PmWiki | Student / DavidOukLab5

Lab 5: Wall Following Conclusion

Summary:

My task was to apply my C programming knowledge and use external distance sensors to program to create to drive along the wall with its trajectory as parallel to the wall as possible without scraping the wall or bump into the wall at all. The concept used to program the Create to do this task was similar to the line following. If the Create is too far from the wall, drive towards the wall, if the Create is too close, drive away from the wall, and if it’s at a favorable range of distance form the wall, drive straight. Another distance sensor is also used to sense the obstacle ahead and avoid it. Safe mode and “pause and resume” mode using the play button are also incorporated into the wall following program. In case the Create bump into something, it is also programmed to back up and turn away from that obstacle.

Lessons learned and problems encountered:

To explore the sensors is necessary before writing the programs
It’s easier to write codes one small piece at a time.
Analog sensors may give out non-linear values.
Finding constants is important to incorporate in P.I.D controls.
Where to place the sensors is very important.
Remembering how to use simple functions such as “while”, “if”, and writing function opens many possibilities to writing a better program.
I had a very hard time finding the right constants for proportional controls so the Create would drive along the wall smoother.

Debugging tools:

The cricket display proved to be helpful in verifying the sensors values used in the program. The cricket display also allowed me to see the values the external sensor was reading while the Create was running the line following program. Beeps and different LEDs were also very helpful in helping me note if the Create was detecting something or was in a certain loop it should be in.

Last thoughts:

Overall, the wall following was quite a successful lab for me; although, it could’ve been better if I could’ve incorporated the P.I.D control to make Create follow the wall more smoothly.