PinkSolver

PinkSolver#

PinkSolver uses Pink and Pinocchio for task-based IK, including frame targets and null-space posture objectives.

Configuration Example#

from embodichain.data import get_data_path
from embodichain.lab.sim.motion.solvers.pink_solver import PinkSolverCfg
from embodichain.lab.sim.motion.solvers.null_space_posture_task import NullSpacePostureTask

posture_task = NullSpacePostureTask(
    cost=1e-3,
    controlled_frames=["ee_link"],
)

cfg = PinkSolverCfg(
    urdf_path=get_data_path("UniversalRobots/UR5/UR5.urdf"),
    end_link_name="ee_link",
    root_link_name="base_link",
    max_iterations=500,
    pos_eps=1e-4,
    rot_eps=1e-4,
    dt=0.05,
    damp=1e-10,
    is_only_position_constraint=False,
    fail_on_joint_limit_violation=True,
    solver_type="osqp",
    variable_input_tasks=None,
    fixed_input_tasks=[posture_task],
)

solver = cfg.init_solver(device="cpu")
solver.update_null_space_joint_targets([0.0] * 6)

Solver-specific behavior#

See shared FK/IK conventions for the common call pattern and return order.

get_ik() returns success flags (B,) and joint solutions (B, 1, DOF). Failed targets retain their seeds. return_all_solutions=True still returns one locally optimal solution per target. Seeds may be unbatched, broadcast from (1, DOF), or supplied per target.

Use fixed_input_tasks for posture objectives and update_null_space_joint_targets() to change their target posture.

References#

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