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Visual Servoing  

Visual servoing is a theoretical framework that allows stability analysis and design of visual feedback control systems. This framework is useful to study the image processing methods that is suitable for feedback control and to study the configuration of robot-camera systems that are robust against calibration errors.

Theoretical Framework of Visual Servoing

One of the most standard problems in visual servoing is for a robot manipulator that has a camera on its end effector to reduce the error between the current image captured by the camera and a desired image. The following movie shows robot motion that achieves the goal while keeping image features in the field of view.

Our works: - G. Chesi and K. Hashimoto. Keeping features in the field of view in eye-in-hand visual servoing:a switching approach. IEEE Trans. on Robotics, Vol. 20, No. 5, pp. 908-913, 2004. - K. Hashimoto. A review on vision-based control of robot manipulators. Advanced Robotics, Vol. 17, No. 10, pp. 969-991, 2003.

Visual Servoing with Occlusion Handling

Visual information is not always suitable for feedback control. For example, a target is invisible when an object passes between the target and the camera. We have proposed a visual servo control technique with occlusion handling with solve the occlusion problem. In the following movie, a micro helicopter was controlled by using visual information given by stationary cameras. The proposed method can keep a stable hover while a man walked in the flight field.

Our works: - Y. Iwatani, K. Watanabe, and K. Hashimoto. Visual tracking with occlusion handling for visual servo control. In Proc. of 2008 IEEE International Conference on Robotics and Automation, pp. 101-106, Pasadena, USA, 2008. - Y. Yoshihata, K. Watanabe, Y. Iwatani, and K. Hashimoto. Visual control of a micro helicopter under dynamic occlusions. In S. Lee, I. H. Suh, and M. S. Kim, editors, Recent Progress in Robotics: Viable Robotic Service to Human, pp. 185-197. LNCIS, Springer-Verlag, 2008.

Formation Control of Micro Helicopters

Our visual servoing techniques have been implemented in a micro helicopter control systems, and formation control of micro helicopters has been accomplished.

Our work: - Y. Iwatani, Kohou, and K. Hashimoto. Multi-camera visual servoing of multiple micro helicopters. In Proc. of SICE Annual Conference 2008, pp. 2432-2435, Tokyo, Japan, 2008.