Full Order High Gain Observer Design for Image-Guided Robotic Flexible Needle Steering

This paper represents a full state observer for the imaged guided robotic flexible needle. In many minimally invasive surgeries flexible needles are utilized, but because of the low accuracy of the imaging systems and needle tip size, the orientation of the needle cannot be measured directly. On the other hand, most of the proposed controllers need needle orientation in feedback law and thus, they are designed based on this fact that these states are directly available. According to the importance of this issue, in this paper a high-gain full observer is proposed and its stability is analyzed. Furthermore, it has been shown that the tracking error of any stable controller under some assumptions will remain bounded in case of utilizing observed states instead of the real states.