Master Thesis - Hochschule Bonn-Rhein-Sieg

5. Algorithms Master Thesis Björn Ostermann page 99 of 126
yes
Start of Algorithm
End = last Pixel
Start = first Pixel
Start =
End?
no
Line = line from
Start to End
Start = Start+1
End of Algorithm
no
End = Start of Line
yes
Start =
above Line?
no
Start =
End?
Store (Line)
yes
Figure 72: Flowchart for the “shortest Line” algorithm
The final path, starting at the robot’s current position, is the combination of this position and of all
stored endpoints of the lines, beginning with the endpoint of the latest line that has been stored.
This first endpoint is transmitted as an intermediary goal point to the robot controlling task (see
chapter 4.4). The remaining points need not be transmitted, since the path is continuously recalculated.
If no changes of the intruding dynamic objects occur in the workplace while the robot is moving, the
next point in line will be transmitted when the first intermediary point is reached. If changes occur the
respective new intermediary goal point is transmitted.
As described in chapter 4.4.1 the robot can not approach every position as exactly as its sensors can
measure the robot’s current position. Thus to avoid problems in the path execution, a goal point is not
transmitted if it is within 3 cm of the current position of the robot’s tool centre point. In this case the
first goal position is transmitted that is father away than 3 cm.