Kinematics APIs

ArmKinematics

ArmKinematics provides kinematics computation interfaces for robotic arms.

Create Robotic Arm Kinematics

This method is a static method.

• Method:

  create(arg0: ArmType) -> ArmKinematics

• Parameter:

  Parameter	Description
  arg0	Robotic arm type. For details, please refer to ArmType.

• Return Value:

  An ArmKinematics instance if creation succeeds, otherwise None.

Compute Forward Kinematics

• Method:

  forward_kinematics(
    self,
    arg0: list[float]
  ) -> tuple[alphabot.core.AbcErrorCode, alphabot.core.Pose]

• Parameter:

  Parameter	Description
  arg0	Joint angles.

• Return Value:

  A tuple containing two elements.

  Element Type	Description
  AbcErrorCode	AbcErrorCode.SUCCESS indicates success. For other error codes, please refer to AbcErrorCode.
  Pose	Pose computed by forward kinematics. For details, please refer to Pose.

Compute Inverse Kinematics

• Method:

  inverse_kinematics(
    self,
    pose: alphabot.core.Pose,
    ref_joints: list[float],
    mode: int = 0
  ) -> tuple[alphabot.core.AbcErrorCode, list[float]]

• Parameters:

  Parameter	Description
  pose	End-effector pose. For details, please refer to Pose.
  ref_joints	Reference joint angles.
  mode	- 0: Numerical solution, single-step mode. Suitable when the current pose is close to the target pose; recommended for continuous motion. - 1: Numerical solution, multi-step mode. Suitable for larger differences between current and target poses; requires more computation time. - 2: Analytical solution.

• Return Value:

  A tuple containing two elements.

  Element Type	Description
  AbcErrorCode	AbcErrorCode.SUCCESS indicates success. For other error codes, please refer to AbcErrorCode.
  list[float]	Joint angles computed by inverse kinematics.

Analytical Inverse Kinematics (Single Solution)

• Method:

  inverse_kinematics_analytical(
    self,
    pose: alphabot.core.Pose,
    parameter: float,
    select: int
  ) -> tuple[alphabot.core.AbcErrorCode, list[float]]

• Parameters:

  Parameter	Description
  pose	End-effector pose. For details, please refer to Pose.
  parameter	Redundancy parameter.
  select	Index of the inverse kinematics solution set. It is recommended to use 0. Important: During continuous end-effector motion, do not change this value; keeping the selected solution fixed ensures motion continuity.

• Return Value:

  A tuple containing two elements.

  Element Type	Description
  AbcErrorCode	AbcErrorCode.SUCCESS indicates success. For other error codes, please refer to AbcErrorCode.
  list[float]	Joint angles.

Set Numerical Precision

• Method:

  set_numerical_precision(self, precision: float) -> None

• Parameter:

  Parameter	Description
  precision	Desired precision.

• Return Value:

  None.

---

ArmType

Note

This class is an enumeration. You should directly use the constant members defined within it and do not need to instantiate it.

Constant Member	Value	Description
RM65_B	0	Robotic arm type
RM65_6FB	1
RM65_6F	2
RM75_B	3
RM75_6FB	4
RM75_6F	5
ZM73L_6F	6
ZM73R_6F	7

---

TorsoKinematics

TorsoKinematics provides kinematics computation interfaces for the torso.

Create Torso Kinematics

This method is a static method.

• Method:

  create(arg0: alphabot.core.RobotType) -> TorsoKinematics

• Parameter:

  Parameter	Description
  arg0	Robot type. For details, please refer to RobotType.

• Return Value:

  A TorsoKinematics instance if creation succeeds, otherwise None.

Compute Forward Kinematics

• Method:

  forward_kinematics(
    self,
    arg0: list[float]
  ) -> tuple[alphabot.core.AbcErrorCode, alphabot.core.AbcTorsoPose4D]

• Parameter:

  Parameter	Description
  arg0	Joint angles.

• Return Value:

  A tuple containing two elements.

  Element Type	Description
  AbcErrorCode	AbcErrorCode.SUCCESS indicates success. For other error codes, please refer to AbcErrorCode.
  AbcTorsoPose4D	Pose computed by forward kinematics. For details, please refer to AbcTorsoPose4D.

Compute Inverse Kinematics

• Method:

  inverse_kinematics(
    self,
    pose: alphabot.core.AbcTorsoPose4D
  ) -> tuple[alphabot.core.AbcErrorCode, list[float]]

• Parameter:

  Parameter	Type	Description
  pose	Input	The target pose. For details, please refer to AbcTorsoPose4D.

• Return Value:

  A tuple containing two elements.

  Element Type	Description
  AbcErrorCode	AbcErrorCode.SUCCESS indicates success. For other error codes, please refer to AbcErrorCode.
  list[float]	Joint angles computed by inverse kinematics.

Check Joint Limits

• Method:

  check_range(self, arg0: list[float]) -> alphabot.core.AbcErrorCode

• Parameter:

  Parameter	Description
  arg0	Joint angles.

• Return Value:

  AbcErrorCode.SUCCESS indicates all joint values are within limits. For other error codes, please refer to AbcErrorCode.

---

RobotType

Note

This class is an enumeration. You should directly use the constant members defined within it and do not need to instantiate it.

Constant Member	Value	Description
AlphaBot1s	1	Robot Type
AlphaBot2	2
AlphaBot1s_HuiKe	3

admittance_control_law

• Method:

  admittance_control_law(
      arm: ArmKinematics,
      pose: alphabot.core.Pose,
      p_stiffness: float,
      r_stiffness: float,
      force: typing.Annotated[list[float], pybind11_stubgen.typing_ext.FixedSize(6)],
      t: float,
      q: list[float]
  ) -> tuple[alphabot.core.AbcErrorCode, list[float]]

• Parameters:

  Parameter	Description
  arm	An object of type ArmKinematics.
  pose	Current end-effector pose. Refer to Pose for details.
  p_stiffness	Translational stiffness.
  r_stiffness	Rotational stiffness.
  force	Six-dimensional spatial force applied at the end-effector, ordered as [Mx, My, Mz, Fx, Fy, Fz].
  t	Integration time, which must be less than or equal to the duration of one control loop.
  q	Current joint angles.

• Return Value:

  A tuple containing two elements.

  Element Type	Description
  AbcErrorCode	AbcErrorCode.SUCCESS indicates success. For other error codes, please refer to AbcErrorCode.
  list[float]	Joint angles for the next time step.