A flexible robotic cell for in-process inspection of multi-pass welds

Welds are currently only inspected after all the passes are complete and after allowing sufficient time for any hydrogen cracking to develop, typically over several days. Any defects introduced between passes are therefore unreported until fully buried, greatly complicating rework and also delaying early corrections to the weld process parameters. In-process inspection can provide early intervention but involves many challenges, including operation at high temperatures with significant gradients affecting acoustic velocities and, hence, beam directions. Reflections from the incomplete parts of the weld would also be flagged as lack-of-fusion defects, requiring the region of interest (ROI) to adapt as the weld is built up. The collaborative SIMPLE (SIngle Manufacturing PLatform Environment) project addresses these challenges by incorporating robotic inspection within a robotic tungsten inert gas (TIG) welding cell. This has been accomplished initially with commercial off-the-shelf ultrasonic phased arrays, but is flexible enough to adapt to future developments with solutions suitable for higher temperatures. The welding and inspection robots operate autonomously. The former can introduce deliberate defects to validate the latter, which uses 5 MHz 64-element phased arrays on high-temperature wedges to generate sector scans after each weld pass. The results are presented, confirming that the challenges have been addressed and demonstrating the feasibility of this approach.

Automated Disassembly of Electronic Components: Feasibility and Technical Implementation

The paper deals with the feasibility of a flexible robotic cell for the disassembly of electronic components. First, the need for an automated process for the end of life management of electronic boards is motivated: the reuse of electronic components represents a potential cost saving opportunity for a class of electronic board producers, other than an effective means to improve the waste management efficiency and the sustainability of the electronics sector. Then, starting from a state of the art survey, a technical implementation of the cell is proposed. Finally, some preliminary tests of the disassembly equipment, aimed at setting the most relevant process parameters, are described.

A mathematical model and simulated annealing algorithm for solving the cyclic scheduling problem of a flexible robotic cell

Flexible robotic cells are used to produce standardized items at a high production speed. In this study, the scheduling problem of a flexible robotic cell is considered. Machines are identical and parallel. In the cell, there is an input and an output buffer, wherein the unprocessed and the finished items are kept, respectively. There is a robot performing the loading/unloading operations of the machines and transporting the items. The system repeats a cycle in its long run. It is assumed that each machine processes one part in each cycle. The cycle time depends on the order of the actions. Therefore, determining the order of the actions to minimize the cycle time is an optimization problem. A new mathematical model is presented to solve the problem, and as an alternative, a simulated annealing algorithm is developed for large-size problems. In the simulated annealing algorithm, the objective function value of a given solution is computed by solving a linear programming model which is the first case in the literature to the best of our knowledge. Several numerical examples are solved using the proposed methods, and their performances are evaluated.

Computer Control of a Flexible Robotic Cell

Intelligent robotic systems require a tremendous flexibility and intelligence to execute complex tasks. To facilitate task planning of intelligent robots and integrate sensory information for on-line task monitoring, there is a need to establish a communication linkage between robot controller and human operator through a computer. This paper presents the design of a generic cell controller for intelligent planning and execution of robotic cell operations and for real-time task monitoring. This paper details the architecture of hardware and software developed for the control of a commercial robot interfaced with a computer through a parallel I/O communication bus. Results indicate that by means of a relatively inexpensive setup, flexibility with regard to coordinated activities of robotic cells can be greatly increased.