Suturing in confined spaces: Constrained motion control of a hybrid 8-DoF robot

We present our work on developing and testing the high-level control for a future tele-robotic system for minimally invasive surgery of the throat and upper airways. As a test-bed for these experiments, we used a hybrid 8 Degrees-of-Freedom (DoF) experimental robot composed of a six DoF robot and a two DoF snake-like unit. The kinematics and weighted redundancy resolution to support suturing in confined spaces, such as the throat, is developed and experimental validation in presented. The kinematics of the hybrid system is described in an 8-dimensional augmented vector space composed from the joint variables of the six DoF robot and two angles describing the configuration of the snake-like unit. Then a weighted, multi objective, optimization framework is used to perform the suturing operation under the assumption of a predefined suture geometry while satisfying joint limits, torque constraints, and minimizing extraneous motions of the system joints.