Unmanned helicopters have broad application prospects and have become a hot research area. The flight control system is the key to achieve the autonomous flight of unmanned helicopters. The computer vision system onboard is a effective way to enhance the functional of unmanned helicopters. This thesis focuses on flight controller design and visual servo system design methods for unmanned helicopters. The main context and contributions of this thesis are as follows: Firstly, according to the analysis of the helicopter's dynamics, a flight controller based on H∞ loop shaping robust control has been designed. A concise and effective parameters tuning method is proposed for this flight controller. This method takes the stability margin, frequency field index, time field index and the limitation of actuators into consideration. The flight controller tuned by this method achieved a balanced performance. To enhance the controller's performance over wide flight envelope, a gain scheduling method which focuses on the key parameters is proposed. The flight controller is validated by simulation. Secondly, a vision system onboard is built using a DSP embedded system. A fast target detection method is designed and implemented on this DSP embedded system. Since the camera is fixed on the helicopter, the varying attitude of the helicopter can bring difficulty to visual servo. A new visual servo method which combines the image information and the inertial navigation information is proposed to deal with the varying attitude of the helicopter. The vision system has successfully controlled an unmanned helicopter to follow a moving target in experimental flights. Thirdly, based on the inverse kinematical analysis of a two degree-of-freedom pan-tilt camera and the Jacobian matrix of the pan-tilt camera, a motion controller which combines the H∞ loop shaping robust control and feed-forward control is proposed to control the pan-tilt camera. The helicopter's angular velocity measured by IMU onboard is used by the feed-forward control to solve the influence of the helicopter's varying attitude on the stabilization of the camera's line-of-sight. The motion controller is validated in simulation. Fourthly, based on the motion controller of the pan-tilt camera, a vision system onboard for tracking ground targets is designed. A ground moving target tracking method for the helicopter is proposed and a tracking control law is designed based this method. The proposed method utili...
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