A specialized robotic system prototype for repairing surface profiles of hydraulic turbine blades

Motta, José Maurício Santos Torres da; Llanos, Carlos H.; Carvalho, Guilherme; Alfaro, Sadek Crisóstomo Absi; Idrobo-Pizo, Gerardo Antonio; Sampaio, Renato Coral

doi:10.1109/carpi.2014.7030073

Cited by 3 publications

(2 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The robot was designed to have easy assembly and fixation on the blades (either belts or magnetic paddles), high rigidity mechanics and trouble-free operation. Portability, low cost, lightweight, good repeatability and high positioning accuracy are features of the resulting robot [8].…”

Section: Robot Characteristicsmentioning

confidence: 99%

“…Nonetheless, although a few dedicated robots have already been constructed for this type of task [4,5,6], this robot features improvements made to the previous ones, since it was designed to be fully automated, with minimal intervention by human operators. Additionally, this robot is capable of operating in conditions comprising large distances between blades, since the turbines in which it is to operate are 8 m in diameter and there is at least 500 mm between blades [7,8,9].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Inverse Kinematics and Model Calibration Optimization of a Five-D.O.F. Robot for Repairing the Surface Profiles of Hydraulic Turbine Blades

Motta

Llanos

Sampaio

2016

International Journal of Advanced Robotic Systems

View full text Add to dashboard Cite

This paper presents and discusses the results of an ongoing R&D project aiming to design and build a fully automated prototype of a specialized spherical robotic welding system for repairing hydraulic turbine surfaces eroded by cavitation pitting and/or cracks produced by cyclic loading. The system has an embedded vision sensor built to acquire range images by laser scanning over the blade's surface and produce 3D models to locate the damaged spots to be registered in a 3D coordinate system into the robot controller, enabling the robot to repair the flaws automatically by welding in layers. The paper is focused on the robot kinematic model and describes an iterative algorithm to process the inverse kinematics with only five degrees-offreedom. The algorithm makes use of data collected from a vision sensor to ensure that the welding gun axis is perpendicular to the blade's surface. Besides this, it proposes a modelling and optimization mathematical routine for more efficient robot calibration, which can be used with any type of robot. This robot calibration optimization scheme finds the optimal error parameter vector based on the condition number of the manipulator transformation composed from the partial derivatives of the error parameters. Experimental results proved both the iterative algorithm to perform the inverse kinematics and the technique to optimize robot calibration to be very efficient.

show abstract

Section: Robot Characteristicsmentioning

confidence: 99%