Individual Blog Week 7 (7/10 - 7/14)

This week was focused on 3-D printing a small rig for the tilting mechanism. Last week, I finished creating a control system to facilitate the pitch control of the bogie. However, before doing kinematic analysis on the design that I had for the bogie, my teammates and I decided to create a small rig to check whether this design would even be plausible.

I began testing the propulsion program on the actual bogie and started to run into some problems related to interference with the hall effect sensor. I attempted two different methods of switching. The first method causes the steering to occur at a specific time with the hall effect sensor detecting a magnet. The second facilitates the steering motion whenever there is a magnet detected. In the first method, the hall effect sensor kept detecting a magnet at a random time within the first few seconds of running. Afterwards, the program would continue as expected, but it messes with the count that we have within the interrupt function. The second method has a problem with interference relating to the relays. Every other time the relays click, the hall effect sensor detects a magnet. The relays emit a strong electromagnetic field whenever the channels open and close. I am considering having a low pass filter soldered onto the hall effect sensor PCB to attempt to counteract this problem.

Figure 1: Tilting mechanism in action
 

IMG_2088.JPG
Figure 2: Low pass filters on the limit switch PCB, which may need to be placed onto the hall effect sensor.

Figure 3: Isometric view of the entire system assembly in Solidworks. 


Comments

Post a Comment

Popular posts from this blog

Individual Blog Week 5 (6/26 - 6/30)

Image
During this week, I focused on getting the test rig to work on the components that will be used for the bogie. As mentioned last week, I had the problem of the steering function getting stuck in loops and activating without having detected a magnet. This was solved by simply including an additional conditional statement. Currently, I am waiting on the parts from the Central Shop to get machined, so I can attach them to the disassembled bogie. I believe that this will be finished some time in the following week. Other than that, the code is working just as expected, and may need to be tinkered with when implementing it on the bogie. Currently, I am designing a tilting mechanism that will take advantage of a PID controlled system with a three-axis gyroscope and accelerometer with a DC motor as an output. This system will utilize chains that pull the front and rear cabin when negotiating the two 17-degree slopes on the track to limit the pitch of the cabin. This is important for maintai...
Read more

Individual Blog Week 8 (7/17 - 7/21)

Image
During this week, we were able to get one of the bogies completely working on the benchtop. After completing the ANSYS Fluent training, I was able to get back to working on the bogie. We are considering having an extra conditional variable that dictates the state of the bogie. For example, forward motion would be "0", reverse would be "1", steering right to left as "2", and steering left to right as "3". These variables would allow the program to be free of delays. One advantage to this type of movement is that we would not have to time the bogie running through specific portions of the track. However, because this has not been tested and we have been set on utilizing delays, there is a small chance that we will try to implement this. Figure 1 shows the gist of how this will go through the program without using delays. As shown below, the directions variable is set to 3 when a magnet is detected, and the modulo two of the counting variable is 0...
Read more