Electric Motors

The main function of electric motors is to convert electromagnetic energy into mechanical energy. The history of motors began when the fundamentals of electromagnetic induction was introduced. In the early 1800's, three popular scientists named Oersted, Faraday, and Gauss came up with the basic concept of electromagnetic induction.



In the year 1820, Andre Ampere and Hans Oersted discovered that electric current produces magnetic field. Then, ten years later in 1830, Ampere, Oersted, and many other scientists were able to create the basic DC motor.

In addition, another person who contributed a lot to the fundamentals of electromagnetic induction was Michael Faraday. In the year 1831, he discovered electromagnetic induction, which is the concept behind the generator, or a motor like ours. This was a huge achievement for enabling electricity to become better understood by scientists. Faraday built inventions that created what he called electromagnetic rotation, or circular motion from the circular magnetic force around a wire. After he found out this concept, he began experimenting which later resulted in his discovery of electromagnetic induction. Faraday's drive to learn more about electricity came from his desire to disprove what Hans Oersted speculated. One of Faraday's inventions included a dish of mercury with a fixed magnet in the middle, a wire hung above the dish, and a battery to connect the circuit. This was one of the first electric motors. A diagram of this invention is shown below.


After the initial invention of the electric motor, then the expansion began. Ten years after the first motor was built, a scientist named Joseph Henry improved on the motor. He created a motor where the rotating part was an electromagnet with a horizontal axis. The motion resulted in two vertical, permanent magnets that repelled and attracted one another as it swayed. This motion made the magnet swing back and forth at 75 cycles per minute. Joseph Henry's edition of the motor is shown below.


Then, in 1828, William Sturgeon came out with an invention that changed the way motors worked; he invented the commutator. In fact, he is credited with the invention of the first rotary electric motor.

My Bridge

For our Honors Freshmen Physics class, we have been assigned to create a balsa wood bridge. This bridge has to be no heavier than 100 grams, with the length around 17 and a half inches, with an inner roadway of at least 3 and a half inches wide. The bridge also cannot have anything wider than 1 inch and it cannot be more than 1/4 of an inch thick. In order to get an A, I have to create a bridge with the requirements above and it must hold at least 120 pounds. For my bridge, I have chosen to build a bridge like the one shown in the diagram above. It is a simple, truss bridge shape that I have looked over and researched to make the best result possible. I have chosen this design for my bridge because it is simple, yet powerful. At this point in time, my bridge is still under construction, but right now it seems to look pretty strong. All in all, I have chosen this simple, yet effective design for my bridge.

Static Equilibrium

Static equilibrium is defined as when all of the particles in a system are at rest and the total force on each particle is permanently zero. Static equilibrium is connected to Newton's First Law of Motion, or the law of inertia. An object that is in static equilibrium has no force acting upon it, therefore remaining in rest.


In fact, we have an example of static equilibrium in our classroom. As shown in the picture above, these little birds are in static equilibrium by being able to balance of their beaks on the shoulders of a wild Charlotte. These three little birds in our classroom are primary examples of static equilibrium. They show this because they have weights in their beaks, enabling them to balance on their beaks. Being in static equilibrium, they can balance on their beaks without falling no matter what surface they are on. In addition, static equilibrium can also apply to bridges. Bridges can be in static equilibrium if the weight on top of the bridge is equal to the amount resistance on the bottom of the bridge. The most effective bridges are in static equilibrium

Bridges

Bridges come in many different shapes and sizes. There are many different kinds of bridges as well. The most popular and common bridges are beam bridges, truss bridges, arch bridges, suspension bridges, and many more.


The first and most simple kind of bridge is the beam bridge. It consists of three main parts which are the pile, the pile base, and the deck, as shown in the diagram above. This type of bridge was the first bridge to be built. In fact, the first beam bridges to be made were made by nature. Then, humans saw the nature bridge and imitated it, then made them more and more advanced as they are today. Beam bridges can either be made by one long piece that spreads across, or it can be made by multiple I-beams, trusses, or box girders. All in all, beam bridges are the most simple of all of the bridges and can easily be made.


The next type of bridge is called a truss bridge. These bridges consist of multiple triangles put together to create a strong base. Truss bridges are usually made with straight, steel bars that are used to make the sides of the triangles. This type of bridge is the oldest type of modern bridges that we see today. This bridge is more complex than beam bridges. Truss bridges consist of floor beams, a deck, stringers, struts, and more as shown in the diagram above. These bridges are the most effective material wise and are still used a lot today.

The next type of bridge are arch bridges. The arch bridges were very popular in ancient times around 1300 BC. They were favored for their natural strength by many. Romans were clever and made arches in door frames as well as bridges because of their strength. A lot of ancient architecture included arches as well. Most arch bridges today are made from steel or concrete and span up to 800 feet. These bridges have many supporting posts and because of their curved shape, they are very strong.

The last type of bridge is a suspension bridge. These bridges have a fairly simple design, but are very powerful and can span for 2,000-7,000 feet long, which is a lot longer than any other type of bridge. In fact, the longest spanning suspension bridge in the world is currently the Akashi Kaikyo Bridge in Japan which spans 6,532 feet. Most suspension bridges today have a truss system beneath the bridge to keep the bridge from bending and twisting.

Robotics in our Everyday Lives

            When I started thinking about robotics, I thought about how they affected our daily lives. As I soon figured out, they are used a lot more than I thought they were. In fact, I found out that in my town they were using new robot technology to help students learn more about robotics.

            

             One use of robots is in education. For example, my brother's high school recently bought a new robot called "Projo". This robot is used in the robotics class at Randolph High School where it is used as a teacher and a robot that students program during class. There, they program it to do certain actions such as walk, talk, move around, and act like a human. In this particular high school, it is used more like a helpful tool to help the students learn more about programming and robotics. However, in other schools around the world, this robot is used as a teacher for younger students. But, they aren't replacing teachers or teaching a whole class, but rather the kids take turns spending time with the robot as an experiment to see how it effects them. Also, the robot is programmed to mimic human actions. In fact, Sophia Hollander from Wall Street Journal states, " the robots are programmed to... swiveling their heads when students speak, crying out when overeager kids get physical, and gesturing as they talk." This shows how these robots mimic certain actions to act more human like to help the students learn. All in all, robots are very useful in our everyday lives and they are very versatile.

Programming

               Programming is the writing or planning of a program. For the Lego Mindstorms ev3 robot, you would program it using the machine above. For the Mindstorms  ev3 robot puppy, we built the puppy and then had to program it. We programmed it to make the puppy show emotion, eat using the bone we built, pee by lifting its hind legs, and pet it and have it show happiness. The robot consisted of a color sensor and the bone. Once we finished building our robot, we programmed it by pressed several buttons on the machine to make it so that when it sensed that the bone was by the robot's mouth, it would make eating noises.
               When programming it to do these actions, we had to use the machine above. On the screen, it showed various colored blocks that had certain purposes in order to program it. The colors were green, orange, yellow, red, dark blue, and light blue. The green block was the action block which controlled the medium motor, large motor, move steering, move tank, display, sound, and the brick status light. The orange block was called the flow block consisted of simple actions such as start, loop, and wait. The yellow block controlled the sensor attachments to the machine and controlled how they worked. The red block was called the actions block and it controlled the movements the robot would do. The dark blue block was in control of advanced programs such as messaging, Bluetooth, and data logging. Lastly, the light blue block had previously used and saved programs. These colored blocks helped us to program our robot.
                All in all, our group used the colored blocks on the machine. This enabled us to truly bring our robot puppy to life and enabled us to make the robot do certain actions. Without the programming, our robot wouldn't have been able to do the actions that it could.

Our Robot Puppy

For our robot, my group decided to build the robot puppy. We built the robot after a course of three total class periods. After building our robot, the puppy had the ability to complete certain actions. Our robot puppy could "eat" using the red, yellow, green, and blue "bone" shown above. In addition, as shown in the picture above, the puppy could sit back on its hind legs. The puppy also had the ability to lift up one of the back hind legs and "pee" while a little sound effect in the background indicated that it was peeing. In addition, you could pet and press down on the robot's back and it would become happy and jump up and down. Also, the robot could demonstrate emotion that it was happy by the eyes becoming hearts and by jumping up. On the other hand, it could also demonstrate anger by having slanted eyebrows and an angry expression and by making a growling noise. All in all, this was an exciting experience and it was interesting to see our robot come alive from random Legos into our very own robot puppy.

                      This is my group after we finally accomplished building our robot puppy.

            P.S. Patrick was also in our group but he was making a funny face and wished to be removed.