RethinkGripper: invalid value for init_qpos?

[Sh0cktr4p]

It seems like the init_qpos value for the RethinkGripper is out of the bounds of the reachable qpos values.

Is there currently a method to obtain the gripper qpos bounds?

By experiment (I created an instance of the reach environment with a panda robot and a rethink gripper) it seems like the reachable gripper qpos values range from ca. [-0.01, 0.01] to ca. [0.01, -0.01], while init_qpos is set to be [ 0.020833, -0.020833].

Script to reproduce:

import robosuite

if __name__ == "__main__":
    rsenv = robosuite.make(
        "Lift",
        robots="Panda",
        gripper_types="RethinkGripper",
        has_renderer=True,
        has_offscreen_renderer=False,
        render_camera="frontview",
        control_freq=20,
        use_camera_obs=False,
        use_object_obs=False,
        horizon=200,
    )

    # Switch between episodes between opening and closing gripper
    # to show both bounds
    gripper_actuation = 1
    init_qpos = rsenv.robots[0].gripper.init_qpos
    print(f"init_qpos: {init_qpos}")
    obs = rsenv.reset()
    print(obs["robot0_gripper_qpos"])

    while True:
        rsenv.render()
        act = rsenv.action_spec[0] * 0
        act[-1] = gripper_actuation
        obs, _, done, _ = rsenv.step(act)
        gqps = obs["robot0_gripper_qpos"]
        print(f"obs: {gqps}")
        if done:
            gripper_actuation *= -1
            rsenv.reset()