from typing import Dict
import numpy as np
from pybullet_industrial.material import Plastic
from pybullet_industrial.raycaster import RayCaster
from pybullet_industrial import RobotBase
[docs]
class Extruder(RayCaster):
"""Special Endeffector Tool which can extrude material from its tcp.
Args:
urdf_model (str): A valid path to a urdf file describint the tool geometry
start_position (np.array): the position at which the tool should be spawned
start_orientation (np.array): the orientation at which the tool should be spawned
extruder_properties(Dict): A dictionary containing the properties of the extrusion head.
During initialization only 'material' has to be set.
Default Values are:
'opening angle':0,'number of rays':1,
'material properties': {'particle size':0.03,
'color' : [1, 0, 0, 1]},
'maximum distance':1,'material':Particle,
coupled_robot (RobotBase, optional): A pybullet_industrial.RobotBase object if
the robot is coupled from the start.
Defaults to None.
tcp_frame (str, optional): The name of the urdf_link
describing the tool center point.
Defaults to None in which case the last link is used.
connector_frame (str, optional): The name of the urdf_link
at which a robot connects.
Defaults to None in which case the base link is used.
Raises:
ValueError: If no material is provided during initialization.
"""
def __init__(self, urdf_model: str, start_position: np.array, start_orientation: np.array,
extruder_properties: Dict, coupled_robot: RobotBase = None,
tcp_frame: str = None, connector_frame: str = None):
super().__init__(urdf_model, start_position, start_orientation,
coupled_robot, tcp_frame, connector_frame)
self.properties['material'] = Plastic
self.properties['material properties'] = {
'particle size': 0.03, 'color': [1, 0, 0, 1]}
self.change_properties(extruder_properties)
[docs]
def calculate_process_force(self, ray_cast_results, tcp_frame=None):
"""Function calculating the process force of the milling tool.
Args:
ray_cast_results (list): The result of a batch ray cast
as performed by the remove function
tcp_frame (str): The name of the tool center point frame. Defaults to None.
Returns:
np.array: a 3 dimensional array containing the process force in the x,y,z direction
"""
return np.zeros(3)
[docs]
def extrude(self, tcp_frame: str = None):
"""Extrudes material from the specified tcp_frame.
Args:
tcp_frame (str, optional): the name of the link from which to extrude the material.
Defaults to None in which case the default tcp is used
"""
position, orientation = self.get_tool_pose(tcp_frame)
ray_cast_results = self.cast_rays(position, orientation)
process_force = self.calculate_process_force(
ray_cast_results, tcp_frame)
self.apply_tcp_force(process_force, tcp_frame)
particle_list = []
for ray_intersection in ray_cast_results:
if ray_intersection[0] != -1:
particle = self.properties['material'](ray_intersection,
self.properties['material properties'])
particle_list.append(particle)
return particle_list