A study on state and perturbation observers of the controller of surgical robot instrument

In spite of the nonlinear characteristic of cable pulley mechanism, surgical robot instrument has adopted it for safety. To operate the instrument properly, it needs robust control algorithm to overcome the nonlinear and uncertainty of the system. In the previous study, the sliding mode control with sliding perturbation observer has been applied to surgical robot instrument. Especially, the research result showed that perturbation observer followed up the operating force on the end effect of the instrument. The result motivated this paper to study the perturbation observer ability to estimate the operating force of surgical robot instrument which is still unable to measure. In this study, Luenberger Observer and sliding Observer are applied and compared in surgical robot instrument control. Also, both two observers are used to build perturbation observer. Those observers are evaluated by simulation test on the dynamic model of cable pulley structure used in surgical robot instrument. And experimental test is performed in same time.