Journal of

# MECHANISMS AND ROBOTICS

## Latest Papers

ASME Journal of Mechanisms and Robotics

• Architecture Singularity Distance Computations for Linear Pentapods
on July 23, 2024 at 12:00 am

AbstractThe kinematic/robotic community is not only interested in measuring the closeness of a given robot configuration to its next singular one but also interested in a geometric meaningful index evaluating how far the robot design is away from being architecturally singular. Such an architecture singularity distance, which can be used by engineers as a criterion within the design process, is presented for a certain class of parallel manipulators called linear pentapods. Geometrically the architecture singular designs are well-understood and can be sub-classified into several cases, which allows for solving the optimization problem of computing the closest architecture singular design to a given linear pentapod with algorithms from numerical algebraic geometry.

# Design of Robotic Motion Platform Utilizing Continuous Contact Skating

Abstract

The continuous contact-based skating technique utilizes the sideway movement of the two skates while changing the orientation of the two skates simultaneously. The skates remain in contact with the surface. A mathematical model mimicking a continuous skating technique is developed to analyze the kinematic behavior of the platform. Kinematic and dynamic equations of motion are derived for the nonholonomic constraints. Heuristic-based motion primitives are defined to steer the robotic platform. For the lateral movement of the platform, a creeping-based motion primitive is proposed. A prototype of the robotic platform is developed with three actuated degrees-of-freedom—orientation of two skates and distance between them. A multibody model of the platform is also developed in matlab. Analytical expressions are verified using simulation and experiments. The robotic platform follows the desired motion profiles. The motion profiles include straight-line motion, motion in a circular curve, and lateral creep-like motion of the platform. However, the initial deviation has been observed in both the simulations and experiments due to the slipping of the roller skate at the contact point with the surface. The platform can be effectively used in a structured environment.