On-line learning of B-spline fuzzy controller to acquire sensor-based assembly skills

We present an on-line learning approach for developing sensor-based controllers and show how it can make the programming of assembly tasks easier. We suggest to combine the qualitative modelling of human expert skills and the self-tuning of control parameters so that a controller for a complex assembly task can be efficiently developed. It is then discussed how to construct a fuzzy controller with B-splines and why rapid convergence of its learning can be achieved. To apply the concept in a screwing operation, we propose several gradual steps of active on-line learning. Experiments were carried out with two independently controlled robot arms. Although general-purpose jaw-grippers are used and diverse uncertainties exist, the `elevator control' of a toy aircraft can be robustly built.