The testing documents included a current limit test and temperature tests. The current limit test was run in conjunction with the component temperature test. An Analog Discovery was used to generate a 5 Volt PWM signal and direction signal. The PWM was set to 1 kHz at 10% duty cycle and the direction signal was set at 1 Hz. Wargo and Brigette took temperature readings on all of the MOSFETs and recorded them in five minute intervals. After half an hour, they stopped the test and let the motor cool down. The test was repeated at a 50%, 75%, and 90% duty cycle. This test concluded that the board will fail before the components reach their current or temperature limits.
The motor temperature test was conducted over a one hour time interval with measurements taken every five minutes. The PWM was set to 1 kHz at 95% duty cycle and the direction signal was set to ground. This test concluded that the motor will need heat sinks to dissipate heat of up to 300 degrees Fahrenheit.
Gabe has spent this week finalizing the generation of a
trajectory from the sidewalk edge data. The vision system is robust enough now
to deal with multiple variations in edge landscape on the edge of the sidewalk
and still return a viable location of the edge. From that information the
program is able to generate a trajectory that the robot can use to localize its
position. Gabe is currently working of improving the prediction of the edge so
that the robot doesn't “lose” its way if it ever can’t reliably identify the
edge.
Gabe is going to continue working on the trajectory and has
set up several test videos to do so. From this point on Gabe will strive to
develop an x and y output to send to Jaya’s control program. This should only take a few days since the vision system
will function essentially as a line follower for now.
This week, Harris was trying to calculate the camera position and pose in real world coordinates. An eight by eight grid map was drawn and registered into the camera feed. Three image points were chosen to match the object points of the grid map. The H homography transformation turns all the real world coordinates into image coordinates. However, a stipulation in the python code is matching the image coordinates with the real world coordinates incorrectly. Once this code is refined, the camera matrix can be entered by using translation and rotation matrices and will be able to output the camera position and pose. The only problem that can be foreseen is entering the translation and rotation matrices incorrectly into the program or solving them with a minor math error in the calculations.
Starting next week , Harris hopes to apply this program using the Tour PNADDER as the inertial frame and make changes accordingly for the minor tests.
This week, Tanner and Jason applied bondo to the edge of the base platform to fill in the honeycomb and then sanded it down to make the edges smooth. They also keyed a keyway into the sprockets and started to align them. Also, they took measurements and started to make the heat sink and tensioner for the motors.
Next week they will continue to smooth out the edges and fabricate the heat sink and tensioner. Alse, they will be learning how to use the new machine in AXFab to be able to finish modifying the intermediate rod.
This week Karl continued development of a filtration program for data from Tour PNADDER’s sensors. This program will help finalize various gains used in the control algorithms in the system. Dr. Isenberg provided all the necessary tools to both formulate the filtration program and simulate system responses, for the sake of testing the program prior to its use on the actual system. The goal for the upcoming week is to complete these two pieces of code so that Jaya can complete his work on the controller. For this to happen, much of the isolated work done by different individuals will need to come together; properly functioning/measured locomotion system, working encoder/decoder sets,
and odometer software.
This week Jaya completed the controller for our robot, and managed to enable it to work for voltages between negative 12 and positive 12 volts. Next week Jaya is planning to work with Karl to get the code translated to a python format. Jaya also plans to start replacing test variables in his code with actual values, and if he complete these two tasks he will start working on imputing the controller into Simulink. There shouldn't be any major issues that he will have to face while completing these tasks.
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