Triple Scissor Extender: A 6-DOF Lifting and Positioning Robot

TL;DR

This paper introduces a novel 6-DOF robotic mechanism called the Triple Scissor Extender, capable of reaching high ceilings and precise positioning through coordinated linear actuators and scissor mechanisms.

Contribution

The paper presents the design, kinematic modeling, and experimental validation of a new 6-DOF robotic extender using three scissor mechanisms with independent actuators.

Findings

Kinematic analysis and inverse Jacobian eigenvalues characterized the robot's properties.

A prototype demonstrated effective reach and positioning capabilities.

Experimental evaluation validated the differential control approach.

Abstract

We present a novel 6 DOF robotic mechanism for reaching high ceilings and positioning an end-effector. The end-effector is supported with three scissor mechanisms that extend towards the ceiling with 6 independent linear actuators moving the base ends of the individual scissors. The top point of each scissor is connected to one of three ball joints located at the three vertices of the top triangular plate holding the end-effector. Coordinated motion of the 6 linear actuators at the base allows the end-effector to reach an arbitrary position with an arbitrary orientation. The design concept of the Triple Scissor Extender is presented, followed by kinematic modeling and analysis of the the Inverse Jacobian relating actuator velocities to the end-effector velocities. The Inverse Jacobian eigenvalues are determined for diverse configurations in order to characterize the kinematic properties. A proof-of-concept prototype has been designed and built. The Inverse Jacobian for use in differential control is evaluated through experiments.