Collision Checking Library

This repository contains a collection of structs, functions and classes to perform collision queries and minimum distance computations for simple geometric shapes. The code is intended and most suitable for motion planning and control applications (i.e,. not dynamics simulations).

Overview

Distance computation The most basic functions provide distance computation for sphere, capsule (a.k.a. sphere swept line) and box geometries. These functions can be found in files named distance_<object>_<object>.h. They are suitable for hard real-time and non real-time systems and can be compiled as CUDA code for use on GPUs. These can be used as building blocks for higher-level functions. Some serial CPU versions are provided in the repository (see below).

Composite object distance computation compute_collisions.h provides a free function that performs distance computations or collision queries for CollisionObjects and a VoxelMapObject. The CollisionObjects are a collection of composite objects that are themselves composed of supported primitive shapes. Each composite object will typically be a single robot link, an object grasped by a robot or a static environment object with simple geometry. The VoxelMapObject is a 'sphere world' intended to represent an environment map that may contain a large number of elements and is generated from sensor data via a voxel map, surfel map or similar representation. There is some basic AABB-based pre-filtering of collision pairs to accelerate distance queries. Which object pairs are considered can be configured via the ObjectFlags variables, see object_id.h.

Collision queries for articulated systems The AssemblyCollisionChecker template provides a higher-level interface for performing collision queries for articulated systems with a floating base and tree topology consisting of hinge and prismatic joints. The class template provides methods that also perform the required forward kinematics. Most applications will want to start with this.

Things to Tweak

If you intend to integrate this into an existing system, you will probably want to edit the code in collision_checking/logging.h to use whatever the target system uses. Likewise, you might want to replace any calls to absl logging functions with something more appropriate.