Motion Planning - Concepts - Configuration Space

Configuration Space

A configuration describes the pose of the robot, and the configuration space C is the set of all possible configurations. For example:

• If the robot is a single point (zero-sized) translating in a 2-dimensional plane (the workspace), C is a plane, and a configuration can be represented using two parameters (x, y).
• If the robot is a 2D shape that can translate and rotate, the workspace is still 2-dimensional. However, C is the special Euclidean group SE(2) = R2 SO(2) (where SO(2) is the special orthogonal group of 2D rotations), and a configuration can be represented using 3 parameters (x, y, θ).
• If the robot is solid 3D shape that can translate and rotate, the workspace is 3-dimensional, but C is the special Euclidean group SE(3) = R3 SO(3), and a configuration requires 6 parameters: (x, y, z) for translation, and Euler angles (α, β, γ).
• If the robot is a fixed-base manipulator with N revolute joints (and no closed-loops), C is N-dimensional.