We introduce a new underwater robotic platform with tilting thruster mechanism for hovering motion. The can implement six-degree-of-freedom (DOF) motion only four thrusters, but makes the system nonlinear. designed selective switching controller in order to solve nonlinear problem, and applied it robot system. divides six-DOF into two three-DOF subsystems, switches between subcontrollers according error real time. Dynamic models of disturbance model an attached manipulator are derived...

The tendon-sheath mechanism (TSM) is widely used for flexible surgical robots owing to its ability transfer motion through complicated paths and small volumes. However, precise control of the difficult nonlinear characteristics TSM due hysteresis, friction, deformation, backlash, etc. hysteretic behavior exhibits a certain tendency depending on shape TSM. In this study, our goal derive hysteresis model that applies arbitrary geometry single-curve A was formulated by combining Preisach model,...

In bone sarcomas, chemotherapy has improved the prognosis with advances in diagnostic and surgical technologies, which led to attempts save limbs. As early detection multidisciplinary treatment have survival rate, curative surgery is considered for selected patients metastatic carcinomas. Limb salvage procedures may vary relation reconstruction method, accompanied by different complications. To overcome them, we devised a novel concept,

This paper presents a forward kinematic model of wire-driven surgical robot arm with an articulated joint structure and path generation algorithms solutions inverse kinematics. The proposed methods were applied to for single-port surgery. has snake-like robotic double segments fit the working space in single port secure stiffness. accuracy is highly important because small arms are usually controlled by open-loop control. A curvature widely used describe control continuum body. However,...

SUMMARY A redundantly actuated parallel kinematic machine (PKM) can be used to avoid singularities, normalize manipulability, and increase the stiffness of anon-redundant mechanism. In this study, a symmetrical PKM with five revolute (5R) joints is optimized for isotropic in workspace. The 5R calculated by superposition actuator structural stiffness. We compared redundant PKM. Compliance ellipses non-redundant resulted same configurations workspace, while those very different configurations....

A hovering control design based on back-stepping method is proposed for a dynamic model of an underwater robot with tilting thrusters. In order to achieve various tasks, robotic platform must be able maintain its position and orientation against ocean currents reaction forces from the manipulator's operation. The which has four thrusters can carry out six degrees-of-freedom (DOF) motion. derived hydrodynamic analysis nonlinear thrust vector mapping. controller by using method, disturbance...

This paper presents a control strategy that secures both precision and manipulation sensitivity of remote center motion with direct teaching for surgical assistant robot. Remote is an essential function conventional laparoscopic surgery, the most intuitive way surgeon manipulates robot through teaching. The must maintain position insertion port in three-dimensional space during four-degree-of-freedom motions such as pan, tilt, spin, forward/backward. In addition, should move smoothly when...

This paper represents a new underwater robotic platform with four tilting thrusters for hovering motion. The mechanism can implement the six degrees-of-freedom (DOF) motion only but causes an increase in nonlinearity of thrust force vector map. In order to overcome nonlinearity, selective switching controller is designed, and applied it robot system. chooses each three-DOF sub-controller according error real-time. experiment, which maintains position orientation under disturbance from...

Starfish are a critical problem for fishermen since they eat every farming product including shellfish. The number of starfish is increasing dramatically because have no natural enemy underwater. We consider the concept capturing using semi-autonomous robot. A new underwater robot design to capture proposed cooperation between humans and requirements list developed two conceptual designs proposed. Each designed as modular platform. kinematic dynamic performance each analyzed compared. This...

This study presents a real-time algorithm for even distributing the torque burden on parallel manipulator with an autonomous underwater vehicle (AUV) through cooperation of AUV and manipulator. For redundant resolution system (UVMS), we used weighting matrix weighted pseudo inverse kinematic dynamic modeling. We made modeling using force distribution characteristics manipulators. Using manipulator’s model, was changed every second to share AUV. The Taguchi method reduce calculation time...

To enable the operator to control surgical assistant robot without a separate joystick, we aim develop an interface using artificial intelligence that responds movement of instruments in laparoscopic screen. In this study, propose method for detecting and tracking tools YOLOv5 (YOU ONLY LOOK ONCE v5) DeepSORT (Deep Learning based Simple Online Real-time Tracking) algorithms. The proposed approach employs algorithm detect real-time, track detected across multiple frames. model requires...

This paper presents gain optimization of a 6-DOF underwater robotic platform with 4 rotatable thrusters. To stabilize the motion platform, back-stepping controller is designed 6 proportional gains and derivative gains. The 12 backstepping are optimized to decrease settling time in step response independently. Stability criterion overshoots used as constraint problem. Trust-region algorithm hybrid Taguchi-Random order Coordinate search determine optimal parameters, results by two methods...

This paper presents control performance improvement by modifying center of gravity (COG) an underwater robotic platform. To reduce the oscillation or to increase positioning accuracy, it is important accurately know COG The determined three measured tilting angles platform in different postures. angle while hanged two strings. Using coordinate transformation, plane intersection defined from and position string. directly calculated intersected point planes. implemented algorithm that...