The workshop will be held on November 4, 2019, in The Venetian Macao Resort Hotel, Macau, China in the context of the IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), one of the largest and highest impact robotics research conferences worldwide.

The workshop will be the first behavior tree-related workshop within the robotics community. We aim to gather all the outstanding researchers interested in BTs to share ideas and lesson learned. For that reason, the workshop format will include invited talks as well as short spotlight presentations followed by interactive sessions.


Behavior Trees is a new powerful tool for task switching and decision making that is receiving an increasing amount of attention in robotics. Recent research is beginning to explore areas such as learning, planning, and control in domains ranging from Micro Air Vehicles to Assembly robotics.

The objectives of this workshop are as follows:

Behavior Trees were developed in the video game industry as a tool to achieve modular, reusable, and flexible behaviors for Non-Player Characters (NPCs), and are now an established tool to the point that BTs are integral parts of game AI textbooks as well as major game engines such as Unity3d, and the Unreal Engine. In the last decade, Behavior Trees have received an increasing amount of attention in robotic as well, with applications in both academia and industry. The main advantages of Behavior Trees with respect to conventional execution architectures, like FSMs, are their ability to combine reactivity with deliberation in a very modular way.

Topics of interest

The following list provides a set of topics (keywords) addressed in the workshop.


Workshop Program

Time Activity
09:15 - 09:45 Invited Talk by Simon Jones
09:45 - 10:00 Spotlight presentations for interactive talks/posters
10:00 - 10:45 Interactive session for interactive talks/posters
10:45 - 11:15 Coffee break
11:15 - 11:45 Invited Talk by Vincent Berenz
11:45 - 12:15 Invited Talk by Chris Paxton
12:00 - 12:15 Spotlight presentations for interactive talks/posters
12:15 - 13:00 Interactive session for interactive talks/posters
13:00 - 14:00 Lunch Break
14:00 - 14:30 Invited Talk by Francesco Rovida
14:30 - 15:00 Invited Talk by Enrique Coronado
15:00 - 15:30 Invited Talk by Petter Ögren
15:45 - 16:15 Coffee Break
16:15 - 18:00 Open Discussion

Invited Speakers

Simon Jones (University of the West of England)

Onboard Evolution of Understandable Swarm Behaviours

Designing the individual robot rules that give rise to emergent swarm behaviours is difficult.
The common method of running evolutionary algorithms to automatically discover controllers
in simulation suffers from a major disadvantage; the evolved controllers are often opaque
and hard to understand. We use behaviour trees as the controller architecture because they
are modular, hierarchical and human understandable. We evolve fit controllers in a swarm with
high processing power, use automatic tools to simplify them, and then explain them, an important
factor for safety and acceptance. We look at the design of a suitable behaviour tree architecture,
applying the techniques of Genetic Programming to behaviour trees, the implementation of a fast
parallel simulator and tree interpreter running on the GPUs of our swarm of robots, how large
evolved trees can be automatically simplified to aid analysis, and then explain one of the
evolved controllers.

Vincent Berenz (Max Planck Institute for Intelligent Systems)

Behavioral Reactivity: Using Reactive Programming to Create Behavior Trees

We will present how to apply reactive programming to the design of robot behavior tree.
Using this paradigm, user defines branches and then associate them with rules of activation.
Contrary to other approaches, the behavior tree is not traversed at runtime. Rather the branches
compete continuously one with another for activation. And because branches can be attached to
targets (discretized high level sensor entities), the activation of a branch will correspond to
the activation of a specific set of sensory motor couplings that will shape the behavior of the robot.
As various videos will show, this programming paradigm supports rich and complex behaviors
characterized by high behavioral reactivity. Playful, our open-source reactive programming
interpreter supporting behavior trees, will be introduced. Our more recent work exploring
the automated generation of reactive programming scripts from human demonstration will also be discussed.

Chris Paxton (NVIDIA)

Building Reactive Task Plans for Real-World Robot Applications

Robots are increasingly an important part of our world, from working in factories and hospitals
to driving on city streets. As robots move into more unstructured environments such as homes,
however, we must be able to create complex, reactive task plns that can deal with stochastic
actions, unreliable sensors, and that above all are intuitive and easy to build. To this end,
we created the Behavior Tree-based CoSTAR system -- which allows novice end users to create
task plans for industrial robot task plans, shown in a 35-person user study to be highly
user friendly and offer a useful set of tools for creating task plans.
We also describe a variant on Behavior Trees, the Robust Logical-Dynamical System (RLDS),
which supports symbolic task planning and guarantees on performance. Finally, we describe a
manipulation case study on an example of an unstructured household manipulation task.

Francesco Rovida (Aalborg University)

Practical application of Behavior trees for industrial robot task design

Reconfigure collaborative robots on new tasks quickly and efficiently is today one
of the great challenges for manufacturing industries. In this respect, behavior trees
already proved to be a great tool to design and execute complex coordination schemes
that are hierarchical, highly modular and with a predicable outcome. Nevertheless,
being a state-less logic in their classical form, BT have more problems representing
sequences w.r.t. other approaches such as e.g. FSMs. In this presentation we will see
how we adapted the classical BT model to fit in a working framework that encompases
dynamic planning, BTs optimization and knowledge management.

Enrique Coronado (Tokyo University of Agriculture and Technology)

Empowering End-Users with Behavior Trees, Development of Human-Robot Applications Performing "in the Wild"

In many cases, the creation of robot applications performed “in the wild” (i.e., moving from
the laboratory to natural and in-situ scenarios) require to include end-users (e.g. therapists,
psychologies, teachers, and artists) for their suitable design and testing. In order to support
end-user goals, we developed RIZE (Robot Interface from Zero Experience) a cross-platform End-User
Development tool back-ended by Component-Based Distributed Robot Frameworks. This interface
enables intuitive robot programming by the use of block-based Visual Programming Languages,
which translate the user code to Behavior Trees for its posterior execution.
In this presentation, we will show how this interface has been used in the development
of short-term and long-term Human-Robot Interaction applications performed in “in the wild”.

Call for Papers

Information for Authors

All submissions must be in PDF format, following the IEEE conference style in two-column and be limited to 2 pages: http://ras.papercept.net/conferences/support/support.php

All submissions will be peer-reviewed. Accepted papers will be presented during the workshop in a poster session. A number of selected papers will be presented as oral presentations or spotlight talks.

Send your PDF manuscript by email, with the subject including the prefix "[BTRS IROS 2019]", to the following email: michele.colledanchise[at]iit.it (replace [at] with @).

Important Dates

September 25, 2019 - Submission Deadline

October 15, 2019 - Acceptance/Rejection Notification

November 4, 2019 - Full-day Workshop