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Block diagram oped loop steering wheel steering
P005 206E
Ve - Vehicle
speed
Qm,Lx
10 ms
100 ms
Ramp
function
Steering
sensitivity
Sse , Sts0, Sts1, Sts2,Sts3, Sts4, Sts5, Vesm, StrkVol, Vcap
Ve
Vehicle speed
100 ms
10 ms
Yact
Actuator position
Transfer
function
Sr, Lr, Tro, Tfo, Lf,
Trh, Tfh, YsetFr, Tfr,
TAbortDownRamp,
Tra, Verm
X_stw
Steering
wheel
angle
10 ms
Backlash
Ri
10 ms
Steering
wheel
angle/dt
Yact
Actuator
position
Q
Port flow
command
Soft
stop
Cf, Off
Yr, Yl
10 ms
Select the Control Principle
Cp is used to select Open loop control for steering wheel steering by setting parameter index 1y02 equal
to 0. Parameter selection values: Y selects the program and ranges from 0 and 9.
Apply Backlash
Ri If elasticity affects the sensor readings when the driver releases the steering wheel and hereby
unintentionally operates the valve, a backlash region (Ri) can be applied to prevent it. The size of the
backlash region is normally set equal to the angle related to elasticity.
However, any set-value greater than zero leads to slower steering responds. Therefore, to minimize these
effects, the steering wheel, sensor shaft and underlying mechanics as shown below must be designed as
stiff as possible.
Since this parameter only effects changes in the set point, stability problems in closed loop are not
related to the set-value of this parameter.
The default value does not remove elasticity effects.
Sensor
Steering wheel
Symbol
Index
Default
Value range
Ri
1y04
0 to 5
0 to 200
0 means 0 degrees backlash, 200 means ~17 degrees backlash. Backlash applies in both steering directions; therefore the total backlash region is twice
the threshold.
Set-point Transfer Function
The transfer function provides two parameters to transform steering wheel positional information to port
flow. It main function is to create the flow request set-point from the steering wheel sensor.
Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Steering by Steering Wheel – Open Loop
40 |
©
Danfoss | May 2016
11025583 | AQ00000216en-US0302