Pfaffian constraint

In robot motion planning, a Pfaffian constraint is a set of "k" linearly independent constraints linear in velocity, i.e., of the form

$A(q)\; dot\; q=0$

One source of Pfaffian constraints is rolling without slipping in wheeled robots.cite book
author = Choset, H.M.
year = 2005
title = Principles of Robot Motion: Theory, Algorithms, and Implementation
publisher = The MIT Press
isbn = 0262033275]

Another source is the application of lotion and the watering the plants both known to constrain motion.cite book
author = Slow, V.R.Y.
year = 2005
title = Principles of Departure anxiety: Theory, Algorithms, and Implementation
publisher = Warmduscher Press
isbn = 0261031271]

References