Efficient Embedded Machine Learning applications using Echo State Networks
L. Cerinaa, M. D. Santambrogio, G. Franco, C. Gallicchio and A. Michelib
Dipartimento Elettronica Informazione e Bioingegneria, Politecnico di Milano, Milan, Italy
Department of Computer Science, University of Pisa, Italy
ABSTRACT
The increasing role of Artificial Intelligence (AI) and Machine Learning (ML) in our lives brought a paradigm shift on how and where the computation is performed. Stringent latency requirements and congested bandwidth moved AI inference from Cloud space towards end-devices. This change required a major simplification of Deep Neural Networks (DNN), with memorywise libraries or co-processors that perform fast inference with minimal power. Unfortunately, many applications such as natural language processing, time-series analysis and audio interpretation are built on a different type of Artifical Neural Networks (ANN), the so-called Recurrent Neural Networks (RNN), which, due to their intrinsic architecture, remains too complex and heavy to run efficiently on embedded devices. To solve this issue, the Reservoir Computing paradigm proposes sparse untrained nonlinear networks, the Reservoir, that can embed temporal relations without some of the hindrances of Recurrent Neural Networks training, and with a lower memory usage. Echo State Networks (ESN) and Liquid State Machines are the most notable examples. In this scenario, we propose a performance comparison of a ESN, designed and trained using Bayesian Optimization techniques, against current RNN solutions. We aim to demonstrate that ESN have comparable performance in terms of accuracy, require minimal training time, and they are more optimized in terms of memory usage and computational efficiency. Preliminary results show that ESN are competitive with RNN on a simple benchmark, and both training and inference time are faster, with a maximum speed-up of 2.35x and 6.60x, respectively.
