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+---- Thread: 2003-Aspect Sequence Chart (/showthread.php?tid=236)
2003-Aspect Sequence Chart - sugavanam nagarajan - 04-06-2009
I have attempted aspect sequence chart for another layout(2003), Please review.
-Sugavanam
RE: 2003-Aspect Sequence Chart - Peter - 07-06-2009
(04-06-2009, 10:37 AM)sugavanam nagarajan Wrote: I have attempted aspect sequence chart for another layout(2003), Please review.
-Sugavanam
I've had a look at this assuming that the area you have produced this for is what was asked for on the paper as I have left the relevant written part of the question paper in the office!
Another fairly good attempt. One important area of concern and two little areas.
The minor areas first:
137 shows R, Y and G+pos4 - the JI on the green was missed as was the fact that the Y goes up to the buffer (a valid exit signal in the sequence) and although there is no "aspect" for G+pos4 to read up to, you woudl do well to say that is it only valid for the Quary - a) to show that you know why the Pos 4 is there and b) to show that you would not have a G up to the buffer.
You have not shown anything for the "tunnel" controls on 115.
The main area where you had a problem was with the G on 107. Your note indicates that you thought about this but I am guessing that you could not quite make sense of it. You have noticed the Del Y in the route boxes for 109 and 113. That is not the end of the story. The route box says that each signal can show two proceed aspects - Del Y and G. The style used in these route boxes gives this information as "Del Y/G". The Del only applies to the Y. Why is this important? Well, look at the approach control condition for these two signals. For 109 "Del Y AL". Try to think what it means. Why have they included the Del Y in the approach control column? Bearing in mind that the route box for 107 positively tells you that it can show a G for the A and B routes, if you can figure out why 109 and 113 both have a delayed yellow, you will see that there is a condition for 107 to show a G (and G+pos1) and what has to be shown in 109 (or 113) for this to happen. [Hint how far is it from 109 to 115?]
If you are having trouble working this bit out, come back, but if you have figured it out, have a go at amending your diagram including the sequences for 107 at G and G+pos1 without the need for your *1 note!
General comment - your table was quite clearly laid out. The only thing that was remotely out of place was the Y in 107 for the ROL. Try to keep aspects for the same destinations together.
Well done for a good attempt and I hope to hear from you soon.
Peter
RE: 2003-Aspect Sequence Chart - sugavanam nagarajan - 11-06-2009
Thank you for the comments.The detailed information about Del Y/G was very much useful to understand concept behind it.I was actualy misleaded by the representation in the route box.
-Sugavanam