L_MC4P_DynamicParIdent

FB L_MC4P_ DynamicParIdent can be used to determine the dynamic parameters of an axes group that are required for a torque feedforward control ( L_MC4P_GroupTorquePreControl ). This involves assigning an internally calculated identification trajectory (path curve) to the axes group and identifying the parameters during this motion.

The function block currently supports the following axes groups:

Delta3_3dof

Delta3_4dof

For basics and further information, see:

Torque feedforward control for reducing following errors

Parameter identification with FB L_MC4P_DynamicParIdent

Note!

The quality of the identified parameters must be ensured after every identification run by using block L_MC4P_GroupTorquePreControl with the setting lrTorqueOverride = 0 to compare alrSetTorque-Out and alrActTorque ! Checking results with a torque comparison

		L_MC4P_DynamicParIdent
AXES_GROUP_KIN	-	AxesGroup	xDone	-	BOOL
BOOL	-	xExecute	xBusy	-	BOOL
L_MC4P_DynamicPar	-	itfDynamicParMin	xActive	-	BOOL
L_MC4P_DynamicPar	-	itfDynamicParMax	xError	-	BOOL
BOOL	-	xUseAxesLimits	eErrorID	-	L_IE1P_Error
ARRAY[1..6] OF LREAL	-	alrMinPos	xCommandAborted	-	BOOL
ARRAY[1..6] OF LREAL	-	alrMaxPos	lrConvergence	-	LREAL
ARRAY[1..6] OF LREAL	-	alrMaxVel
ARRAY[1..6] OF LREAL	-	alrMaxAcc

Inputs

Name Data type	Information/possible settings
AxesGroup AXES_GROUP_KIN	axes group reference
xExecute BOOL	FALSE ä TRUE	Start identification.
TRUE ä FALSE	Reset FB. The identified values can no longer be read out from a PreControl FB via the iftDynamicPar interface.
itfDynamicParMin L_MC4P_DynamicPar	Optional lower limits for the parameters to be identified. L_MK4P_DynamicParDelta3_3dof L_MK4P_DynamicParDelta3_4dof L_MK4P_DynamicParScara_3dof L_MK4P_DynamicParScara_4dof UseCase 1: If different parameter settings are made for alrGraviationVector in itfDynamicParMin and itfDynamicParMax , an error results. UseCase 2: No parameterisation of alrGraviationVector in itfDynamicParMin and itfDynamicParMax , since no interface FBs are connected. The Gravitation y and Gravitation z parameters are read out from the axes group instead.
itfDynamicParMax L_MC4P_DynamicPar	The optional upper limits for the parameters to be identified. L_MK4P_DynamicParDelta3_3dof L_MK4P_DynamicParDelta3_4dof Note: If the parameter limits in itfDynamicParMin and itfDynamicParMax are set the same for individual parameters, these are not varied during identification. This option can be used if certain variables are already known with sufficient accuracy from other measurements.
xUseAxesLimits BOOL	TRUE	Axes parameters ( Standard values of the axes and Software limit positions ) are used as limit values for the identification trajectory. If these parameters are not set in the axes, an error is output.
FALSE	Inputs alrMinPos , alrMaxPos , alrMaxVel , alrMaxAcc , alrMaxJerk are used as limit values for the identification trajectory.
alrMinPos ARRAY [1..6] OF LREAL	Minimal position of the Cartesian axes (workspace limitation).
alrMaxPos ARRAY [1..6] OF LREAL	Maximum position of the Cartesian axes (workspace limitation).
alrMaxVel ARRAY [1..6] OF LREAL	Maximum velocity of the Cartesian axes.
alrMaxAcc ARRAY [1..6] OF LREAL	Maximum acceleration of the Cartesian axes.

Name

Data type

Information/possible settings

AxesGroup

AXES_GROUP_KIN

axes group reference

xExecute

BOOL

FALSE ä TRUE

Start identification.

TRUE ä FALSE

Reset FB.

The identified values can no longer be read out from a PreControl FB via the iftDynamicPar interface.

itfDynamicParMin

L_MC4P_DynamicPar

Optional lower limits for the parameters to be identified.

L_MK4P_DynamicParDelta3_3dof

L_MK4P_DynamicParDelta3_4dof

L_MK4P_DynamicParScara_3dof

L_MK4P_DynamicParScara_4dof

UseCase 1: If different parameter settings are made for alrGraviationVector in itfDynamicParMin and itfDynamicParMax , an error results.

UseCase 2: No parameterisation of alrGraviationVector in itfDynamicParMin and itfDynamicParMax , since no interface FBs are connected. The Gravitation y and Gravitation z parameters are read out from the axes group instead.

itfDynamicParMax

L_MC4P_DynamicPar

The optional upper limits for the parameters to be identified.

L_MK4P_DynamicParDelta3_3dof

L_MK4P_DynamicParDelta3_4dof

Note: If the parameter limits in itfDynamicParMin and itfDynamicParMax are set the same for individual parameters, these are not varied during identification. This option can be used if certain variables are already known with sufficient accuracy from other measurements.

xUseAxesLimits

BOOL

TRUE

Axes parameters ( Standard values of the axes and Software limit positions ) are used as limit values for the identification trajectory.

If these parameters are not set in the axes, an error is output.

FALSE

Inputs alrMinPos , alrMaxPos , alrMaxVel , alrMaxAcc , alrMaxJerk are used as limit values for the identification trajectory.

alrMinPos

ARRAY [1..6] OF LREAL

Minimal position of the Cartesian axes (workspace limitation).

alrMaxPos

ARRAY [1..6] OF LREAL

Maximum position of the Cartesian axes (workspace limitation).

alrMaxVel

ARRAY [1..6] OF LREAL

Maximum velocity of the Cartesian axes.

alrMaxAcc

ARRAY [1..6] OF LREAL

Maximum acceleration of the Cartesian axes.

Outputs

Name Data type	Value/meaning
xDone BOOL	TRUE	The identification process has been successfully completed. Internal plausibility tests on the identified parameters were also successful.
xBusy BOOL	TRUE	Processing is running.
xActive BOOL	TRUE	The FB assigns the identification trajectory to the axes group.
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.
xCommandAborted BOOL	TRUE	Identification cancelled
lrConvergence LREAL	Quality criterion for the convergence of the identified parameters. The output assumes values between 0 ... 1. This corresponds to a quality of 0...100%. Good identification should have values > 75%.

Interconnection example