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Auto-steering
EHPS Type 2 Automatic Steering System Diagram
Curvature command
Q
Steering
cylinder
EHPS Valve
OSP
PVE
Steering angle sensor
Position sensor
Vehicle speed
Steering
cylinder
EHPS valve
OSP
PVE
Q
Guidance Commands
To facilitate the implementation of the PVED-CL for auto-steering or guidance, it is designed to use
ISO11783 auto-guide messages. This means the PVED-CL can easily be integrated with any GPS, row-
guide, or similar controller sending ISOBUS specific curvature commands.
Calculating the Wheel Angle
The messages GuidanceSystemCommand and GuidanceMachineStatus are defined in the
PVED-CL
Communication Protocol Technical Information
, 11079551.
To position the wheels or the articulation angle correctly some vehicle geometry information is needed.
The parameter values are used by the control algorithm to calculating from Curvature into wheel set-
point (and from wheel set-point to Curvature for generating estimated curvature. The parameters and
shown in the parameter table below.
Other parameters mentioned in this chapter can be used with default values and should only be adjusted
if the performance needs fine-tuning.
Symbol
Index
Default
Value range
MaxWheelAngleLeft
65099
35 000
Maximum wheel angle to the left [mdeg].
Measured on the wheel where the wheel angle sensor is mounted.
MaxWheelAngleRight
65100
35 000
Maximum wheel angle to the right [mdeg].
Measured on the wheel where the wheel angle sensor is mounted.
VehicleLength
65112
4000
Wheelbase from front to rear axle in mm. Articulated vehicle: Distance from front
axle to joint.
ValveType
65121
1
1 means EHPS or PVB, 2 means EH.
SteeringType
65122
1
1 means front wheel steering, 2 means rear wheel steering, 3 means articulated
steering
VehicleLength2
(Only articulated)
65123
4000
Only used for articulated vehicles.
Length from joint to rear axle.
Closing the Loop
Kp
Port flow
limiter
Sse, Sts0, Sts1,
Sts2, Sts3, Sts4,
Sts5, Vesm
Yact -
Actuator
position
Ve Vehicle speed
Q - Port flow
command
20 ms
P005 208E
X
ext
Set-point
20 ms
Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Auto-steering
94 |
©
Danfoss | May 2016
11025583 | AQ00000216en-US0302