Describes the robot state. More...

#include <robot_state.h>

Collaboration diagram for franka::RobotState:

[legend]

Public Attributes
std::array< double, 16 >	O_T_EE {}
	\(^{O}T_{EE}\) Measured end effector pose in base frame.

std::array< double, 16 >	O_T_EE_d {}
	\({^OT_{EE}}_{d}\) Last desired end effector pose of motion generation in base frame.

std::array< double, 16 >	F_T_EE {}
	\(^{F}T_{EE}\) End effector frame pose in flange frame.

std::array< double, 16 >	F_T_NE {}
	\(^{F}T_{NE}\) Nominal end effector frame pose in flange frame.

std::array< double, 16 >	NE_T_EE {}
	\(^{NE}T_{EE}\) End effector frame pose in nominal end effector frame.

std::array< double, 16 >	EE_T_K {}
	\(^{EE}T_{K}\) Stiffness frame pose in end effector frame.

double	m_ee {}
	\(m_{EE}\) Configured mass of the end effector.

std::array< double, 9 >	I_ee {}
	\(I_{EE}\) Configured rotational inertia matrix of the end effector load with respect to center of mass.

std::array< double, 3 >	F_x_Cee {}
	\(^{F}x_{C_{EE}}\) Configured center of mass of the end effector load with respect to flange frame.

double	m_load {}
	\(m_{load}\) Configured mass of the external load.

std::array< double, 9 >	I_load {}
	\(I_{load}\) Configured rotational inertia matrix of the external load with respect to center of mass.

std::array< double, 3 >	F_x_Cload {}
	\(^{F}x_{C_{load}}\) Configured center of mass of the external load with respect to flange frame.

double	m_total {}
	\(m_{total}\) Sum of the mass of the end effector and the external load.

std::array< double, 9 >	I_total {}
	\(I_{total}\) Combined rotational inertia matrix of the end effector load and the external load with respect to the center of mass.

std::array< double, 3 >	F_x_Ctotal {}
	\(^{F}x_{C_{total}}\) Combined center of mass of the end effector load and the external load with respect to flange frame.

std::array< double, 2 >	elbow {}
	Elbow configuration.

std::array< double, 2 >	elbow_d {}
	Desired elbow configuration.

std::array< double, 2 >	elbow_c {}
	Commanded elbow configuration.

std::array< double, 2 >	delbow_c {}
	Commanded elbow velocity.

std::array< double, 2 >	ddelbow_c {}
	Commanded elbow acceleration.

std::array< double, 7 >	tau_J {}
	\(\tau_{J}\) Measured link-side joint torque sensor signals.

std::array< double, 7 >	tau_J_d {}
	\({\tau_J}_d\) Desired link-side joint torque sensor signals without gravity.

std::array< double, 7 >	dtau_J {}
	\(\dot{\tau_{J}}\) Derivative of measured link-side joint torque sensor signals.

std::array< double, 7 >	q {}
	\(q\) Measured joint position.

std::array< double, 7 >	q_d {}
	\(q_d\) Desired joint position.

std::array< double, 7 >	dq {}
	\(\dot{q}\) Measured joint velocity.

std::array< double, 7 >	dq_d {}
	\(\dot{q}_d\) Desired joint velocity.

std::array< double, 7 >	ddq_d {}
	\(\ddot{q}_d\) Desired joint acceleration.

std::array< double, 7 >	joint_contact {}
	Indicates whether contact is reported for each joint.

std::array< double, 6 >	cartesian_contact {}
	Indicates whether contact is reported for each Cartesian dimension \((x,y,z,R,P,Y)\).

std::array< double, 7 >	joint_collision {}
	Indicates whether a collision is reported for each joint.

std::array< double, 6 >	cartesian_collision {}
	Indicates whether a collision is reported for each Cartesian dimension \((x,y,z,R,P,Y)\).

std::array< double, 7 >	tau_ext_hat_filtered {}
	\(\hat{\tau}_{\text{ext}}\) Low-pass filtered torques generated by external forces on the joints.

std::array< double, 6 >	O_F_ext_hat_K {}
	\(^OF_{K,\text{ext}}\) Estimated external wrench (force, torque) acting on stiffness frame, expressed relative to the base frame.

std::array< double, 6 >	K_F_ext_hat_K {}
	\(^{K}F_{K,\text{ext}}\) Estimated external wrench (force, torque) acting on stiffness frame, expressed relative to the stiffness frame.

std::array< double, 6 >	O_dP_EE_d {}
	\({^OdP_{EE}}_{d}\) Desired end effector twist in base frame.

std::array< double, 3 >	O_ddP_O {}
	\({^OddP}_O\) Linear component of the acceleration of the robot's base, expressed in frame parallel to the base frame, i.e.

std::array< double, 16 >	O_T_EE_c {}
	\({^OT_{EE}}_{c}\) Last commanded end effector pose of motion generation in base frame.

std::array< double, 6 >	O_dP_EE_c {}
	\({^OdP_{EE}}_{c}\) Last commanded end effector twist in base frame.

std::array< double, 6 >	O_ddP_EE_c {}
	\({^OddP_{EE}}_{c}\) Last commanded end effector acceleration in base frame.

std::array< double, 7 >	theta {}
	\(\theta\) Motor position.

std::array< double, 7 >	dtheta {}
	\(\dot{\theta}\) Motor velocity.

std::array< std::array< float, 3 >, 6 >	accelerometer_top {}
	\(\ddot{x}\) Translational acceleration data from the accelerometers located on the top of the PCB of Joint 1 through Joint 6 (no accelerometers in the last joint).

std::array< std::array< float, 3 >, 6 >	accelerometer_bottom {}
	\(\ddot{x}\) Translational acceleration data from the accelerometers located on the bottom of the PCB of Joint 1 through Joint 6 (no accelerometers in the last joint).

Errors	current_errors {}
	Current error state.

Errors	last_motion_errors {}
	Contains the errors that aborted the previous motion.

double	control_command_success_rate {}
	Percentage of the last 100 control commands that were successfully received by the robot.

RobotMode	robot_mode = RobotMode::kUserStopped
	Current robot mode.

Duration	time {}
	Strictly monotonically increasing timestamp since robot start.

Detailed Description

Describes the robot state.

Examples: cartesian_impedance_control.cpp, communication_test.cpp, echo_robot_state.cpp, force_control.cpp, generate_cartesian_pose_motion.cpp, generate_cartesian_pose_motion_external_control_loop.cpp, generate_cartesian_velocity_motion.cpp, generate_cartesian_velocity_motion_external_control_loop.cpp, generate_consecutive_motions.cpp, generate_elbow_motion.cpp, generate_joint_position_motion.cpp, generate_joint_position_motion_external_control_loop.cpp, generate_joint_velocity_motion.cpp, generate_joint_velocity_motion_external_control_loop.cpp, joint_impedance_control.cpp, motion_with_control.cpp, motion_with_control_external_control_loop.cpp, and print_joint_poses.cpp.

Member Data Documentation

◆ accelerometer_bottom

std::array<std::array<float, 3>, 6> franka::RobotState::accelerometer_bottom {}

\(\ddot{x}\) Translational acceleration data from the accelerometers located on the bottom of the PCB of Joint 1 through Joint 6 (no accelerometers in the last joint).

Unit: \([\frac{m}{s^2}]\)

◆ accelerometer_top

std::array<std::array<float, 3>, 6> franka::RobotState::accelerometer_top {}

\(\ddot{x}\) Translational acceleration data from the accelerometers located on the top of the PCB of Joint 1 through Joint 6 (no accelerometers in the last joint).

Unit: \([\frac{m}{s^2}]\)

◆ cartesian_collision

std::array<double, 6> franka::RobotState::cartesian_collision {}

Indicates whether a collision is reported for each Cartesian dimension \((x,y,z,R,P,Y)\).

The signal is derived from the estimated external wrench and the upper force threshold configured with Robot::setCollisionBehavior. Unlike contact, collision is a latching signal: it remains non-zero even after the external wrench drops, until the error is explicitly cleared via automaticErrorRecovery().

A collision triggers a reflex stop; while the reflex is active, the robot enters RobotMode::kReflex.

Values: 0.0 = no collision, non-zero = collision detected (latched).

See also: Robot::setCollisionBehavior for configuring collision thresholds.; Robot::automaticErrorRecovery for clearing the collision state.; RobotState::O_F_ext_hat_K for the underlying wrench estimate.

◆ cartesian_contact

std::array<double, 6> franka::RobotState::cartesian_contact {}

Indicates whether contact is reported for each Cartesian dimension \((x,y,z,R,P,Y)\).

The signal is derived from the estimated external wrench and the lower force threshold configured with Robot::setCollisionBehavior. The value is 0.0 when no contact is reported and non-zero while contact is active. It returns to zero automatically once contact is no longer detected.

See also: Robot::setCollisionBehavior for configuring contact thresholds.; RobotState::O_F_ext_hat_K for the underlying wrench estimate.

◆ control_command_success_rate

double franka::RobotState::control_command_success_rate {}

Percentage of the last 100 control commands that were successfully received by the robot.

Shows a value of zero if no control or motion generator loop is currently running.

Range: \([0, 1]\).

Examples: communication_test.cpp.

◆ ddelbow_c

std::array<double, 2> franka::RobotState::ddelbow_c {}

Commanded elbow acceleration.

The values of the array are:

ddelbow_c[0] Acceleration of the 3rd joint in \(\frac{rad}{s^2}\)
ddelbow_c[1] is always 0.

◆ ddq_d

std::array<double, 7> franka::RobotState::ddq_d {}

\(\ddot{q}_d\) Desired joint acceleration.

Unit: \([\frac{rad}{s^2}]\)

◆ delbow_c

std::array<double, 2> franka::RobotState::delbow_c {}

Commanded elbow velocity.

The values of the array are:

delbow_c[0] Velocity of the 3rd joint in \(\frac{rad}{s}\)
delbow_c[1] is always 0.

◆ dq

std::array<double, 7> franka::RobotState::dq {}

\(\dot{q}\) Measured joint velocity.

Unit: \([\frac{rad}{s}]\)

Examples: cartesian_impedance_control.cpp, motion_with_control.cpp, and motion_with_control_external_control_loop.cpp.

◆ dq_d

std::array<double, 7> franka::RobotState::dq_d {}

\(\dot{q}_d\) Desired joint velocity.

Unit: \([\frac{rad}{s}]\)

◆ dtau_J

std::array<double, 7> franka::RobotState::dtau_J {}

\(\dot{\tau_{J}}\) Derivative of measured link-side joint torque sensor signals.

Unit: \([\frac{Nm}{s}]\)

◆ dtheta

std::array<double, 7> franka::RobotState::dtheta {}

\(\dot{\theta}\) Motor velocity.

Unit: \([\frac{rad}{s}]\)

◆ EE_T_K

std::array<double, 16> franka::RobotState::EE_T_K {}

\(^{EE}T_{K}\) Stiffness frame pose in end effector frame.

Pose is represented as a 4x4 matrix in column-major format.

◆ elbow

std::array<double, 2> franka::RobotState::elbow {}

Elbow configuration.

The values of the array are:

elbow[0]: Position of the 3rd joint in \([rad]\).
elbow[1]: Flip direction of the elbow (4th joint):
- +1 if \(q_4 > q_{elbow-flip}\)
- 0 if \(q_4 == q_{elbow-flip} \)
- -1 if \(q_4 < q_{elbow-flip} \)
with \(q_{elbow-flip}\) as specified in the robot interface specification page in the FCI Documentation.

Examples: generate_elbow_motion.cpp.

◆ elbow_c

std::array<double, 2> franka::RobotState::elbow_c {}

Commanded elbow configuration.

The values of the array are:

elbow_c[0]: Position of the 3rd joint in \([rad]\).
elbow_c[1]: Flip direction of the elbow (4th joint):
- +1 if \(q_4 > q_{elbow-flip}\)
- 0 if \(q_4 == q_{elbow-flip} \)
- -1 if \(q_4 < q_{elbow-flip} \)
with \(q_{elbow-flip}\) as specified in the robot interface specification page in the FCI Documentation.

◆ elbow_d

std::array<double, 2> franka::RobotState::elbow_d {}

Desired elbow configuration.

The values of the array are:

elbow_d[0]: Position of the 3rd joint in \([rad]\).
elbow_d[1]: Flip direction of the elbow (4th joint):
- +1 if \(q_4 > q_{elbow-flip}\)
- 0 if \(q_4 == q_{elbow-flip} \)
- -1 if \(q_4 < q_{elbow-flip} \)
with \(q_{elbow-flip}\) as specified in the robot interface specification page in the FCI Documentation.

◆ F_T_EE

std::array<double, 16> franka::RobotState::F_T_EE {}

\(^{F}T_{EE}\) End effector frame pose in flange frame.

Pose is represented as a 4x4 matrix in column-major format.

See also: F_T_NE; NE_T_EE; Robot for an explanation of the F, NE and EE frames.

◆ F_T_NE

std::array<double, 16> franka::RobotState::F_T_NE {}

\(^{F}T_{NE}\) Nominal end effector frame pose in flange frame.

Pose is represented as a 4x4 matrix in column-major format.

See also: F_T_EE; NE_T_EE; Robot for an explanation of the F, NE and EE frames.

◆ joint_collision

std::array<double, 7> franka::RobotState::joint_collision {}

Indicates whether a collision is reported for each joint.

The signal is derived from the estimated external joint torque and the upper torque threshold configured with Robot::setCollisionBehavior. Unlike contact, collision is a latching signal: it remains non-zero even after the external torque drops, until the error is explicitly cleared via automaticErrorRecovery().

A collision triggers a reflex stop; while the reflex is active, the robot enters RobotMode::kReflex.

Values: 0.0 = no collision, non-zero = collision detected (latched).

See also: Robot::setCollisionBehavior for configuring collision thresholds.; Robot::automaticErrorRecovery for clearing the collision state.; RobotState::tau_ext_hat_filtered for the underlying torque estimate.

◆ joint_contact

std::array<double, 7> franka::RobotState::joint_contact {}

Indicates whether contact is reported for each joint.

The signal is derived from the estimated external joint torque and the lower torque threshold configured with Robot::setCollisionBehavior. The value is 0.0 when no contact is reported and non-zero while contact is active. It returns to zero automatically once contact is no longer detected.

See also: Robot::setCollisionBehavior for configuring contact thresholds.; RobotState::tau_ext_hat_filtered for the underlying torque estimate.

◆ K_F_ext_hat_K

std::array<double, 6> franka::RobotState::K_F_ext_hat_K {}

\(^{K}F_{K,\text{ext}}\) Estimated external wrench (force, torque) acting on stiffness frame, expressed relative to the stiffness frame.

Forces applied by the robot to the environment are positive, while forces applied by the environment on the robot are negative. Becomes \([0,0,0,0,0,0]\) when near or in a singularity. See also Stiffness frame K. Unit: \([N,N,N,Nm,Nm,Nm]\).

◆ NE_T_EE

std::array<double, 16> franka::RobotState::NE_T_EE {}

\(^{NE}T_{EE}\) End effector frame pose in nominal end effector frame.

Pose is represented as a 4x4 matrix in column-major format.

See also: Robot::setEE to change this frame.; F_T_EE; F_T_NE; Robot for an explanation of the F, NE and EE frames.

◆ O_ddP_EE_c

std::array<double, 6> franka::RobotState::O_ddP_EE_c {}

\({^OddP_{EE}}_{c}\) Last commanded end effector acceleration in base frame.

Unit: \([\frac{m}{s^2},\frac{m}{s^2},\frac{m}{s^2},\frac{rad}{s^2},\frac{rad}{s^2},\frac{rad}{s^2}]\).

◆ O_ddP_O

std::array<double, 3> franka::RobotState::O_ddP_O {}

\({^OddP}_O\) Linear component of the acceleration of the robot's base, expressed in frame parallel to the base frame, i.e.

the base's translational acceleration. If the base is resting this shows the direction of the gravity vector. It is harcoded for now to {0, 0, -9.81}.

◆ O_dP_EE_c

std::array<double, 6> franka::RobotState::O_dP_EE_c {}

\({^OdP_{EE}}_{c}\) Last commanded end effector twist in base frame.

Unit: \([\frac{m}{s},\frac{m}{s},\frac{m}{s},\frac{rad}{s},\frac{rad}{s},\frac{rad}{s}]\).

◆ O_dP_EE_d

std::array<double, 6> franka::RobotState::O_dP_EE_d {}

\({^OdP_{EE}}_{d}\) Desired end effector twist in base frame.

Unit: \([\frac{m}{s},\frac{m}{s},\frac{m}{s},\frac{rad}{s},\frac{rad}{s},\frac{rad}{s}]\).

◆ O_F_ext_hat_K

std::array<double, 6> franka::RobotState::O_F_ext_hat_K {}

\(^OF_{K,\text{ext}}\) Estimated external wrench (force, torque) acting on stiffness frame, expressed relative to the base frame.

Forces applied by the robot to the environment are positive, while forces applied by the environment on the robot are negative. Becomes \([0,0,0,0,0,0]\) when near or in a singularity. See also Stiffness frame K. Unit: \([N,N,N,Nm,Nm,Nm]\).

◆ O_T_EE

std::array<double, 16> franka::RobotState::O_T_EE {}

\(^{O}T_{EE}\) Measured end effector pose in base frame.

Pose is represented as a 4x4 matrix in column-major format.

Examples: cartesian_impedance_control.cpp, generate_cartesian_pose_motion.cpp, and generate_elbow_motion.cpp.

◆ O_T_EE_c

std::array<double, 16> franka::RobotState::O_T_EE_c {}

\({^OT_{EE}}_{c}\) Last commanded end effector pose of motion generation in base frame.

Pose is represented as a 4x4 matrix in column-major format.

◆ O_T_EE_d

std::array<double, 16> franka::RobotState::O_T_EE_d {}

\({^OT_{EE}}_{d}\) Last desired end effector pose of motion generation in base frame.

Pose is represented as a 4x4 matrix in column-major format.

◆ q

std::array<double, 7> franka::RobotState::q {}

\(q\) Measured joint position.

Unit: \([rad]\)

Examples: generate_joint_position_motion.cpp, motion_with_control.cpp, and motion_with_control_external_control_loop.cpp.

◆ q_d

std::array<double, 7> franka::RobotState::q_d {}

\(q_d\) Desired joint position.

Unit: \([rad]\)

Examples: motion_with_control.cpp, and motion_with_control_external_control_loop.cpp.

◆ tau_ext_hat_filtered

std::array<double, 7> franka::RobotState::tau_ext_hat_filtered {}

\(\hat{\tau}_{\text{ext}}\) Low-pass filtered torques generated by external forces on the joints.

It does not include configured end-effector and load nor the mass and dynamics of the robot. tau_ext_hat_filtered is the error between tau_J and the expected torques given by the robot model. Unit: \([Nm]\).

◆ tau_J

std::array<double, 7> franka::RobotState::tau_J {}

\(\tau_{J}\) Measured link-side joint torque sensor signals.

Unit: \([Nm]\)

Examples: force_control.cpp.

◆ tau_J_d

std::array<double, 7> franka::RobotState::tau_J_d {}

\({\tau_J}_d\) Desired link-side joint torque sensor signals without gravity.

Unit: \([Nm]\)

◆ theta

std::array<double, 7> franka::RobotState::theta {}

\(\theta\) Motor position.

Unit: \([rad]\)

◆ time

Duration franka::RobotState::time {}

Strictly monotonically increasing timestamp since robot start.

Inside of control loops time_step parameter of Robot::control can be used instead.

The documentation for this struct was generated from the following file:

include/franka/robot_state.h

Public Attributes

Detailed Description

Member Data Documentation

◆ accelerometer_bottom

◆ accelerometer_top

◆ cartesian_collision

◆ cartesian_contact

◆ control_command_success_rate

◆ ddelbow_c

◆ ddq_d

◆ delbow_c

◆ dq

◆ dq_d

◆ dtau_J

◆ dtheta

◆ EE_T_K

◆ elbow

◆ elbow_c

◆ elbow_d

◆ F_T_EE

◆ F_T_NE

◆ joint_collision

◆ joint_contact

◆ K_F_ext_hat_K

◆ NE_T_EE

◆ O_ddP_EE_c

◆ O_ddP_O

◆ O_dP_EE_c

◆ O_dP_EE_d

◆ O_F_ext_hat_K

◆ O_T_EE

◆ O_T_EE_c

◆ O_T_EE_d

◆ q

◆ q_d

◆ tau_ext_hat_filtered

◆ tau_J

◆ tau_J_d

◆ theta

◆ time