markymark31
Member
Hi Guys,
I'm struggling to get my head round how to do this ?
I have an inclined belt conveyor with a PEC at the top and a PEC at the bottom.
The thinking is to track the totes up the belt conveyor and compare their expected position with their actual position.
If
a) a tote is expected but not at the PEC
or
b) a tote is at the PEC but not expected then I stop the conveyor and signal an alarm as it is probable it has slippped back down the conveyor or jammed somewhere.
Now I can create a DB, use the bottom PEC to insert the tote into the DB, and move this data through the DB with simple clock pulses. It's not a massively long conveyor and doesn't stop / start very often so this should be fine.
What I am struggling with is the logic at the top to compare what I think should be there with what is actually there - can anyone point me in the right direction please ?
For this example lets say that the PEC is effectively at tracking.pos[100].
I think I need to create a "window" with the PEC in the centre, so lets say tracking.pos[95] to tracking.pos[105] the tote is only approx 4 pulses long. Each pulse is therefore approx. 150mm travel.
I think there are two scenarios that I have to deal with :-
1. On the rising edge of the top PEC, look in the window to see if anything is there
but also
2. Look in the window and if something is there I should see the rising edge of the PEC
This is the bit that I am struggling to get my head around.........
Many thanks,
Mark
I'm struggling to get my head round how to do this ?
I have an inclined belt conveyor with a PEC at the top and a PEC at the bottom.
The thinking is to track the totes up the belt conveyor and compare their expected position with their actual position.
If
a) a tote is expected but not at the PEC
or
b) a tote is at the PEC but not expected then I stop the conveyor and signal an alarm as it is probable it has slippped back down the conveyor or jammed somewhere.
Now I can create a DB, use the bottom PEC to insert the tote into the DB, and move this data through the DB with simple clock pulses. It's not a massively long conveyor and doesn't stop / start very often so this should be fine.
What I am struggling with is the logic at the top to compare what I think should be there with what is actually there - can anyone point me in the right direction please ?
For this example lets say that the PEC is effectively at tracking.pos[100].
I think I need to create a "window" with the PEC in the centre, so lets say tracking.pos[95] to tracking.pos[105] the tote is only approx 4 pulses long. Each pulse is therefore approx. 150mm travel.
I think there are two scenarios that I have to deal with :-
1. On the rising edge of the top PEC, look in the window to see if anything is there
but also
2. Look in the window and if something is there I should see the rising edge of the PEC
This is the bit that I am struggling to get my head around.........
Many thanks,
Mark