Figure 1. The use of visual servo control for helicopter stabilization-Design and Implementation of a Fully Autonomous UAV's Navigator Based on Omni-directional Vision System

Visual servoing is an approach to control motion of a helicopter using information feedback
from a camera mounted on it. For their tremendous potential applications in various areas including
environmental monitoring and anti-terrorism, unmanned small helicopters are being extensively
studied in robotics and control in recent years. However, the research advance in dynamic control of
small helicopters is limited due to highly coupled non- linear dynamics and the existence of various
uncertain- ties. Many people studied controller design based on a Publisher Item Identifier.
linearized or simplified model, but the controllers developed under linearized models cannot
guarantee dynamic stability rigorously. Another effort is application of modern non-linear control
theory to helicopter control because small helicopter are good test beds for sophisticated control
techniques for their small size and highly coupled dynamics [4].