1. Final Report Alpha Squad Seven
Members:
Erik Bass
Benjamin Carter
Rahul Kapoor
Steven Koegler
Jared Schlicher
Matthew Werner
Coach:
Alex Hsieh
Date:
3/15/07

2. Software Architecture

3. Camera Controlling used ptzProxy() Creating Image captureframe
undefined jpeg
Headerfile not accessible
cameraproxy
framgrabber
Undefined inbuilt function
Downloaded header; not compiling

4. Point Translation and Boundaries
Use Direction and Robot relative points to find global points
Robot relative points come from the lidar
Robot direction based on Δx and Δy
Global points checked to with boundary conditions
Boundaries are the G.P.S. coordinates of the walls

5. LIDAR Function ID 1 : Object Avoidance
Filters out objects out of the box
Returns y-distance (R) of closest object
Y-dimension is a variable
X-dimension hardcoded at .7 m

6. LIDAR Function ID 2 : Intersection Scans 180 degrees
Translates points of objects detected
Compare with intersection coordinates
Wait/Go

7. Way-point Following The Initial Problem The Solution (Look-Up Table)
The Implementation
The Calibration

8. The Initial Problem
The way-point program initially had problems when the robot was not aligned properly with the first way-points.
Swerve back and forth on the ideal line from one way-point to the next.
However if the robot was aligned properly to the first way-point, the robot could navigate the given seven way-points with some what of a smooth line.

9. The Solution
Create a look up table based on two values the angle and distance to the way-point.
The look up tables angle was incremented in units of fifteen degrees until it reached seventy five degrees.
The distance started at 0.5 m and was incremented by a full meter until the distance reached 4.5 m.
With five distance states and six angle states the table gives a total combination of thirty steering inputs.

10. The Implementation The look-up table was implemented in C++.
Six stacked if-else conditional statements for the angle check.
Nested if-else statement for the distance check.
With in the appropriate if-else statement the steering angle is assigned.

11. The Calibration
First every steering input was set at the maximum steering.
Adjusted the steering for the table by multiplying the maximum steering by a value from zero to one, basically to take a percentage of the maximum steering available depending on the state.
Then entered a guess for each state, through trial and error for way-point following, tuned the steering.
Applied the table to the intersection problem, the lane change problem, and then to object avoidance problem and made adjustments where they were needed.

12. Object Avoidance Use Lidar to scan for object
When object is found check distance
Ignore large distances
If distance too small stop
If distance in between then
If link has 1 lane then stop
If link has 2 lanes then switch lanes

13. Lane Switch Logic Find current lane position
Create line based on opposite lane points
Found using two closest opposite lane points
Once line is found create a new waypoint in the other lane.
Once past the object switch back into original lane.

14. Intersection Problem How to determine if we are at an intersection
How to determine if there is a stop sign for the intersection

15. Reading the Network File
The Intersection Problem is solved by reading the Network File
The Network file contains node and stop sign information
The code reads this information to determine if the robot is at the end of a link
Then the code determines if there is a node at the end of the link the robot is located at
Finally, the code determines if the node contains a stop sign

16. Navigating an Intersection
If stop sign, then stop for set time
During stop use lidar data to determine if an object is within defined intersection
If object is, pause for more time than initial stop
If object is not, proceed after initial pause
If node has no stop sign, continue driving

17. Conclusion Control Issues Point Translation and Boundary Conditions
Driving Control
LiDAR Function
Obstacle Avoidance
Intersection Navigation

18. Questions