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Biol Cybern (2013) 107:397419 DOI 10.1007/s00422-013-0563-5
REVIEW
Walknet, a bio-inspired controller for hexapod walking
Malte Schilling Thierry Hoinville Josef Schmitz
Holk Cruse
Received: 13 November 2012 / Accepted: 18 June 2013 / Published online: 4 July 2013 The Author(s) 2013. This article is published with open access at Springerlink.com
Abstract Walknet comprises an articial neural network that allows for the simulation of a considerable amount of behavioral data obtained from walking and standing stick insects. It has been tested by kinematic and dynamic simulations as well as on a number of six-legged robots. Over the years, various different expansions of this network have been provided leading to different versions of Walknet. This review summarizes the most important biological ndings described by Walknet and how they can be simulated. Walknet shows how a number of properties observed in insects may emerge from a decentralized architecture. Examples are the continuum of so-called gaits, coordination of up to 18 leg joints during stance when walking forward or backward over uneven surfaces and negotiation of curves, dealing with leg loss, as well as being able following motion trajectories without explicit precalculation. The different Walknet versions are compared to other approaches describing insect-inspired hexapod walking. Finally, we briey address the ability of this decentralized reactive controller to form the basis for the simulation of higher-level cognitive faculties exceeding the capabilities of insects.
Keywords Insect locomotion Motor control
Decentralized architecture
1 Control of walking
The fundamental task of a brain is to allow an organism for controlling active locomotion (e.g., Wolpert et al. 2001). Comparing the three basic types of active locomotion, swimming, ying, and walking, the latter is presumably the most complex one with respect to controllability, making the investigation of the control structure of such a system a challenging task. Due to its complexity, a system that is able to control multi-legged walking does not suit well the approach applied in traditional physics or in physiology, for example. The latter systems are characterized by a clearly denable input and a measurable output which together can be used for system identication. In contrast, a walking system is characterized by a high number of degrees of freedom. Here we focus on a six-legged insect (or robot) with three active joints per...