simulo.DifferentialIKController

Differential inverse kinematics controller for task-space robot control.

Attaches to a robot and computes joint commands to move the end-effector to desired poses. User must explicitly specify which joints to control.

Example:

import simulo

class MyScenario(simulo.Scenario):
    def build(self, scene):
        self.robot = simulo.Robot(asset=simulo.Asset.usd("builtin://franka_panda"))
        scene.add(self.robot, at="/World/Robot")

    def on_start(self):
        # Create IK controller - explicitly specify joints
        self.ik = simulo.DifferentialIKController(
            robot=self.robot,
            end_effector="panda_hand",
            joints=self.robot.find_joints("panda_joint.*"),
        )

        # Define target pose
        self.target = simulo.Pose(
            position=[0.5, 0.3, 0.7],
            orientation=[1.0, 0.0, 0.0, 0.0],
        )

    def on_step(self):
        # Move end-effector to target
        self.ik.move_to(self.target)

Attributes:

• robot — The robot this controller is attached to
• end_effector — Name of the end-effector body/link
• joints — List of joint indices being controlled
• ik_method — IK solver method (“dls”, “pinv”, “svd”, “trans”)

simulo.DifferentialIKController(
    robot: Robot,
    end_effector: str,
    joints: List[int],
    ik_method: Literal['dls', 'pinv', 'svd', 'trans'] = 'dls',
    command_type: Literal['pose', 'position'] = 'pose',
)

move_to()

DifferentialIKController.move_to(target: Union[Pose, torch.Tensor, List[float]]) -> None

Move end-effector toward target pose.

Call this every simulation step. The controller computes joint commands and applies them to the robot automatically.

Args:

• target — Target pose in robot base frame. Can be: - simulo.Pose object - Tensor of shape (7,) or (num_envs, 7) with [x, y, z, qw, qx, qy, qz] - List [x, y, z, qw, qx, qy, qz]

Example:

# Using Pose object
target = simulo.Pose(position=[0.5, 0.3, 0.7], orientation=[1, 0, 0, 0])
self.ik.move_to(target)

# Using list
self.ik.move_to([0.5, 0.3, 0.7, 1.0, 0.0, 0.0, 0.0])

reset()

DifferentialIKController.reset() -> None

Reset controller state.

Call this when resetting the robot to a new state.

ee_body_idx

DifferentialIKController.ee_body_idx: Optional[int]

property

Get the end-effector body index.