Robotics

Lego robotics combine the ability to build a robot and the ability to program the robot using its 'intelligent brick.' The Lego Mindstorms EV3 Core Set included all the necessary parts and instructions for building robots. Instructions for Gyro Boy, Color Sorter, Puppy, amongst others are included.

   

  

Besides educational Lego robots, there are many different kinds of robots which can perform wide array of tasks. Some are created to imitate people, for military purposes, for research purposes, or for commercial use. Military robots are often used to perform jobs that are hazardous to humans - like detaining a bomb. Possible the most commonly known commercially used robots are those that are meant to act as traveling vacuums. When someone is trying to develop a robot, after determining its purpose the next thing to figure out it what is its power source. Possible robotic power sources could include compressed gasses or hydraulic energy. The Lego robots utilized the most common source of robotic power - a battery. 

Gyro Boy

The class was split up into 6 teams, each trying to build a robot. My team chose Gyro Boy. Gyro Boy is able to travel, stand on its own, turn, sense objects based on its visual component, and it also utilizes an ultrasonic sensor. Our team successfully built the robot, but unfortunately the battery was either not charged or malfunctioning when it came time to download the Gyro Boy program.

                              Main Parts:
                              Stand - holds Gyro Boy when it is unmoving
                              Ultrasonic Sensor - allows Gyro Boy to stop
                              when it senses an object in its path of motion
Gyro Sensor - allows Gyro Boy to sense left and right                                                            Color/Visual Sensor - allows Gyro Boy to stop and start based on visual/color cues
2 Medium motors - allow Gyro Boy to move
Programming 'Brick' - allows user to program Gyro Boy

Programming Robots

Programming lego robots is relatively simple.  It is just creating a string of commands for the robot to follow, that can later be saved or erased. For instance, you might instruct the robot to travel for 5 seconds, turn 45º, then travel in a straight line until something is noticed by its visual sensor. Commands include, time-based motion, turning motions, color-based functions, and touch-based functions. You can create strings of programs by manually entering each command onto the robot's 'brick, as it is referred to on the Lego robotics website, or you can plug in the robot to a computer with the lego robotics software and download strings of previously created commands.

Programming Main Screen - Lego Robotics 

EV3 Intelligent Brick

Catapults

A catapult uses tension to fling a projectile across a far distance. The stored energy is released and 'transfers' into velocity which pushes the projectile onwards. In the case of a mousetrap catapult, the tension comes from the springs in the mousetrap. To build a catapult, you will need a mousetrap, electrical tape, pliers, a jumbo popsicle stick, some kind of holder for the projectile, and
                                                      erasers.


Building a Mousetrap Catapult:
1) Remove the catch and the hold-down bar using the pliers
2) Tape erasers in front of the springs so that they lean back slightly (you want to achieve a 45º angle)
3) Attach jumbo popsicle stick to the hammer using electrical tape and attack the 'holder' for your projectile
4) Release!

The Physics Behind a Catapult
Catapults use the elastic potential energy that is stored within the spring/launch mechanism of the catapult to launch the payload or projectile. The potential energy is transferred into mechanical energy when the projectile is launched. When you stretch the catapult's elastic you are increasing the potential energy thus creating an accelerating projectile.

Keep in mind:

• 45º gives maximum horizontal displacement 
• A longer catapult arm does not necessarily translate into a further horizontal displacement 

Types of Catapults 

Trebuchet - heavy payload & long distance 

     -uses energy of a falling counterweight to launch projectile with a high speed 

     -a counterweight that is much heavier than the payload produces maximum launch speed because 

     that means that it will fall quickly 

Mangonel - launch velocity equals velocity of the arm near the projectile holder/bucket 

     -uses a crossbar to stop the arm at the desired angle 

     -launches projectiles best at lower angles with a large range 

     -not as energy efficient as a trebuchet because the stored energy goes towards accelerating the arm, 

      which means wasted energy 

Onager - nearly identical to the trebuchet except that it uses a torsion bundle to rotate the arm

     -allows for a greater throwing distance than the mangonel but this distance was not consistent due to  

     the wearing down of the tension source 

Ballista - 'large crossbow' 

     -uses twisted ropes as the energy source 

     -used to launch darts, bolts, and spears great accuracy and force 

Trebuchet 

Ballista 

Mangonel

The Challenges of Honors Freshman Physics

Honors freshman physics will be challenging at best. After taking the first test, I think there are many ways I could have improved my score. I need to learn how to first attack a problem and how to interpret the question and then draw the correct diagram. After I successfully learn to do those two things, I think my test scores will definitely improve. Another challenge of this class is independence we have as students. Rather than being assigned homework to do in order to prepare for a test, we have to decide which problems to spend time on. I have trouble narrowing down the types of problems that I will have to be comfortable doing and I end up trying problems that we didn't even spend time on in class. To prepare for the next test,  my plan will be to review the types of problems that we do during class. Overall to succeed in this class I think I will have to figure out how to learn to solve problems on my own. Looking back, all other teachers never really showed us how to solve problems on our own; we always had all the information needed given to us. That's why this class is so challenging; we have to think about how to get the necessary information and also how to solve the problem.