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ENGINEERING TOMORROW
General information
As user comfort receives higher and higher focus along with higher demands for automation and safety, new
technologies are necessary to take on this challenge. The new technologies are using electro-hydraulics, combining
hydraulic power with electronics and computer power.
Electro-hydraulic steering system has the advantages over pure hydraulic steering systems such as the ability to
meet specific functionalities on request.
Increasing demand from OEM s shows a trend for a higher safety-level up t
In order to give this functionality Danfoss has developed the PVED-CLS. The PVED-CLS is based on Danfoss PVE
technology, as used in electro hydraulic proportional valves for decades. PVE modules are used with PVG spool
valves as well as dedicated spool valves for steering applications, OSPE and EHPS as well as the EHI.
The PVED-CLS is designed according to state-of-the-art standards regarding functional safety, including ISO 13849,
EN 16590 (ISO 25119) and IEC 65108. Dedicated safety functions are integrated that offer suitable risk reduction,
when applied in accordance with Danfoss recommendations.
In combination with the OSPE steering unit the PVED-CLS forms a category 3 architecture according to ISO 13849.
Ac
suitable for off road application, for instance with typical agricultural vehicles. Actual required performance level for
any particular vehicle should be determined through appropriate hazard and risk assessment by the OEM.
Important
The OEM is fully responsible for making and document their own hazard and risk assessment and can only use the Danfoss
documentation as input for their own hazard and risk assessment.
For more details on EHPS- and EHI with PVED-CLS, please see the Danfoss document, PVED-CLS Safety Manual.
STEERING INPUT DEVICES
1.1
The PVED-CLS supports ISOBUS 11783 curvature commands (format-option to support GMS message according to
ISO11783-7:2009 or ISO11783-7:2015 by parameter P3326), as well as input from a Danfoss SASA steering wheel
sensor.
ISOBUS curvature commands: Required for Auto-guidance.
SASA Steering wheel position commands: Required for being able to start-up the PVED-CLS, quick steer and
disengagement of Auto-guidance.
AUX steering device; Joystick or mini-steering wheel: Required for being able to use any of the AUX-
functions build into the PVED-CLS.
Both steering inputs (SASA and AUX) devices may exist simultaneously on the CAN bus in a steering system, though
only one of the three available AUX steering devices (open loop- and closed loop joystick, and mini-steering wheel)
can be configured per steering system. For SASA and AUX mini-steering wheel, up to five individual predefined
programs may be configured for quick steering, and made available for operators through the vehicle MMI.
1.2
CAN INTERFACE
Danfoss recommends installation of steering related CAN nodes on a separate CAN bus, in order to avoid excessive
bus load. In some situations, particularly when several status messages are enabled, the PVED-CLS and accompanying
CAN nodes may occupy most of the useful bandwidth of a 250K CAN bus.
Danfoss recommend that installation guidelines from CAN bus standard J1939/15 are followed (unshielded twisted
pair (UTP), etc.)
-road driving.
-CLS combination
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Troubleshooting
