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The Local Cluster Neural Network (LCNN) chip

Description

The LCNN chip is low cost neural network hardware device developed specifically for real-time control applications. Because it is an analog computing device it achieves a high degree of parallel computation in a smaller size and at lower power consumption than a digital equivalent. Furthermore, it simplifies electronic control systems because it does not require analog to digital (A/D) and digital to analog (D/A) conversion on inputs and outputs.

The LCNN chip implements the neural network architecture developed at QUT by S.Geva and J.Sitte. Local Cluster networks are feed forward neural nets that have much in common with Radial Basis Function neural nets but are more general. They can be used as classifiers, function approximators and as generalised fuzzy inference engines.

 

T. Koerner designed, fabricated and tested the LCNN analog VLSI chip at the Heinz Nixdorf Institute (HNI) of the University of Paderborn under the direction of Prof. U. Rückert in collaboration with J. Sitte (QUT). The current version of the chip has 6 analog inputs, 8 local clusters and one output. Multiple chips can be combined into networks with larger numbers of local clusters. The current implementation uses digital storage for the network weight coefficients. Network training will typically occur in a chip-in-the-loop arrangement with a computer that carries out the calculations for the weight adaptation algorithm. For fuzzy control applications the precalculated weights for multidimensional membership functions may be downloaded onto the chip

LCNN chip features

Support

The LCNN chip is supported by feedforward neural net simulation software and a development board with associated control software for Windows NT/2000 platforms.

Contacts:

Dr. Joaquin Sitte
School of Computing Science
Faculty of Information Technology
Queensland University of Technology
GPO Box 2434, Brisbane, Q 4001
Australia
Phone +61 7 3864 2925
Fax +61 7 3864 1801 e-mail j.sitte@qut.edu.au http://www.fit.qut.edu.au/~sitte
Prof. Dr. Ing. Ulrich Rückert
Heinz Nixdorf Institut
Fachgebiet Schaltungstechnik
Heinz Nixdorf Institut
Universität-GH Paderborn
Fürstenallee 11, 33102 Paderborn
Germany
Phone +49 5251 606346
Fax. +49 5251 606351
e-mailrueckert@hni.uni-paderborn.de
http://hni.uni-paderborn.de/sct

References

T. Koerner, U. Rueckert and J Sitte, Local cluster neural net analog {VLSI} design, Neurocomputing, 19 (1998) 185-197.

S. Geva, K. Malmstrom and J. Sitte, Local Cluster Neural Net: Architecture, Training and Applications, Neurocomputing 20 (1998) 35 - 56.

S. Geva and J. Sitte, A Constructive Method for Multivariate Function Approximation by Multi-Layer Perceptrons, IEEE Transactions on Neural Networks 3 (1992) 621-623.

T. Koerner, J. Sitte and U. Rueckert, An Analog Local Cluster Neural Net for a 3V supply, Proceedings of the 7th International Conference on Microelectronics for Neural, Fuzzy and Bio-inspired Systems, Granada, Spain (1999), pp. 292- 298.

T. Koerner, U. Rueckert and J. Sitte, An Analog Current Mode {VLSI} Local Cluster Neural Net, Proceedings of the 6th International Conference on Microelectronics for Neural Networks . Evolutionary \& Fuzzy Systems, Dresden, Germany (1997) pp. 257 -- 262.