Development of PVDF tactile dynamic sensing in a behaviour-based assembly robot

The research presented in this thesis focuses on the development of tactile event sig¬ nature sensors and their application, especially in reactive behaviour-based robotic assembly systems.In pursuit of practical and economic sensors for detecting part contact, the application ofPVDF (polyvinylidene fluoride) film, a mechanical vibration sensitive piezo material, is investigated. A Clunk Sensor is developed which remotely detects impact vibrations, and a Push Sensor is developed which senses small changes in the deformation of a compliant finger surface. The Push Sensor is further developed to provide some force direction and force pattern sensing capability.By being able to detect changes of state in an assembly, such as a change of contact force, an assembly robot can be well informed of current conditions. The complex structure of assembly tasks provides a rich context within which to interpret changes of state, so simple binary sensors can conveniently supply a lot more information than in the domain of mobile robots. Guarded motions, for example, which require sensing a change of state, have long been recognised as very useful in part mating tasks. Guarded motions are particularly well suited to be components of assembly behavioural modules.In behaviour-based robotic assembly systems, the high level planner is endowed with as little complexity as possible while the low level planning execution agent deals with actual sensing and action. Highly reactive execution agents can provide advantages by encapsulating low level sensing and action, hiding the details of sensori-motor complexity from the higher levels.Because behaviour-based assembly systems emphasise the utility of this kind of quali¬ tative state-change sensor (as opposed to sensors which measure physical quantities), the robustness and utility of the Push Sensor was tested in an experimental behaviourbased system. An experimental task of pushing a ring along a convoluted stiff wire is chosen, in which the tactile sensors developed here are aided by vision. Three differ¬ ent methods of combining these different sensors within the general behaviour-based paradigm are implemented and compared. This exercise confirms the robustness and utility of the PVDF-based tactile sensors. We argue that the comparison suggests that for behaviour-based assembly systems using multiple concurrent sensor systems, bottom-level motor control in terms of force or velocity would be more appropriate than positional control. Behaviour-based systems have traditionally tried to avoid symbolic knowledge. Considering this in the light of the above work, it was found useful to develop a taxonomy of type of knowledge and refine the prohibition

Using reconstructed visual reality in ant navigation research

Insects have low resolution eyes and a tiny brain, yet they continuously solve very complex navigational problems; an ability that underpins fundamental biological processes such as pollination and parental care. Understanding the methods they employ would have profound impact on the fields of machine vision and robotics. As our knowledge on insect navigation grows, our physical, physiological and neural models get more complex and detailed. To test these models we need to perform increasingly sophisticated experiments. Evolution has optimised the animals to operate in their natural environment. To probe the fine details of the methods they utilise we need to use natural visual scenery which, for experimental purposes, we must be able to manipulate arbitrarily. Performing physiological experiments on insects outside the laboratory is not practical and our ability to modify the natural scenery for outdoor behavioural experiments is very limited. The solution is reconstructed visual reality, a projector that can present the visual aspect of the natural environment to the animal with high fidelity, taking the peculiarities of insect vision into account. While projectors have been used in insect research before, during my candidature I designed and built a projector specifically tuned to insect vision. To allow the ant to experience a full panoramic view, the projector completely surrounds her. The device (Antarium) is a polyhedral approximation of a sphere. It contains 20 thousand pixels made out of light emitting diodes (LEDs) that match the spectral sensitivity of Myrmecia. Insects have a much higher fusion frequency limit than humans, therefore the device has a very high flicker frequency (9kHz) and also a high frame rate (190fps). In the Antarium the animal is placed in the centre of the projector on a trackball. To test the trackball and to collect reference data, outdoor experiments were performed where ants were captured, tethered and placed on the trackball. The apparatus with the ant on it was then placed at certain locations relative to the nest and the foraging tree and the movements of the animal on the ball were recorded and analysed. The outdoor experiments proved that the trackball was well suited for our ants, and also provided the baseline behaviour reference for the subsequent Antarium experiments. To assess the Antarium, the natural habitat of the experimental animals was recreated as a 3-dimensional model. That model was then projected for the ants and their movements on the trackball was recorded, just like in the outdoor experiments Initial feasibility tests were performed by projecting a static image, which matches what the animals experienced during the outdoor experiments. To assess whether the ant was orienting herself relative to the scene we rotated the projected scene around her and her response monitored. Statistical methods were used to compare the outdoor and in-Antarium behaviour. The results proved that the concept was solid, but they also uncovered several shortcomings of the Antarium. Nevertheless, even with its limitations the Antarium was used to perform experiments that would be very hard to do in a real environment. In one experiment the foraging tree was repositioned in or deleted from the scene to see whether the animals go to where the tree is or where by their knowledge it should be. The results suggest the latter but the absence or altered location of the foraging tree certainly had a significant effect on the animals. In another experiment the scene, including the sky, were re-coloured to see whether colour plays a significant role in navigation. Results indicate that even very small amount of UV information statistically significantly improves the navigation of the animals. To rectify the device limitations discovered during the experiments a new, improved projector was designed and is currently being built

2023- The Twenty-seventh Annual Symposium of Student Scholars

The full program book from the Twenty-seventh Annual Symposium of Student Scholars, held on April 18-21, 2023. Includes abstracts from the presentations and posters.https://digitalcommons.kennesaw.edu/sssprograms/1027/thumbnail.jp

EVA London 2022: Electronic Visualisation and the Arts

The Electronic Visualisation and the Arts London 2022 Conference (EVA London 2022) is co-sponsored by the Computer Arts Society (CAS) and BCS, the Chartered Institute for IT, of which the CAS is a Specialist Group. Of course, this has been a difficult time for all conferences, with the Covid-19 pandemic. For the first time since 2019, the EVA London 2022 Conference is a physical conference. It is also an online conference, as it was in the previous two years. We continue with publishing the proceedings, both online, with open access via ScienceOpen, and also in our traditional printed form, for the second year in full colour. Over recent decades, the EVA London Conference on Electronic Visualisation and the Arts has established itself as one of the United Kingdom’s most innovative and interdisciplinary conferences. It brings together a wide range of research domains to celebrate a diverse set of interests, with a specialised focus on visualisation. The long and short papers in this volume cover varied topics concerning the arts, visualisations, and IT, including 3D graphics, animation, artificial intelligence, creativity, culture, design, digital art, ethics, heritage, literature, museums, music, philosophy, politics, publishing, social media, and virtual reality, as well as other related interdisciplinary areas. The EVA London 2022 proceedings presents a wide spectrum of papers, demonstrations, Research Workshop contributions, other workshops, and for the seventh year, the EVA London Symposium, in the form of an opening morning session, with three invited contributors. The conference includes a number of other associated evening events including ones organised by the Computer Arts Society, Art in Flux, and EVA International. As in previous years, there are Research Workshop contributions in this volume, aimed at encouraging participation by postgraduate students and early-career artists, accepted either through the peer-review process or directly by the Research Workshop chair. The Research Workshop contributors are offered bursaries to aid participation. In particular, EVA London liaises with Art in Flux, a London-based group of digital artists. The EVA London 2022 proceedings includes long papers and short “poster” papers from international researchers inside and outside academia, from graduate artists, PhD students, industry professionals, established scholars, and senior researchers, who value EVA London for its interdisciplinary community. The conference also features keynote talks. A special feature this year is support for Ukrainian culture after its invasion earlier in the year. This publication has resulted from a selective peer review process, fitting as many excellent submissions as possible into the proceedings. This year, submission numbers were lower than previous years, mostly likely due to the pandemic and a new requirement to submit drafts of long papers for review as well as abstracts. It is still pleasing to have so many good proposals from which to select the papers that have been included. EVA London is part of a larger network of EVA international conferences. EVA events have been held in Athens, Beijing, Berlin, Brussels, California, Cambridge (both UK and USA), Canberra, Copenhagen, Dallas, Delhi, Edinburgh, Florence, Gifu (Japan), Glasgow, Harvard, Jerusalem, Kiev, Laval, London, Madrid, Montreal, Moscow, New York, Paris, Prague, St Petersburg, Thessaloniki, and Warsaw. Further venues for EVA conferences are very much encouraged by the EVA community. As noted earlier, this volume is a record of accepted submissions to EVA London 2022. Associated online presentations are in general recorded and made available online after the conference