CS148 Labs
Light Seeking and Obstacle Avoidance Lab
Checkpoint: In lab the week beginning March 11, 1996
Due: In lab the week beginning March 18, 1996
Contest: To be announced.
In this assignment, you will be building a robot that seeks light
(going toward the light and either stopping in front of it or orbiting
it) and also avoids obstacles on its way toward the light. Use the
microswitches to make whiskers, long bump switches, short bump
switches, etc., and an infrared emitter and infrared sensors, to
detect and go around obstacles.
Your robot will be tested in a hallway with obstacles in a series of
progressively more difficult configurations. They will be either in
the fourth floor atrium in a cardboard "hallway" or in a real hallway
on the fourth floor. The light will be the same light in
Vehicles and the obstacles will be bricks covered with white
paper. See the handout for the approximate course configurations.
Notes
- The starting orientation of your robot is arbitrary; it may not be
directly facing the light but it will be within the range -90 to
90 degrees from the direction of the light.
- The diagrams shown in the handout are approximate drawings; the
actual arena will be similar. The light, bricks, "hallways",
etc. are available in the Lego Lab for testing purposes.
Your individual grade will be based on the overall functionality of
your group's robot and on your individual lab report. Your robot
should be able to pass tests 1 - 3 above but test 4 is worth major
extra credit. Speed (within reason) is not an issue.
The Checkpoint
The checkpoint for this lab will be in your lab section the week of
March 11th. By that time, all of the sensors you plan to use should
be built, in place, and well-braced on your robot, and your obstacle
avoidance-ligh seeking strategy should be roughly coded in Rex. You
should use the checkpoint both as a milestone to work toward and as an
opportunity for your group to bounce ideas off of other groups and to
learn from their experiences.
What to hand in?
This assignment should be done in groups. Your group will demo your
robot during your lab sec tion. Please bring your robot with your
program in place on your robot to lab. Also, please elec tronically
hand in your code, including the makem instruction; to do so, type:
handin obstacles filename
You need only hand in one file per group.
However, you should write your own lab report. It should include a
description of the expected behavior of your robot and its resulting
actions in each of the four configurations. What is your strategy for
avoiding walls? For detecting and going around obstacles? How do you
use the sen sors to detect conditions in the world? How did you
integrate obstacle avoidance behavior into your light seeking
behavior? What conditions in the world would cause your scheme to
fail?
The Contest
The grand CS148 Light Seeking-Obstacle Avoidance Contest will be
sometime in March. It is not necessary to participate in the contest,
but we will be awarding extra credit points, fame, and prizes. Your
robots will be tested in the four configurations either in the fourth
floor atrium in a cardboard "hallway" or in a real hallway on the
fourth floor, with prizes based on the most difficult achievable
configuration and on overall robustness.
Have Fun!
Bill Smart