Visual Servoing Platform  version 3.4.0
Public Types | Public Member Functions | Protected Attributes | Static Protected Attributes | List of all members
vpRobotFranka Class Reference
robot: Robot module » Real robots » Anthropomorphic arm

#include <vpRobotFranka.h>

+ Inheritance diagram for vpRobotFranka:

Public Types

enum  vpRobotStateType {
  STATE_STOP, STATE_VELOCITY_CONTROL, STATE_POSITION_CONTROL, STATE_ACCELERATION_CONTROL,
  STATE_FORCE_TORQUE_CONTROL
}
 
enum  vpControlFrameType {
  REFERENCE_FRAME, ARTICULAR_FRAME, JOINT_STATE = ARTICULAR_FRAME, END_EFFECTOR_FRAME,
  CAMERA_FRAME, TOOL_FRAME = CAMERA_FRAME, MIXT_FRAME
}
 

Public Member Functions

 vpRobotFranka ()
 
 vpRobotFranka (const std::string &franka_address, franka::RealtimeConfig realtime_config=franka::RealtimeConfig::kEnforce)
 
virtual ~vpRobotFranka ()
 
void connect (const std::string &franka_address, franka::RealtimeConfig realtime_config=franka::RealtimeConfig::kEnforce)
 
vpHomogeneousMatrix get_fMe (const vpColVector &q)
 
vpHomogeneousMatrix get_fMc (const vpColVector &q)
 
vpHomogeneousMatrix get_eMc () const
 
void get_eJe (vpMatrix &eJe)
 
void get_eJe (const vpColVector &q, vpMatrix &eJe)
 
void get_fJe (vpMatrix &fJe)
 
void get_fJe (const vpColVector &q, vpMatrix &fJe)
 
void getCoriolis (vpColVector &coriolis)
 
void getForceTorque (const vpRobot::vpControlFrameType frame, vpColVector &force)
 
void getGravity (vpColVector &gravity)
 
franka::RobotState getRobotInternalState ()
 
franka::Gripper * getGripperHandler ()
 
franka::Robot * getHandler ()
 
vpColVector getJointMin () const
 
vpColVector getJointMax () const
 
void getMass (vpMatrix &mass)
 
void getPosition (const vpRobot::vpControlFrameType frame, vpColVector &position)
 
void getPosition (const vpRobot::vpControlFrameType frame, vpPoseVector &pose)
 
void getVelocity (const vpRobot::vpControlFrameType frame, vpColVector &d_position)
 
int gripperClose ()
 
int gripperGrasp (double grasping_width, double force=60.)
 
void gripperHoming ()
 
int gripperMove (double width)
 
int gripperOpen ()
 
void gripperRelease ()
 
void move (const std::string &filename, double velocity_percentage=10.)
 
bool readPosFile (const std::string &filename, vpColVector &q)
 
bool savePosFile (const std::string &filename, const vpColVector &q)
 
void set_eMc (const vpHomogeneousMatrix &eMc)
 
void setForceTorque (const vpRobot::vpControlFrameType frame, const vpColVector &ft, const double &filter_gain=0.1, const bool &activate_pi_controller=false)
 
void setLogFolder (const std::string &folder)
 
void setPosition (const vpRobot::vpControlFrameType frame, const vpColVector &position)
 
void setPositioningVelocity (double velocity)
 
vpRobot::vpRobotStateType setRobotState (vpRobot::vpRobotStateType newState)
 
void setVelocity (const vpRobot::vpControlFrameType frame, const vpColVector &vel)
 
void stopMotion ()
 
Inherited functionalities from vpRobot
double getMaxTranslationVelocity (void) const
 
double getMaxRotationVelocity (void) const
 
vpColVector getPosition (const vpRobot::vpControlFrameType frame)
 
virtual vpRobotStateType getRobotState (void) const
 
void setMaxRotationVelocity (double maxVr)
 
void setMaxTranslationVelocity (double maxVt)
 
void setVerbose (bool verbose)
 

Static Public Member Functions

Static Public Member Functions inherited from vpRobot
static vpColVector saturateVelocities (const vpColVector &v_in, const vpColVector &v_max, bool verbose=false)
 

Protected Member Functions

Protected Member Functions Inherited from vpRobot
vpControlFrameType setRobotFrame (vpRobot::vpControlFrameType newFrame)
 
vpControlFrameType getRobotFrame (void) const
 

Protected Attributes

double maxTranslationVelocity
 
double maxRotationVelocity
 
int nDof
 
vpMatrix eJe
 
int eJeAvailable
 
vpMatrix fJe
 
int fJeAvailable
 
int areJointLimitsAvailable
 
double * qmin
 
double * qmax
 
bool verbose_
 

Static Protected Attributes

static const double maxTranslationVelocityDefault = 0.2
 
static const double maxRotationVelocityDefault = 0.7
 

Detailed Description

This class is a wrapper over the libfranka component part of the Franka Control Interface (FCI).

Before using vpRobotFranka follow the installation instructions to install libfranka. We suggest to build libfranka from source if you are not using ROS.

Moreover, you need also to setup a real-time kernel following these instructions.

Up to now, this class provides the following capabilities to:

What is not implemented is:

  • move to a given cartesian end-effector position
  • gripper controller
  • force/torque feadback and control

Known issues:

  • sometimes the joint to joint trajectory generator provided by Franka complains about discontinuities.

We provide also the getHandler() function that allows to acces to the robot handler and call the native libfranka API fonctionalities:

vpRobotFranka robot("192.168.1.1");
franka::Robot *handler = robot.getHandler();
// Get end-effector cartesian position
std::array<double, 16> pose = handler->readOnce().O_T_EE;
Examples:
frankaGripper.cpp, frankaMoveToPosition.cpp, frankaSavePosition.cpp, servoFrankaIBVS.cpp, servoFrankaPBVS.cpp, testFrankaCartForceTorque-2.cpp, testFrankaCartForceTorque.cpp, testFrankaCartVelocity-2.cpp, testFrankaCartVelocity-3.cpp, testFrankaCartVelocity.cpp, testFrankaGetPose.cpp, testFrankaJointPosition.cpp, testFrankaJointTorque.cpp, testFrankaJointVelocity-2.cpp, testFrankaJointVelocity-3.cpp, testFrankaJointVelocity.cpp, testFrankaJointVelocityLimits.cpp, and tutorial-franka-acquire-calib-data.cpp.

Definition at line 223 of file vpRobotFranka.h.

Member Enumeration Documentation

enum vpRobot::vpControlFrameType
inherited

Robot control frames.

Enumerator
REFERENCE_FRAME 

Corresponds to a fixed reference frame attached to the robot structure.

ARTICULAR_FRAME 

Corresponds to the joint state. This value is deprecated. You should rather use vpRobot::JOINT_STATE.

JOINT_STATE 

Corresponds to the joint state.

END_EFFECTOR_FRAME 

Corresponds to robot end-effector frame.

CAMERA_FRAME 

Corresponds to a frame attached to the camera mounted on the robot end-effector.

TOOL_FRAME 

Corresponds to a frame attached to the tool (camera, gripper...) mounted on the robot end-effector. This value is equal to vpRobot::CAMERA_FRAME.

MIXT_FRAME 

Corresponds to a "virtual" frame where translations are expressed in the reference frame, and rotations in the camera frame.

Definition at line 75 of file vpRobot.h.

enum vpRobot::vpRobotStateType
inherited

Robot control states.

Enumerator
STATE_STOP 

Stops robot motion especially in velocity and acceleration control.

STATE_VELOCITY_CONTROL 

Initialize the velocity controller.

STATE_POSITION_CONTROL 

Initialize the position controller.

STATE_ACCELERATION_CONTROL 

Initialize the acceleration controller.

STATE_FORCE_TORQUE_CONTROL 

Initialize the force/torque controller.

Definition at line 64 of file vpRobot.h.

Constructor & Destructor Documentation

vpRobotFranka::vpRobotFranka ( )

Default constructor.

Definition at line 56 of file vpRobotFranka.cpp.

vpRobotFranka::vpRobotFranka ( const std::string &  franka_address,
franka::RealtimeConfig  realtime_config = franka::RealtimeConfig::kEnforce 
)

Establishes a connection with the robot.

Parameters
[in]franka_addressIP/hostname of the robot.
[in]realtime_configIf set to kEnforce, an exception will be thrown if realtime priority cannot be set when required. Setting realtime_config to kIgnore disables this behavior.

Definition at line 74 of file vpRobotFranka.cpp.

References connect(), and vpRobot::nDof.

vpRobotFranka::~vpRobotFranka ( )
virtual

Destructor.

Definition at line 105 of file vpRobotFranka.cpp.

References setRobotState(), and vpRobot::STATE_STOP.

Member Function Documentation

void vpRobotFranka::connect ( const std::string &  franka_address,
franka::RealtimeConfig  realtime_config = franka::RealtimeConfig::kEnforce 
)

Establishes a connection with the robot and set default behavior.

Parameters
[in]franka_addressIP/hostname of the robot.
[in]realtime_configIf set to kEnforce, an exception will be thrown if realtime priority cannot be set when required. Setting realtime_config to kIgnore disables this behavior.
Examples:
frankaGripper.cpp, frankaMoveToPosition.cpp, frankaSavePosition.cpp, servoFrankaIBVS.cpp, servoFrankaPBVS.cpp, testFrankaCartForceTorque-2.cpp, testFrankaCartForceTorque.cpp, testFrankaCartVelocity-2.cpp, testFrankaCartVelocity-3.cpp, testFrankaCartVelocity.cpp, testFrankaGetPose.cpp, testFrankaJointPosition.cpp, testFrankaJointTorque.cpp, testFrankaJointVelocity-2.cpp, testFrankaJointVelocity-3.cpp, testFrankaJointVelocity.cpp, testFrankaJointVelocityLimits.cpp, and tutorial-franka-acquire-calib-data.cpp.

Definition at line 129 of file vpRobotFranka.cpp.

References vpException::fatalError.

Referenced by vpRobotFranka().

void vpRobotFranka::get_eJe ( vpMatrix &  eJe_)
virtual

Gets the robot Jacobian in the end-effector frame relative to the end-effector frame represented as a 6x7 matrix in row-major format and computed from the robot current joint position.

Parameters
[out]eJe_: Body Jacobian expressed in the end-effector frame.

Implements vpRobot.

Examples:
testFrankaCartVelocity-2.cpp, and testFrankaGetPose.cpp.

Definition at line 490 of file vpRobotFranka.cpp.

References vpException::fatalError, getRobotInternalState(), and vpArray2D< Type >::resize().

void vpRobotFranka::get_eJe ( const vpColVector &  q,
vpMatrix &  eJe_ 
)

Gets the robot Jacobian in the end-effector frame relative to the end-effector frame represented as a 6x7 matrix in row-major format and computed from the robot current joint position.

Parameters
[in]q: 7-dim vector corresponding to the robot joint position [rad].
[out]eJe_: Body Jacobian expressed in the end-effector frame.

Definition at line 514 of file vpRobotFranka.cpp.

References vpException::fatalError, getRobotInternalState(), and vpArray2D< Type >::resize().

vpHomogeneousMatrix vpRobotFranka::get_eMc ( ) const

Return the $ ^{e}{\bf M}_c$ homogeneous transformation that gives the position of the camera frame (or in general of any tool frame) in the robot end-effector frame.

By default, this transformation is set to identity, meaning that the camera (or tool) frame is located on the end-effector.

To change the position of the camera (or tool) frame on the end-effector frame, use set_eMc().

Definition at line 1014 of file vpRobotFranka.cpp.

Referenced by getForceTorque().

void vpRobotFranka::get_fJe ( vpMatrix &  fJe_)
virtual

Gets the robot Jacobian in the end-effector frame relative to the base frame represented as a 6x7 matrix in row-major format and computed from the robot current joint position.

Parameters
[out]fJe_: Zero Jacobian expressed in the base frame.

Implements vpRobot.

Examples:
testFrankaGetPose.cpp.

Definition at line 542 of file vpRobotFranka.cpp.

References vpException::fatalError, getRobotInternalState(), and vpArray2D< Type >::resize().

void vpRobotFranka::get_fJe ( const vpColVector &  q,
vpMatrix &  fJe_ 
)

Gets the robot Jacobian in the end-effector frame relative to the base frame represented as a 6x7 matrix in row-major format and computed from the robot joint position given as input.

Parameters
[in]q: 7-dim vector corresponding to the robot joint position [rad].
[out]fJe_: Zero Jacobian expressed in the base frame.

Definition at line 566 of file vpRobotFranka.cpp.

References vpException::fatalError, getRobotInternalState(), vpArray2D< Type >::resize(), and vpArray2D< Type >::size().

vpHomogeneousMatrix vpRobotFranka::get_fMc ( const vpColVector &  q)

Given the joint position of the robot, computes the forward kinematics (direct geometric model) as an homogeneous matrix ${^f}{\bf M}_c$ that gives the position of the camera frame (or in general of any tool attached to the robot) in the robot base frame.

By default, the transformation $^{e}{\bf M}_c$ that corresponds to the transformation between the end-effector and the camera (or tool) frame is set to identity, meaning that the camera (or tool) frame is located on the end-effector.

To change the position of the camera (or tool) frame , use set_eMc().

Parameters
[in]q: Joint position as a 7-dim vector.
Returns
Position of the camera frame (or tool frame) in the robot base frame.

Definition at line 435 of file vpRobotFranka.cpp.

References get_fMe().

Referenced by getPosition().

vpHomogeneousMatrix vpRobotFranka::get_fMe ( const vpColVector &  q)

Given the joint position of the robot, computes the forward kinematics (direct geometric model) as an homogeneous matrix ${^f}{\bf M}_e$ that gives the position of the end-effector in the robot base frame.

Parameters
[in]q: Joint position as a 7-dim vector.
Returns
Position of the end-effector in the robot base frame.

Definition at line 395 of file vpRobotFranka.cpp.

References vpException::fatalError, getRobotInternalState(), and vpArray2D< Type >::size().

Referenced by get_fMc(), and getPosition().

void vpRobotFranka::getCoriolis ( vpColVector &  coriolis)

Get the Coriolis force vector (state-space equation) calculated from the current robot state: $ c= C \times dq$, in $[Nm]$.

Parameters
[out]coriolis: Coriolis force vector.
Examples:
testFrankaGetPose.cpp.

Definition at line 324 of file vpRobotFranka.cpp.

References vpException::fatalError, getRobotInternalState(), and vpColVector::resize().

void vpRobotFranka::getForceTorque ( const vpRobot::vpControlFrameType  frame,
vpColVector &  force 
)

Get robot force torque.

Parameters
[in]frame: Type of forces and torques to retrieve. Admissible values are:
[out]force: Measured forced and torques.

If you want to get a cartesian position, use rather getPosition(const vpRobot::vpControlFrameType, vpPoseVector &)

Definition at line 241 of file vpRobotFranka.cpp.

References vpRobot::END_EFFECTOR_FRAME, vpException::fatalError, get_eMc(), getRobotInternalState(), vpHomogeneousMatrix::inverse(), vpRobot::JOINT_STATE, vpColVector::resize(), and vpRobot::TOOL_FRAME.

void vpRobotFranka::getGravity ( vpColVector &  gravity)

Get the gravity vector calculated form the current robot state. Unit: $[Nm]$.

Parameters
[out]gravity: Gravity vector
Examples:
testFrankaGetPose.cpp.

Definition at line 346 of file vpRobotFranka.cpp.

References vpException::fatalError, getRobotInternalState(), and vpColVector::resize().

franka::Gripper* vpRobotFranka::getGripperHandler ( )
inline

Get gripper handler to access native libfranka functions.

Returns
Robot handler if it exists, an exception otherwise.

Definition at line 300 of file vpRobotFranka.h.

References vpException::fatalError.

franka::Robot* vpRobotFranka::getHandler ( )
inline

Get robot handler to access native libfranka functions.

Returns
Robot handler if it exists, an exception otherwise.
Examples:
testFrankaGetPose.cpp.

Definition at line 314 of file vpRobotFranka.h.

References vpException::fatalError, vpRobot::getPosition(), vpRobot::setPosition(), vpRobot::setRobotState(), and vpRobot::setVelocity().

vpColVector vpRobotFranka::getJointMax ( ) const

Gets maximum joint values.

Returns
A 7-dimension vector that contains the maximum joint values for the 7 dof. All the values are expressed in radians.
Examples:
testFrankaJointVelocityLimits.cpp.

Definition at line 995 of file vpRobotFranka.cpp.

vpColVector vpRobotFranka::getJointMin ( ) const

Gets minimal joint values.

Returns
A 7-dimension vector that contains the minimal joint values for the 7 dof. All the values are expressed in radians.
Examples:
testFrankaJointVelocityLimits.cpp.

Definition at line 982 of file vpRobotFranka.cpp.

void vpRobotFranka::getMass ( vpMatrix &  mass)

Get the 7x7 mass matrix. Unit: $[kg \times m^2]$.

Parameters
[out]mass: 7x7 mass matrix, row-major.
Examples:
testFrankaGetPose.cpp.

Definition at line 368 of file vpRobotFranka.cpp.

References vpException::fatalError, getRobotInternalState(), and vpArray2D< Type >::resize().

double vpRobot::getMaxRotationVelocity ( void  ) const
inherited

Get the maximal rotation velocity that can be sent to the robot during a velocity control.

Returns
Maximum rotation velocity expressed in rad/s.

Definition at line 273 of file vpRobot.cpp.

References vpRobot::maxRotationVelocity.

Referenced by vpSimulatorAfma6::computeArticularVelocity(), vpSimulatorViper850::computeArticularVelocity(), vpSimulatorAfma6::findHighestPositioningSpeed(), vpSimulatorViper850::findHighestPositioningSpeed(), vpSimulatorAfma6::setPosition(), vpRobotTemplate::setVelocity(), vpSimulatorCamera::setVelocity(), vpRobotCamera::setVelocity(), vpSimulatorPioneer::setVelocity(), vpRobotPioneer::setVelocity(), vpSimulatorPioneerPan::setVelocity(), vpRobotKinova::setVelocity(), vpRobotFlirPtu::setVelocity(), vpSimulatorAfma6::setVelocity(), vpSimulatorViper850::setVelocity(), vpRobotAfma4::setVelocity(), vpRobotAfma6::setVelocity(), setVelocity(), vpRobotViper650::setVelocity(), and vpRobotViper850::setVelocity().

double vpRobot::getMaxTranslationVelocity ( void  ) const
inherited

Get the maximal translation velocity that can be sent to the robot during a velocity control.

Returns
Maximum translational velocity expressed in m/s.

Definition at line 251 of file vpRobot.cpp.

References vpRobot::maxTranslationVelocity.

Referenced by vpSimulatorAfma6::setPosition(), vpRobotTemplate::setVelocity(), vpSimulatorCamera::setVelocity(), vpRobotCamera::setVelocity(), vpSimulatorPioneer::setVelocity(), vpRobotPioneer::setVelocity(), vpSimulatorPioneerPan::setVelocity(), vpRobotKinova::setVelocity(), vpRobotFlirPtu::setVelocity(), vpSimulatorAfma6::setVelocity(), vpSimulatorViper850::setVelocity(), vpRobotAfma4::setVelocity(), vpRobotAfma6::setVelocity(), setVelocity(), vpRobotViper650::setVelocity(), and vpRobotViper850::setVelocity().

vpColVector vpRobot::getPosition ( const vpRobot::vpControlFrameType  frame)
inherited

Return the current robot position in the specified frame.

Definition at line 216 of file vpRobot.cpp.

References vpRobot::getPosition().

void vpRobotFranka::getPosition ( const vpRobot::vpControlFrameType  frame,
vpColVector &  position 
)
virtual

Get robot position.

Parameters
[in]frame: Type of position to retrieve. Admissible values are:
[out]position: Robot position. When joint position is asked this vector is 7-dim. Otherwise for a cartesian position this vector is 6-dim. Its content is similar to a vpPoseVector, with first the 3 tranlations in meter and then the 3 orientations in radian as a $\theta {\bf u}$ vector (see vpThetaUVector).

If you want to get a cartesian position, use rather getPosition(const vpRobot::vpControlFrameType, vpPoseVector &)

Implements vpRobot.

Examples:
frankaSavePosition.cpp, testFrankaGetPose.cpp, testFrankaJointVelocityLimits.cpp, and tutorial-franka-acquire-calib-data.cpp.

Definition at line 187 of file vpRobotFranka.cpp.

References vpRobot::END_EFFECTOR_FRAME, vpException::fatalError, get_fMc(), get_fMe(), getRobotInternalState(), vpRobot::JOINT_STATE, vpColVector::resize(), and vpRobot::TOOL_FRAME.

void vpRobotFranka::getPosition ( const vpRobot::vpControlFrameType  frame,
vpPoseVector &  pose 
)

Get robot cartesian position.

Parameters
[in]frame: Type of cartesian position to retrieve. Admissible values are:
[out]pose: Robot cartesian position. This vector is 6-dim. Its content is similar to a vpPoseVector, with first the 3 tranlations in meter and then the 3 orientations in radian as a $\theta {\bf u}$ vector (see vpThetaUVector).

Definition at line 451 of file vpRobotFranka.cpp.

References vpPoseVector::buildFrom(), vpRobot::END_EFFECTOR_FRAME, vpException::fatalError, getRobotInternalState(), vpRobot::JOINT_STATE, and vpRobot::TOOL_FRAME.

vpControlFrameType vpRobot::getRobotFrame ( void  ) const
inlineprotectedinherited

Definition at line 172 of file vpRobot.h.

Referenced by vpSimulatorAfma6::computeArticularVelocity(), and vpSimulatorViper850::computeArticularVelocity().

franka::RobotState vpRobotFranka::getRobotInternalState ( )

Definition at line 956 of file vpRobotFranka.cpp.

References vpException::fatalError.

Referenced by get_eJe(), get_fJe(), get_fMe(), getCoriolis(), getForceTorque(), getGravity(), getMass(), getPosition(), getVelocity(), and setForceTorque().

virtual vpRobotStateType vpRobot::getRobotState ( void  ) const
inlinevirtualinherited

Definition at line 144 of file vpRobot.h.

Referenced by vpRobotBiclops::getPosition(), vpRobotBiclops::getVelocity(), vpRobotPtu46::setPosition(), vpRobotBiclops::setPosition(), vpSimulatorCamera::setPosition(), vpRobotCamera::setPosition(), vpSimulatorAfma6::setPosition(), vpRobotAfma4::setPosition(), vpSimulatorViper850::setPosition(), vpRobotAfma6::setPosition(), setPosition(), vpRobotViper650::setPosition(), vpRobotViper850::setPosition(), vpRobotPtu46::setRobotState(), vpRobotBiclops::setRobotState(), vpRobotFlirPtu::setRobotState(), vpSimulatorAfma6::setRobotState(), vpSimulatorViper850::setRobotState(), vpRobotAfma4::setRobotState(), vpRobotAfma6::setRobotState(), setRobotState(), vpRobotViper650::setRobotState(), vpRobotViper850::setRobotState(), vpRobotTemplate::setVelocity(), vpRobotBiclops::setVelocity(), vpRobotPtu46::setVelocity(), vpSimulatorCamera::setVelocity(), vpRobotCamera::setVelocity(), vpSimulatorPioneer::setVelocity(), vpSimulatorPioneerPan::setVelocity(), vpRobotKinova::setVelocity(), vpRobotFlirPtu::setVelocity(), vpSimulatorAfma6::setVelocity(), vpSimulatorViper850::setVelocity(), vpRobotAfma4::setVelocity(), vpRobotAfma6::setVelocity(), setVelocity(), vpRobotViper650::setVelocity(), vpRobotViper850::setVelocity(), vpRobotFlirPtu::stopMotion(), vpSimulatorAfma6::stopMotion(), vpSimulatorViper850::stopMotion(), stopMotion(), vpRobotViper650::stopMotion(), and vpRobotViper850::stopMotion().

void vpRobotFranka::getVelocity ( const vpRobot::vpControlFrameType  frame,
vpColVector &  d_position 
)

Get robot velocity.

Parameters
[in]frame: Type of velocity to retrieve. Admissible values are:
[out]d_position: Robot velocity. When joints velocity is asked this vector is 7-dim. Otherwise for a cartesian velocity this vector is 6-dim. Its content is similar to a vpPoseVector, with first the 3 tranlations in meter and then the 3 orientations in radian as a $\theta {\bf u}$ vector (see vpThetaUVector).
Warning
For the moment, cartesian velocities measurement in vpRobot::END_EFFECTOR_FRAME, vpRobot::CAMERA_FRAME, vpRobot::TOOL_FRAME are not implemented.

Definition at line 295 of file vpRobotFranka.cpp.

References vpException::fatalError, getRobotInternalState(), vpRobot::JOINT_STATE, and vpColVector::resize().

int vpRobotFranka::gripperClose ( )

Closes the gripper.

Returns
EXIT_SUCCESS if the success, EXIT_FAILURE otherwise.
See also
gripperHoming(), gripperGrasp(), gripperRelease(), gripperOpen()
Examples:
frankaGripper.cpp.

Definition at line 1276 of file vpRobotFranka.cpp.

References gripperMove().

int vpRobotFranka::gripperGrasp ( double  grasping_width,
double  force = 60. 
)

Grasp an object that has a given width.

An object is considered grasped if the distance d between the gripper fingers satisfies grasping_width - 0.005 < d < grasping_width + 0.005.

Parameters
[in]grasping_width: Size of the object to grasp. [m]
[in]force: Grasping force. [N]
Returns
EXIT_SUCCESS if grasping succeed, EXIT_FAILURE otherwise.
See also
gripperHoming(), gripperOpen(), gripperRelease()
Examples:
frankaGripper.cpp.

Definition at line 1335 of file vpRobotFranka.cpp.

void vpRobotFranka::gripperHoming ( )

Performing a gripper homing.

See also
gripperGrasp(), gripperMove(), gripperRelease()
Examples:
frankaGripper.cpp.

Definition at line 1227 of file vpRobotFranka.cpp.

References vpException::fatalError.

int vpRobotFranka::gripperMove ( double  width)

Moves the gripper fingers to a specified width.

Parameters
[in]width: Intended opening width. [m]
Returns
EXIT_SUCCESS if the success, EXIT_FAILURE otherwise.
See also
gripperHoming(), gripperGrasp(), gripperRelease()
Examples:
frankaGripper.cpp.

Definition at line 1247 of file vpRobotFranka.cpp.

References vpException::fatalError.

Referenced by gripperClose().

int vpRobotFranka::gripperOpen ( )

Closes the gripper.

Returns
EXIT_SUCCESS if the success, EXIT_FAILURE otherwise.
See also
gripperHoming(), gripperGrasp(), gripperRelease(), gripperOpen()
Examples:
frankaGripper.cpp.

Definition at line 1289 of file vpRobotFranka.cpp.

References vpException::fatalError.

void vpRobotFranka::gripperRelease ( )

Release an object that is grasped.

See also
gripperHoming(), gripperMove(), gripperRelease()
Examples:
frankaGripper.cpp.

Definition at line 1310 of file vpRobotFranka.cpp.

References vpException::fatalError.

void vpRobotFranka::move ( const std::string &  filename,
double  velocity_percentage = 10. 
)

Moves the robot to the joint position specified in the filename. The positioning velocity is set to 10% of the robot maximal velocity.

Parameters
filename: File containing a joint position to reach.
velocity_percentage: Velocity percentage. Values in range [1, 100].
Examples:
frankaMoveToPosition.cpp.

Definition at line 1045 of file vpRobotFranka.cpp.

References vpRobot::JOINT_STATE, readPosFile(), setPosition(), setPositioningVelocity(), setRobotState(), and vpRobot::STATE_POSITION_CONTROL.

bool vpRobotFranka::readPosFile ( const std::string &  filename,
vpColVector &  q 
)

Read joint positions in a specific Franka position file.

This position file has to start with a header. The seven joint positions are given after the "R:" keyword and are expressed in degres to be more representative for the user. Theses values are then converted in radians in q. The character "#" starting a line indicates a comment.

A typical content of such a file is given below:

#PANDA - Joint position file
#
# R: q1 q2 q3 q4 q5 q6 q7
# with joint positions q1 to q7 expressed in degrees
#
R: 0.1 0.3 -0.25 -80.5 80 0 0
Parameters
[in]filename: Name of the position file to read.
[out]q: 7-dim joint positions: q1 q2 q3 q4 q5 q6 q7 with values expressed in radians.
Returns
true if the positions were successfully readen in the file. false, if an error occurs.

The code below shows how to read a position from a file and move the robot to this position.

vpRobotFranka robot;
vpColVector q; // Joint position
robot.readPosFile("myposition.pos", q); // Set the joint position from the file
robot.setRobotState(vpRobot::STATE_POSITION_CONTROL);
robot.setPositioningVelocity(5); // Positioning velocity set to 5%
robot.setPosition(vpRobot::ARTICULAR_FRAME, q); // Move to the joint position
See also
savePosFile(), move()

Definition at line 1099 of file vpRobotFranka.cpp.

References vpMath::rad(), vpColVector::resize(), and vpIoTools::splitChain().

Referenced by move().

vpColVector vpRobot::saturateVelocities ( const vpColVector &  v_in,
const vpColVector &  v_max,
bool  verbose = false 
)
staticinherited

Saturate velocities.

Parameters
v_in: Vector of input velocities to saturate. Translation velocities should be expressed in m/s while rotation velocities in rad/s.
v_max: Vector of maximal allowed velocities. Maximal translation velocities should be expressed in m/s while maximal rotation velocities in rad/s.
verbose: Print a message indicating which axis causes the saturation.
Returns
Saturated velocities.
Exceptions
vpRobotException::dimensionError: If the input vectors have different dimensions.

The code below shows how to use this static method in order to saturate a velocity skew vector.

#include <iostream>
#include <visp3/robot/vpRobot.h>
int main()
{
// Set a velocity skew vector
vpColVector v(6);
v[0] = 0.1; // vx in m/s
v[1] = 0.2; // vy
v[2] = 0.3; // vz
v[3] = vpMath::rad(10); // wx in rad/s
v[4] = vpMath::rad(-10); // wy
v[5] = vpMath::rad(20); // wz
// Set the maximal allowed velocities
vpColVector v_max(6);
for (int i=0; i<3; i++)
v_max[i] = 0.3; // in translation (m/s)
for (int i=3; i<6; i++)
v_max[i] = vpMath::rad(10); // in rotation (rad/s)
// Compute the saturated velocity skew vector
vpColVector v_sat = vpRobot::saturateVelocities(v, v_max, true);
std::cout << "v : " << v.t() << std::endl;
std::cout << "v max: " << v_max.t() << std::endl;
std::cout << "v sat: " << v_sat.t() << std::endl;
return 0;
}

Definition at line 163 of file vpRobot.cpp.

References vpException::dimensionError, and vpArray2D< Type >::size().

Referenced by vpRobotTemplate::setVelocity(), vpSimulatorCamera::setVelocity(), vpRobotCamera::setVelocity(), vpSimulatorPioneer::setVelocity(), vpRobotPioneer::setVelocity(), vpSimulatorPioneerPan::setVelocity(), vpRobotKinova::setVelocity(), vpRobotFlirPtu::setVelocity(), vpRobotAfma4::setVelocity(), vpRobotAfma6::setVelocity(), setVelocity(), vpRobotViper650::setVelocity(), and vpRobotViper850::setVelocity().

bool vpRobotFranka::savePosFile ( const std::string &  filename,
const vpColVector &  q 
)

Save joint positions in a specific Panda position file.

This position file starts with a header on the first line. After convertion of the rotations in degrees, the joint position q is written on a line starting with the keyword "R: ". See readPosFile() documentation for an example of such a file.

Parameters
filename: Name of the position file to create.
q: Joint positions vector to save in the filename with values expressed in radians.
Warning
The joint rotations written in the file are converted in degrees to be more representative for the user.
Returns
true if the positions were successfully saved in the file. false, if an error occurs.
See also
readPosFile()
Examples:
frankaSavePosition.cpp.

Definition at line 1182 of file vpRobotFranka.cpp.

References vpMath::deg().

void vpRobotFranka::set_eMc ( const vpHomogeneousMatrix &  eMc)

Set the $ ^{e}{\bf M}_c$ homogeneous transformation that gives the position of the camera frame (or in general of any tool frame) in the robot end-effector frame.

By default, this transformation is set to identity, meaning that the camera (or tool) frame is located on the end-effector.

This transformation has to be set before controlling the robot cartesian velocity in the camera frame or getting the position of the robot in the camera frame.

Parameters
[in]eMc: End-effector to camera frame transformation.
Examples:
servoFrankaIBVS.cpp, servoFrankaPBVS.cpp, and testFrankaCartVelocity-3.cpp.

Definition at line 1031 of file vpRobotFranka.cpp.

void vpRobotFranka::setForceTorque ( const vpRobot::vpControlFrameType  frame,
const vpColVector &  ft,
const double &  filter_gain = 0.1,
const bool &  activate_pi_controller = false 
)
Examples:
testFrankaCartForceTorque-2.cpp, testFrankaCartForceTorque.cpp, and testFrankaJointTorque.cpp.

Definition at line 906 of file vpRobotFranka.cpp.

References vpRobot::END_EFFECTOR_FRAME, getRobotInternalState(), vpRobot::JOINT_STATE, vpRobot::MIXT_FRAME, vpRobot::REFERENCE_FRAME, vpArray2D< Type >::size(), vpRobot::TOOL_FRAME, and vpRobotException::wrongStateError.

void vpRobotFranka::setLogFolder ( const std::string &  folder)

Set the folder or directory used to record logs at 1Kz when setVelocity() is used. By default the log folder is empty.

When the log folder is empty, logs are not created.

Parameters
[in]folder: A path to a folder that will contain a basket of log files. If the folder doesn't exist it will be created recursively.
Examples:
testFrankaCartForceTorque-2.cpp, testFrankaCartForceTorque.cpp, testFrankaCartVelocity-2.cpp, testFrankaCartVelocity-3.cpp, testFrankaCartVelocity.cpp, testFrankaJointTorque.cpp, and testFrankaJointVelocity.cpp.

Definition at line 600 of file vpRobotFranka.cpp.

References vpIoTools::checkDirectory(), vpException::fatalError, and vpIoTools::makeDirectory().

void vpRobot::setMaxRotationVelocity ( double  w_max)
inherited

Set the maximal rotation velocity that can be sent to the robot during a velocity control.

Parameters
w_max: Maximum rotational velocity expressed in rad/s.
Examples:
servoMomentPoints.cpp, servoSimu4Points.cpp, servoSimuSphere.cpp, testFeatureSegment.cpp, testFrankaJointVelocityLimits.cpp, and testRobotFlirPtu.cpp.

Definition at line 260 of file vpRobot.cpp.

References vpRobot::maxRotationVelocity.

Referenced by vpRobotViper650::getControlMode(), vpRobotViper850::getControlMode(), vpRobotViper650::setMaxRotationVelocity(), vpRobotViper850::setMaxRotationVelocity(), vpSimulatorAfma6::setPosition(), vpRobotCamera::vpRobotCamera(), and vpSimulatorCamera::vpSimulatorCamera().

void vpRobot::setMaxTranslationVelocity ( double  v_max)
inherited

Set the maximal translation velocity that can be sent to the robot during a velocity control.

Parameters
v_max: Maximum translation velocity expressed in m/s.
Examples:
servoMomentPoints.cpp, servoSimu4Points.cpp, servoSimuSphere.cpp, simulateCircle2DCamVelocity.cpp, simulateFourPoints2DCartesianCamVelocity.cpp, simulateFourPoints2DPolarCamVelocity.cpp, and testFeatureSegment.cpp.

Definition at line 239 of file vpRobot.cpp.

References vpRobot::maxTranslationVelocity.

Referenced by vpSimulatorAfma6::setPosition(), vpRobotCamera::vpRobotCamera(), and vpSimulatorCamera::vpSimulatorCamera().

void vpRobotFranka::setPosition ( const vpRobot::vpControlFrameType  frame,
const vpColVector &  position 
)
virtual

Set robot position. This function is blocking; it returns when the desired position is reached.

Parameters
[in]frame: The only possible value is vpRobot::JOINT_STATE. Other values are not implemented.
[in]position: This is a 7-dim vector that corresponds to the robot joint positions expressed in rad.

Implements vpRobot.

Examples:
testFrankaCartVelocity-2.cpp, testFrankaCartVelocity-3.cpp, testFrankaCartVelocity.cpp, testFrankaJointPosition.cpp, testFrankaJointVelocity-2.cpp, testFrankaJointVelocity-3.cpp, testFrankaJointVelocity.cpp, and testFrankaJointVelocityLimits.cpp.

Definition at line 625 of file vpRobotFranka.cpp.

References vpException::fatalError, vpException::functionNotImplementedError, vpRobot::getRobotState(), vpRobot::JOINT_STATE, setRobotState(), and vpRobot::STATE_POSITION_CONTROL.

Referenced by move().

void vpRobotFranka::setPositioningVelocity ( double  velocity)

Set the maximal velocity percentage to use for a position control.

Parameters
[in]velocity: Percentage of the maximal velocity. Values should be in ]0:100].
Examples:
testFrankaCartVelocity-2.cpp, testFrankaCartVelocity-3.cpp, and testFrankaCartVelocity.cpp.

Definition at line 673 of file vpRobotFranka.cpp.

Referenced by move().

vpRobot::vpControlFrameType vpRobot::setRobotFrame ( vpRobot::vpControlFrameType  newFrame)
protectedinherited

Definition at line 207 of file vpRobot.cpp.

Referenced by vpSimulatorAfma6::init(), vpSimulatorViper850::init(), vpSimulatorCamera::setVelocity(), vpSimulatorPioneer::setVelocity(), vpSimulatorPioneerPan::setVelocity(), vpSimulatorAfma6::setVelocity(), and vpSimulatorViper850::setVelocity().

vpRobot::vpRobotStateType vpRobotFranka::setRobotState ( vpRobot::vpRobotStateType  newState)
virtual

Change the robot state.

Parameters
[in]newState: New requested robot state.

Reimplemented from vpRobot.

Examples:
frankaMoveToPosition.cpp, frankaSavePosition.cpp, servoFrankaIBVS.cpp, servoFrankaPBVS.cpp, testFrankaCartForceTorque-2.cpp, testFrankaCartForceTorque.cpp, testFrankaCartVelocity-2.cpp, testFrankaCartVelocity-3.cpp, testFrankaCartVelocity.cpp, testFrankaJointPosition.cpp, testFrankaJointTorque.cpp, testFrankaJointVelocity-2.cpp, testFrankaJointVelocity-3.cpp, testFrankaJointVelocity.cpp, and testFrankaJointVelocityLimits.cpp.

Definition at line 684 of file vpRobotFranka.cpp.

References vpRobot::getRobotState(), vpRobot::setRobotState(), vpRobot::STATE_FORCE_TORQUE_CONTROL, vpRobot::STATE_POSITION_CONTROL, vpRobot::STATE_STOP, and vpRobot::STATE_VELOCITY_CONTROL.

Referenced by move(), setPosition(), stopMotion(), and ~vpRobotFranka().

void vpRobotFranka::setVelocity ( const vpRobot::vpControlFrameType  frame,
const vpColVector &  vel 
)
virtual

Apply a velocity to the robot.

Parameters
[in]frame: Control frame in which the velocity is expressed. Velocities could be expressed as joint velocities, cartesian velocity twist expressed in the robot reference frame, in the end-effector frame or in the camera or tool frame.
[in]vel: Velocity vector. Translation velocities are expressed in m/s while rotation velocities in rad/s. The size of this vector is always 6 for a cartesian velocity skew, and 7 for joint velocities.
  • When joint velocities have to be applied, frame should be set to vpRobot::JOINT_STATE, and $ vel = [\dot{q}_1, \dot{q}_2, \dot{q}_3, \dot{q}_4, \dot{q}_5, \dot{q}_6]^t, \dot{q}_7]^T $ correspond to joint velocities in rad/s.
  • When cartesian velocities have to be applied in the reference frame (or in a frame also called fixed frame in ViSP), frame should be set to vpRobot::REFERENCE_FRAME, $ vel = [^{f} v_x, ^{f} v_y, ^{f} v_z, ^{f} \omega_x, ^{f} \omega_y, ^{f} \omega_z]^T $ is a velocity twist vector corresponding to the velocity of the origin of the camera frame (or tool frame) expressed in the reference frame, with translations velocities $ ^{f} v_x, ^{f} v_y, ^{f} v_z $ in m/s and rotation velocities $ ^{f}\omega_x, ^{f} \omega_y, ^{f} \omega_z $ in rad/s.
  • When cartesian velocities have to be applied in the end-effector frame, frame should be set to vpRobot::END_EFFECTOR_FRAME, $ vel = [^{e} v_x, ^{e} v_y, ^{e} v_z, ^{e} \omega_x, ^{e} \omega_y, ^{e} \omega_z]^T $ is a velocity twist vector corresponding to the velocity of the origin of the end-effector frame expressed in the end-effector frame, with translations velocities $ ^{e} v_x, ^{e} v_y, ^{e} v_z $ in m/s and rotation velocities $ ^{e}\omega_x, ^{e} \omega_y, ^{e} \omega_z $ in rad/s.
  • When cartesian velocities have to be applied in the camera frame or more generally in a tool frame, frame should be set to vpRobot::CAMERA_FRAME or vpRobot::TOOL_FRAME, $ vel = [^{c} v_x, ^{c} v_y, ^{c} v_z, ^{c} \omega_x, ^{c} \omega_y, ^{c} \omega_z]^T $ is a velocity twist vector corresponding to the velocity of the origin of the camera (or tool frame) frame expressed in the camera (or tool frame), with translations velocities $ ^{c} v_x, ^{c} v_y, ^{c} v_z $ in m/s and rotation velocities $ ^{c}\omega_x, ^{c} \omega_y, ^{c} \omega_z $ in rad/s.
Exceptions
vpRobotException::wrongStateError: If a the robot is not configured to handle a velocity. The robot can handle a velocity only if the velocity control mode is set. For that, call setRobotState( vpRobot::STATE_VELOCITY_CONTROL) before setVelocity().
Warning
Velocities could be saturated if one of them exceed the maximal autorized speed (see vpRobot::maxTranslationVelocity and vpRobot::maxRotationVelocity). To change these values use setMaxTranslationVelocity() and setMaxRotationVelocity().

Implements vpRobot.

Examples:
servoFrankaIBVS.cpp, servoFrankaPBVS.cpp, testFrankaCartVelocity-2.cpp, testFrankaCartVelocity-3.cpp, testFrankaCartVelocity.cpp, testFrankaJointVelocity-2.cpp, testFrankaJointVelocity-3.cpp, testFrankaJointVelocity.cpp, and testFrankaJointVelocityLimits.cpp.

Definition at line 831 of file vpRobotFranka.cpp.

References vpRobot::END_EFFECTOR_FRAME, vpRobot::getMaxRotationVelocity(), vpRobot::getMaxTranslationVelocity(), vpRobot::getRobotState(), vpRobot::JOINT_STATE, vpRobot::MIXT_FRAME, vpRobot::REFERENCE_FRAME, vpRobot::saturateVelocities(), vpArray2D< Type >::size(), vpRobot::STATE_VELOCITY_CONTROL, vpRobot::TOOL_FRAME, and vpRobotException::wrongStateError.

Referenced by stopMotion().

void vpRobot::setVerbose ( bool  verbose)
inlineinherited
Examples:
tutorial-ibvs-4pts-wireframe-robot-afma6.cpp, and tutorial-ibvs-4pts-wireframe-robot-viper.cpp.

Definition at line 159 of file vpRobot.h.

Referenced by vpRobotAfma4::vpRobotAfma4(), vpRobotAfma6::vpRobotAfma6(), vpRobotViper650::vpRobotViper650(), and vpRobotViper850::vpRobotViper850().

void vpRobotFranka::stopMotion ( void  )

Stop the robot when it is controlled in velocity and set the robot state to vpRobot::STATE_STOP.

Exceptions
vpRobotException::lowLevelError: If the low level controller returns an error during robot stopping.

Definition at line 1212 of file vpRobotFranka.cpp.

References vpRobot::getRobotState(), vpRobot::JOINT_STATE, setRobotState(), setVelocity(), vpRobot::STATE_STOP, and vpRobot::STATE_VELOCITY_CONTROL.

Member Data Documentation

int vpRobot::areJointLimitsAvailable
protectedinherited

Definition at line 112 of file vpRobot.h.

Referenced by vpRobot::operator=(), vpRobotCamera::vpRobotCamera(), vpSimulatorCamera::vpSimulatorCamera(), vpSimulatorPioneer::vpSimulatorPioneer(), and vpSimulatorPioneerPan::vpSimulatorPioneerPan().

vpMatrix vpRobot::eJe
protectedinherited

robot Jacobian expressed in the end-effector frame

Definition at line 104 of file vpRobot.h.

Referenced by vpRobotFlirPtu::get_eJe(), vpSimulatorCamera::get_eJe(), vpRobotCamera::get_eJe(), vpRobot::operator=(), vpRobotAfma4::setVelocity(), vpRobotCamera::vpRobotCamera(), and vpSimulatorCamera::vpSimulatorCamera().

int vpRobot::eJeAvailable
protectedinherited

is the robot Jacobian expressed in the end-effector frame available

Definition at line 106 of file vpRobot.h.

Referenced by vpRobot::operator=(), vpRobotCamera::vpRobotCamera(), vpSimulatorCamera::vpSimulatorCamera(), vpSimulatorPioneer::vpSimulatorPioneer(), and vpSimulatorPioneerPan::vpSimulatorPioneerPan().

vpMatrix vpRobot::fJe
protectedinherited

robot Jacobian expressed in the robot reference frame available

Definition at line 108 of file vpRobot.h.

Referenced by vpRobotFlirPtu::get_fJe(), and vpRobot::operator=().

int vpRobot::fJeAvailable
protectedinherited

is the robot Jacobian expressed in the robot reference frame available

Definition at line 110 of file vpRobot.h.

Referenced by vpRobot::operator=(), vpRobotCamera::vpRobotCamera(), vpSimulatorCamera::vpSimulatorCamera(), vpSimulatorPioneer::vpSimulatorPioneer(), and vpSimulatorPioneerPan::vpSimulatorPioneerPan().

double vpRobot::maxRotationVelocity
protectedinherited

Definition at line 98 of file vpRobot.h.

Referenced by vpRobot::getMaxRotationVelocity(), vpRobotTemplate::init(), vpRobotFlirPtu::init(), vpRobotKinova::init(), vpRobot::operator=(), vpRobot::setMaxRotationVelocity(), vpRobotPtu46::setVelocity(), vpRobotViper650::vpRobotViper650(), and vpRobotViper850::vpRobotViper850().

const double vpRobot::maxRotationVelocityDefault = 0.7
staticprotectedinherited

Definition at line 99 of file vpRobot.h.

Referenced by vpRobotTemplate::init(), vpRobotFlirPtu::init(), and vpRobotKinova::init().

double vpRobot::maxTranslationVelocity
protectedinherited

Definition at line 96 of file vpRobot.h.

Referenced by vpRobot::getMaxTranslationVelocity(), vpRobotTemplate::init(), vpRobotFlirPtu::init(), vpRobotKinova::init(), vpRobot::operator=(), and vpRobot::setMaxTranslationVelocity().

const double vpRobot::maxTranslationVelocityDefault = 0.2
staticprotectedinherited

Definition at line 97 of file vpRobot.h.

Referenced by vpRobotTemplate::init(), vpRobotFlirPtu::init(), and vpRobotKinova::init().

int vpRobot::nDof
protectedinherited

number of degrees of freedom

Definition at line 102 of file vpRobot.h.

Referenced by vpRobotKinova::getJointPosition(), vpRobotTemplate::init(), vpRobotFlirPtu::init(), vpRobotKinova::init(), vpRobot::operator=(), vpRobotKinova::setDoF(), vpRobotKinova::setJointVelocity(), vpRobotKinova::setPosition(), vpRobotTemplate::setVelocity(), vpRobotFlirPtu::setVelocity(), vpRobotKinova::setVelocity(), vpRobotCamera::vpRobotCamera(), vpRobotFranka(), vpSimulatorCamera::vpSimulatorCamera(), vpSimulatorPioneer::vpSimulatorPioneer(), and vpSimulatorPioneerPan::vpSimulatorPioneerPan().

double* vpRobot::qmax
protectedinherited

Definition at line 114 of file vpRobot.h.

Referenced by vpRobot::operator=(), vpRobotCamera::vpRobotCamera(), vpSimulatorCamera::vpSimulatorCamera(), vpSimulatorPioneer::vpSimulatorPioneer(), vpSimulatorPioneerPan::vpSimulatorPioneerPan(), and vpRobot::~vpRobot().

double* vpRobot::qmin
protectedinherited

Definition at line 113 of file vpRobot.h.

Referenced by vpRobot::operator=(), vpRobotCamera::vpRobotCamera(), vpSimulatorCamera::vpSimulatorCamera(), vpSimulatorPioneer::vpSimulatorPioneer(), vpSimulatorPioneerPan::vpSimulatorPioneerPan(), and vpRobot::~vpRobot().

bool vpRobot::verbose_
protectedinherited

Definition at line 116 of file vpRobot.h.

Referenced by vpRobotAfma4::init(), vpRobotAfma6::init(), vpRobotViper650::init(), vpRobotViper850::init(), vpRobot::operator=(), vpRobotAfma4::vpRobotAfma4(), vpRobotAfma6::vpRobotAfma6(), vpRobotViper650::vpRobotViper650(), and vpRobotViper850::vpRobotViper850().