|Field Trials were concluded on April 27 under cloudy skies and widely scattered showers. Results: Team 1, 1st place; Team 2, 2nd Place; Team 3, 3rd place. All teams qualified and ran the unpublished course.|
The Computer Science Embedded & Real-Time Systems course will hold field trials demonstrating this year's class project: autonomous GPS navigation for a computer controlled vehicle. Anyone interested in observing the trials, learning about the vehicle, or the subject of embedded systems is invited to attend and encouraged to talk to the participants. This document describes the trials and what you can expect to see.
The vehicle's sensory array includes a Global Positioning System (GPS)
sensor which acquires lattitude-logitude readings at regular intervals.
The navigation system uses this information together with a pre-loaded course of
waypoints (GPS coordinate and target radius) to guide steering and speed.
A good solution will ``plan ahead'' to negotiate turns and other maneuvers in an economical way. Each of three project teams will first demonstrate their navigation solutions on a course published in advance of the trial. These trial runs last approximately fifteen minutes.
If their system passes that test, the team qualifies to run a ``blind'' course, disclosed at the time of the trial. These trial runs last approximately twenty minutes.
Evaluation criteria include:
Benchmark Trial. The first trial provides a performance benchmark, using a very basic navigation program. You will see the vehicle moving through the course, possibly missing target points or circling around trying to hit one.
First Trials. Each of three student groups will perform a trial on a pre-published course. The trials last 10-15 minutes each, including time change personnel, hook up computers, and clear the test field. A team of Scorers will keep a score sheet for each trial.
Second Trials. Those groups who pass the First Trial will test their navigation software again on a more advanced, un-published course that they will be given at the start of the trial. These trials will 15-20 minutes each
Retries. After the two rounds of trials, groups who may wish to make a second attempt at either course, will do so.
The E&RT laboratory is a golf car modified for computer control. The initial instructional implementation was developed by members of the Computer Science Department's Faculty and Technical Staff. As they are learning learning embedded-system concepts and design methods, E&RT students are assigned to solve guidance problems such as GPS navigation and obstacle avoidence.
As higher functionality develops over time, the E&RT lab vehicle is targetted for future research in two primary areas:
The Global Positioning System is an array of low-orbit satellites
broadcasting positioning information world-wide. A GPS sensor is
a device that calculates its lattitude, longitude, and altitude
by ``triangulating'' signals from some of these satellites.
A course is a list of GPS waypoints, containing a target postion, and an accuracy radius (how close is close enough). The navigation problem is to steer the vehicle through these waypoints in the order given by the course.
The vehicle Navigator is a program that samples the GPS
sensor at regular intervals and adjusts the vehicle's heading
and speed to guide it through the waypoints.
The Navigator must contend with several issues, including:
|A trial scores more highly if the vehicle is visibly exhibiting path-planning behavior. Ideally, the vehicle will remain inside a corridor determined by connecting the specified waypoint accuracy radii. However, in a complex maneuver, this may not be possible.|