API Reference

fourier_grx_client.client.RobotClient

Bases: ZenohSession

Client class for GR series robots. Example:

>>> from fourier_grx_client import RobotClient
>>> r = RobotClient(namespace="gr/my_awesome_robot", server_ip="192.168.6.6")

base_pose property

Get the current base pose.

base_velocity property

Get the current base velocity.

imu_angles property

Get the current IMU orientation as Euler angles.

imu_angular_velocity property

Get the current IMU angular velocity.

imu_linear_acceleration property

Get the current IMU linear acceleration.

imu_quaternion property

Get the current IMU orientation as a quaternion.

is_moving property writable

Whether the robot is currently moving.

joint_currents property

Get the current joint currents of the robot.

joint_efforts property

Get the current joint efforts of the robot.

joint_positions property

Get the current joint positions of the robot. The joint positions are in radians.

joint_velocities property

Get the current joint velocities of the robot. The joint velocities are in radians per second.

__init__(freq=400, namespace=None, server_ip='localhost', verbose=False)

The client class for GR series robots.

Parameters:

Name	Type	Description	Default
server_ip	str	IP address of the grx server. Please make sure to properly setup the firewall to allow port 7447. Defaults to "localhost".	'localhost'
freq	int	Robot state update frequency. Usually the user doesn't need to modify this. Defaults to 400.	400
namespace	str	Robot namespace. If not provided, it will try to use the robot_id provided in the environment variable GRX_ROBOT_ID. If the environment variable is not set, it will try to load the robot_id from the file ~/.fourier/robot_id.yaml. If the file does not exist, it will fall back to the default namespace gr. Defaults to None.	None

Raises:

Type	Description
FourierConnectionError	If the connection to the server failed.

calibrate_sensors()

Get sensor offsets and save to sensor_offset.json

control_joints(control_type, commands, degrees=False)

Control the joints in a group with the specified control type.

Parameters:

Name	Type	Description	Default
control_type	Literal['position', 'velocity', 'current']	The control type to set.	required
commands	ndarray | list	The control commands to set.	required
degrees	bool	Whether the joint positions and velocities are in degrees. Defaults to False.	False

disable()

Disable the motors.

enable()

Enable the motors.

forward_kinematics(chain_names, q=None)

Get the end effector pose of the specified chains in base_link frame.

Info

The available chain names are: head, left_arm, right_arm, with corresponding end effector frames: head_yaw_link, left_end_effector_link, right_end_effector_link, and the transformation matrices are in the base_link frame.

Parameters:

Name	Type	Description	Default
chain_names	list[str]	The chains to get the end effector pose of. Available chain names: 'head', 'left_arm', 'right_arm'.	required
q	ndarray	The robot confiuration to do forward kinematics in. Defaults to None.	None

Returns:

Name	Type	Description
list	list[ndarray]	The end effector pose is a list of 4x4 transformation matrices. The order of the matrices is the same as the order of the chain names. The transformation matrix is in the base_link frame.

get_control_modes()

Get the control modes for all joints.

get_gains()

Get the control gains for all joints.

get_group_current(group)

Get the joint currents of a group.

get_group_effort(group)

Get the joint efforts of a group.

get_group_position(group)

Get the joint positions of a group.

get_group_position_by_name(name)

Get the joint positions of a group by its name.

Parameters:

Name	Type	Description	Default
name	str	The name of the group. Available group names: 'left_leg', 'right_leg', 'waist', 'head', 'left_arm', 'right_arm'.	required

get_group_velocity(group)

Get the joint velocities of a group.

get_transform(target_frame, source_frame, q=None)

Get the transformation matrix between two frames in configuration q. If q is None, the current joint positions are used.

Parameters:

Name	Type	Description	Default
target_frame	str	Name of the frame to get the pose of.	required
source_frame	str	Name of the frame to get the pose in.	required
q	ndarray	The robot confiuration to do forward kinematics in. Defaults to None.	None

Returns:

Type	Description
	np.ndarray: The transformation matrix.

inverse_kinematics(chain_names, targets, move=False, dt=0.005, velocity_scaling_factor=1.0, convergence_threshold=1e-08)

Get the joint positions for the specified chains to reach the target pose in base_link frame.

Parameters:

Name	Type	Description	Default
chain_names	list[str]	The chains to get the joint positions for. Available chain names: 'head', 'left_arm', 'right_arm'.	required
targets	list[ndarray]	The target poses in base_link frame.	required
move	bool	Whether to move the robot to the target pose. Defaults to False.	False
dt	float	The time step for the inverse kinematics.	0.005

Returns:

Type	Description
ndarray	np.ndarray: The joint positions to reach the target pose (in radians).

list_frames()

List all available frames.

liveness_check(timeout=1.0)

Check if the robot server is alive.

Parameters:

Name	Type	Description	Default
timeout	float	Timeout in seconds. Defaults to 1.0.	1.0

Raises:

Type	Description
FourierConnectionError	If the connection to the server failed.

move_joints(group, positions, duration=0.0, degrees=False, blocking=True, gravity_compensation=False)

Move in joint space with time duration.

Move in joint space with time duration in a separate thread. Can be aborted using abort(). Can be blocking. If the duration is set to 0, the joints will move in their maximum speed without interpolation.

GR1T2 Joint Order

The joints order is as follows: 0: left_hip_roll_joint 1: left_hip_yaw_joint 2: left_hip_pitch_joint 3: left_knee_pitch_joint 4: left_ankle_pitch_joint 5: left_ankle_roll_joint 6: right_hip_roll_joint 7: right_hip_yaw_joint 8: right_hip_pitch_joint 9: right_knee_pitch_joint 10: right_ankle_pitch_joint 11: right_ankle_roll_joint 12: waist_yaw_joint 13: waist_pitch_joint 14: waist_roll_joint 15: head_pitch_joint 16: head_roll_joint 17: head_yaw_joint 18: left_shoulder_pitch_joint 19: left_shoulder_roll_joint 20: left_shoulder_yaw_joint 21: left_elbow_pitch_joint 22: left_wrist_yaw_joint 23: left_wrist_roll_joint 24: left_wrist_pitch_joint 25: right_shoulder_pitch_joint 26: right_shoulder_roll_joint 27: right_shoulder_yaw_joint 28: right_elbow_pitch_joint 29: right_wrist_yaw_joint 30: right_wrist_roll_joint 31: right_wrist_pitch_joint

Example:

>>> # Move the left arm to a specific position
>>> r.move_joints("left_arm", [0, 0, 0, 20, 0, 0, 0], degrees=True)

>>> # or use the ControlGroup enum
>>> r.move_joints(ControlGroup.LEFT_ARM, [0, 0, 0, 20, 0, 0, 0], degrees=True)

>>> # or use indices, with radians instead of degrees
>>> r.move_joints([23, 24], [0.17, 0.17], degrees=False)

Parameters:

Name	Type	Description	Default
group	ControlGroup | list | str	The group of joints to move, specified by a string or a ControlGroup enum, or a list of joint indices.	required
positions	ndarray[float]	target joint position in degrees.	required
duration	float	Time duration in seconds. If set to 0, the joints will move in their maximum speed without interpolation. Defaults to 0.0.	0.0
degrees	bool	Whether the joint positions are in degrees. Defaults to False.	False
blocking	bool	If True, block until the move is completed. Defaults to True.	True
gravity_compensation	bool	Whether to enable gravity compensation. Defaults to False.	False

movej(sides, target_positions, target_velocity=None, target_acceleration=None, max_velocity=None, max_acceleration=None, max_jerk=None, degrees=False, move=True)

move the joints of the arms to the target position.

Parameters:

Name	Type	Description	Default
sides	list[Literal['left', 'right']]	Sides of the arms to move. Can be "left" or "right".	required
target_positions	list[ndarray | list]	Desired joint positions.	required
target_velocity	list[ndarray | list] | None	Desired joint velocities. Defaults to None. If None, the robot will estimate the velocity based on the target position.	None
target_acceleration	list[ndarray | list] | None	Desired accelerations. Defaults to None.	None
max_velocity	list[ndarray | list] | None	Max velocity during trajectory generation. Defaults to None. If None, the robot will use the default max velocity at 5 rad/s.	None
max_acceleration	list[ndarray | list] | None	Max acceleration during trajectory generation. Defaults to None. If None, the robot will use the default max acceleration at 10 rad/s^2.	None
max_jerk	list[ndarray | list] | None	Max jerk during trajectory generation. Defaults to None. If None, the robot will use the default max jerk at 50 rad/s^3.	None
degrees	bool	True if the input is in degrees. Defaults to False.	False
move	bool	Whether to execute the trajectory. Defaults to True.	True

Returns:

Name	Type	Description
list	list[list[ndarray]]	The trajectory of joint positions and velocities for controlled arms to reach the target pose.

movel(sides, target_poses, max_velocity=None, max_acceleration=None, max_jerk=None, move=True)

Move the specified arm to the target position.

Parameters:

Name	Type	Description	Default
sides	list[Literal['left', 'right']]	Sides of the arms to move. Can be "left" or "right".	required
target_poses	list[ndarray]	Desired end effector poses.	required
max_velocity	float | None	Max velocity during trajectory generation. Defaults to None.	None
max_acceleration	float | None	Max acceleration during trajectory generation. Defaults to None.	None
max_jerk	float | None	Max jerk during trajectory generation. Defaults to None.	None
move	bool	Whether to execute the trajectory. Defaults to True.	True

Return

list: The trajectory to reach the target pose.

play_traj(group, traj, timestamps=None, dt=0.005)

Play a trajectory in joint space.

reboot()

Reboot the motors.

set_control_modes(control_mode=None)

Set the control modes for all joints.

Parameters:

Name	Type	Description	Default
control_mode	ControlMode | list[ControlMode] | None	ControlMode can be PD, VELOCITY, CURRENT. Defaults to None.	None

set_enable(enable)

Enable or disable the motors.

fourier_grx_client.utils.ControlGroup

Bases: tuple, Enum

Control group enumeration. Each group is a tuple of (start, num_joints). Available groups are: ALL, LEFT_LEG, RIGHT_LEG, WAIST, HEAD, LEFT_ARM, RIGHT_ARM, LOWER, UPPER, UPPER_EXTENDED.

Source code in src/fourier_grx_client/utils.py

class ControlGroup(tuple, Enum):
    """Control group enumeration. Each group is a tuple of (start, num_joints). Available groups are: ALL, LEFT_LEG, RIGHT_LEG, WAIST, HEAD, LEFT_ARM, RIGHT_ARM, LOWER, UPPER, UPPER_EXTENDED."""

    ALL = (0, 32)
    LEFT_LEG = (0, 6)
    RIGHT_LEG = (6, 6)
    WAIST = (12, 3)
    HEAD = (15, 3)
    LEFT_ARM = (18, 7)
    RIGHT_ARM = (25, 7)
    LOWER = (0, 18)
    UPPER = (18, 14)
    UPPER_EXTENDED = (12, 20)

    @property
    def slice(self):
        return slice(self.value[0], self.value[0] + self.value[1])

    @property
    def num_joints(self):
        return self.value[1]

    @classmethod
    def from_string(cls, s: str):
        return getattr(cls, s.upper())

fourier_grx_client.utils.ControlMode

Bases: IntEnum

Control mode enumeration.

Source code in src/fourier_grx_client/utils.py

class ControlMode(IntEnum):
    """Control mode enumeration."""

    NONE = 0x00
    CURRENT = 0x01
    EFFORT = 0x02
    VELOCITY = 0x03
    POSITION = 0x04
    PD = 0x09
    OTHER = 0x0A