why is the mocap position not fixed

[yijing2050]

Hello ,when I test the examples/mobile_tidybot.py, run it,the output is as follows。
pinch_site pose: [0.57666519 0.0013501 0.76872431]
the code of mobile_tidybot.py is as follows:
from dataclasses import dataclass
from pathlib import Path

import mujoco
import mujoco.viewer
import numpy as np
from dm_control.viewer import user_input
from loop_rate_limiters import RateLimiter

import mink

_HERE = Path(file).parent
_XML = _HERE / "stanford_tidybot" / "scene.xml"

@DataClass
class KeyCallback:
fix_base: bool = True
pause: bool = True

def __call__(self, key: int) -> None:
    if key == user_input.KEY_ENTER:
        self.fix_base = not self.fix_base
    elif key == user_input.KEY_SPACE:
        self.pause = not self.pause

if name == "main":
model = mujoco.MjModel.from_xml_path(_XML.as_posix())
data = mujoco.MjData(model)

# Joints we wish to control.
# fmt: off
joint_names = [
    # Base joints.
    "joint_x", "joint_y", "joint_th",
    # Arm joints.
    "joint_1", "joint_2", "joint_3", "joint_4", "joint_5", "joint_6", "joint_7",
]
# fmt: on
dof_ids = np.array([model.joint(name).id for name in joint_names])
actuator_ids = np.array([model.actuator(name).id for name in joint_names])

configuration = mink.Configuration(model)

end_effector_task = mink.FrameTask(
    frame_name="pinch_site",
    frame_type="site",
    position_cost=1.0,
    orientation_cost=1.0,
    lm_damping=1.0,
)

posture_cost = np.zeros((model.nv,))
posture_cost[3:] = 1e-3
posture_task = mink.PostureTask(model, cost=posture_cost)

immobile_base_cost = np.zeros((model.nv,))
immobile_base_cost[:3] = 100
damping_task = mink.DampingTask(model, immobile_base_cost)

tasks = [
    end_effector_task,
    posture_task,
]

limits = [
    mink.ConfigurationLimit(model),
]

# IK settings.
solver = "quadprog"
pos_threshold = 1e-4
ori_threshold = 1e-4
max_iters = 20

key_callback = KeyCallback()

with mujoco.viewer.launch_passive(
    model=model,
    data=data,
    show_left_ui=True,
    show_right_ui=True,
    key_callback=key_callback,
) as viewer:
    mujoco.mjv_defaultFreeCamera(model, viewer.cam)

    mujoco.mj_resetDataKeyframe(model, data, model.key("home").id)
    configuration.update(data.qpos)
    posture_task.set_target_from_configuration(configuration)
    mujoco.mj_forward(model, data)

    # Initialize the mocap target at the end-effector site.
    mink.move_mocap_to_frame(model, data, "pinch_site_target", "pinch_site", "site")

    rate = RateLimiter(frequency=200.0, warn=False)
    dt = rate.period
    t = 0.0
    while viewer.is_running():
        # Update task target.
        T_wt = mink.SE3.from_mocap_name(model, data, "pinch_site_target")
        end_effector_task.set_target(T_wt)

        # Compute velocity and integrate into the next configuration.
        for i in range(max_iters):
            if key_callback.fix_base:
                vel = mink.solve_ik(
                    configuration, [*tasks, damping_task], rate.dt, solver, 1e-3
                )
            else:
                vel = mink.solve_ik(configuration, tasks, rate.dt, solver, 1e-3)
            configuration.integrate_inplace(vel, rate.dt)

            # Exit condition.
            pos_achieved = True
            ori_achieved = True
            err = end_effector_task.compute_error(configuration)
            pos_achieved &= bool(np.linalg.norm(err[:3]) <= pos_threshold)
            ori_achieved &= bool(np.linalg.norm(err[3:]) <= ori_threshold)
            if pos_achieved and ori_achieved:
                break

        if not key_callback.pause:
            data.ctrl[actuator_ids] = configuration.q[dof_ids]
            mujoco.mj_step(model, data)
        else:
            mujoco.mj_forward(model, data)

        # Visualize at fixed FPS.
        viewer.sync()
        rate.sleep()
        t += dt
    print("pinch_site pose:", data.sensordata[:3])

in the examples/stanford_tidybot/tidybot.xm I added




I am curious the position of mocap ,we set it pos="0.5 0 .5",as follows









after running the code,why the output is " pinch_site pose: [0.57666519 0.0013501 0.76872431]",the pinch _site pose is also the mocap pose.When I modify the pose of pinch_site_target to pos="2.5 0 1.5", the output is the same after running the code.Looking forwards to your reply! Thanks

[yijing2050]

in the examples/stanford_tidybot/tidybot.xm I added
...

...

I am curious the position of mocap ,we set it pos="0.5 0 .5",as follows