Research Of Pipeline Welding Robot On Heterotypic Cross Section

Expansion bellows are widely used in oil drilling industry, but because the shape of the cross-section is very complex, bellows are often welded by hand. Therefore, the welding quality is affected and reduced, the efficiency is usually low, besides. In order to renovate the manual-operation, new automatic welding equipment is needed to be developed, which can clearly minimize the environmental and subjective factors of the production process. This paper is closely grounded on the actual requirement of the industrial production, and a general research plan is put forward. The main contents of the paper are stated as below:(1) With a view to the characteristic of cross section of the expansion bellows, a three-dimensional physical model of welding robot is designed, which can move in line with the feature of the cross section. Furthermore, Pro/E simulation is carried out, and the results indicate that the welding robot can move regularly according to the scheduled path.(2) D/H Methods are used to build a kinematics model of the welding robots, and then forward kinematics and inverse kinematics solution is obtained. Moreover, MATLAB simulation is performed, the results of which validate the rationality of the model in the end.(3) The welding speed model is divided into different part and built individually. Two variables which affect the welding speed are analyzed on the basis of the vector diagram of the welding speed, and the value of each stage is obtained, which ensures the welding quality accordingly.(4) The gas metal arc welding used by the welding robot in laboratory. The experiments under different shield gases,different shield gases,different divided edges and different wires wered tesed, the optimal experimental conditions and process parameters are obtained, and the experiment results indicate that the performance of welding robot is very stable, which fulfill the requirement of the expansion bellows welding process.In addition, the welding robot devised in the paper can be put into use in expansion bellows groove cutting, which extends the versatility of the equipment further.