Pallet Model

In this example, you will define a pallet simulation model as well as a simulation with a pallet and a box, see Fig. 9.

Fig. 9 The pallet and the box in the voraus simulation

Run the Simulation

Open localhost:8077 in your web browser to display the simulation. Open a terminal in VS Code and start the pallet.py Python script with the following command:

python models/pallet/pallet.py

The static pallet object will be loaded into the simulation. A box falls onto the pallet and remains leaning against it as shown in Fig. 9.

The Pallet Python File

The Python file models/pallet/pallet.py defines the pallet simulation model.

"""Describes a pallet simulation model."""

from pathlib import Path

from voraus_3d_visu import Visu

from voraus_simulation import StaticObject

models = Path(__file__).parent


class Pallet(StaticObject):
    """Defines a pallet simulation model."""

    def __init__(self, position: list[float] | None = None, rotation: list[float] | None = None) -> None:
        """Initializes a pallet simulation model.

        Args:
            position: The initial position. Defaults to None.
            rotation: The initial rotation. Defaults to None.
        """
        glb_path = models / "pallet.glb"
        urdf_path = models / "pallet.urdf"
        super().__init__(glb_path, urdf_path, position, rotation)


if __name__ == "__main__":
    import sys
    from math import radians

    sys.path.append(str(Path(__file__).parent.parent.parent))
    from models.box.box import Box

    from voraus_simulation import Simulation

    simulation = Simulation(frequency=50, visualization=Visu("http://voraus-3d-visu/"))

    with simulation.run():
        StaticObject(glb_file=None, urdf_path=Path("plane_transparent.urdf"))
        pallet = Pallet([0.76, 0.10, 0.11], rotation=[0, 0, radians(5)])
        Box([1.24, 0.10, 0.3])

        frame = 0
        while frame < 100:
            simulation.step()
            simulation.sleep()
            frame += 1

The Pallet URDF File

The URDF file models/pallet/pallet.urdf defines the pallet simulation parameters.

<?xml version="1.0" ?>
<robot name="box">
  <link name="baseLink">
    <contact>
      <lateral_friction value="1.0"/>
      <rolling_friction value="0.0"/>
      <contact_cfm value="0.0"/>
      <contact_erp value="1.0"/>
    </contact>
    <inertial>
      <origin rpy="0 0 0" xyz="0 0 0"/>
       <mass value="0"/>
       <inertia ixx="1" ixy="0" ixz="0" iyy="1" iyz="0" izz="1"/>
    </inertial>
    <visual>
      <origin rpy="0 0 0" xyz="0 0 0"/>
      <geometry>
		    <mesh filename="pallet.obj" scale="1 1 1"/>
      </geometry>
      <material name="white">
        <color rgba="1 1 1 1"/>
      </material>
    </visual>
    <collision>
      <origin rpy="0 0 0" xyz="0 0 0"/>
      <geometry>
	      <mesh filename="pallet.obj" scale="1 1 1"/>
      </geometry>
    </collision>
  </link>
</robot>