Kinematics Model for Guiding a 3D Printing Nozzle Using a Continuum-soft Arm.

This article presents a solution based on a soft-continuum arm for depositing material in predictive maintenance of complex structures susceptible to deformation-induced micro-cracks. The soft-continuum robots are chosen for their agility in navigating confined spaces and accessing hard-to-reach areas, making them ideal for precise material injection into cracks. The soft-continuum arm is attached to an Unmanned Aerial Vehicle (UAV) equipped with a camera, enabling the localisation of cracks on wall surfaces and material deposition for on-site repairs, offering a swift and cost-effective intervention without the need for scaffolding. To ensure precise material deposition, maintaining the soft-continuum arm's bending speed and trajectory tracking is essential. This article primarily focuses on modelling the soft arm, assuming a stationary drone and minimal force during material deposition. The modelling approach draws inspiration from concepts used in parallel rigid manipulators and incorporates effort-based deformation into a kinematic model. To evaluate the proposed approach's efficiency, a series of experiments using a flexible section of the CBHA is conducted, complemented by a study of deformation as a function of pressure using Finite Element Method (FEM) analysis through Ansys software. A series of experiments using a section flexible of the CBHA is conducted to evaluate the efficiency of the proposed approach.