Suggested Valve Auto-Calibration Command Values; Valve Auto-Calibration Quick-Guide; Valve Auto-Calibration Procedure; Parameter Tuning Order - Danfoss pved-cl Operation Manual

Operation Manual
PVED-CL Controller for Electro-Hydraulic Steering, Version 1.38
Installation

Suggested valve auto-calibration command values

Command parameter
XspStartSearch
XspIncrementSize
YactDiffThreshold
TimeOutPeriod

Valve auto-calibration quick-guide

© Danfoss | May 2016
shifted 10 Xsp steps towards neutral compared to the previous Xspr_0, then Xpsr_1000 is shifted 10
Xsp steps as well. This maintains the transfer function slope.
The same procedure is applied to the left dead-band. When both open-loop dead-bands are calculated
and written, the changes are automatically committed to eeprom. The progress through the valve auto-
calibration procedure can be monitored on the CAN bus.
Operating the steering wheel during valve auto-calibration will immediately abort the valve auto-
calibration process. The PVED-CL will remain in calibration mode until power is cycled.
Suggested valve auto-calibration command values
The following table shows the suggested valve auto-calibration command values for the different valve
types. Other settings may be more appropriate. The optimum parameters for a particular vehicle must be
found by experimentation and testing.
EH dynamic
35
5
20
500
Changing TimeOutPeriod will affect the criterion where a flow is detected. Fix the TimeOutPeriod to 500
ms or 1000 ms, and adjust YactDiffThreshold until
a repeatable and robust performance is obtained.

Valve auto-calibration procedure

1. Issue the start valve auto-calibration command from a MMI.
2. Monitor valve auto-calibration status messages. Optionally, enable status set 1 for detailed
monitoring of the analogue wheel angle sensor signal and the spool position set-point
3. Wait for status 'auto-calibration completed'
See StartValveAutoCalibration and AutoCalibrationStatus in PVED-CL Communication Protocol,
11079551.

Parameter tuning order

1. Adjust XspCalibrationOffset. Use 65 as a starting reference.
2. Adjust and test valve auto-calibration command values (PVED-CL calibration mode)
See Suggested valve auto-calibration command values
3. Test and evaluate open-loop steering performance (operation mode)
4. Repeat step (1)2-3 until satisfactory results are obtained.
5. Adjust parameter ClosedLoopXspOffset. Use 65 as a starting reference.
6. Test and evaluate closed-loop steering performance (PVED-CL operation mode)
7. Repeat step 5-6 until satisfactory results are obtained.
The PVED-CL shall be powered-cycled after an auto-calibration before the new dead-band
parameters take effect.
The PVED-CL closed-loop performance can also be evaluated in calibration mode by issuing the
SetFlow command. To evaluate the smallest possible actuator speed, set 'Requested Flow' to ±1 and
apply 'Closed-loop flow-to-spool-position scaling'. See SetFlow in PVED-CL Communication Protocol,
11079551.
EH static OSPEH
50 50
5 5
20 20
500 500
on page 29 for starting values.
11025583 | AQ00000216en-US0302 | 29
EHPS
130
5-10
20-30
500-1000