Kin_Scara3_Z (FB)¶

FUNCTION_BLOCK Kin_Scara3_Z EXTENDS Kin_Coupled

Transformation FB for Scara3 kinematics with an additional Z-axis.

The Selective Compliance Assembly Robot Arm (SCARA) is a special type of industrial robot which resembles to an human arm. A Scara3 system exhibits three axes and three degrees of freedom. However, the motion is still limited to the X-Y-plane.

Machine coordinate system (MCS)
Origin	The intersection of axis 0 and the X-Y-plane.
X	Defined by the direction the first arm points to when the first rotary axis (a0) is at 0°.
Y	The Y axis results automatically from the definitions of the X and Z axis by rotating the X axis by +90° around the Z axis.
( Z )	This FB features an additional linear axis (a3) perpendicular to the X-Y-plane. The Z axis corresponds directly to the positive direction of this additional axis.

The location of the tool coordinate system (TCS) relative to the MCS in zero position:

Tool coordinate system (TCS)
Origin	Relative to MCS: dX = dArmLength1 + dArmLength2 + dArmLength3 dY = 0 dZ = 0
X	Along the X-Axis of the MCS in positive direction
Y	Along the Y-Axis of the MCS in positive direction
Z	Along the Z-Axis of the MCS in positive direction

The system consists of

1. a rotary axis a0 that turns the robot around the Z axis

2. the first joint with length dArmLength1,

3. a second rotary axis a1 that turns the following parts of the robot around the Z axis,

4. the second joint with length dArmLength2,

5. a third rotary axis a2 that turns the following parts of the robot around the Z axis,

6. the third joint with length dArmLength3 and

7. a linear axis (a3) that is orientated in direction of Z.

There are two configurations that can be switched with the input xElbowRight of Kin_Scara3_Z_Config.

The single axes values have the following interpretation:

The zero position of the kinematics can be adjusted by defining constant offsets for the axes. See inputs dOffsetA1, dOffsetA2, dOffsetA3 and dOffsetZ. Changing the offsets affects the location and orientation of the TCS.

Attributes:

sm_kin_libdoc

InOut:

Scope	Name	Type	Comment	Inherited from
Input	itfPosKin	ISMPositionKinematics		Kin_Coupled
	itfOriKin	ISMOrientationKinematics		Kin_Coupled
	dArmLength1	LREAL	Arm length of 1st joint
	dArmLength2	LREAL	Arm length of 2nd joint
	dArmLength3	LREAL	Arm length of 3rd joint
	dOffsetA1	LREAL	Additional offset of axis A1. This offset is subtracted before the forward transformation and added after the inverse transformation.
	dOffsetA2	LREAL	Additional offset of axis A2. This offset is subtracted before the forward transformation and added after the inverse transformation.
	dOffsetA3	LREAL	Additional offset of axis A3. This offset is subtracted before the forward transformation and added after the inverse transformation.
	dOffsetZ	LREAL	Additional offset of axis Z. This offset is subtracted before the forward transformation and added after the inverse transformation.

Properties:

NumAxes, inherited from Kin_Coupled

Methods:

GetAxisMapping2

GetKinematicsName

Initialize

JoinAxes

SplitAxes

ActivateAutomaticRotaryPeriods, inherited from Kin_Coupled

AxesToCartesian, inherited from Kin_Coupled

AxisSettings, inherited from Kin_Coupled

CPConnectible, inherited from Kin_Coupled

CartesianToAxes, inherited from Kin_Coupled

GetAxisMapping, inherited from Kin_Coupled

GetAxisProperties, inherited from Kin_Coupled

GetConfigurationDataSize, inherited from Kin_Coupled

GetDefaultConfigurationData, inherited from Kin_Coupled

GetFlangeOrientationImageTotal, inherited from Kin_Coupled

GetFlangeOrientationImageWithOri, inherited from Kin_Coupled

GetPeriods, inherited from Kin_Coupled

GetPosAndToolKinematics, inherited from Kin_Coupled

IsConfigSingular, inherited from Kin_Coupled

IsInitialized, inherited from Kin_Coupled

IsSingularity, inherited from Kin_Coupled

JoinConfig, inherited from Kin_Coupled

SplitConfig, inherited from Kin_Coupled

Structure: