Review of Robotics

This is my last blog for my Robotics class. I have had a great experience in Robotics class. I liked this class very much. On the first day, we started to build the robot. I guess, without the instruction manual for how to build the robot, no one would have been able to make it!! But, as the class went on, we got more used to the parts of the robot.I had never known that LEGOcould be so coplex.There were some students in the class who made extremely cool and fascinating robots. The "Goliath" made by Bart and Kenny was truly a classic.

Another fascinating thing I liked about this class was using the LEGO MINDSTORM software to program the NXT. This was something new to me and it was very interesting because we were making software on the computer and then transferring it to the NXT. we could basically make any software we wanted and the robot would do what we liked- provided that we programmed the software properly. As we got more and more knowledge about robotics, we learned how to make more complex software using the sensors etc.

Another thing I like about the NXT ROBOT was the different types of sound sensors it uses. There were four sensors. They were the touch, light and utrasonic and the sound sensor. The touch sensor is a sensor which besically continues to program when it is pressed, released or both before continuing.The light sensor reads the light value of the light which it senses.The sound sensor basically records the level of the sound which has been emmitted from a ceratin place and the Utrasonic sensor basicvally measures the distance between the robot and an object.the way it does that is that it sends out ultrasonic rays and the rays bounce back if they hit an object. We were able to use all of them. we had done an investigation for each of the sensors. After we had done an investigaiton for all of the sensors, we then had a challenge set by Mr Inskeep. In that challenge, we had to use all of the sensors of the robot to complete a course. We had to use all of our knowledge to do that. It was a challenging course.

Overall, this class has been a very good experience for me and I enjoyed every moment of this Robotics experience.

Tractor Pull

This is our last and final challenge in our robotics class. IN this challenge, we will have to make our robot a big piecee of lego. IN this challenge, we will be testing the strength of the robot. We need to design the robot to pull that weight with ease.

The team that pulls that amount of weight the fastest will win the challenge. They would prpbably get an A+.

Get in Gear Investigation

We had worked on the get i gear investigation a while back. It involved changing gears of our NXT robot and seeing which changes caused the robot to go faster and which ones caused the robot to go slower.
There are two gears: the drivin gear and the driven gear. The driving gear is directly connected to the motor with a stick that goes through the centers of both of them, and the driven gear is a gear that is attached to the wheel and connected to the driving gear.

Gears and Speed (Investigation Summary)

In this investigation, the aim is to find out which hypothesis is correct and how er can apply the hypothesis to the real speed of the robt.
There are two hypotheses:
Hypothesis A : speed1/ gear ratio 1= speed2/gear ratio2
Hypothesis B : speed1 X gear ration1 = speed 2 X gear ratio 2

In our investigation we found out that hypothesis B was correct because the assumed value was pretty close to the actual value. It also means that for a robot to move faster, the gear ratio has to decrease. As the gear rato is less, the speed is faster.

Drag Race

In the drag race challlenge, we have to design our robot to go the fastet that it can go down a straight path/ line and achieve the fastest time and beat the robots to win.
The length of the course is three meters,

There will be heats in which all the robots will compete and race each other. The final will be between two robots who will compete each other and battle it out for eternal glory. The winning team will get an A+.

I hope that our team (Avery, me and Clare) are the team that get the A+. I wish all the teams the best of luck and look forward to racing with them on the couirse. May the best team win.

Chapter 14: Classic Projects

This chapter deals with several projects can be the inspiration of several others of your own creation. The first project is exploring your room.

In this project, the aim of the robot is to move around the room, detecting objects and change it route accordingly. For simplicity of design, and for the robot to turn in place, it is suggested to make the robot from differential drive architecture. If you coose a gear ratio that makes the robot rather sow: 1:9, obtained fro two 1:3 stages. This ensures th at if you make some error in the code and the except everything to go well on the first try but it won't.

The second project is detecting edges. If you're room has a flight of stairs going down, simply equipping the robot with an ultrasonic sensor facing the floor to sense the edge can avoid a bad fall. You could also use a touch sensor instead, connecting the touch to a feeler flush with the ground. When the feeler in front of the robot drops, you have detected an edge.

The third project is following a line. You must follow the edge the tape and te floor, reading an average value between dark and bright so that when you read dark or too bright you know which direction to turn to fnd the route back. You must remove the bumpers and mount a light sensor facing down.

Chapter 2 Gears

This chapter discusses about the different types of gears that we can use in a robot. A single gear wheelis not very useful- it isn't useful at all. We need atleast two gears. The most imprtant property of a gear is its teeth. Gears are classified by the number of teeth they have. An example is that a gear with 24 teeth wll become a 24t gear or a gear with 8 teeth will become an 8t gear. The fundamental property of a gear is that they transfer motion from one axle to another. Another important thing you should notice is thaat you are not required to apply much strangth to make them turn. Their teeth match well and there is only a small amount of friction. A fourth, and subtler, property you should have picked up is that the two axles revolve at different speeds. To get an increase in speed, you have to sacrifice a decrease in torque. Torque is a measure of the tendancyof a force to rotate an object.

The largest gear is the geartrain. It has 40 teeth (40t). Geartrains give you incredible power because you can trade as much velocity as you want with the same amount of torque.

Idler gears usually help you connect distant axles. An advantage is that they change the direction of the output.

Backlash is the amount of oscilation a gear can endure withou affecting its meshing gear. Backlash is amplified when gearing up, and reduced when gearing down. It generally has a bad effect on a system, reducing the amount of precision with which you cannot control the output axle, and for this reason, ti should be kept to a minimum.

Pulleys are like wheels with a groove (calleda race) along their diameter. Photo of a pulley below.

A worm gear is a strange gear that resembles a sort of cylinder with a spiral wound around it. A photo of a worm gear below.

A crown gear is a secia gear with front teeth that can be used like an ordinary 24t, but can also combinewith another straight gear to transformotion in an orthogonal direction, possibly achieving at same time a ratio different from 1:1.