brom-drake 0.0.2

A set of convenient logging and testing tools for the Drake robotics toolbox.

brom_drake-py

Brom is a helper library for the Drake robotics simulation and verification library. Its goal is to simplify logging and robustness characterization of Drake simulations.

Use Cases

Here are a few of the features available in brom_drake and how they work.

Easily Log Your Diagram's Signals

It is recommended that you use the convenience function add_watcher_and_build to add a DiagramWatcher to your diagram.

# Drake imports
from pydrake.all import (
    DiagramBuilder, Simulator,
)
# All your other imports

from brom_drake.all import add_watcher_and_build

# Create a diagram builder
builder = DiagramBuilder()

# Add and connect your systems...

# Add the watcher and build the diagram
dw, diagram, diagram_context = add_watcher_and_build(builder)

# Set up simulation
simulator = Simulator(diagram, diagram_context)
simulator.set_target_realtime_rate(1.0)
simulator.set_publish_every_time_step(False)

# Run simulation
simulator.Initialize()
simulator.AdvanceTo(15.0)

What will happen whenever you use this function is that:

• The DiagramWatcher will be created.
  • It will search through all systems that the DiagramBuilder has added.
  • For each system, the watcher will add a VectorLogger to each output port that is a kVectorValued port.
  • The DiagramWatcher will connect all loggers to all targeted ports (in the above case, we will target all available output ports).
• After the simulation is run and the script completes, the watcher will save all data traces for each port in .png files. These plots will be in a new .brom directory.

Installation

brom_drake is available on PyPI and installable with pip:

pip install brom-drake

Developer install

You can also install the package during local development by cloning the repository and running the following commands from inside it:

pip install -r requirements.txt
pip install -e .

FAQs

Why the name Brom?

Brom the storyteller is a character from the Inheritance series by Christopher Paolini. He is a wise mentor that helps Eragon (the protagonist) master dragons. ;)

Related Work

Some other work in the open-source drake community:

• kinova_drake - A Drake-based library that builds a simple version of the manipulation station for the Kinova Gen3 robot arm. Also works with the hardware.
• airo-drake - A python package meant to simplify working with Drake and the airo-mono repository from the AI and Robotics Lab at Ghent University.

To-Dos

• Figure out how to tell if two systems are connected in Drake.
• Demonstrate how to create a simple Vector logger for the tutorial's diagram.
  • Determine if we can use DiagramTarget objects to do everything (assuming that they are all valid). i.e., with the name and the port # can we do waht we want?
• Add more examples
• Add Code coverage
• Add support for abstract output ports?
• Add more readme explanations of what is going on under the hood.
• Add support for giving DiagramTarget (or simpler objects) to the convenience functions.
• Add to PyPI