We develop a theory of continuous decoupling with bounded controls from a
geometric perspective. Continuous decoupling with bounded controls can
accomplish the same decoupling effect as the bang-bang control while using
realistic control resources and it is robust against systematic implementation
errors. We show that the decoupling condition within this framework is
equivalent to average out error vectors whose trajectories are determined by
the control Hamiltonian. The decoupling pulses can be intuitively designed once
the structure function of the corresponding SU(n) is known and is represented
from the geometric perspective. Several examples are given to illustrate the
basic idea. From the physical implementation point of view we argue that the
efficiency of the decoupling is determined not by the order of the decoupling
group but by the minimal time required to finish a decoupling cycle