This FB is suitable for the identification of closed-loop control parameters of a motor-load combination, for instance in order to utilise them for feedforward control and to adapt the control loops.

All parameters determined (parameters of the mechanical model equation) refer to the gearbox output end. The parameters are identified whilst the machine is moving. In order to identify the parameters, no special excitation signals and no additional sensors are required.

		L_CT1P_OnlineIdentStiffMechanics
AXIS_REF	-	Axis	xBusy	-	BOOL
BOOL	-	xEnable	xError	-	BOOL
BOOL	-	xReStart	eErrorID	-	L_IE1P_Error
L_CT1P_StartMode	-	eStartMode	xValidAll	-	BOOL
LREAL	-	lrStartInertia	xValidInertia	-	BOOL
LREAL	-	lrStartViscousFriction	xValidViscousFriction	-	BOOL
LREAL	-	lrStartCoulombFriction	xValidCoulombFriction	-	BOOL
LREAL	-	lrStartConstantTorque	xValidConstantTorque	-	BOOL
LREAL	-	lrThresholdValue	lrIdentVelocity	-	LREAL
			lrIdentInertia	-	LREAL
			lrIdentViscousFriction	-	LREAL
			lrIdentCoulombFriction	-	LREAL
			lrIdentConstantTorque	-	LREAL
			lrConvergence	-	LREAL

Inputs

Name Data type	Information/possible settings
Axis AXIS_REF	Transfer of the axis data structure Motion axes (AXIS_REF)
xEnable BOOL	TRUE	Activation of the online identification
xReStart BOOL	FALSE ä TRUE	The parameters identified ( IrIdent... outputs) are set to the starting values set ( IrStart... inputs).
eStartMode L_CT1P_StartMode	Selection of the source for the starting values of the parameters to be identified: AutoInit Setting for the case that no starting values can be specified via the FB inputs, e.g. because no data regarding the path are available. Note: The duration of the identification run may be longer with the StartMode = AutoIdent setting than with StartMode = FBInputs . In particular if the actual moment of inertia is considerably greater than the motor moment of inertia, e.g. factor 5 ... 20. FBInputs The identification run is started with the values preselected via the starting value inputs. StartMode = FBInputs is recommendable if starting values approximately matching the path can be preselected. The starting value and the value for the moment of inertia identified at the end should not deviate from each other by more than factor 2, otherwise the xValid output signal remains FALSE.
lrStartInertia LREAL	Starting value of the mass inertia of the overall system in [kgcm ² ], relating to the gearbox output end.
lrStartViscousFriction LREAL	Starting value of the viscous friction in [Nm(rad/s) ^-1 ], relating to the gearbox output end.
lrStartCoulombFriction LREAL	Starting value of the sliding friction in [Nm], relating to the gearbox output end.
lrStartConstantTorque LREAL	Starting value of the constant torque in [Nm], relating to the gearbox output end. A constant torque can be generated by a hanging load.
lrThresholdValue LREAL	Percentage tolerance for the deviation of the starting values with regard to the associated values identified as condition for the respective xValid .... status outputs The value in percent in each case refers to the value identified at the end of the identification run and is divided symmetrically: Tolerance = +/- (2 * tolerance) ^-1 . Example: The entry lrTresholdValue = 30 % means ± 15 % from the value determined.

Name

Data type

Information/possible settings

Axis

AXIS_REF

Transfer of the axis data structure

Motion axes (AXIS_REF)

xEnable

BOOL

TRUE

Activation of the online identification

xReStart

BOOL

FALSE ä TRUE

The parameters identified ( IrIdent... outputs) are set to the starting values set ( IrStart... inputs).

eStartMode

L_CT1P_StartMode

Selection of the source for the starting values of the parameters to be identified:

AutoInit

Setting for the case that no starting values can be specified via the FB inputs, e.g. because no data regarding the path are available.

Note:

The duration of the identification run may be longer with the StartMode = AutoIdent setting than with StartMode = FBInputs . In particular if the actual moment of inertia is considerably greater than the motor moment of inertia, e.g. factor 5 ... 20.

FBInputs

The identification run is started with the values preselected via the starting value inputs. StartMode = FBInputs is recommendable if starting values approximately matching the path can be preselected.

The starting value and the value for the moment of inertia identified at the end should not deviate from each other by more than factor 2, otherwise the xValid output signal remains FALSE.

lrStartInertia

LREAL

Starting value of the mass inertia of the overall system in [kgcm ² ], relating to the gearbox output end.

lrStartViscousFriction

LREAL

Starting value of the viscous friction in [Nm(rad/s) ^-1 ], relating to the gearbox output end.

lrStartCoulombFriction

LREAL

Starting value of the sliding friction in [Nm], relating to the gearbox output end.

lrStartConstantTorque

LREAL

Starting value of the constant torque in [Nm], relating to the gearbox output end.

A constant torque can be generated by a hanging load.

lrThresholdValue

LREAL

Percentage tolerance for the deviation of the starting values with regard to the associated values identified as condition for the respective xValid .... status outputs

The value in percent in each case refers to the value identified at the end of the identification run and is divided symmetrically:

Tolerance = +/- (2 * tolerance) ^-1 .

Example:

The entry lrTresholdValue = 30 % means ± 15 % from the value determined.

Outputs

Name Data type	Value/meaning
xBusy BOOL	TRUE	Processing is running.
xError BOOL	TRUE	An error has occurred. For details see eErrorID .
eErrorID L_IE1P_Error	If xError = TRUE: Error number for the error that has occurred.
xValidAll BOOL	TRUE	All parameters identified are within the tolerance range specified for the lrThresholdValue input.
xValidInertia BOOL	TRUE	The identified moment of inertia is within the tolerance range defined for the lrThresholdValue input.
xValidViscousFriction BOOL	TRUE	The viscous friction identified is within the tolerance range defined for the lrThresholdValue input.
xValidCoulombFriction BOOL	TRUE	The sliding friction identified is within the tolerance range defined for the lrThresholdValue input.
xValidConstantTorque BOOL	TRUE	The identified constant load torque of the active load is within the tolerance range defined for the lrThresholdValue input.
lrIdentVelocity LREAL	Model-based, i.e. the actual velocity of the axis in [units/s] calculated on the basis of the identified system parameters.
lrIdentInertia LREAL	Identified mass inertia of the overall system in [kgcm ² ], relating to the gearbox output.
lrIdentViscousFriction LREAL	Identified viscous friction in [Nm(rad/s) ^-1 ], relating to the gearbox output
lrIdentCoulombFriction LREAL	Identified static friction in [Nm], relating to the gearbox output
lrIdentConstantTorque LREAL	Identified constant torque in [Nm], relating to the gearbox output A constant torque can be a hanging load.
lrConvergence LREAL	Quality criterion for the convergence of the identified parameters Value range: 0 ... 100 %. 0 %: The values identified are not plausible 100 %: The values identified are converged in a stationary value and remain in this value. The corresponding tolerance is parameterised via lrThresholdValue .

L_CT1P_OnlineIdentStiffMechanics

Inputs

Outputs