Danfoss PVED-CLS User Manual page 143

ENGINEERING TOMORROW
Init = not ok
Act_WA >
Calib_WA_R?
no
Control loop =
100ms
SpoolSetPoint =
test_cl_db_R
While the calibration algorithm is executed, the calibration tool shall continuously capture TR and TL and
individually evaluate these values against the success criteria. The calibration tool shall individually adjust test_db_R
and test_db_L until the calibration success criteria is met. When success criteria are met the closed-loop dead-band
can directly be derived as follows:
16.5.4.2.5 Open loop dead-band calibration
As illustrated in Table 80, the open loop dead-bands are the previously found closed loop dead-bands, P3166 and
P3168, added or subtracted by the offset value determined by P3170, respectively. After the closed loop dead-band
are found, check if the default (P3170 = 25) satisfies the open-loop dead-band criteria (no output flow when the
spool is positioned in the open-loop dead-band e.g. verify by direct output control-function to test these
parameters. Do it across a small population to gain confidence in the offset). If the wheels are still moving, increase
P3170 by 5 and do the verification again. Repeat until acceptance criteria has been fulfilled.
The open-loop dead-bands are directly derived from the measured closed-loop dead-bands as follows:
P1 from Figure 52
P2 from Figure 52
16.5.4.2.6 Determining TL and TR for a specific vehicle type
When determining the success criteria for a specific vehicle type, the goal is to determine target TR and TL values
through a learning phase that can subsequently be used for multiple vehicles of the same type.
For learning TR and TL for a specific vehicle, the following should be considered:
1. For a given test_db_L/R, observe that the steered wheels move very slowly and continuously.
2. Use the calibration procedure in Figure 54 to determine TR and TL.
PVED-CLS in service
mode?
yes
Wait for new
test_cl_db_R and
test_cl_db_L
Init = ok
yes Act_WA ≥
Calib_WA_R?
SpoolSetPoint =
Capture TR
test_cl_db_L
TR=0
Init = OK
SpoolSetPoint =
test_cl_db_L
test_db_L = test_cl_db_L =
test_db_R = test_cl_db_R =
Spool open-loop dead-band left =
Spool open-loop dead-band right =
no
Evalution &
adjustment
Captured TR and TL
Init = ok Init = ok
Act_WA ≤
SpoolSetPoint =
Calib_WA_L? test_cl_db_L?
yes
Capture TL TR=TR+100ms
TL=0
SpoolSetPoint =
test_cl_db_R
Figure 54
P3166
P3168
Test_cl_db_L + P3170
Test_cl_db_R - P3170
Table 80
PVED-CLS not in
service mode or
power-cycled
no
TR=TR+100ms Stop
P3166 + P3170
P3168 - P3170