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Group4WaitDistanceCommandExperiment Problem 3 Hypothesis: I think that the wait angle command works by either using sensors to sense polarization OR by computing the ratio of the right and left wheel travel distance relative to the 248mm wheel separation. I believe that the angle waited will be very accurate at a low speeds and on flat ground. Materials: 1. Computer with Real Term and serial port connections 2. iRobot Create 3. 3 different colored markers 4. measuring tape 5. protractor 6. a large sheet of paper Procedure 1: How Wait Angle is Calculated 1. Plug in the iRobot and open up Real Term 2. We need to determine if the create measures angle by sensing its polarization (direction) or if it uses sensors on the wheels to compute the ration of the wheels relative to the 248mm wheel separation. I will do this by flipping the iRobot upside down so the robot wouldn't sense polarization. 3. Start up the iRobot by pressing power, enter the start opcode (128) and switch the iRobot to full mode (132) 4. Set up a script to tell the robot to turn (we will use drive direct in this experiment), (in place or an arced motion - it doesn’t matter) to wait an angle of 90 degrees counter clockwise, then tell it to stop. (152 9 145 0 100 255 155 157 0 90 128) 5. Run the Script (153) if the robot stops after a few seconds, this means that the robot computes the distance each wheel rotates in relation to its 248mm wheel separation in order to calculate wait angle. Procedure 2: How accurate is wait angle 1. Set up a large angle-measuring sheet by taking the sheet of paper and drawing a line that runs up the center of the paper as well as that line's perpendicular bisector. 2. position the iRobot so that it's center is directly on the intersection of the lines (be as accurate as possible)Tape a colored marker facing downward to the exact front of the iRobot so that it just touches the paper. 3. Tell the iRobot to rotate clockwise until it reaches 90 degrees, then stop. Mark with a different colored marker where the very exact front of the robot is. Replace the iRobot to its original position. (152 9 145 255 155 0 100 157 255 165 128) 4. Repeat step 3, using different colored markers except this time rotate until 180 degrees, and 360 degrees. (152 9 145 255 155 0 100 157 255 75 128) (152 9 145 255 155 0 100 157 254 150 128) 5. Tell the iRobot to rotate counterclockwise until it reaches 90 degrees (the other way), then stop. Mark with yet another kind of marker at the very exact front of the iRobot. Replace iRobot to its original position. (152 9 145 0 100 255 155 157 0 90 128) 6. Repeat step five, this time rotate until 180 degrees and 360 degrees. (152 9 145 0 100 255 155 157 0 180 128) (152 9 145 0 100 255 155 157 1 105 128) 7. Measure the angles the iRobot rotated during each of the steps. 8. Find the percent error of the experimental results by using the percent error calculations. Observations/Results: Experiment 1 Experiment 2 - format is a little wierd cause i just copy pasted from my microsoft word app. -> Jon Hohrath |