Master-slave system using a 4-DOF parallel mechanism

Master-Slave System Using a 4-DOF Parallel Mechanism with 1-DOF Translation and 3-DOF Rotation

This technology is a master-slave system that enhances operational feel and positioning precision during delicate tasks by applying a 4-DOF parallel mechanism—providing 1-DOF translational and 3-DOF rotational motion—to both the master and slave devices. The master device detects user movement through a spherical mechanism (3-DOF) and a translational link (1-DOF), while the slave device performs precise tasks such as needle insertion via a parallel link and guide link. A control unit provides force-reflection (haptic) feedback.

Serial robots suffer from low precision due to inertia and cumulative errors, while existing 3-DOF or 6-DOF parallel mechanisms often face issues with reduced efficiency and hardware complexity due to degree-of-freedom mismatches in specific precision tasks like needle insertion.

This technology aligns degrees of freedom by designing an identical 4-DOF parallel mechanism (3-DOF rotation, 1-DOF translation) for both the master and slave ends. It increases structural rigidity by introducing a rack-and-pinion-based sliding joint and a spherical mechanism where rotational axes intersect at a single point. Precise haptic feedback is delivered to the user through reaction force signal control using force sensors and actuators. It can be applied to precision surgical robots, needle insertion procedures, and remote manipulation, ensuring high efficiency in delicate tasks by improving operational feel and positioning accuracy.

‍

‍

Key Features:

• A slave device comprising a parallel link unit connected between a slave base and a movable part to enable 3-DOF rotational and 1-DOF translational motion of the movable part relative to the slave base, and a guide link unit that directs the translational motion of the movable part.
• A parallel link unit connected between a slave base and a movable part to enable 3-DOF rotational and 1-DOF translational motion of the movable part relative to the slave base.
• A master device comprising a translational link unit connected to an input part to enable 1-DOF translational motion of the input part relative to a master base.
• A spherical mechanism connected between a master base and an input part to enable 3-DOF rotational motion of the input part relative to the master base.

‍

This invention was developed with support from the Basic Research Support Program for research on intelligent continuum robot theory and applications.