposed to be activated whenever it picked up sound when it was moving forward

PROGRAMMING UPDATES:

SPEEDING UP HORSEPOWER FROM 75 TO 100 SO THAT THE ROBOT CAN PULL THE BATTERY BACK ON IT'S OWN



TRIAL 4:

PROBLEMS WITH TRIAL:

  • similar problem to earlier sensor programming
  • the sensor cannot be activated until after 15 rotations
  • the ultrasonic sensor did not sense
  • no reverse movement was triggered

ATTEMPTS AT PROGRAMMING MORE THAN ONE SENSOR AT A TIME

TRIAL 5:

TRIAL 6: (follow left down then right down)


PROBLEMS WITH TRIAL:

  • was not programmed correctly
  • all sensors are supposed to be able to be activated at any time while moving forward
  • the switch is a useless feature programmed in this as there is no alternative option
  • the sound sensor can only be activated after the light sensor

TRIAL 7:















Activity 5: Version 2 - Walls and edges

Activity Details:
Title: Walls and edges
Task: This task uses the touch sensor, an activator and simple loops program to move your robot and negotiate collisions.
Date of task: May 15th 
Number of versions:2 of 2
Lego NXT Programming Screenshot:

Videos/Pictures:
Comments/Modifications:
  • Again, we unfortunately did not take a video of this version, but since we had no further versions, it is acceptable to say that we completed activity 5 using the version 2 programming. 
  • The picture above is of, what was, our new back wheel. Due to the fact that it broke off during the testing of the first version, we tried to create a better suited structure for the back wheel, so that it was stable enough to stay on, as well as not scraping against the floor. 

Activity 5: Version 1 - Walls and edges

Activity Details:
Title: Walls and edges
Task: This task uses the touch sensor, an activator and simple loops program to move your robot and negotiate collisions.
Date of task: May 15th 
Number of versions:1 of 2
Lego NXT Programming Screenshot:

Videos/Pictures:
Comments/Modifications:
  • In the video above there are two problems that are shown, one of them is the fact that our robot did not travel in the correct direction and went off the mat, the second is that our robot's back wheel fell off. 
  • Regarding the wheel, due to the fact that we did not have enough pieces within our kit, we were not able to build the back wheel, meaning that we had to try our best to improvise. 

Activity 4: Version 2 - Edge Finder

Activity Details:
Title: Edge Finder
Task: This task uses the light sensor and simple loop program to navigate your robot safely round a table top. 
Date of task: May 15th 
Number of versions:2 of 2
Lego NXT Programming Screenshot:

Videos/Pictures:
Comments/Modifications:
  • In this video, our robot does exactly what occurred in the last version, except this time it completed its turn. Although it continued to go in circles, we had accomplished what was asked of us. 

Activity 4: Version 1 - Edge Finder

Activity Details:
Title: Edge Finder
Task: This task uses the light sensor and simple loop program to navigate your robot safely round a table top. 
Date of task: May 15th 
Number of versions:1 of 2
Lego NXT Programming Screenshot:

Videos/Pictures:
Comments/Modifications:
  • In this video, our robot can be seen going in a forward direction and once a change of light was sensed, (in this case a bright light was shone upon the sensor), it reacted and turned, though it did not turn all the way.