dynamic¶

Submodules¶

Classes¶

class brom_drake.productions.motion_planning.offline.dynamic.chem_lab2.ChemLab2(time_step: float = 0.001, meshcat_port_number: int = 7001, plan_execution_speed: float = 0.2, pose_WorldBeaker: RigidTransform = None, table_length: float = 0.6, table_width: float = 2.0, table_height: float = 0.1, shelf_pose: RigidTransform = None, gripper_type: GripperType = GripperType.Robotiq_2f_85, **kwargs)[source]¶

Description

This production is the second in the chemistry lab series. It is used to test the motion planning capabilities of the robot in a chemistry lab setting with minimal constraints, but with full dynamics of the robot included in the simulation.

The earlier chemistry lab production (ChemLab1) ignored the physics of the arm and objects in order to simplify some calculations.

Parameters

time_step: float, optional: The time step for the production, by default 1e-3.
meshcat_port_number: int, optional: The port number for meshcat visualization, by default 7001.
plan_execution_speed: float, optional: The speed at which to execute the motion plan, by default 0.2.
pose_WorldBeaker: RigidTransform, optional: The pose of the beaker in the world frame, by default None.
table_length: float, optional: The length of the table, by default 0.6.
table_width: float, optional: The width of the table, by default 2.0.
table_height: float, optional: The height of the table, by default 0.1.
shelf_pose: RigidTransform, optional: The pose of the shelf in the world frame, by default None.
gripper_type: GripperType, optional: The type of gripper to use, by default GripperType.Robotiq_2f_85.

Usage

To use this production, create an instance of the ChemLab2 class, provide it with a motion planning function, and then build it.

from brom_drake.motion_planning.algorithms.rrt.bidirectional_connect import (
    BidirectionalRRTConnectPlanner,
    BidirectionalRRTConnectPlannerConfig,
)
from brom_drake.productions import ChemLab2

# Create the production
production = ChemLab2()

# Create a planner object which will be used to plan the motion
config = BidirectionalRRTConnectPlannerConfig(
    steering_step_size=0.2,
)
planner2 = BidirectionalRRTConnectPlanner(
    production.arm,
    production.plant,
    production.scene_graph,
    config=config,
)

# To build the production, we only need to provide a planning function
# (can come from anywhere, not just a BaseRRTPlanner object)
diagram, diagram_context = production.easy_cast_and_build(
    planner2.plan,
    with_watcher=True,
)

print("Simulating...")

# Simulate the diagram
simulator = Simulator(diagram, diagram_context)
simulator.set_target_realtime_rate(2.0)

# Run simulation
simulator.Initialize()
simulator.AdvanceTo(0.05)
planned_trajectory = production.plan_dispenser.planned_trajectory

print(f"Expected end time of trajectory: {planned_trajectory.end_time()}")
simulator.AdvanceTo(planned_trajectory.end_time()+2.0)

add_beaker()[source]¶

Description

This method adds the beaker URDF to the production’s plant. The beaker’s URDF comes from the brom_drake robots directories.

add_cast_and_build(cast: List[Tuple[Role, LeafSystem | Diagram]] = [], with_watcher: bool = False) → Tuple[Diagram, Context][source]¶

Description

Modifies the normal add_cast_and_build, so that we share the context of the plant with the appropriate parts of the system.

TODO(kwesi): Consider making this a standard part of the OfflineDynamicMotionPlanningProduction class.

Parameters

cast: List[Tuple[Role, Performer]], optional: The cast to add to the production, by default [].
with_watcher: bool, optional: A Boolean that determines whether to add a watcher to the diagram, by default False.

Returns

diagram: Diagram: The built diagram.
diagram_context: Context: The context for the built diagram. This context will be used to initialize the watcher.

add_motion_planning_components()[source]¶

Description

Add the following components to the production’s builder in order to help with motion planning:

plan_dispenser: An OpenLoopPlanDispenser which will describe the reference robot trajectory.
Connections between reference trajectory and UR10e station.
Gripper control components (type of control and an “open” command)

add_shelf()[source]¶

Description

Add the shelf to the production’s plant. Welds the shelf to the world frame.

add_supporting_cast()[source]¶

Description

This method adds all secondary cast members to the builder. The secondary cast members in the production are the:

Table, where the robot exists
Test Tube Holders
Component which share’s the robot model reference
Motion Planning components (e.g., dispensers, etc.)
Start and Goal sources

add_table()[source]¶

Description

This method adds the table to the production’s plant. Welds the table to the world frame.

add_test_tube_holders()[source]¶

Description

This method adds the test tube holders to the production’s plant. Welds the test tube holders to the world frame with using predefined poses.

configure_collision_filter(scene_graph_context: Context)[source]¶

Description

This method configures the collision filter in the scene graph so that we ignore: - Self collisions of the shelf - Collisions between adjacent robot links (TODO)

Parameters

scene_graph_context: Context: The context for the scene graph.

define_pose_ik_problem(pose_WorldTarget: RigidTransform, target_frame_name: str, eps0: float = 0.025, orientation_cost_scaling: float = 0.25) → InverseKinematics[source]¶

Description

Sets up the inverse kinematics problem for the start pose input to theis function. :return:

easy_cast_and_build(planning_algorithm: Callable[[ndarray, ndarray, Callable[[ndarray], bool]], Tuple[DiGraph | ndarray, bool]], with_watcher: bool = False) → Tuple[Diagram, Context][source]¶

Description

This function is used to easily cast and build the production.

Parameters

planning_algorithm: Callable[[np.ndarray, np.ndarray, Callable[[np.ndarray], bool]],Tuple[MotionPlan, bool]]: The algorithm that we will use to plan the motion.
with_watcher: A Boolean that determines whether to add a watcher to the diagram.: by default False.

Returns

diagram: Diagram: The built diagram.
diagram_context: Context: The context for the built diagram. If with_watcher is True, this context will be used to initialize the watcher.

property goal_configuration: ndarray¶

Description

Get the goal pose.

Returns

q_goal: np.ndarray: The goal configuration of the robot.

property goal_pose: RigidTransform¶

Description

Get the goal pose of the end effector frame.

Returns

pose_WorldGoal: RigidTransform: The goal pose of the end effector frame.

property id: ProductionID¶

Description

Always returns the ProductionID for ChemLab2.

Returns

ProductionID.kChemLab2: ProductionID: The ProductionID for ChemLab2.

initialize_pose_data()[source]¶

Description

Initialize the following poses if they are not already set:

pose_WorldShelf
pose_WorldBeaker
pose_WorldHolder
pose_BeakerGoal
pose_HolderStart

solve_forward_kinematics_problem_for_arm(robot_joint_positions: ndarray) → RigidTransform[source]¶

Description

This method solves the forward kinematics problem for the UR10e arm by itself.

property start_configuration¶

Description

Get the start configuration of the robot in the production.

Returns

q_start: np.ndarray: The start configuration of the robot.

property start_pose: RigidTransform¶

Description

Get the start pose. This should be defined by the subclass.

Returns

pose_WorldStart: RigidTransform: The start pose of the end effector frame.

Functions¶

(None found)

Variables¶

brom_drake.productions.motion_planning.offline.dynamic.chem_lab2.DEFAULT_BROM_MODELS_DIR = './brom/models'¶

str(object=’’) -> str str(bytes_or_buffer[, encoding[, errors]]) -> str

Create a new string object from the given object. If encoding or errors is specified, then the object must expose a data buffer that will be decoded using the given encoding and error handler. Otherwise, returns the result of object.__str__() (if defined) or repr(object). encoding defaults to sys.getdefaultencoding(). errors defaults to ‘strict’.