A Fully-distributed Shape-aware Neural Controller for Modular Robots

Modular robots are promising for their versatility and large design freedom. Modularity can also enable automatic assembly and reconfiguration, be it autonomous or via external machinery. However, these procedures are error-prone and often result in misassemblings. This, in turn, can cause catastrophic effects on the robot functionality, as the controller deployed in each module is optimized for a different robot shape than the actual one. In this work, we address such shortcoming by proposing a shape-aware modular controller, operating with (1) a self-discovery phase, in which each module controller identifies the shape it is assembled in, followed by (2) a parameter selection phase, where the controller selects its parameters according to the inferred shape. We deploy a self-classifying neural cellular automaton for phase (1), and we leverage evolutionary optimization for implementing a library of controller parameters for phase (2). We test the validity of the proposed method considering voxel-based soft robots, a class of modular soft robots, and the task of locomotion. Our findings confirm the effectiveness of such a controller paradigm, and also show that it can be used to partially overcome unforeseen damages or assembly mistakes

A design method for modular energy-aware software

Nowadays achieving green software by reducing the overall energy consumption of the software is becoming more and more important. A well-known solution is to make the software energy-aware by extending its functionality with energy optimizers, which monitor the energy consumption of software and adapt it accordingly. Modular design of energy-aware software is necessary to make the extensions manageable and to cope with the complexity of the software. To this aim, we require suitable methods that guide designers through the necessary design activities and the models that must be prepared during each activity. Despite its importance, such a method is not investigated in the literature. This paper proposes a dedicated design method for energy-aware software, discusses a concrete realization of this method, and—by means of a concrete example—illustrates the suitability of this method in achieving modularity

In-band control, queuing, and failure recovery functionalities for openflow

In OpenFlow, a network as a whole can be controlled from one or more external entities (controllers) using in-band or out-of-band control networks. In this article, we propose in-band control, queuing, and failure recovery functionalities for OpenFlow. In addition, we report experimental studies and practical challenges for implementing these functionalities in existing software packages containing different versions of OpenFlow. The experimental results show that the in-band control functionality is suitable for all types of topologies. The results with the queuing functionality show that control traffic can be served with the highest priority in in-band networks and hence, data traffic cannot affect the communication between the controller and networking devices. The results with the failure recovery functionality show that traffic can be recovered from failures within 50 ms

Functional Testing Approaches for "BIFST-able" tlm_fifo

Evolution of Electronic System Level design methodologies, allows a wider use of Transaction-Level Modeling (TLM). TLM is a high-level approach to modeling digital systems that emphasizes on separating communications among modules from the details of functional units. This paper explores different functional testing approaches for the implementation of Built-in Functional Self Test facilities in the TLM primitive channel tlm_fifo. In particular, it focuses on three different test approaches based on a finite state machine model of tlm_fifo, functional fault models, and march tests respectivel

PID control system analysis, design, and technology

Designing and tuning a proportional-integral-derivative (PID) controller appears to be conceptually intuitive, but can be hard in practice, if multiple (and often conflicting) objectives such as short transient and high stability are to be achieved. Usually, initial designs obtained by all means need to be adjusted repeatedly through computer simulations until the closed-loop system performs or compromises as desired. This stimulates the development of "intelligent" tools that can assist engineers to achieve the best overall PID control for the entire operating envelope. This development has further led to the incorporation of some advanced tuning algorithms into PID hardware modules. Corresponding to these developments, this paper presents a modern overview of functionalities and tuning methods in patents, software packages and commercial hardware modules. It is seen that many PID variants have been developed in order to improve transient performance, but standardising and modularising PID control are desired, although challenging. The inclusion of system identification and "intelligent" techniques in software based PID systems helps automate the entire design and tuning process to a useful degree. This should also assist future development of "plug-and-play" PID controllers that are widely applicable and can be set up easily and operate optimally for enhanced productivity, improved quality and reduced maintenance requirements