motion. Using a video camera with a timing feature, fruit's reactions to these disturbances were

recorded and analyzed.

 Results from these tests indicated that the fruit could swing with a peak-to-peak

magnitudes ranging from 25 cm to 100 cm with cycle times ranging from 0.9 sec to 2.6 sec. The

results of these tests are presented in Figure 7.1 with the shaded region of the plot indicating

the observed fruit motion. Extreme cases of fruit motion which could take place during picking

were noted as the worst case that the robot could encounter. These extreme cases lie along the

sloping line which limits the upper side of the graph's shaded region and is established by

motions of 100 cm peak-to-peak magnitudes at 0.5 HZ and 25 cm peak-to-peak magnitudes at 1.1

HZ. The robot's control algorithms were required to manipulate the robot to be able to track

and pick fruit with any motion. The best case from the picking standpoint would have the

targeted fruit hanging motionless from the branch. Based on the results of this fruit motion test,

the worst cases that the robot would encounter ranged from small magnitudes with small cycle

times (12.5 cm, 1.1 HZ) to large magnitudes with long cycle times (50 cm, 0.5 HZ) (Figure 7.1).



 120-

 100-
 100 3 Fruit Motion

 80 -




 40 -
 40

 20
 0.2 0.4 0.6 0.8 1.0 1.2

 Frequency (HZ)


Figure 7.1. Typical observations of the motion of fruit swinging from the canopy of a tree
 indicating the peak-to-peak magnitude of the fruit for various periods of
 oscillation.