Miniature Robotic Arm Research Articles

A cost-effective device for online measurement of sheet metal bending angle on CNC press brakes based on capacitive sensors

Sheet metal bending on press brakes is one of the most widespread manufacturing processes. A common issue in press brake bending is the deviation of the actual bending angle from the theoretical one due to elastic spring-back of the sheet metal. This is typically rectified by a systematic trial-and-error process, which has to be based on a suitable measuring device that is flexible enough to adapt to a wide range of computer numerically controlled machines, accurate enough with respect to modern manufacturing needs and cost effective enough to be used on low cost press brakes. This work presents the development of such a device resembling a miniature robotic arm and employing capacitive sensors. Two stepping motors adapt the arm to any bending angle sheet configuration. The measuring process is commanded by a microcontroller. Statistical evidence on accuracy and repeatability of the system is provided, being better than 0.1° and 0.3° whilst cost is kept reasonable.

Design and modeling of a novel robotic arm with multiple-segment joints

This paper presents a novel miniature robotic arm with four degrees of freedom and one end-effector. The two joints of the robotic arm are multiple-segment, which consist of several serial plates with tiny cavities. Kinematic modeling of the robotic arm has been completed for subsequent implementation. With multiple-segment joints, the robotic arm gets smooth, linear, and flexible property. Simulations and experiments show that the robot can be used in abdominal single-port minimally invasive surgery for its unique operation capability.

Hybrid Soft-Rigid Actuators for Minimally Invasive Surgery.

Fluidic mechanisms have stimulated research and development in minimally invasive surgery instrumentations, because of their good performance in limited size and their force/torque generation with respect to other types of actuation systems. Fluidic solutions can be divided in two major classes: (i) elastic fluidic actuators and (ii) piston-cylinder actuators. Elastic fluidic actuators generate lower forces with smaller displacements; nevertheless, piston-cylinder solutions require seals, which can generate friction and require maintenance costs for a good reliability. The proposed solution is based on a hybrid soft-rigid actuation, which aims to overcome the limitations of both previous solutions while preserving the main advantages of the overall fluidic approach. This approach results in very compact, powerful, and low-cost actuators, which are highly customizable and adaptable to specific constraints, in medical applications but even beyond. This article proposes a novel design of hybrid soft-rigid actuators to be used as basic mechanical joints for enabling pitch and roll degrees of freedom for a miniature robotic arm. Forces up to 1.4 N and up to 2.77 N have been obtained for the above joints, respectively, and even better performance can be reached (up to 3 N) with further improvements, as demonstrated in this article.

Optimization through Simulation of Poly-Articulated Mechanical Systems Used in Medical Robotics

Conception of certain mechanical systems used in medical robotics is limited due to the ranges of allowed values for different design factors: weight, volume, quality, safety, and cost. It was identified the need to design these products and to simplify/optimize the concept, so that, with minimal changes, can be created families like products with the same functions but with different technical characteristics. Still, there are ways to use modern instruments parametrization design, finite element analysis of dynamic behavior of a poly-articulated miniature robotic arm. The research consists in the development of a methodology applied to result concrete data relating to the design of the poly-articulated mechanical system, simulation and validation of geometric patterns models predetermined of a FEM analysis. Also, the obtained information during tests will be used to determine the final configuration of the optimized concept.