### Challenge: Figure 8 Race

In this challenge you need to successfully surround two small obstacles
placed a distance of D apart, where *50cm < D < 100cm*. You must
completely surround each obstacle at least once without touching it in a
figure-8-like fashion. Your robot must return to within a circle of 30 cm of its
starting position. You may choose your starting position and orientation.

One possible path to complete the challenge

Your programming environment can be either NXT-G, LeJOS, or MS Robotics Studio, but NXT-G is recommended for this assignment.

#### Scoring:

You must be successful in at least 1 of 2 trials and you have 10 minutes to prepare after learning the distance D, as well as 5 additional minutes between trials if necessary.

- bumping into an obstacle: -10
- not surrounding an obstacle: -20
- not finishing in the target circle: -5

The team with the fastest time to complete the challenge properly receives 5 bonus points.

### Results from 9/24/2008:

The obstacles were placed 60 cm apart. No team used gears, all used their "standard" differential drive robot. Two teams used circular paths: one team used two full circles, the other half-circles with "diagonal crossings - very impressive! One team used a "piecewise linear" path but they initially had trouble completing the challenge (they eventually succeeded, though). The other teams used "safer" rectangular paths. One team did not completely finish the challenge, but they came close.

In terms of time, *everyone* beat the instructor's time of 29
seconds! The fastest times were obtained using circular paths. Here are the
results of the timed laps:

TimeScoreTeam A:19 secs100 Team B:22 secs100 Team C:11 secs100 + 5 Team D:?85 Team E:22 secs100

Click here to watch the outcomes of this challenge

**Instructor Sample Movie**