User:Cwoo4792/enes100/Robot Arm 2

Link to team page: TFCWNS

Give instructor top 3 project choice list
1.Robot Arm 2.Robot end effector 3.Rube Goldburg

Write problem statement
Find a way to build a system that would raise and lower the robot arm, raise and lower the individual wires, and contract the end effector.

Assign Task1
Look up push/pull systems or think up of possible push pull systems to implement onto the robot arm.

Compare actual work done to Task1
My goal was to look up push/pull systems or think up of possible push pull systems to implement onto the robot arm and I came up with the idea of using a train wheel like system that pushes and pulls all in one rotation of wheel. This way we would only need a motor to move in one direction for me to raise and lower the arm. I also discovered with the help of one of the engineering room maintainers that I could utilize the Lego mindstorm nxt system and was able to create a pull system for the end effector.

Week1 Narrative
Week one of this project cycle my goal was to find ways to lift and lower the Robot arm. I started of by thinking a screw and bolt system that works by raising a platform by turning a long central screw. This would allow a platform to be lifted by turning the screw in one direction, and to be lowered when turned in the other. The problem with this design was that we didn't have the parts necessary to build it. I then thought of the Idea of using a type of train wheel system. This would allow a platform to be raised and lowered in one rotation of a wheel. I implemented this idea by using Lego Mindsorm pieces and I was able to get a system that lowered and raised the arm. Although it doesn't raise and lower smoothly, this is the kind of system that be the most probable to work for our arm considering parts available and time. I will continue to figure out the structural problems of this system so that it will be able to raise and lower the arm smoothly. I was also, with the help of Patrick, able to learn how to use a simple Lego Mindstorm nxt programming system to use on Lego motors. With this I was able to program a motor to pull the End effector string to enable grabbing. Here are some pictures of what I have:
 * http://commons.wikimedia.org/wiki/File:Robot_arm_raising_system_1_(lowered).jpg
 * http://commons.wikimedia.org/wiki/File:Robot_arm_raising_system_1_(raised).jpg
 * http://commons.wikimedia.org/wiki/File:Raising_system_(side_view).jpg
 * http://commons.wikimedia.org/wiki/File:Raising_system_(back_view).jpg
 * http://commons.wikimedia.org/wiki/File:Raising_system_(back_view_raised).jpg
 * http://commons.wikimedia.org/wiki/File:Lego_Mindstorm_motor_with_pulling_wheel_attached.jpg
 * http://commons.wikimedia.org/wiki/File:Raising_system_with_Lego_Mindstorm_motor_and_controller.jpg

Week1 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Assign Task2
Work on fixing problems with raising and lowering system by creating a more sturdy structure.

Compare actual work done to Task2
My goal was to work on fixing problems with the raising and lowering system by creating a more sturdy structure, but through further testing I found that with the train wheel system I would not be able to distribute the pulling and pushing torque evenly among the wires. I decided to just implement the train wheel pulling and pushing system to each wire by giving each wire a sliding system and motor.

Week2 Narrative
During Week two of this project I began by trying to refine the lift and lower system of the Robot arm however, I was unable to get any success in making this system lift the arm smoothly without getting stuck or tilted to one side. I then began exploring different ways to lift and lower the arm. I thought of using some sort of pulley system similar to that used in bicycle breaks by using fishing wire and hard plastic tubing but creating a structure for this would take longer than the time I had so I had to think of something different. Finally I referred back to the original idea of having a motor next to each wire except this time I would use the Lego motors. I then thought of incorporating the train wheel system to each wire rather than just one for all the wires. This way I wouldn't run into the problem of uneven push and pull. I was able to create a system like this to one of the wires and I will add one to the rest of the arms when time allows.
 * http://commons.wikimedia.org/wiki/File:Lego_Raising_and_Lowering_motor.jpg
 * http://commons.wikimedia.org/wiki/File:Lego_Raising_and_Lowering_motor_(Raised).jpg
 * http://commons.wikimedia.org/wiki/File:Plastic_tube.jpg
 * http://commons.wikimedia.org/wiki/File:Wire_raisers.jpg

Week2 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Assign Task3
Add lift/lower system to each one of the wheels and test it out to find if there are any problems.

Compare actual work done to Task3
My goal was to add a lift/lower system to each one of the wires and test it out to find if there are any problems. I was able to construct a frame to hold the two lateral motors with a lift/lower system attached. I was able to get the two lateral wires to correspond to a simple program which successfully raised and lowered the arm. The arm however, wiggled slightly from side to side when raising. This may be due to the fact that I was unable to connect a motor to the front wire which moved freely when the others were being raised and lowered.

Week3 Narrative
During this section of the Project I set out to add the other motors to the wires of the robot arm. I began by first trying to build a frame to hold the motors in place so that they could move the wires without themselves moving. I needed to make sure that the motors were placed in the right position to utilize the best and smoothest lifting and lowering motion. I was able to construct the frame by adding multiple cross beams that connected to the motors and to the axle posts around the top. I had to make sure both motors were symmetrical in where they were placed and how they were held in, in order for each of them to work the same. After finishing this I moved on to make a program so to test how it worked. I needed to slow the motors down so that the peg holding the wires into the top of the push/pull system wouldn't fall out. I made a motor command for both motors so that they would run for 0.125 seconds and then put a loop around it so that this would repeat over and over. This resulted in the motors acting somewhat like a stepper motor. When I ran the program the arm lifted and lowered repeatedly and the pegs didn't fall out. The arm however would somewhat sway back and fourth due possibly to the fact that the front wire was not connected to a motor. I need to glue all the pegs in and connect a front motor to the front wire. In addition I need to create a system to open and close the end effector smoothly.
 * http://commons.wikimedia.org/wiki/File:Motor_Frame_(back_view).jpg
 * http://commons.wikimedia.org/wiki/File:Motor_Frame_(side_view).jpg
 * http://commons.wikimedia.org/wiki/File:Motor_Frame_(front_view).jpg

Week3 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Assign Task4
Add front motor, glue pegs in, refine NXT programming, and create a better way to pull the end effector.

Compare actual work done to Task4
My goal of week 4 of the project was to add the front motor, glue the pegs in, refine the NXT programming, and create a better way to pull the end effector. I was able to add the front motor to the frame create a demonstration program and attach the wire of the end effector to a motor mounted at the rear of the frame. I decided that it would be better to leave the pins unglued and attach rubber bands so that the height of the wires could be adjusted.

Week4 Narrative
During this last segment of the Project I needed to work on mounting the forward motor to the frame, add an end effector motor, and make programs for the robot arm. I was able to figure out a configuration of Legos that could fit a front motor for the front wire and a back motor for the end effector. I then needed to make a program for the motors. The problem I have is that the nxt block only has 3 motor ports when I need 4. However I was still able to create a program that demonstrated its grabbing ability by only controlling the front wire and the end effector. I then was able to make a program that demonstrated it's range of motion by allowing all three wire motors to be powered simultaneously.
 * http://commons.wikimedia.org/wiki/File:Final_Robot_Arm.jpg
 * http://commons.wikimedia.org/wiki/File:Motors_and_NXT_Brick_controlling_the_robot_arm..jpg
 * http://commons.wikimedia.org/wiki/File:Side_view_of_control_system.jpg
 * http://commons.wikimedia.org/wiki/File:NXT_program_1.jpg
 * http://commons.wikimedia.org/wiki/File:NXT_program_2.jpg

Week4 Peer Review
Go to each team mates weekly summary wiki page. Read their activities and narrative. Then go the associated discussion page. Say something positive on this page. Try some constructive criticism. Add your name and a signature ~ by entering four tildes in a row to create a time and date stamp. Create a new category if another team mate has already commented here.

Complete Project Page
Follow the "project done" format.

Start Next Project Week0 activities
End of semester