Archive for February 2011

Measured Drawing..   Leave a comment

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Posted February 17, 2011 by paddyjamiemikey in Uncategorized

Finished Design..   Leave a comment

Posted February 17, 2011 by paddyjamiemikey in Uncategorized

Sensors   Leave a comment

This is something we are new to so it took quite abit of researching to understand how the sensors work. We know that we need two types of sensors, one to detect the position of the opposing robot and one to detect the edge of the ring so as our sumobot stays inside the edge!

Firstly I will go through what we have learned about sensors to detect the opposition. We found 4 main types of sensors that would be relevant to us.

PIR (passive infrared sensor) Sensor: These are sensors that don’t actually emit an infrared beam but simply accept the beam from other objects and can detect where they are. There are advantages with using this sensor such as the fact that it can detect an object from yards away. On the other hand, they are very expensive. Also because they work only on receiving infrared light we are depending on other teams having infrared on their robots.

 

Infrared Proximity Sensors: An IR proximity sensor works by applying a voltage to a pair of IR light emitting diodes which in turn, emit infrared light. The light goes through the air and once it hits an object it is reflected back towards the sensor.

Ultrasonic Sensors: Ultrasonic sensors generate high frequency sound waves and evaluate the echo which is received back by the sensor, Sensors calculate the time interval between sending the signal and receiving the echo to calculate the distance to the object.

Microwave Sensors: Microwave sensors, operate at frequencies of 10 Mhz. They utilize a doppler radar signal which bounces microwaves off of an object, then measures the frequency of the returning microwaves. If an object is moving in the sensor’s field, the returning microwave will be at a different frequency, higher or lower than the original signal transmitted. Microwave sensors offer a greater distance of coverage and are more reliable at greater distances. Microwaves can also penetrate walls

Now I will go through what we learned about sensors that could be used to keep the robot in the ring..

LDR (Light Dependant Resistor):

LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000 000 ohms, but when they are illuminated with light resistance drops dramatically.

This is an example of a light sensor circuit :

When the light level is low the resistance of the LDR is high. This prevents current from flowing to the base of the transistors. Consequently the LED does not light.

However, when light shines onto the LDR its resistance falls and current flows into the base of the first transistor and then the second transistor. The LED lights.

Phototransistors:

Like diodes, all transistors are light-sensitive. Phototransistors are designed specifically to take advantage of this fact. The most-common variant is an NPN bipolar transistor with an exposed base region. Here, light striking the base replaces what would ordinarily be voltage applied to the base — so, a phototransistor amplifies variations in the light striking it. Note that phototransistors may or may not have a base lead (if they do, the base lead allows you to bias the phototransistor’s light response.

Photocell:

A photocell is a type of resistor. When light strikes the cell, it allows current to flow more freely. When dark, its resistance increases dramatically. Photocells need some calibration to be responsive in the exact lighting scenario you have. They can be used to detect large or small fluctuations in light levels to distinguish between one light bulb and two, direct sunlight and total darkness, or anything in between.

Posted February 13, 2011 by paddyjamiemikey in Uncategorized

Keeping the sumobot in the ring..   Leave a comment

We now have to consider how to go about keeping the sumobot inside the ring. This is obviously very important as whatever robot stays in the ring longer wins! We researched this on the internet and consulted our peers about this challenge. We have learned that using PHOTOCELLS would achieve this function. The ring will be a black disc and the surroundings will be completely white. The photocell can detect the change in colour and then the robot knows to move away from the white colour.

Posted February 13, 2011 by paddyjamiemikey in Uncategorized

Our final design/working drawings   Leave a comment

Posted February 13, 2011 by paddyjamiemikey in Uncategorized

How will the sumobot move?   Leave a comment

We have been doing alot of research on how our robot will run.

Friction is very important to keep in mind here as it will prevent the robot to move better!

We could use wheels or tracks. Here are some of the images we saw:

http://www.youtube.com/watch?v=c1sgV7UBGUo&feature=related

 

 

Posted February 11, 2011 by paddyjamiemikey in Uncategorized

Inspirational Ideas..   Leave a comment

From looking at the sumobot links on YouTube and some of the ideas the lads in the class were coming up with it was evident that the most commonly used idea was a wedge type approach. So we felt we need to think outside the box and come up with a unique idea which would not enforce the same strategy as the wedge.

WHERE TO GET USEFULL INSPIRATION FROM :

  • Spinning top toys .
  • UFO s (shape)
  • Beyblades.
  • YouTube.

The UfO pictures are what we are hoping to base our shape around with the electronics been placed in the top part of the spaceship as such.

 

Another picture which shows the shape design we are hoping to incorporate into our design.

We feel by using this shape style that we will be able to counteract the strategy of the wedge attach as it will be very difficult to ramp underneath this shape  of robot.

BEYBLADES

After watching sumobot competitions on the web I noticed the similarity with it and the kids game beyblades. I noticed very few of the robots were shaped like the beyblade but we felt as a group there was many benefits that we could take from the beyblade principal and encounter into our idea. e.g.

  • Spinning not just moving forwards and backwards.
  • Had the desired ufo shape we were looking for.
  • We would also try incorporate the stylish attractive look of the beyblade.  Haveing our sumobot looking well is also important.

 

Posted February 10, 2011 by paddyjamiemikey in Uncategorized