Danfoss PVED-CLS, User Manual

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© Danfoss | August 2018 AQ00000211 |
121
ENGINEERING TOMORROW
12.3 GPS CONFIG
As a risk mitigation method, disengaging the Auto-guidance-program and return to STW mode (hydraulic steering only)
is possible by activating/turning the steering wheel. When driving off-road, an uneven surface etc. may disengage the
Auto-guidance steering mode. In order to allow small movements of the steering wheel without disengaging the Auto-
guidance steering, appropriate disengage threshold values should be written in P3583 and P3584.
The PVED-CLS detects that the steering wheel is used when both the threshold P3583 and P3584 are being exceeded. In
order to switch to auto-guidance program from STW or AUX program, following conditions shall be satisfied
•
To switch from STW program to auto-guidance program, the steering wheel shall not be in use i.e. the absolute
steering wheel velocity shall be lower than or equal to STW in use – Velocity threshold (P3583).
•
To switch from AUX program to auto-guidance program, if an AUX device is present in the system i.e. P3239
set to 255 AND
-
The AUX steering device is a ‘mini-steering wheel’ i.e. P3240 set to 2 AND absolute value of ‘ AUX
mini-steering wheel velocity’ is less than or equal to the ‘AUX mini-steering in use – Velocity
threshold’ i.e. P3646.
OR
-
The AUX steering device is an ‘open loop joystick’ (P3240 set to 0 - Open Loop Joystick OR P3240
set to 3 - Analogue Joystick OR P3240 set to 20 - Elobau joystick ) AND the absolute value of
‘ Requested AUX joystick flow command’ is lower than ‘ AUX joystick in use – Flow command
threshold ’ i.e. P3647.
OR
-
The AUX steering device is a ‘closed loop joystick’ i.e. P3240 set to 1 AND the absolute value of
‘
AUX steering device related closed loop error’ is lower than ‘ AUX joystick - Max. CL steady
state error threshold ’ i.e. P3730 for at least the time specified by P3731 (AUX joystick - Min time
for CL steady state error threshold) AND closed loop joystick is inactive (see flags in the AUX
messages in PVED-CLS communication protocol).
Important
The same “steering wheel in use”-algorithm is used for AUX-steering programs, hence the same rules are used to perform
a transition to the AUX-program.
P3484 controls a Low-pass filter, which can be applied upon the calculated flow command. If P3484 is set to 0, the filter
is disabled. This filter can be used to dampen machine steering commands for minimizing jerky vehicle movements and
hereby avoid introducing oscillations in the auto-guidance feedback loop.
Important
Setting the filter value too low will slow down the auto-guidance steering performance.
Danfoss recommends not to change the default value of P3484.