Exploração inteligente de objetos por manipulador robótico

The end goal of this dissertation is to develop an autonomous exploration robot that is capable of choosing the Next Best View which reveals the most amount of information about a given volume. The exploration solution is based on a robotic manipulator, a RGB-D sensor and ROS. The manipulator provides movement while the sensor evaluates the scene in its Field of View. Using an OcTree implementation to reconstruct the environment, the portions of the de ned exploration volume where no information has been gathered yet are segmented. This segmentation (or clustering) will help on the pose sampling operation in the sense that all generated poses are plausible. Ray casting is performed, either based on the sensor's resolution or the characteristics of the unknown scene, to assess the pose quality. The pose that is estimated to provide the evaluation of the highest amount of unknown space is the one chosen to be visited next, i.e., the Next Best View. The exploration reaches its end when all the unknown voxels have been evaluated or, those who were not, are not possible to be measured by any reachable pose. Two case studies are presented to test the performance and adaptability of this work. The developed system is able to explore a given scene which, initially, it has no information about. The solution provided is, not only, adaptable to changes in the environment during the exploration, but also, portable to other manipualtors rather than the one used in the development.O objetivo nal desta dissertação é desenvolver um robot de exploração autônomo capaz de escolher a Próxima Melhor Vista que revela a maior quantidade de informações sobre um determinado volume. A solução de exploração é baseada num manipulador robótico, num sensor RGB-D e em ROS. O manipulador proporciona movimento enquanto o sensor avalia a cena no seu campo de visão. Usando uma implementação Oc- Tree para reconstruir o ambiente, as partes do volume de exploração de nido onde nenhuma informação ainda foi recolhida são segmentadas. Esta segmenta ção (ou agrupamento) ajudará na operação de amostragem de poses no sentido em que todas as poses geradas são plausíveis. Ray casting é realizado, seja com base na resolução do sensor ou nas características da cena desconhecida, para avaliar a qualidade da pose. A pose que é estimado fornecer a avaliação da maior quantidade de espaço desconhecido é a escolhida para ser visitada em seguida, ou seja, a Próxima Melhor Vista. A exploração chega ao m quando todos os voxels desconhecidos tiverem sido avaliados ou, aqueles que não o foram, não sejam possíveis de serem medidos por qualquer pose alcançável. Dois casos de estudo são apresentados para testar o desempenho e adaptabilidade deste trabalho. O sistema desenvolvido é capaz de explorar uma determinada cena sobre a qual, inicialmente, não tem informação. A solução apresentada é, não só, adaptável às mudanças no ambiente durante a explora ção, mas também, portável para outros manipuladores que não o utilizado no desenvolvimento.Mestrado em Engenharia Mecânic

Design and Implementation of Indoor Disinfection Robot System

After the outbreak of COVID-19 virus, disinfection has become one of the important means of epidemic prevention. Traditional manual disinfection can easily cause cross infection problems. Using robots to complete disinfection work can reduce people's social contact and block the spread of viruses. This thesis implements an engineering prototype of a indoor disinfection robot from the perspective of product development, with the amin of using robots to replace manual disinfection operations. The thesis uses disinfection module, control module and navigation module to compose the hardware of the robot. The disinfection module uses ultrasonic atomizers, UV-C ultraviolet disinfection lamps, and air purifiers to disinfect and disinfect the ground and air respectively. The control module is responsible for the movement and obstacle avoidance of the robot. The navigation module uses Raspberry Pi and LiDAR to achieve real-time robot positioning and two-dimensional plane mapping. In terms of robot software,we have done the following work: (1) Based on the ROS framework, we have implemented functions such as SLAM mapping, location positioning, and odometer data calibration.(2) Customize communication protocols to manage peripheral devices such as UV-C lights, ultrasonic atomizers, air purifiers, and motors on the control board. (3) Develop an Android mobile app that utilizes ROSBridge's lightweight communication architecture to achieve cross platform data exchange between mobile devices and navigation boards, as well as network connectivity and interaction between mobile phones and robots Finally, this thesis implements an engineering prototype of a household disinfection robot from the perspective of product development

Radioactivists: community, controversy and the rise of nuclear physics

This dissertation is a social and technical history of radioactivity research in the 1920s, and of the emergence of nuclear physics in the 1930s. It is concerned with the production, circulation and certification of practice and knowledge in these fields of scientific research. By 1914, the study of radioactivity was confined to a few centres - Paris, Berlin, Manchester and Vienna - possessing relatively large quantities of radium. The politics and organisation of this relatively closed network were irrevocably altered by the First World War. The election of Ernest Rutherford to the Cavendish Chair of Experimental Physics at Cambridge in 1919 brought radioactivity research, and a programme of Imperial physics, to the Cavendish Laboratory. Rutherford’s programme of research, based on his speculative nuclear model of the atom (1911), sought to map the internal topography of the atomic nucleus by means of scintillation counting experiments. Rutherford’s work on artificial disintegration, combined with F.W. Aston’s elucidation of the isotopes of the light elements by means of the mass-spectrograph, brought about a profound change in physicists’ and chemists’ views of atomic architecture. In the early 1920s, as laboratories in Europe recovered from the war, the work of the Cavendish Laboratory was unchallenged. During the 1920s, as other laboratories entered the field of nuclear research, however, a series of controversies brought into question the reliability of the scintillation technique and the integrity of all experimental results based upon it. The foundational data yielded by the mass-spectrograph, too, were contested, occasioning a ‘crisis of certitude’ in radioactivity research, and prompting a redistribution of trust into alternative sources of experimental evidence - electronic (Geiger) counters and cloud chambers. The crediting of these techniques (which proved to be as problematic as those they ostensibly replaced) opened up new kinds of problems to experimental investigation. In virtue of the new kinds of skills now required in the laboratory, a re-definition of the investigative community accompanied technical innovation. In the wake of a prolonged controversy between Cambridge and Vienna, a conference was convened at the Cavendish Laboratory in 1928, as a direct result of which researchers in several other European laboratories (including Maurice de Broglie and the Joliot-Curies in Paris, Bothe in Berlin and Pose at Halle) entered the field of nuclear research, multiplying the number of sites at which the new techniques were deployed. Theoretical physicists like George Gamow, too, began to apply the novel methods of wave mechanics to nuclear problems, gradually transforming the bounds of the possible and the plausible in nuclear research. A reconfigured network of embodied practice gradually crystallised around the development of these material and conceptual technologies. This network - including laboratories and researchers in Cambridge, Paris, Berlin, Rome, Vienna, New York, Berkeley and Washington D.C. - embodied the emergent discipline of ‘nuclear physics.’ Chadwick’s disclosure of the ‘neutron’ in 1932 using the new experimental techniques ratified this social and technical re-alignment. The emergence of Nuclear Physics as a recognised discipline by 1934 was thus the simultaneous certification of a new regime of practice, a new sociopolitical network of laboratories and a new ontology