Thursday, December 18, 2008

Expieriences of Robotics

Robotics is FUN!!

In the start, I thought the class would be basically programing and building, but throughout the semester, it seemed to get more and more interesting by the second(s). Although there were some confusing parts at first (with the programing), the class helped me to understand more and more about the robot(s). In the class, we studied Mathmatics, Science and Mechanics. Mathmatics basically involved calculating the ratio and average of speed/time. Science invovled using the Scientific Method, using hypothesis and conclusion. Last but not least, mechanics involved building the robot itself, inducing parts, rotating gears, and programing the robot to move.
In the start of the year, we would have to keep switching partners to coop with one another as we learned how to work with different types of sensors. After learning all gears ratios and sensor, I paired up with Bart as a partner for the rest of the semester. Of COURSE!! Without telling it was FUN!!. We had build our major robot (and its still the biggest one of the year) name the "Goliath" for some reason which I still wanted to rename it. Utilizing the kit, we had barly pass obsticle courses and some sensor usage. Each sensor had its own use:
Ultrasound Sensor: The ultrasound sensor is the sensor which senses what is ahead using the ultrasound (same as the bats).
Touch Sensor: Touch Sensor is basically relying on bump, press, or released. It's the most simplest sensor.
Light Sensor: The Light Sensor detects the lights off the ground which is determined by the threshold put. High or low would change the movement of the motors.
Sound Sensor: The Sensor is basically attracted to sound. It reads a sound whether it's high or low. Then it moves the robot.
the end, we had a race between speed and pull. The speed is basically making the robot run fast, and the pull was to lift the biggest amount of weight past an amount of space.
All in all, WE had a very fun Time!!!!

Tuesday, December 9, 2008

Tracktor Pull

Our Idea of the Tractor Pull is to increase the Driven Gear since with a smaller driving gear, the driving gear could push the driven gear harder with more friction, although this might be hard to push the wheels, it has the best way of friction and reducing slip. Instead of wheels, we decided to use belts, they are similar to tank wheels, hope we could use the the produce a high amount of friction to pull.

Gears and Speed

During the Gears and Speed Investigation, we measured speed differences, and using the speed differences and the gear ratios, we then could find how to make our bot faster. We knew that by having a larger gear in the driving area, the movement speed would increase, but if we were to get more friction and power, we would need to use the gears the other way, meaning if the driven gear is bigger, the robot would move slower but with more power. Out of our investigation, we made a table with a 1:1 Ratio, 2:1 Ratio, and a 1:2 Ratio. With those 3 ratios, we timed the movement for 3 seconds, and the results were averaged later on.

Draggy Drag Race

Pretty much, the speed challange is just about gaining the fastest speed. For us, we are using the 40 teeth gear, and 8 teeth gear, which makes it a 5: 1 Ratio. Using that, our speed would be 5 times faster than the original. The original was 2 x 16 tooth gears, meaning it was a 1: 1 Ratio. Using the 5: 1 Ratio idea, we think we could be able to succeed.

Monday, November 24, 2008

Get in Gear Investigation


During our investigation about Gears, we knew physically that the robot would not be able to run fast if the driven gear is faster than the driving gear. For the robot to be fast, the robot would have to have a smaller gear in the driven area and the driving gear would have to be larger in comparison. Throughout our investigation, we have actually did the ratios, using the 16:16 Ratio (1:1), 16:8 (2:1), and the 24:1 (3:1). Out of those 3, the 3:1 ratio was actually the most fastest, but sadly we didn't have enough time to add the 40:8 ratio since the sizes would not have fit.

Thursday, November 20, 2008

Chapter 6 Summary

The whole idea of Chapter 6 is about Supports. Mainly every robot built or car built is in need of supports. Having Gears is one of the most important parts of supports, a gear that is placed next to a supporting beam holds the beam well and decreases the slipping of the attached parts to the gear. The best way to resist both Tension and Compression is by adding extra connectors, by adding the connectors, the Tension and the Compression would have been lessened dramatically and with the Rigid assemably, it would not easily fall apart. The way that the new idea of studless beam works is that the studless beams can add both beams with stud and without. The old one only allows stud beams to connect. A creative reason for the studless beams was to let it cover up all the parts that show out. In any case, the most important part is the NXT itself, it is needed to be placed at the center just as a shape of a triangle. The reason for placing it at the middle is because it needs to keep the front and back both balanced, if either side is imbalanced, the robot would fall back or drop forth if it moves. Mainly, all problems lead to weight balance, the NXT itself has quite a big weight, as much as 2-3 Motors, if those both were placed in the middle, both front and back would be fine, but if they were all placed at back, they would tilt. The best ideal way would to be placing the NXT at the back/front, and the Motors at the opposite like a scale balance.

Monday, November 10, 2008

Building Stratagies


We have many ideas to increase our robots chance of passing any test, but before that, the main problem is with the robot itself. Since some robots are large in length, one of their problems would be its weight on each side. Using beams attached to other beams would allow each beam to reinforce each other. The idea of our build requires absolute symmetry in order for it to preform turns and actions which include the use of all our 4 sensors. The main idea of all this is to use beams to hold the NXT and the bot together without letting it tilt while turning or breaking up while moving.

Thursday, November 6, 2008

Overview of the Obsticle Course Challenge


The Obsticle Course Challenge involves using all 4 of the sensors that were learned during the whole time. The image on the right side shows the sensors that we have to use and what the recomendation was for the programming. Mostly always, we start with the sound sensor to make it move, then using the Light sensor, we add it with a motion to stop program. After that, using the touch sensor, we make it bump the wall and back up. Then, we make it turn and go straight to the second wall where we use the Ultrasound sensor to sense the wall (since this challenge says we cannot bump the 2nd wall) then turning and going straight. After that we could either dodge the cans or shoot at it, but we cannot touch it. at the end we stop by using the Light sensor again.

Robotics Chapter 1 Review: Lego Blocks

Lego cubes (also known as special Lego bricks due to their size) were not really in a cube shape. A special Lego brick as the dimensions of 1 x 1 x 1. Even though it was called "Lego cubes" it isn't really in a size of a cube since its dimensions of its area/surface area aren't the same. Years after the invention of legos, the idea of new Lego bricks with holes were called "Beams". The main idea of the Beams were to allow axles to connect on to the holes and allowing them to connect to one another. The reasons for the beams to change studless to change in the 8448 and 8840 set were because the old beams with stud only allowed right turns, and now with the studless ones, we are able to make more real-life turns. An example of beams connecting is a shape of a right triangle with a right angle degree of 90. Using 3 of the longest beams: 1 x 13, 1 x 11, and 1 x 9. To make the shape, you would use the beam with 1 x 13 as the hypotenuse, 1 x 11 as the base, and 1 x 9 as the height. A Liftarm is a very useful tool, which is also known as a half-beam; the reason that it has advantage is because it is very light weighted.

Tuesday, November 4, 2008

Kenny's Field Of View


The Ultrasound is a type of detector that measures obsticles and their distance from the detector itself. For our Module, we tested it with Aluminum Cans from a distance of a meter. The Results were shown on the pictures below. As you can see the picture of the measurements were all measured by how far the sensor could detect before it couln't catch a value.