This is the problem, I need to solve it using a ladder diagram:
Write a table of inputs and outputs and propose a control solution for
a screw sorting and packing process. The process starts
by pressing the START key and can be stopped at any time by pressing
the STOP key. While the system is working, the green lamp must be on, otherwise
the red lamp must be on.
Screws of three different lengths һ1, һ2 and 3 move on a conveyor belt driven by
motor M1, according to which they are to be sorted. Three sensors B1, B2 and B3 are
placed at the end of the tape, which determine the length of each of the screws passing by
them. The tape can only move if the three boxes in which the screws are packed are in
the correct positions, which is detected by sensors B4, B5 and B6.
From the tape, the screws fall into a channel that directs them into the
corresponding box. The position of this channel depends on which box the screw next to sort
should go into, and is determined by the piston D. Its positioning for the boxes K1, K2 and
KZ is done using the detection sensors on the piston itself do, d1 and d2.
The smallest screws go into the K3 box (which should be filled with 500 pieces),
the medium ones go into the K2 box (which should be filled with 300 pieces), and the largest
into the K1 box (which should be filled with 200 pieces). As soon as one of the boxes is full,
one of the pistons A, B or s extends to transfer the full box to the corresponding auxiliary belt
(these belts are in motion all the time). After this transfer, the corresponding piston is withdrawn
and a new empty box is placed in the following way: one of the pistons E, F or G lowers
the stack of empty boxes, after which one of the pistons H, I or J is withdrawn and places the
last empty box from the warehouse at position B4, B5 or B6. After the completion of this
positioning, all previously mentioned pistons are retracted to their initial positions. The main belt
should continue to operate during transfer and repositioning, until it is the turn of a screw for
which there is no free box to be sorted and packed.
On the auxiliary tapes there are scales T1, T2 and T3 which measure the weight of each
of the boxes and give the result in milligrams in analog form at the inputs IW10, IW20 and IW30
respectively. The weight of the screws is 0.75g, 1.25g and 2g respectively, and the weight of the
empty boxes is 15%. An alarm should be raised and the process stopped if for any of the three
types of boxes three times in a row it is detected that there is a shortage or an excess of more than
two screws.
All pistons consist of two actuators (X_F, X_B) and two sensors (SX_F, SX_B)
for detection of full retraction and extension, except for piston D which is a
three-position piston - it has three actuators D1, D2 and D3 as in the image.
The reaction time of D when changing an order from the PLU is half a
second, and the norm that the entire plant must meet is 25,000 screws per day. If at
any time it becomes clear that the plant cannot operate within these limits, the red
light should flash (but not stop the process).
If someone can help me, thanks a lot!
Write a table of inputs and outputs and propose a control solution for
a screw sorting and packing process. The process starts
by pressing the START key and can be stopped at any time by pressing
the STOP key. While the system is working, the green lamp must be on, otherwise
the red lamp must be on.
Screws of three different lengths һ1, һ2 and 3 move on a conveyor belt driven by
motor M1, according to which they are to be sorted. Three sensors B1, B2 and B3 are
placed at the end of the tape, which determine the length of each of the screws passing by
them. The tape can only move if the three boxes in which the screws are packed are in
the correct positions, which is detected by sensors B4, B5 and B6.
From the tape, the screws fall into a channel that directs them into the
corresponding box. The position of this channel depends on which box the screw next to sort
should go into, and is determined by the piston D. Its positioning for the boxes K1, K2 and
KZ is done using the detection sensors on the piston itself do, d1 and d2.
The smallest screws go into the K3 box (which should be filled with 500 pieces),
the medium ones go into the K2 box (which should be filled with 300 pieces), and the largest
into the K1 box (which should be filled with 200 pieces). As soon as one of the boxes is full,
one of the pistons A, B or s extends to transfer the full box to the corresponding auxiliary belt
(these belts are in motion all the time). After this transfer, the corresponding piston is withdrawn
and a new empty box is placed in the following way: one of the pistons E, F or G lowers
the stack of empty boxes, after which one of the pistons H, I or J is withdrawn and places the
last empty box from the warehouse at position B4, B5 or B6. After the completion of this
positioning, all previously mentioned pistons are retracted to their initial positions. The main belt
should continue to operate during transfer and repositioning, until it is the turn of a screw for
which there is no free box to be sorted and packed.
On the auxiliary tapes there are scales T1, T2 and T3 which measure the weight of each
of the boxes and give the result in milligrams in analog form at the inputs IW10, IW20 and IW30
respectively. The weight of the screws is 0.75g, 1.25g and 2g respectively, and the weight of the
empty boxes is 15%. An alarm should be raised and the process stopped if for any of the three
types of boxes three times in a row it is detected that there is a shortage or an excess of more than
two screws.
All pistons consist of two actuators (X_F, X_B) and two sensors (SX_F, SX_B)
for detection of full retraction and extension, except for piston D which is a
three-position piston - it has three actuators D1, D2 and D3 as in the image.
The reaction time of D when changing an order from the PLU is half a
second, and the norm that the entire plant must meet is 25,000 screws per day. If at
any time it becomes clear that the plant cannot operate within these limits, the red
light should flash (but not stop the process).
If someone can help me, thanks a lot!
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