Path Planning for Laser Cladding Robot on Artificial Joint Surface Based on Topology Reconstruction

Abstract

Artificial joint surface coating is a hot issue in the interdisciplinary fields of manufacturing, materials and biomedicine. Due to the complex surface characteristics of artificial joints, there are some problems with efficiency and precision in automatic cladding path planning for coating fabrication. In this study, a path planning method for a laser cladding robot for artificial joints surface was proposed. The key of this method was the topological reconstruction of the artificial joint surface. On the basis of the topological relation, a set of parallel planes were used to intersect the CAD model to generate a set of continuous, directed and equidistant surface transversals on the artificial joint surface. The arch height error method was used to extract robot interpolation points from surface transversal lines according to machining accuracy requirements. The coordinates and normal vectors of interpolation points were used to calculate the position and pose of the robot tool center point (TCP). To ensure that the laser beam was always perpendicular to the artificial joint surface, a novel laser cladding set-up with a robot was designed, of which the joint part clamped by a six-axis robot moved while the laser head was fixed on the workbench. The proposed methodology was validated with the planned path on the surface of an artificial acetabular cup using simulation and experimentation via an industrial NACHI robot. The results indicated that the path planning method based on topological reconstruction was feasible and more efficient than the traditional robot teaching method.

Finite Element Study on the Wear Performance of Movable Jaw Plates of Jaw Crushers after a Symmetrical Laser Cladding Path

“…The material of the setting ring in FEPG is 40Cr, the inner part of the cylinder is WDB620 (movable jaw plate material), and the outer part is laser cladding ceramic powder. The specific physical parameter settings of the cylinder-ring are shown in Table 3 [31][32][33][34]. The model of the cylinder-ring was built in UG (Figure 3).…”

Development of Integrated Automatic System of Laser Cladding for Repairing of Polycrystalline Diamond Compact Bits

“…Its most important application is to repair high-value equipment, which can greatly save cost compared to buying another brand new, and, at the same time, the repaired work piece has at least the same performance to the original. Therefore, laser-cladding technology can be used in repairing the hard facing of turbine blade [2][3][4][5][6][7][8], forging die [9][10][11], as well as in various material processing industries for complex curved surface generating [12][13][14][15], and repairs of rail-surface scratch [16], artificial joints in medical treatment [17], broken gears [18], and worn sprockets [19].…”

“…die [9][10][11], as well as in various material processing industries for generating [12][13][14][15], and repairs of rail-surface scratch [16], artificia ment [17], broken gears [18], and worn sprockets [19].…”

Novel surface optimization for trajectory reconstruction in industrial robot tasks

“…The industrial robot-workpiece interaction has an important role to perform tasks over complex surfaces such as painting [1][2][3] milling, 4 grinding, 5 laser cladding, 6 nondestructive examinations, 7,8 and robotic automated fiber placement applications. 9,10 The path planning can be classified into online and offline programming.…”

“…To generate the optimal overlap distance and the velocity for a given paint pass (SS), a genetic algorithm is used and the process ends when the whole surface is reached. Li et al 6 propose a path planning method whose key lies in the topological reconstruction of the artificial joint surface. From an STL file, the information to create the relations among points, edges, and facets is extracted, facilitating the path planning method.…”