Adaptive Grasping

GraspComp

GraspComp

Description: This primitive controls the gripper to perform compliant grasping motions. The gripper moves along the contact direction to contact the surface of the object and maintains contact with the surface of the object during grasping. This primitive terminates when the grip force or grip force reaches the set value. During the grasping process, the robot keeps moving compliantly to avoid damaging the gripper or the object.
Example Usage: Use this primitive to grasp objects whose position is uncertain.

Input Parameter	Description	Type	Unit	Default Value & Range
gripperType	Type of gripper used by the primitive	TYPE	none	GripperFlexivModbus ∈ [GripperDahuan GripperDahuanModbus Flexiv-GN01 GripperFlexivModbus Robotiq-2F-85 Robotiq-Hand-E]
gripVel	Gripper opening/closing velocity	DOUBLE	m/s	0.01 ∈ [0.001 … 0.05]
gripWidth	Target gripping width	DOUBLE	m	0.0 ∈ [0.0 … 0.1]
gripForce	Target gripping force. When using Grav, you can set gripVel and gripWidth to 0 to enable pure force control mode for the gripper.	DOUBLE	N	30.0 ∈ [-50.0 … 50.0]
contactAxis	Contact (force control) direction in TCP coordinate system, which should be along one of TCP’s principal axes [X, Y, Z]	VEC_3i	none	0 0 0 ∈ [-1 -1 -1 … 1 1 1]
contactForce	Target force along the contact axis after engaging the contact	VEC_3d	N	0.0 0.0 0.0 ∈ [0 0 0 … ]
compAxis	Compliant axis in TCP coordinate system during gripping	VEC_3i	none	0 0 0 ∈ [0 0 0 … 1 1 1]
compForce	Minimum force for robot to move compliantly	VEC_3d	N	0.0 0.0 0.0 ∈ [0 0 0 … ]
maxVelForceDir	Maximum movement velocity along force control direction	DOUBLE	m/s	0.5 ∈ [0.002 … 0.5]

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 gripping width. This variable is only valid when the time period of this primitive exceeds 0.5s.	DOUBLE	m
reachGripForce	Flag to indicate if the gripper reached the target gripping force. This variable is only valid when the time period of this primitive exceeds 0.5s.	BOOL	none
reachGripWidth	Flag to indicate if the gripper reached the target gripping width. This variable is only valid when the time period of this primitive exceeds 0.5s.	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 0.5s.	BOOL	none
gripComplete	Flag to indicate if the grasping action is complete	BOOL	none

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

State Parameter	Condition	Value
graspComplete	=	1