Basic Force Control

ZeroFTSensor

Primitive Description and Usage

• Description: This primitive is used to reset the Cartesian force/torque offset to zero. It is usually used before force control primitives. This primitive can be used for all Flexiv robots, including those with a 6DoF sensor. The robot should be static enough (i.e. the previous primitive cannot trigger extremely aggressive motions) when entering this primitive. During the calibration, the robot should neither be touched nor contact with the environment.

• Example Usage: Use this primitive to reset the Cartesian force/torque offset (to zero) before polishing or contacts.

Primitive Input Parameters

Input Parameter	Description	Type	Unit	Default Value & Range
dataCollectTime	The amount of time used to collect force/torque offset prior to resetting the FT sensor	DOUBLE	s	0.2 ∈ [0.1 … 1.0]
enableStaticCheck	Enable checking if the robot is static or not	BOOL	none	0 ∈ [0 / 1]
calibExtraPayload	Flag to indicate whether the extra payload is accounted for in the end-of-arm tool payload during force/torque calibration	BOOL	none	0 ∈ [0 / 1]

Primitive State Parameters

State Parameter	Description	Type	Unit
terminated	Flag to indicate whether the primitive is terminated. It is set to TRUE if the primitive is terminated.	BOOL	none
timePeriod	The time spent on running the current primitive.	DOUBLE	s

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
terminated	=	1

Contact

Primitive Description and Usage

• Description: This primitive maintains force control and moves the robot in a predefined direction with a set force until it contacts with the environment. The robot stops immediately when its contact force with the object reaches the set max contact force value. Primitive [ZeroFTSensor] should always be used before executing this primitive.

• Example Usage: Use this primitive when the robot performs tasks that require contact with the environment. For example, use this primitive to make robot’s tool contact with the parts before performing polishing or peg-in-hole tasks.

Primitive Input Parameters

Input Parameter	Description	Type	Unit	Default Value & Range
contactCoord	Reference coordinate system for the contact direction	TYPE	none	world ∈ [world tcp general]
generalContactCoord	If the parameter [contactCoord] is set to “general”, this parameter will be used as the reference coordinate system for the contact direction	COORD	m-deg	0 0 0 0 0 0 WORLD WORLD_ORIGIN ∈ [traj_start* traj_prev* world*]
contactDir	Approaching direction toward the contact surface in the contact coordinate system	VEC_3d	none	0.0 0.0 -1.0
contactVel	TCP linear velocity while moving to contact	DOUBLE	m/s	0.02 ∈ [0.001 … 0.1]
maxContactForce	Maximum contact force. The primitive will be terminated when external force exceeds this limit.	DOUBLE	N	5.0 ∈ [1.0 … 120]
enableFineContact	Enabling this mode allows the robot to automatically adjust the velocity upon contact; otherwise, the robot will only move at a constant velocity	BOOL	none	1 ∈ [0 / 1]
waypoint	Waypoint pose	ARRAY_COORD	m-deg	[traj_start* traj_prev* world*]
vel	TCP linear velocity	ARRAY_DOUBLE	m/s	0.02 ∈ [0.001 … 2.2]
acc	TCP linear acceleration	ARRAY_DOUBLE	m/s^2	1.5 ∈ [0.1 … 3.0]
zoneRadius	Blending zone radius when TCP approaches the waypoint	ARRAY_TYPE	none	[ZFine Z1 Z5 Z10 Z15 Z20 Z30 Z40 Z50 Z60 Z80 Z100 Z150 Z200]
jerk	TCP linear jerk	DOUBLE	m/s^3	50.0 ∈ [50.0 … 1000.0]

*Coordinate System Definition

Coordinate	Definition	Value Format
world	WORLD coordinate system, which is a fixed Cartesian coordinate system located at the center of the robot base	X Y Z Rx Ry Rz WORLD WORLD_ORIGIN
work	WORK coordinate system, which defines the position of the workpiece relative to the WORLD coordinate system	X Y Z Rx Ry Rz WORK WorkCoordName
tcp	TCP coordinate system, which is located at the Tool Center Point relative to the center of robot flange	X Y Z Rx Ry Rz TCP ONLINE
tcp_start	The fixed coordinate system which is located at the initial TCP pose of the primitive	X Y Z Rx Ry Rz TCP START
traj_start	The offset of a waypoint relative to the initial TCP pose in the TCP coordinate system	X Y Z Rx Ry Rz TRAJ START
traj_goal	The offset of a waypoint relative to the target TCP pose in the TCP coordinate system	X Y Z Rx Ry Rz TRAJ GOAL
traj_prev	The offset of a waypoint relative to the previous waypoint in the TCP coordinate system	X Y Z Rx Ry Rz TRAJ PREVIOUSWAYPOINT

• You can use the simplified value format above to describe a waypoint, while the complete description of a Cartesian waypoint is: X Y Z Rx Ry Rz ReferenceCoordinate A1 A2 A3 A4 A5 A6 A7 E1 E2 E3 E4 E5 E6. A1 to A7 are the preferred joint positions of the robot; X1 to X6 are the target positions of external axes. The additional data can be added if necessary.

• Add “:” to separate the waypoints. For example: 0.2 0 0.3 0 180 0 WORLD WORLD_ORIGIN : 0.2 0.1 0.3 0 180 0 WORLD WORLD_ORIGIN.

Primitive State Parameters

State Parameter	Description	Type	Unit
terminated	Flag to indicate whether the primitive is terminated. It is set to TRUE if the primitive is terminated.	BOOL	none
timePeriod	The time spent on running the current primitive.	DOUBLE	s
curContactForce	Current force in the contact direction	DOUBLE	N
forwardDis	Forward distance from the start position to the contact point	DOUBLE	m

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
terminated	=	1

ForceHybridLite

Primitive Description and Usage

• Description: This primitive controls the robot TCP to move linearly through waypoints to the target pose in hybrid motion/force control mode, while applying a constant force in the TCP direction. It is the basic version of the primitive [ForceHybrid]. You can use [ForceHybrid] for more versatile and safer force control performance.

• Example Usage: Use this primitive for better hybrid motion/force control performance when the robot needs to apply a constant external force while running a trajectory.

Primitive Input Parameters

Input Parameter	Description	Type	Unit	Default Value & Range
target*	Target TCP pose	COORD	m-deg	[traj_start* world*]
waypoint	Waypoint pose	ARRAY_COORD	m-deg	[traj_start* traj_goal* traj_prev* world*]
vel	TCP linear velocity	DOUBLE	m/s	0.25 ∈ [0.001 … 2.2]
acc	TCP linear acceleration	DOUBLE	m/s^2	10 ∈ [0.1 … 15.0]
zoneRadius	Blending zone radius when TCP approaches the waypoint	TYPE	none	Z50 ∈ [ZFine Z1 Z5 Z10 Z15 Z20 Z30 Z40 Z50 Z60 Z80 Z100 Z150 Z200]
targetTolerLevel	Tolerance level to determine if the robot has reached the target. 1 means to check with the smallest tolerance, 0 means no tolerance check.	INT	none	0 ∈ [0 … 10]
forceAxis*	Activated axes of force control coordinate system to apply force or torque	VEC_6i	none	0 0 1 0 0 0 ∈ [0 0 0 0 0 0 … 1 1 1 0 0 0]
targetWrench*	Target force and torque applied to the robot’s running trajectory	VEC_6d	N	0.0 0.0 -5.0 0.0 0.0 0.0
jerk	TCP linear jerk	DOUBLE	m/s^3	50.0 ∈ [50.0 … 1000.0]
stiffScale	Robot stiffness scale during motion. The lower the stiffness scale, the more compliant the motion.	VEC_6d	none	1.0 1.0 1.0 0.0 0.0 0.0 ∈ [0.01 0.01 0.01 0.0 0.0 0.0 … 1.0 1.0 1.0 0.0 0.0 0.0]
maxVelForceDir	Maximum movement velocity along force control direction	VEC_3d	m/s	2.0 2.0 2.0 ∈ [0.005 0.005 0.005 … 2.0 2.0 2.0]

*Parameters marked with an asterisk must be assigned a value prior to executing the primitive.

*Coordinate System Definition

Coordinate	Definition	Value Format
world	WORLD coordinate system, which is a fixed Cartesian coordinate system located at the center of the robot base	X Y Z Rx Ry Rz WORLD WORLD_ORIGIN
work	WORK coordinate system, which defines the position of the workpiece relative to the WORLD coordinate system	X Y Z Rx Ry Rz WORK WorkCoordName
tcp	TCP coordinate system, which is located at the Tool Center Point relative to the center of robot flange	X Y Z Rx Ry Rz TCP ONLINE
tcp_start	The fixed coordinate system which is located at the initial TCP pose of the primitive	X Y Z Rx Ry Rz TCP START
traj_start	The offset of a waypoint relative to the initial TCP pose in the TCP coordinate system	X Y Z Rx Ry Rz TRAJ START
traj_goal	The offset of a waypoint relative to the target TCP pose in the TCP coordinate system	X Y Z Rx Ry Rz TRAJ GOAL
traj_prev	The offset of a waypoint relative to the previous waypoint in the TCP coordinate system	X Y Z Rx Ry Rz TRAJ PREVIOUSWAYPOINT

• You can use the simplified value format above to describe a waypoint, while the complete description of a Cartesian waypoint is: X Y Z Rx Ry Rz ReferenceCoordinate A1 A2 A3 A4 A5 A6 A7 E1 E2 E3 E4 E5 E6. A1 to A7 are the preferred joint positions of the robot; X1 to X6 are the target positions of external axes. The additional data can be added if necessary.

• Add “:” to separate the waypoints. For example: 0.2 0 0.3 0 180 0 WORLD WORLD_ORIGIN : 0.2 0.1 0.3 0 180 0 WORLD WORLD_ORIGIN.

Primitive State Parameters

State Parameter	Description	Type	Unit
terminated	Flag to indicate whether the primitive is terminated. It is set to TRUE if the primitive is terminated.	BOOL	none
timePeriod	The time spent on running the current primitive.	DOUBLE	s
reachedTarget	Flag to indicate whether the robot has reached the target	BOOL	none
waypointIndex	Index of the current waypoint the robot just passed. 0 means the initial pose.	INT	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
reachedTarget	=	1

ForceCompLite

Primitive Description and Usage

• Description: This primitive compliantly moves the robot TCP to a target pose while passing through multiple waypoints. It is the basic version of the primitive [ForceComp]. You can use [ForceComp] for more precise compliant motion control performance.

• Example Usage: Use this primitive when the robot has a chance to collide with an unknown environment during Cartesian movement or when you want to compliantly interact with the robot during movement. You can also use primitive [ForceComp] for better compliant motion performance.

Primitive Input Parameters

Input Parameter	Description	Type	Unit	Default Value & Range
target*	Target TCP pose	COORD	m-deg	[traj_start* world*]
waypoints	Waypoints between initial and target poses	ARRAY_COORD	m-deg	[traj_start* traj_goal* traj_prev* world*]
zoneRadius	Blending zone radius when TCP approaches the waypoint	TYPE	none	Z50 ∈ [ZFine Z1 Z5 Z10 Z15 Z20 Z30 Z40 Z50 Z60 Z80 Z100 Z150 Z200]
targetTolerLevel	Tolerance level to determine if the robot has reached the target. 1 means to check with the smallest tolerance, 0 means no tolerance check.	INT	none	0 ∈ [0 … 10]
vel	TCP linear velocity	DOUBLE	m/s	0.25 ∈ [0.001 … 2.2]
compAxis	Compliant axis in compliance coordinate system	VEC_6i	none	0 0 0 0 0 0 ∈ [0 0 0 0 0 0 … 1 1 1 0 0 0]
acc	TCP linear acceleration	DOUBLE	m/s^2	10 ∈ [0.1 … 15.0]
jerk	TCP linear jerk	DOUBLE	m/s^3	50.0 ∈ [50.0 … 1000.0]
compCoord	Reference coordinate system for the compliant motion	COORD	m-deg	0 0 0 0 0 0 WORLD WORLD_ORIGIN ∈ [world* tcp_start* tcp*]

*Parameters marked with an asterisk must be assigned a value prior to executing the primitive.

*Coordinate System Definition

Coordinate	Definition	Value Format
world	WORLD coordinate system, which is a fixed Cartesian coordinate system located at the center of the robot base	X Y Z Rx Ry Rz WORLD WORLD_ORIGIN
work	WORK coordinate system, which defines the position of the workpiece relative to the WORLD coordinate system	X Y Z Rx Ry Rz WORK WorkCoordName
tcp	TCP coordinate system, which is located at the Tool Center Point relative to the center of robot flange	X Y Z Rx Ry Rz TCP ONLINE
tcp_start	The fixed coordinate system which is located at the initial TCP pose of the primitive	X Y Z Rx Ry Rz TCP START
traj_start	The offset of a waypoint relative to the initial TCP pose in the TCP coordinate system	X Y Z Rx Ry Rz TRAJ START
traj_goal	The offset of a waypoint relative to the target TCP pose in the TCP coordinate system	X Y Z Rx Ry Rz TRAJ GOAL
traj_prev	The offset of a waypoint relative to the previous waypoint in the TCP coordinate system	X Y Z Rx Ry Rz TRAJ PREVIOUSWAYPOINT

• You can use the simplified value format above to describe a waypoint, while the complete description of a Cartesian waypoint is: X Y Z Rx Ry Rz ReferenceCoordinate A1 A2 A3 A4 A5 A6 A7 E1 E2 E3 E4 E5 E6. A1 to A7 are the preferred joint positions of the robot; X1 to X6 are the target positions of external axes. The additional data can be added if necessary.

• Add “:” to separate the waypoints. For example: 0.2 0 0.3 0 180 0 WORLD WORLD_ORIGIN : 0.2 0.1 0.3 0 180 0 WORLD WORLD_ORIGIN.

Primitive State Parameters

State Parameter	Description	Type	Unit
terminated	Flag to indicate whether the primitive is terminated. It is set to TRUE if the primitive is terminated.	BOOL	none
timePeriod	The time spent on running the current primitive.	DOUBLE	s
reachedTarget	Flag to indicate whether the robot has reached the target	BOOL	none
waypointIndex	Index of the current waypoint the robot just passed. 0 means the initial pose.	INT	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
reachedTarget	=	1