Off This parameter sets the permitted actuation speed when hitting the end lock defined by Yr or Yl.
When the steering actuator passed Yr or Yl, actuation speed will decay to zero.
The default sets a speed that allows building up pressure when the actuator is located at Yr or Yl.
Symbol
Index
Default
Value range
Yr
10y7
1000
-1000 – 1000, Values smaller than 0 will be set equal to the positive equivalent
Yl
10y8
-1000
-1000 – 1000, Values greater than 0 will be set equal to the negative equivalent
Off
1y28
50
0 to 1000 (0.0 - 100.0% of max port flow)
Cf
1y29
333
1 to 1000
See chapters Mapping Steering Signals, Steering Actuator Sensor (feedback from vehicle wheels) and Steering Actuator Position to acquire “steering
actuator position”.
Main Spool Dead-band Control Function
Tolsout maximum time where the main spool is allowed to be operated proportionally within the valve
dead-bands. The main spool control range for this function can be seen on the
on page 50. This function is useful to eliminate frequent spool relocating events from its neutral to its
dead-band position and back (so called jumps) at low steering wheel speeds.
The flow request is 0 while moving the steering wheel within the defined steering wheel backlash range
Dead-band Jump Control
Set Tolsout lower than 21 (ms) to momentarily set the main spool in neutral as soon as the flow request is
0, No proportional main spool movement will take place. The spool will jump from neutral to either of the
valve dead-bands depending on the flow request. The backlash parameter has no impact for these
Tolsout values.
Dead-band Hold and Proportional Control
Setting Tolsout between 21 and 30 000 (ms) defines the maximum time where the main spool is either
set on the valve dead-band or controlled proportionally within the dead-band (granted that the flow
request is 0 during this time).
After a flow request to either left or right port, the main spool will be set on the respective left or right
valve dead-band. Any steering wheel movement within the defined backlash region will result in
proportional main spool movement as a function of the steering wheel movement. Proportional control
will be allowed for Tolsout ms.
If the flow request has been 0 for Tolsout ms, the main spool will be set in neutral and any steering wheel
movements within the backlash range is ignored.
To utilize proportional control, a steering wheel backlash range needs to be created. If the backlash range
is set a low value, the main spool will effectively be operated as dead-band jump control.
Responding to Flow Requests after Tolsout
If the main spool has been set in neutral after Tolsout ms, any flow request will cause the spool to
immediately jump to the relevant spool position with no initial proportional dead-band control.
Symbol
Index
Default
Value range
Tolsout
116
10 000
1 to 30 000 (ms)
Magnetic Valve Control
Magnetic valves off delay time disables the magnetic valve bridge after a time specified in ms when the
flow request is 0, otherwise it remains enabled. This parameter is used when electrical energy
Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Steering by Steering Wheel – Open Loop
50 |
©
Danfoss | May 2016
11025583 | AQ00000216en-US0302