Impedance control of a robot needle with a fiber optic force sensor

Abstract

In this paper, an impedance control is proposed for a robotic needle with a fiber optic force sensor. The fiber optic force sensor is placed at the tip of the needle to directly measure the interaction force between needle and soft tissue, overcoming the noise like friction force. The sensor is sensitive to the temperature condition, and their relationship is first established, and then used to compensate for the temperature influence to enhance the force measurement. An impedance control is presented based on insertion model whose impedance parameters are identified in terms of acquired test data, and experimental results show that the control strategy is effective to avoid excessive insertion force, reducing the risk of robotic needle.