Discrete Element Modeling to Robotic Fabrication Using the COMPAS Framework
Tutors: Tom Van Mele, Gonzalo Casas
November 7-9, 2022
10 AM–5 PM CET
Hosted by McNeel Europe (Zoom)
Digital Fabrication in the Architecture, Engineering, and Construction industry requires the combination of various toolchains and software platforms across the boundaries of multiple scientific, socio-economic and technological domains into efficient pipelines for integrated computational development and project delivery. Over the past six years, the NCCR Digital Fabrication at ETH Zurich has significantly invested in the development of COMPAS, a comprehensive open-source computational framework written in Python. COMPAS aims to streamline these multi-disciplinary workflows and integrate state-of-the-art tooling to simplify their adoption by architects, designers, and researchers from within parametric design environments.
In this 3-day workshop, Tom Van Mele of Block Research Group and Gonzalo Casas of Gramazio Kohler Research will introduce participants to COMPAS by providing an overview of the functionality of the core framework, the extension packages, the UI system, and its relation to CAD software. Together with the participants, they will explore an example application focused on the modeling, equilibrium analysis, and robotic fabrication of a discrete assembly.
By the end of this workshop, participants will be able to:
- Use the geometry kernel and core data structures of COMPAS.
- Exchange data between different processes, plugins and tools.
- Design a simple discrete element model, identify the interfaces between the blocks, and manage block interactions with a specialized data structure.
- Calculate the required conditions for equilibrium.
- Analyze and explain the kinematic structure of a robot model based on its URDF model.
- Apply fundamental building blocks of robotics (forward and inverse kinematics, cartesian and kinematic planning, planning scene).
- Design and plan stereotypical assembly processes (e.g., bricklaying) in simulation, and execute them in a simulated robot environment.
Day 1: Focus on core framework
- Overview of COMPAS framework
- Geometry & Data structures: deep dive into the geometry kernel.
- Packages & Extensions: an overview of the ecosystem.
- Integration with CAD: geometry representations and artists.
- Remote Procedure Calls: leveraging the entire Python ecosystem from within the CAD.
- Plugins & Tools, creating and distributing Grasshopper components in pure Python.
Day 2: Focus on COMPAS Masonry and FAB
- Discrete element Models: Blocks, Interfaces, Equilibrium.
- Parametric generation of discrete wall geometries using the assembly data structures.
- Definition of boundary conditions and interfaces recognition.
- Equilibrium evaluation of the assembly sequence using the solvers available in COMPAS Masonry.
- Global equilibrium of the structure subject to self-weight and after applying different loading conditions.
- Robotic fabrication.
- Fundamental concepts of robotics: control modes, positioning and singularities, robot coordinate frames and transformations.
- Description of robot models and the URDF format.
- Forward Kinematics and Inverse Kinematics (analytic and numerical solvers).
- Robotic backends: ROS (RobotOperatingSystem) and the MoveIt! Motion planning framework, Pybullet, pure-python solvers.
- Path planning: Cartesian and kinematic path planning. Goal constraints definition.
- Planning scene manipulation. Dynamic end-effector attachment and detachment.
- Prototypical structure of pick and place applications.
- Sequencing and planning of a discrete element model for robotic fabrication.
- Robot control (ABB and UR).
Day 3: Integrative project
- Procedural generation of curved wall geometry.
- Conversion to assembly data structure.
- Methods for interface detection.
- Stability assessment of intermediate assembly stages.
- Stability assessment of the complete structure.
- Path planning for robotic assembly.
- Fabrication simulation.
Course requirements: Participants are expected to be familiar with Rhino/Grasshopper and have at least a basic knowledge of python programming.
Online course fees: EUR 395,- (+VAT); full-time students and university teachers get a 50% discount (proof of status required). Please note that we will confirm your seat after your payment has cleared.
Max. number of participants: 25. If there is no quorum, the course will be canceled two weeks before.
Course language: English
Educational seats are limited. Sign up now by contacting McNeel Europe!
Posted Oct 13, 2022 by Verena Vogler on Rhino News, etc.