Magnetic Valves Off Control; Resolving A Steering Control Conflict; Low Priority Steering Device Enable/Disable Control; System Requirements - Danfoss pved-cl Operation Manual

Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Steering by Low Priority Steering Device – Closed Loop

Magnetic Valves OFF Control

Symbol
Magnetic Valves Off Delay Time

Low Priority Steering Device Enable/Disable Control

Symbol
LowPrioritySteeringDeviceInterface
OSP present
92 | © Danfoss | May 2016
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
consumption by the magnetic valve bridge in the PVED must be reduced or to resolve a steering control
conflict between the OSP and the PVED-CL (implementing EHPS type 1 systems only).
The default value disables this functionality i.e. the magnetic valve bridge is enabled at all times. The
magnetic valve bridge is enabled when the PVED-CL receives a non-zero flow request
Index
416

Resolving a Steering Control Conflict

On systems utilizing a PVED-CL, an EHPS valve, an OSP, a CAN or analogue steering device but no
steering wheel angle sensor (SASA) (EHPS type 1), the PVED-CL has no means to detect that the steering
wheel is being activated. A steering conflict between OSP steering and steering device steering is thus
possible. To resolve this conflict, set Tolsout to a value (typically 50 ms – 200 ms) to disable the magnetic
valve bridge when no flow request is being commanded with the steering device.
The PVED functionality allows the user to dynamically enable or disable a steering device during
operation from the cabin MMI (via CAN bus). This functionality enables e.g. an armrest device to be
folded away for easy access to the cabin, while the system operational, to avoid the risk of unintended
device activation when the user enters or leaves the cabin.
Another user scenario is to disable one or more lower priority steering devices when only the steering
wheel device is in use for a longer period of time and the user wishes to eliminate the risk of
unintentional device activation.

System Requirements

The device enable/disable control functionality is only functional if the following conditions are fulfilled.
The system must be in operational state. The device that shall be enabled/disabled is mapped. An OSP for
hydraulic backup exists and the presence of the OSP is configured in the PVED.
Index
65103
65109
If an OSP is not present, the device enable/disable control command is ignored. The OSP shall be present
because it is theoretically possible to electrically disable all steering devices if the primary steering wheel
sensor is not mapped. In this situation only the OSP pilot signals are driving the valve.
C
Caution
The vehicle system integrator shall consider the following to ensure a safe and reliable device enable/
disable functionality. The vehicle velocity shall be included in the decision whether a device disable
request shall be sent to the PVED or not. The location of the enable/disable button shall be well-
considered to avoid unintentional enabling/disabling of a steering device. Unintended enabling/
disabling should be further avoided by requiring the enable/disable button to be pressed for a well-
defined period of time. The OEM shall ensure that a steering device outputs a signal within a valid range
when the device is enabled.

Device Diagnostic Operation

The steering device diagnostic checks are performed both when the device is enabled and disabled.
Default
30 000
Default Value range
0 0 (NONE), 1 (AD1), 2 (AD2), 4 (CAN)
0 0 (NONE), 255 (PRESENT)
Value range
1 to 30 000 (ms)
11025583 | AQ00000216en-US0302