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Hardware

3 May

Our group, Robopower, has been working on building a robot for the past four months. A few weeks ago we finally finished it. Our goal is to get our robot to write FAU.  The robot has various parts to it, and each has to be properly tested in order to make sure the robot can function as a whole and move according to the program. Our robot consists of 3 sensors – 2 IR sensors and 1 ultrasound sensor. The IR sensors are on the left and right side of the robot and the ultrasound sensor is in the front. The first component we tested was the IR sensors. We set up a reflector wall at the end of a sheet of paper and set the robot at the opposite end of the paper. We measured the distance from the wall to the robot and recorded the analog output numbers. We moved the wall closer to the robot by 1 cm and repeated the same action as above. We recorded our information and analyzed the numbers in the graphs shown below.

When the robot was 4 cm away from the reflector wall, the analog numbers decreased and randomized. Therefore, the optimum usage of the IR sensor is when the robot is more than 4 cm away from the reflector walls.The diameter of the wheels is about 6.5 cm. Therefore the circumference is 6.5π which estimates to about 20.42 cm. We can use this information to figure out the distance that the robot has traveled after one full wheel turn. We believe that the robot moves 20.42 cm in one wheel PWM rotation. To test the PWM pulses, we devised a code that would send 10 pulses in order to make a full rotation, using the motor pins 6, 7, 8 and 9. We realized that ten pulses were not adequate enough to make one full wheel rotation. We kept increasing the number by increments of 10. Unfortunately, we did not have enough time to finish testing the PWM pulses. We will continue testing them in class on Thursday. Although the Ultra sound sensor  is pretty much reliable we will also conduct a sanity check, much like we tested the IR.To recapitulate,  we must test each part of our robot to make sure that they work because the job can only be done properly if all the parts work together, correctly. We have tested the IR sensors and we found that the optimum usage is 4cm, we are also in the process of testing the PWM and ultra sound sensors.

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