Select A Fixed Sensitivity; Vehicle Speed Dependent Sensitivity - Danfoss pved-cl Operation Manual

Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Auto-steering
Symbol Index
Tclpout 517
Qth 518

Select a Fixed Sensitivity

Symbol Index
Sse 5y09
Sts0 5y10

Vehicle Speed Dependent Sensitivity

96 | © Danfoss | May 2016
Default
3000
0
Qth may introduce a control dead-band which may not be desired. Set Qth to 0 for tight closed-loop
control and for maximum precision.
A fixed steering sensitivity is chosen if the valve shall output a flow which is only dependent on the
control error and Kp.
Sse Selects between a fixed steering sensitivity, variable to steering actuator position or vehicle speed.
Set Sse to 1 to select the fixed sensitivity
Sts0 Sets a gradient between steering angle and requested port flow. Sts0 is normally set when max port
flow (defined by Qm) is achieved at maximum steering device input.
The default value is a gradient matching maximum requested port flow to maximum port flow at the
maximum steering angle.
Default
1
1000
Variable steering sensitivity related to vehicle speed is normally used to optimize directional stability
automatically and beyond the notice of the driver. The values and correlation is normally close related to
the present vehicle dynamics of the individual vehicle model. The Sts value is used to amplify the input
signal as described in Set-point Transfer Function
The correlation is defined by seven parameters. All Sts-parameters may be set equal to each other or set
monotonically falling for increasing vehicle speeds. The steering sensitivity between two table
coordinates is found by linear interpolation. The relation is equal for negative speeds.
max Sts = 1000
120
Sts0=105
100
Sts1=90
80
Sts2=75
Sts3=60
60
Sts4=45
40
min Sts = 20
0
100 200 300 400
Ve - Vehicle speed: 1 unit = 0.1 km/h
Sse Selects between a fixed steering sensitivity, variable to steering actuator position or vehicle speed.
Set Sse to 3 to select the sensitivity related to vehicle speed.
Sts0 Sets the linear gradient between steering angle and requested port flow when the vehicle is
standing still. When the vehicle signal unintentionally not is mapped, Sts0 is applied constantly since
variable Ve remains 0.
In case the vehicle signal not is diagnosed, it is recommended to set Sts0 at a value where sufficient
directional stability at maximum vehicle speed is present.
Sts1 Sets the linear gradient between steering angle and requested port flow when the vehicle is driving
at 6.25% of the speed defined by parameter Vesm.
Value range
1 to 30000 (ms)
0 to 100 (0.0 to 10.0 % of max port flow)
Value range
Must be set at 1
0 to 1000 (amplification of 0 to 100 %)
Default Sts0 shall be changed to 1000.
on page 78 .
Vesm=500
Sts saturates
(Ve)
Sts5=30
500 600 700 800 900 1000
11025583 | AQ00000216en-US0302