the region in which a successful pick could be guaranteed, the end-effector was required to

girdle the fruit successfully in seven of seven attempts. Positions at which the rotating lip

pushed the orange away or the orange was caught between the rotating lip and the body of the

picking mechanism were considered unsuccessful attempts. Initially, the fruit was positioned in

the center of the picking mechanism, touching the protective shield of the camera with its

center located on the Z axis of joint 2 of the robot (home position). Thus, the position of the fruit

was defined in terms of the camera coordinate frame with the home position located at x = 0 cm,

y = 0 cm, and z = 10.2 cm. The fruit was then moved out along the Z axis in 1 cm increments until

the mechanism was unable to successfully girdle the orange in all of seven attempts. From this

location, the orange was moved to a location 1 cm up from the home position along the Y axis

and back to a point which was easily picked by the mechanism. Again, the fruit was moved out

from the picking mechanism until it could no longer be picked. As the orange was moved to the

edge of the picking range of the robot, the increments were reduced to one half centimeter. Each

location was noted along with the number successful attempts. This operation was repeated

until the complete region in which the robot could possibly pick fruit was covered.

 The results of the picking envelope tests are graphically presented in Figures 7.3, 7.4,

 and 7.5. In each of the figures, the shaded, circular region represents the fruit positioned

 against the protective shield of the camera and centered vertically in the tube of the picking

 mechanism. The centroid of the fruit in this position was used as the origin of the picking

 envelope. The outer ranges of the orange centroid for a successful pick are represented by the

 bold lines in the figures. The range in which the picking mechanism could pick a fruit whose

 center lay in a vertical plane that intersected the centerline of tube (Z2) is presented in Figure

 7.3. The region in which the orange could be picked if its center point was in a vertical plane 1

 cm to the right or left of the centerline of the tube is shown in Figure 7.4. Similarly, the

 successful picking region in the vertical plane located 2 cm from the centerline is displayed in

Figure 7.5. In these tests, if the center of the orange was more than 2 cm away from the center of