Multiple-point contact with friction: Computing forces and motions in configuration space

This article summarizes ideas on representing translational friction and computing reaction forces in configuration space. The configuration space of an object is the parameter space describing the object's degrees of freedom. Kinematic constraints imposed on the object by obstacles in the environment may be represented as hypersurfaces in the configuration space. Physical and dynamical constraints such as those imposed by friction may be represented as constraints in the generalized force space that accompanies the configuration space. This article develops a representation of friction in this generalized force space that is analogous to the classical friction cone in real space.