This article presents a unified mathematical approach for modeling, identifying, and solving the friction-inclusive dynamics of robotic mechanisms driven by sliding contact transmission systems. This approach is applied to the most common industrial screw-based drives: 1) the worm drive, 2) the simple lead screw drive, and 3) the antibacklash lead screw drive. The resulting dynamics, handily transferable to single and multiple degree of freedom (DoF) manipulators, are complemented with an algorithm for the solution of the forward dynamics problem as well as a framework for friction identification based on nonlinear optimization. The presented theory is experimentally tested on single-DoF screw-based drives for a variety of payloads and at different operation speeds. Simulation and parameter identification results using the classical Coulomb model, the Coulomb model with Stribeck friction, and the Armstrong model with Stribeck friction, rising static friction, and frictional memory are compared with experimental data, showcasing the effectiveness of the presented approach toward framing the concepts of friction and motion transmission into a robotics setting.

Despite several robots having been proposed for vitreoretinal surgery, there is limited information on their dynamic modeling. This gap leads to sub-optimal motor selection and hinders the application of advanced control schemes that would fulfill the goal of micro-precise surgery. This paper presents the design process and a dynamics study of a multi-Degree of Freedom (DoF) robotic system, which is inspired by established co-manipulation architectures. A rigorous kinematics and dynamics analysis of the robot's part that is responsible for manipulating the surgical tool during the retinal surgery phase is provided. In particular, the Euler-Lagrange equations of motion, which describe the dynamics of the 3-link surgical manipulator, are combined with novel analytical models of each link's corresponding transmission mechanism, including an anti-backlash lead screw assembly and a worm drive. The resulting models, transferable to existing manipulators, provide a meticulous analysis of the robot's performance that can be used both for mechanical design and control purposes.

We propose a biomechatronics-based master/slave topology which is going to provide an Extended Physiological Proprioception (EPP)-equivalent control but without the use of a harness, cineplasty, or Bowden cable. The proposed control uses an implanted micro servo actuator. The original Bowden-cable EPP topology is compared to the proposed one and their simulation results are presented. The simulation results are encouraging since they indicate the materialization potential of the topology, both in terms of control and of low power, two essential factors in making the presence of an implant in the human body feasible. This control topology will provide a modern EPP-equivalent control scheme for upper-limb prostheses without the disadvantages of previous EPP configurations but with the control advantages of proprioceptive feedback.