An automated reconfigurable flexible fixture for aerospace pipeline assembly before welding

In order to improve assembly quality and efficiency, reduce reliance on operators' experience and skills, and satisfy diversified assembly requirements, an automated reconfigurable and flexible assembly fixture for aerospace pipelines prior to welding is designed and implemented. The developed novel fixture is composed of three systems, namely a configuration system, a control system, and a mechanical system. The mechanical system is the fundamental of the fixture and mainly contains a 3-DOF gantry-hoisting platform and a number of 4-DOF locators, which is served to precisely locate and clamp all the tube joints of a pipeline and then to assemble the pipeline together with corresponding tubes. The configuration system is the core of the fixture and is used for configuring the specific fixture based on the 3D model of a pipeline. Using One-Master Multi-Slave control mode, the control system is able to precisely control the mechanical system in accordance with the configuration information, which covers the location and orientation data of all the locators for positioning and clamping tube joints of a pipeline, automatically generated by the configuration system. At last the experimental and shop-floor validation show that the proposed fixture system can significantly improve the assembly quality and efficiency for a variety of pipelines. In addition to aerospace pipelines, this fixture system is also suitable for pipeline assembly from other industries including shipping, vehicle, etc.