Neural processing of naturalistic optic flow

Kern R, Petereit C, Egelhaaf M. Neural processing of naturalistic optic flow. The Journal of Neuroscience. 2001;21(8):1-5.Stimuli traditionally used for analyzing visual information processing are much simpler than what an animal sees in normal life. When characterized with traditional stimuli, neuronal responses were found to depend on various parameters such as contrast, texture, or velocity of motion, and thus were highly ambiguous. In behavioral situations, all of these parameters change simultaneously and differently in different parts of the visual field. Thus it is hardly possible to predict from traditional analyses what information is encoded by neurons in behavioral situations. Therefore, we characterized an identified neuron in the optomotor system of the blowfly with image sequences as they were seen by animals walking in a structured environment. We conclude that during walking, the response of the neuron reflects the animal's turning direction nearly independently of the texture and spatial layout of the environment. Our findings stress the significance of analyzing the performance of neuronal circuits under their natural operating conditions

Neuronal processing of behaviourally generated optic flow: experiments and model simulations

Kern R, Lutterklas M, Petereit C, Lindemann JP, Egelhaaf M. Neuronal processing of behaviourally generated optic flow: experiments and model simulations. Network: computation in neural systems. 2001;12(3):351-369.The stimuli traditionally used for analysing visual information processing are much simpler than what an animal sees when moving in its natural environment. Therefore, we analysed in a previous study the performance of an identified neuron in the optomotor system of the fly by using as visual stimuli image sequences that were experienced by the animal while walking in a structured environment. These electrophysiological experiments revealed that the fly visual system computes from behaviourally generated optic flow a rather unambiguous representation of the animal's self-motion. In contrast to conclusions based on simple stimuli, the directions of turns are represented by an interneuron, the HSE cell, quite independent of the spatial layout of the environment and its textural properties when the cell is stimulated with behaviourally generated optic flow. This conclusion is substantiated here by further experimental evidence. Moreover, it is shown that the largely unambiguous responses of the HSE cell to behaviourally generated optic flow can be replicated to a large extent by a network model of the fly's visual motion pathway. These results stress the significance of naturalistic stimuli for analysing what is encoded by neuronal circuits under natural operating conditions

Safe mobile robot motion planning for waypoint sequences in a dynamic environment

Safe and efficient path planning for mobile robots in dynamic environments is still a challenging research topic. Most approaches use separate algorithms for global path planning and local obstacle avoidance. Furthermore, planning a path for a sequence of goals is mostly done by planning to each next goal individually. These two strategies generally result in sub-optimal navigation strategies. In this paper, we present an algorithm which addresses these problems in a single combined approach. For this purpose, we model the static and dynamic risk of the environment in a consistent way and propose a novel graph structure based on a state x time x goal lattice with hybrid dimensionality. It allows the joint planning for multiple goals while incorporating collision risk due to dynamic and static obstacles. It computes hybrid solutions which are part trajectory and part path. Finally, we provide some results of our algorithm in action to prove its high quality solutions and real-time capability

Toward a multifaceted platform for humanitarian demining: Paper presented at 13th IARP Workshop on Humanitarian Demining and Risky Interventions, HUDEM 2015, Beograd, Croatia, 27-28 April 2015

The D-BOX project aims to increase deminers' confidence in technology developing a web-enabled platform which allows them to better utilize existing technologies and foster the development of the use of new ones. The idea behind D-BOX is to create an Information Management System which incorporates the process of Land Release, whereby the use of technologies is part of the process. The system will be flexible to adapt to local needs but at the same time it will be compliant with the IMAS. In a complex domain like demining, single technologies are rarely effective. The new platform will foster functional tool chains to realize complex tasks, information merging and synergies amongst heterogeneous tools to increase the effectiveness of the tool combinations. In the paper we establish the requirements for the new platform and give examples of Functional Tool Chain(s) and of Synergies among tools being developed by D-BOX partners