Hej there.
I need some input for a new project I got this week.
I am replacing an old Siemens S5 app. that controls a pick and place hoist.
The hoist picks product from a storage area with about 100 places. The storage area look like a spreadsheet i excel. 10 Rows and 10 columns.
y-Distance = 0-10 meter
X-Distance = 0-50 meter
The old system used 3 asyncron motors with encoders controled by VFD, and a "stop" sensor to positioning the hoist (X-,Y-,Z- akse).
The old VFD's is replaced by new ones from Siemens Micromaster 420 or 440 with profibus DP and the S5-PLC is replaced with S7-3152DP.
Encoders is replaced with laser distance measuring sensor from SICK.
My quistion:
What is the best way to positioning the hoist?
1. Err = (SP-PV)
IF Err > xx distance THEN Speed = Max Speed.
IF Err < xx distance THEN Speed = Creep Speed
IF Err = 0 AND Stop Sensor = TRUE THEN Stop hoist
2. I have read this in another thread.
Speed = SQR(SP-PV) * K + Min_Speed
IF Speed > Max_Speed THEN Speed = Max_Speed
3. Other Way
Can I set the RAMP UP/DOWN time like this:
Hoist data X-akse: Max speed = 105 m/min
Max Acc, = 0,4 m/s²
v0 = 0 m/s
v = at + v0 => t = v/a => t = (105/60)/0,4 = 4,4 s.
I Hope some one could give me some input on this.
Thanks
Jesper.
I need some input for a new project I got this week.
I am replacing an old Siemens S5 app. that controls a pick and place hoist.
The hoist picks product from a storage area with about 100 places. The storage area look like a spreadsheet i excel. 10 Rows and 10 columns.
y-Distance = 0-10 meter
X-Distance = 0-50 meter
The old system used 3 asyncron motors with encoders controled by VFD, and a "stop" sensor to positioning the hoist (X-,Y-,Z- akse).
The old VFD's is replaced by new ones from Siemens Micromaster 420 or 440 with profibus DP and the S5-PLC is replaced with S7-3152DP.
Encoders is replaced with laser distance measuring sensor from SICK.
My quistion:
What is the best way to positioning the hoist?
1. Err = (SP-PV)
IF Err > xx distance THEN Speed = Max Speed.
IF Err < xx distance THEN Speed = Creep Speed
IF Err = 0 AND Stop Sensor = TRUE THEN Stop hoist
2. I have read this in another thread.
Speed = SQR(SP-PV) * K + Min_Speed
IF Speed > Max_Speed THEN Speed = Max_Speed
3. Other Way
Can I set the RAMP UP/DOWN time like this:
Hoist data X-akse: Max speed = 105 m/min
Max Acc, = 0,4 m/s²
v0 = 0 m/s
v = at + v0 => t = v/a => t = (105/60)/0,4 = 4,4 s.
I Hope some one could give me some input on this.
Thanks
Jesper.