Time-suboptimal inspection task sequence planning for two cooperative robot arms using mixed optimization algorithms

Abstract

The objective of inspection task sequence planning for two robot arms is not only to find a series of common optimal final configurations, but to find a time-optimal task sequence of inspection points. The time-suboptimal final configurations are solved using a (continuous) nonlinear optimization method. The task sequence planning is formulated as a variation of the travelling salesman problem (an integer optimization) and is solved by simulated annealing. The time-suboptimal task sequence planning and time-efficient trajectory planning are integrated and the related computational problems are addressed and solved. The proposed method is applied to an environment containing two cooperative SCARA type inspection robot arms. Computations have been carried out for 4-20 moving points/cities in a route where both arms move. This is compared with completing the task with the same goal points in a route where only one arm moves. The conclusion is that it is much more efficient if two robot arms work in cooperative mode. Experiments have also been conducted on an experimental system, this gave satisfactory results which are consistent with those obtained by simulation.