Investigation of the influence of the length of the intermediate magnetic circuit on the characteristics of magnetic gripper for robotic complexes of the mining industry

The analysis of the existing systems of mechanical grippers of various operating principles and operating environments, in the design of which both soft and hard magnetic materials are executed. The characteristics of existing prototypes are shown and the results of our own research are presented. The article presents a study of the effect of the intermediate magnetic circuit length on the characteristics of magnetic gripper, the principle of which is based on the control of the field of a permanent magnet. The gripper based on this principle of action does not require constant energy expenditures to maintain both on and off states. The description of the magnetic gripper design and the design of the test bench is given, as well as the results of a series of experiments to determine the strength of the release of the gripper at different lengths of the magnetic circuit in the on and off states, followed by statistical processing of the data. The intervals of the ranges in which with a high degree of probability there will be a value of the gripping disengagement force for various lengths of the intermediate magnetic circuit are identified. The nature of the distribution of a random variable, which is the force of decoupling of the gripper, is determined. The dependences of the gripper decoupling force on the length of the intermediate magnetic circuit for each of the gripper states are constructed. It has been established that a decrease in the length of the intermediate magnetic circuit is the cause of a decrease in the gripping adhesion force. Plots of the dependence of the gripper decoupling force were constructed using the modes of the force values varieties to visually display the experimental results. The maximum adhesion force of magnetic pickup – 9.5 kg – was achieved with an intermediate magnetic core length of 50 mm, the minimum with a length of 25 mm – 5.6 kg

Разработка устройства сопряжения для модульной сельскохозяйственной робототехнической платформы

To create multifunctional robotic platforms for agricultural use, it is reasonable to use a modular principle that will allow installing various equipment depending on the tasks assigned to the robotic tool. Providing autonomous reconfiguration capabilities will reduce human interference and maintenance costs. (Research purpose) This work is aimed at developing a scalable device for interfacing functional modules with the agricultural robotic base platform, which can provide mechanical fixation, energy transfer and information exchange. (Materials and methods) This article analyzes the previous research into the solutions for interfacing modules in robotic complexes and points out their benefits and drawbacks. Based on the analysis and own research, the interface mechanism structure was developed to ensure the correct mutual position and fixation of the module to the base platform under the assumption of possible energy and information exchange. (Results and discussion) In the course of the work, the design ratios for the interface device were derived, making it possible to calculate the permissible linear displacements and permissible angular deviation of the mechanism interfacing elements. Based on the permissible linear deviations up to 10-13 millimeters and a permissible angular deviation of 20 degrees, the main dimensions of the device prototype were obtained. A prototype interface device was operationalized with the dimensional specifications of 200 millimeters in length, 130 millimeters in width, 58 millimeters in height. Several experiments with the device prototype were carried out based on various linear and angular deviations of the interfacing elements. (Conclusions) It was found out that successful interfacing occurs in 98 percent of cases subject to admissible calculated displacements. It was concluded that the proposed interface device will allow for the autonomous replacement of modules of multifunctional robotic platforms.Показали, что для создания многофункциональных робототехнических платформ сельскохозяйственного применения актуально использовать модульный принцип, который позволит устанавливать различное навесное оборудование в зависимости от задач, поставленных перед робототехническим средством. Отметили, что автономная реконфигурация снизит вмешательство человека в эксплуатацию и затраты на обслуживание. (Цель исследования) Разработать масштабируемое устройство сопряжения функциональных модулей с базовой сельскохозяйственной робототехнической платформой, которое сможет обеспечить механическую фиксацию, передачу энергии и информационный обмен. (Материалы и методы) Провели анализ исследовательских работ в направлении решений для сопряжения модулей в робототехнических комплексах, отметили их достоинства и недостатки. Создали структуру механизма сопряжения для обеспечения корректного взаимного положения и фиксации модуля с базовой платформой при возможности энергетического и информационного обмена. (Результаты и обсуждение) Вывели расчетные соотношения для устройства сопряжения, позволяющие вычислять допустимые линейные смещения и допустимое угловое отклонение сопрягаемых элементов механизма. Определили основные размеры прототипа устройства по заданным допустимым линейными отклонениями в диапазоне до 10-13 миллиметров и с допустимым угловым отклонением 20 градусов. Реализовали прототип устройства сопряжения с габаритными размерами: длина – 200 миллиметров, ширина – 130, высота – 58 миллиметров. Провели с ним эксперименты, изменяя линейные и угловые отклонения сопрягаемых элементов. (Выводы) Определили, что успешное сопряжение происходит в 98 процентах случаев при соблюдении допустимых расчетных смещений. Заключили, что предложенное устройство сопряжения позволит реализовать автономную замену модулей многофункциональных робототехнических платформ

Investigation of Cue-Based Aggregation Behaviour in Complex Environments

© 2021, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.Swarm robotics is mainly inspired by the collective behaviour of social animals in nature. Among different behaviours such as foraging and flocking performed by social animals; aggregation behaviour is often considered as the most basic and fundamental one. Aggregation behaviour has been studied in different domains for over a decade. In most of these studies, the settings are over-simplified that are quite far from reality. In this paper, we investigate cue-based aggregation behaviour using BEECLUST in a complex environment having two cues –one being the local optimum and the other being the global optimum– with an obstacle between the two cues. The robotic validation of the BEECLUST strategy in a complex environment is the main motivation of this paper. We measured the aggregation size on both cues with and without the obstacle varying the number of robots. The simulations were performed on a custom open-source simulation platform, Bee-Ground, using MONA robots. The results showed that the aggregation behaviour with BEECLUST strategy was able to overcome a certain degree of environmental complexities revealing the robustness of the method. We also verified these results using our stock-flow model

Phyllocarid crustaceans from the Upper Devonian Gogo Formation, Western Australia

Phyllocarids (Crustacea: Malacostraca) from the Upper Devonian (Givetian-Frasnian) Gogo Formation of Western Australia are described and two new species are reconstructed. The mineralized exoskeleton is well preserved in concretions, but the appendages, apart from the mandible, are unknown. Montecaris gogoensis sp. nov. (Echinocarididae) is represented by > 600 specimens; a possible second species of Montecaris is represented only by similar to 14 specimens of antero-dorsal fragments of the valves, which are highly tuberculate. Schugurocaris wami sp. nov. (Ceratiocarididae) is represented by > 300 specimens; a possible second species with a very elongate telson is represented by four specimens. An undetermined species of Dithyrocaris (Dithyrocarididae) is represented by > 80 specimen