Adaptive Grasping

Compliant Grasping

GripCompExt

Primitive Description and Usage

• Description: This primitive drives grippers to perform compliant gripping motions while limiting the maximum contact force between the gripper and the object. Gripper fingers close in this primitive to grip objects from outside. When the object is not in the center of two fingertips, the gripper may contact the object with one finger first and push the object toward the other finger. However, this can cause damage to the object if it is fixed. This primitive eliminates this risk by allowing the robot TCP to move compliantly during gripping.

• Example Usage: Use this primitive to grip objects from outside.

Primitive Input Parameters

Input Parameter	Description	Type	Unit	Default Value & Range
gripVel	Gripper closing velocity	DOUBLE	m/s	0.01 ∈ [0.0 … 0.05]
gripWidth	Target grip width	DOUBLE	m	0.0 ∈ [0.0 … 0.1]
gripForce	Target grip force	DOUBLE	N	30.0 ∈ [0.0 … 50.0]
compAxis	Compliant axis of TCP coordinate during gripping	TYPE	none	Y ∈ [X Y Z XY XZ YZ XYZ]

Primitive State Parameters

State Parameter	Description	Type	Unit
terminated	The termination flag of the primitive. It is set to true if the primitive is terminated.	BOOL	none
timePeriod	The time spent on running the current primitive.	DOUBLE	s
curGripWidth	Current grip width. This variable is only valid when the time period of this primitive exceeds 0.1s.	DOUBLE	m
reachGripForce	Flag to indicate if the gripper reached the target grip force. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
reachGripWidth	Flag to indicate if the gripper reached the target grip width. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
isGripMoving	Flag to indicate if gripper fingers are still moving. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
graspComplete	Flag to indicate if the grasping action is complete	BOOL	none

Primitive Output Parameters

Output Parameter	Description	Type	Unit
tcpPoseOut	The TCP pose when the primitive is terminated. It is represented in the world coordinate system.	COORD	m-deg

Default Transition Condition

State Parameter	Condition	Value
graspComplete	=	1

GripCompInt

Primitive Description and Usage

• Description: This primitive drives grippers to perform compliant gripping motions while limiting the maximum contact force between the gripper and the object. Gripper fingers open in this primitive to grip objects from inside. When the object is not in the center of two fingertips, the gripper may contact the object with one finger first and push the object toward the other finger. However, this can cause damage to the object if it is fixed. This primitive eliminates this risk by allowing the robot TCP to move compliantly during gripping.

• Example Usage: Use this primitive to grip objects from inside.

Primitive Input Parameters

Input Parameter	Description	Type	Unit	Default Value & Range
gripVel	Gripper opening velocity	DOUBLE	m/s	0.01 ∈ [0.0 … 0.05]
gripWidth	Target grip width	DOUBLE	m	0.1 ∈ [0.0 … 0.1]
gripForce	Target grip force	DOUBLE	N	30.0 ∈ [0.0 … 50.0]
compAxis	Compliant axis of TCP coordinate during gripping	TYPE	none	Y ∈ [X Y Z XY XZ YZ XYZ]

Primitive State Parameters

State Parameter	Description	Type	Unit
terminated	The termination flag of the primitive. It is set to true if the primitive is terminated.	BOOL	none
timePeriod	The time spent on running the current primitive.	DOUBLE	s
curGripWidth	Current grip width. This variable is only valid when the time period of this primitive exceeds 0.1s.	DOUBLE	m
reachGripForce	Flag to indicate if the gripper reached the target grip force. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
reachGripWidth	Flag to indicate if the gripper reached the target grip width. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
isGripMoving	Flag to indicate if gripper fingers are still moving. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
graspComplete	Flag to indicate if the grasping action is complete	BOOL	none

Primitive Output Parameters

Output Parameter	Description	Type	Unit
tcpPoseOut	The TCP pose when the primitive is terminated. It is represented in the world coordinate system.	COORD	m-deg

Default Transition Condition

State Parameter	Condition	Value
graspComplete	=	1

Contact Grasping

GripContactExt

Primitive Description and Usage

• Description: This primitive is designed to grip small/thin objects on flat surfaces. The gripper contacts the surface first and keeps maintaining the contact while closing the fingers. Users can specify the contact force in primitive parameters. Gripper fingers close in this primitive to grip objects from outside.

• Example Usage: Use this primitive to grip small/thin objects on flat surfaces from outside.

Primitive Input Parameters

Input Parameter	Description	Type	Unit	Default Value & Range
gripVel	Gripper closing velocity	DOUBLE	m/s	0.01 ∈ [0.0 … 0.05]
gripWidth	Target grip width	DOUBLE	m	0.0 ∈ [0.0 … 0.1]
gripForce	Target grip force	DOUBLE	N	30.0 ∈ [0.0 … 50.0]
contactAxis	Approaching direction toward the contact surface in TCP coordinate system	TYPE	none	Z ∈ [X -X Y -Y Z -Z]
contactForce	Target force in the approaching direction after engaging the contact	DOUBLE	N	5 ∈ [1.0 … 6.0]

Primitive State Parameters

State Parameter	Description	Type	Unit
terminated	The termination flag of the primitive. It is set to true if the primitive is terminated.	BOOL	none
timePeriod	The time spent on running the current primitive.	DOUBLE	s
curGripWidth	Current grip width. This variable is only valid when the time period of this primitive exceeds 0.1s.	DOUBLE	m
reachGripWidth	Flag to indicate if the gripper reached the target grip width. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
reachGripForce	Flag to indicate if the gripper reached the target grip force. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
isGripMoving	Flag to indicate if gripper fingers are still moving. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
graspComplete	Flag to indicate if the grasping action is complete	BOOL	none

Primitive Output Parameters

Output Parameter	Description	Type	Unit
tcpPoseOut	The TCP pose when the primitive is terminated. It is represented in the world coordinate system.	COORD	m-deg

Default Transition Condition

State Parameter	Condition	Value
graspComplete	=	1

GripContactInt

Primitive Description and Usage

• Description: This primitive is designed to grip small/thin objects on flat surfaces. The gripper contacts the surface first and keeps maintaining the contact while opening the fingers. Users can specify the contact force in primitive parameters. Gripper fingers open in this primitive to grip objects from inside.

• Example Usage: Use this primitive to grip small/thin objects on flat surfaces from inside.

Primitive Input Parameters

Input Parameter	Description	Type	Unit	Default Value & Range
gripVel	Gripper opening velocity	DOUBLE	m/s	0.01 ∈ [0.0 … 0.05]
gripWidth	Target grip width	DOUBLE	m	0.1 ∈ [0.0 … 0.1]
gripForce	Target grip force	DOUBLE	N	30.0 ∈ [0.0 … 50.0]
contactAxis	Approaching direction toward the contact surface in TCP coordinate	TYPE	none	Z ∈ [X -X Y -Y Z -Z]
contactForce	Target force in the approaching direction after engaging the contact	DOUBLE	N	5 ∈ [1.0 … 6.0]

Primitive State Parameters

State Parameter	Description	Type	Unit
terminated	The termination flag of the primitive. It is set to true if the primitive is terminated.	BOOL	none
timePeriod	The time spent on running the current primitive.	DOUBLE	s
curGripWidth	Current grip width. This variable is only valid when the time period of this primitive exceeds 0.1s.	DOUBLE	m
reachGripWidth	Flag to indicate if the gripper reached the target grip width. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
reachGripForce	Flag to indicate if the robot reached the target grip force. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
isGripMoving	Flag to indicate if gripper fingers are still moving. This variable is only valid when the time period of this primitive exceeds 0.1s.	BOOL	none
graspComplete	Flag to indicate if the grasping action is complete	BOOL	none

Primitive Output Parameters

Output Parameter	Description	Type	Unit
tcpPoseOut	The TCP pose when the primitive is terminated. It is represented in the world coordinate system.	COORD	m-deg

Default Transition Condition

State Parameter	Condition	Value
graspComplete	=	1