Optimal control of non-linear systems through hybrid cell-mapping/artificial-neural-networks techniques

In this paper, a real-time optimal control technique for non-linear plants is proposed. The control system makes use of the cell-mapping (CM) techniques, widely used for the global analysis of highly non-linear systems. The CM framework is employed for designing approximate optimal controllers via a control variable discretization. Furthermore, CM-based designs can be improved by the use of supervised feedforward artificial neural networks (ANNs), which have proved to be universal and efficient tools for function approximation, providing also very fast responses. The quantitative nature of the approximate CM solutions fits very well with ANNs characteristics. Here, we propose several control architectures which combine, in a different manner, supervised neural networks and CM control algorithms. On the one hand, different CM control laws computed for various target objectives can be employed for training a neural network, explicitly including the target information in the input vectors. This way, tracking problems, in addition to regulation ones, can be addressed in a fast and unified manner, obtaining smooth, averaged and global feedback control laws. On the other hand, adjoining CM and ANNs are also combined into a hybrid architecture to address problems where accuracy and real-time response are critical. Finally, some optimal control problems are solved with the proposed CM, neural and hybrid techniques, illustrating their good performance.

Choking RECtified: embodied expertise beyond Dreyfus

On a Dreyfusian account performers choke when they reflect upon and interfere with established routines of purely embodied expertise. This basic explanation of choking remains popular even today and apparently enjoys empirical support. Its driving insight can be understood through the lens of diverse philosophical visions of the embodied basis of expertise. These range from accounts of embodied cognition that are ultra conservative with respect to representational theories of cognition to those that are more radically embodied. This paper provides an account of the acquisition of embodied expertise, and explanation of the choking effect, from the most radically enactive, embodied perspective, spelling out some of its practical implications and addressing some possible philosophical challenges. Specifically, we propose: (i) an explanation of how skills can be acquired on the basis of ecological dynamics; and (ii) a non-linear pedagogy that takes into account how contentful representations might scaffold skill acquisition from a radically enactive perspective.