The control theory of motion-based communication: problems in teaching robots to dance

The paper describes results on two components of a research program focused on motion-based communication mediated by the dynamics of a control system. Specifically we are interested in how mobile agents engaged in a shared activity such as dance can use motion as a medium for transmitting certain types of messages. The first part of the paper adopts the terminology of motion description languages and deconstructs an elementary form of the well-known popular dance, Salsa, in terms of four motion primitives (dance steps). Several notions of dance complexity are introduced. We describe an experiment in which ten performances by an actual pair of dancers are evaluated by judges and then compared in terms of proposed complexity metrics. An energy metric is also defined. Values of this metric are obtained by summing the lengths of motion segments executed by wheeled robots replicating the movements of the human dancers in each of the ten dance performances. Of all the metrics that are considered in this experiment, energy is the most closely correlated with the human judges' assessments of performance quality. The second part of the paper poses a general class of dual objective motion control problems in which a primary objective (artistic execution of a dance step or efficient movement toward a specified terminal state) is combined with a communication objective. Solutions of varying degrees of explicitness can be given in several classes of problems of communicating through the dynamics of finite dimensional linear control systems. In this setting it is shown that the cost of adding a communication component to motions that steer a system between prescribed pairs of states is independent of those states. At the same time, the optimal encoding problem itself is shown to be a problem of packing geometric objects, and it remains open. Current research is aimed at solving such communication-through-action problems in the context of the motion control of mobile robots.Support for this work is gratefully acknowledged to ODDR&E MURI07 Program Grant Number FA9550-07-1-0528, the National Science Founda tion ITR Program Grant Number DMI-0330171, and the Office of Naval Research, and by ODDR&E MURI10 Program Grant Number N00014-10- 1-0952. (FA9550-07-1-0528 - ODDRE MURI07; DMI-0330171 - National Science Foundation ITR Program; Office of Naval Research; N00014-10-1-0952 - ODDRE MURI10

Unreduced Dynamic Complexity: Towards the Unified Science of Intelligent Communication Networks and Software

Operation of autonomic communication networks with complicated user-oriented functions should be described as unreduced many-body interaction process. The latter gives rise to complex-dynamic behaviour including fractally structured hierarchy of chaotically changing realisations. We recall the main results of the universal science of complexity (http://cogprints.org/4471/) based on the unreduced interaction problem solution and its application to various real systems, from nanobiosystems (http://cogprints.org/4527/) and quantum devices to intelligent networks (http://cogprints.org/4114/) and emerging consciousness (http://cogprints.org/3857/). We concentrate then on applications to autonomic communication leading to fundamentally substantiated, exact science of intelligent communication and software. It aims at unification of the whole diversity of complex information system behaviour, similar to the conventional, "Newtonian" science order for sequential, regular models of system dynamics. Basic principles and first applications of the unified science of complex-dynamic communication networks and software are outlined to demonstrate its advantages and emerging practical perspectives

The imperfect hiding : some introductory concepts and preliminary issues on modularity

In this work we present a critical assessment of some problems and open questions on the debated notion of modularity. Modularity is greatly in fashion nowadays, being often proposed as the new approach to complex artefact production that enables to combine fast innovation pace, enhanced product variety and reduced need for co-ordination. In line with recent critical assessments of the managerial literature on modularity, we sustain that modularity is only one among several arrangements to cope with the complexity inherent in most high-technology artefact production, and by no means the best one. We first discuss relations between modularity and the broader (and much older within economics) notion of division of labour. Then we sustain that a modular approach to labour division aimed at eliminating technological interdependencies between components or phases of a complex production process may have, as a by-product, the creation of other types of interdependencies which may subsequently result in inefficiencies of various types. Hence, the choice of a modular design strategy implies the resolution of various tradeoffs. Depending on how such tradeoffs are solved, different organisational arrangements may be created to cope with ‘residual’ interdependencies. Hence, there is no need to postulate a perfect isomorphism, as some recent literature has proposed, between modularity at the product level and modularity at the organisational level

Software integration testing based on communication coverage criteria and partial model generation

This paper considers the problem of integration testing the components of a timed distributed software system. We assume that communication between the components is specified using timed interface automata and use computational tree logic (CTL) to define communication-based coverage criteria that refer to send- and receive-statements and communication paths. The proposed method enables testers to focus during component integration on such parts of the specification, e.g. behaviour specifications or Markovian usage models, that are involved in the communication between components to be integrated. A more specific application area of this approach is the integration of test-models, e.g. a transmission gear can be tested based on separated models for the driver behaviour, the engine condition, and the mechanical and hydraulical transmission states. Given such a state-based specification of a distributed system and a concrete coverage goal, a model checker is used in order to determine the coverage or generate test sequences that achieve the goal. Given the generated test sequences we derive a partial test-model of the components from which the test sequences are derived. The partial model can be used to drive further testing and can also be used as the basis for producing additional partial models in incremental integration testing. While the process of deriving the test sequences could suffer from a combinatorial explosion, the effort required to generate the partial model is polynomial in the number of test sequences and their length. Thus, where it is not feasible to produce test sequences that achieve a given type of coverage it is still possible to produce a partial model on the basis of test sequences generated to achieve some other criterion. As a result, the process of generating a partial model has the potential to scale to large industrial software systems. While a particular model checker, UPPAAL, was used, it should be relatively straightforward to adapt the approach for use with other CTL based model checkers. A potential additional benefit of the approach is that it provides a visual description of the state-based testing of distributed systems, which may be beneficial in other contexts such as education and comprehension