Orthodromic navigation through conic rotation driven by active universal joints with three degrees of freedom

The universal joint is a senior machine element. With the purpose of exploring new applications this paper focuses on active universal joints with three degrees of freedom. This means to embed small motors acting on its gimbals. The objective of this study is therefore to investigate the viability of the proposition through an experiment and formulate a mathematical model that allows for exploring the limits of the design using numerical simulations. A specific joint was designed and manufactured that included, in addition to the driving motor, two further drives at the crosshead. In terms of the operation of the system, this study aimed to investigate its limitations and analyze its kinematics and dynamics, identifying the backlash and possible impact torque. A new approach was proposed for the control of the active universal joint by moving the manipulator’s end-effector from one point to another on an orthodromic trajectory. The orthodromic trajectory is related to a fixed Euler vector, which is presented in a conical motion context combined with a spin motion of the end-effector. Numerical results using the physical model were compared to the experimental results to determine the application limits of the joint.