SYSTEM DRILL

3. Animate operational sequences

The DRILL_VIEWL system configuration can be used as shown below to produce static animations of both normal and abnormal operational sequences for the drilling example . Abnormal sequences include blocked and starved operational states and their recovery.

3.1 Normal operation

The sequence shown below is one of many possible normal operational sequences, depending on the relative speed of operation of the various physical components of the system.

1. A workpiece (disc) is fed into the supply transfer bar.	2. The disc is transported to the end of the supply bar.	3. The disc is loaded from the supply bar to the slide.	4. The disc is clamped onto the slide and the supply bar begins to return to its initial position.

5. The clamped disc is transported toward the drill and the drill spindle starts turning.	6. The clamped disc arrives under the drill, which begins moving down.	7. The drill completes its downward motion, making the disc into a ring. Meanwhile a new disc has been loaded to the supply bar.	8. The drill begins retracting. Meanwhile, the supply bar begins to bring in the new disc.

9. Once the drill is clear of the workpiece, the slide begins to remove it.	10. The drill reaches the home position and its spindle turns off. The ring has reached the home position of the slide and is being unclamped. Meanwhile, the supply bar is waiting for its disc to be removed.	11. Once the ring is unclamped, it is unloaded to the takeoff bar.	12. Now the disc can be loaded and the clamping and drilling repeats from #3. Meanwhile, the ring is carried off by the takeoff bar, which will then return after unloading the ring.

[Normal][Blocked][Starved]

3.2 Blocked operation

Blocked operation occurs when a "downstream" physical element fails, causing a backup of workpieces in the "upstream" elements. When the downstream element is restored to service, normal operation of the system should resume smoothly.

1. In this case, normal operation of the takeoff bar has stopped, possibly due to loss of power or a mechanical jam, as indicated by the red dot in its upper left corner. The slide is blocked while waiting for the ring to be taken off, and the supply bar is blocked while waiting for the ring to be removed from the slide.	2. When normal operation of the takeoff bar is restored as indicated by the green dot, the ring is transported to the end.	3. Upon reaching the end of the takeoff bar, it is removed and the takeoff bar begins to return to its home position.	4. When the empty takeoff bar returns to its home position, operation can resume from #11 of the normal case and the blocked condition is ended.

[Normal][Blocked][Starved]

3.3 Starved operation

Starved operation occurs when an "upstream" physical element fails, causing a lack of workpieces in the "downstream" elements. When the upstream element is restored to service, normal operation of the system should resume smoothly.

1. In this case, normal operation of the supply bar has stopped, possibly due to loss of power or a mechanical jam, as indicated by the red dot in its upper left corner. The slide is starved while waiting for a new disc, and the takeoff bar is starved while waiting for a new ring.	2. When normal operation of the supply bar is restored as indicated by the green dot, the disc is transported to the end and operation can resume from #2 of the normal case.

[Normal][Blocked][Starved]