Application of Distributed Robotic Systems in Earthquakes: Search, Planning and Control Abstract

In order to search and rescue injured during earthquake, we proposed a method for multi-robots motion planning and distributed control in this paper. At first, we have created two probabilistic search models to considering the search area and the characteristics of sensors, which we used to search the injured targets. And after finding the targets, they are assigned to the mobile robots on the land to afford emergency rescue. In order to reach to the targets, a path planning method based on map matching is proposed. There are three parts here. Firstly, to obtain the global and local map: continuous ground images are first collected using the UAV’s vision system, and subsequently, a global map of the ground environment is created by processing the collected images. The local map of the ground environment is obtained using the 2D laser radar sensor of the leader (UGA). Established the coordinate conversion relationship between UAV and UGV, unknown values during map matching are determined via the least square method. Secondly, our robots moved by group (leader-follower). The leader’s path was planned globally and locally. The other multi-robots moved along the path planned by the leader. Thirdly, in order to plan and coordinate the robots in the group, the finite state machine is used to describe the logical level of control system for each robot in the group. After that, at the tactical level of the control system, the movement control law of formation maintaining mode and formation switching mode is designed.

Improving the Quality of the Underwater Robot’s Contactless Battery Charging System

A special feature of the contactless battery charging system of an autonomous underwater robot is the use of a transformer with separating primary and secondary windings. As a result, a non-magnetic gap arises, which leads to the need to increase the primary current and the output current of the autonomous inverter. One of the ways to improve the quality of the system is the use of a resonant circuit at the inverter output in combination with the "soft switching" mode of its power switches. The use of resonance on the transformer secondary side also allows you to equalize the current loads of the primary and secondary windings. In this way, a minimum of losses in the inverter is achieved and the power transformer of the system is optimized. This allows you to reduce the size of the system while maintaining the transmitted power, or increase the transmitted power while maintaining the dimensions. The problem solved by using mathematical modelling with verification of the solution adequacy in a full-scale experiment.

Capillaric - Field Effect Transistors

Controling fluid flow in capillaric circuits is a key requirement to increase their uptake for assay applications. Capillary action off-valves provide such functionality by pushing an occluding bubble into the channel using a difference in capillary pressure. Previously, we utilised the binary switching mode of this structure to develop a powerful set of fundamental fluidic valving operations. In this work we provide evidence that these structures are in fact functionally complementary to electronic Junction Field Effect Transistors and thus warrant the use of the new term of capillaric- Field Effect Transistor to describe these types of valves. To support this conclusion, we present a theoretical description, experimental characterisation, and practical application of analog flow resistance control. In addition, we demonstrate that the valves can also be re-opened. These are two key capabilities previously missing for a full analogy to electronic transistors. We show modulation of the flow resistance from fully open to pinch-off, determine the flow rate – trigger channel volume relationship and demonstrate that the latter can be modelled using Shockley’s equation for electronic transistors. Finally, we provide a first example of how the valves can be opened and closed repeatedly.

Conduction and Resistive Switching Memory in Al/MoS2+PVP/Ag Devices Fabricated using Drop cast Method

Resistive switching in MoS2 embedded PVP composite-based ReRAM with Al and Ag electrodes is reported. A cost-free drop cast method was used to deposit active layers consisting of 30 wt%, 40 wt%, and 70 wt% of MoS2 in PVP. Each system exhibited unique electroforming and switching mode. Asymmetrical bipolar resistive switching occurring only in the positive voltage bias, a typical bipolar resistive switching and a typical ‘O-type’ resistive switching were observed for the 30 wt%, 40 wt%, and 70 wt% systems, respectively. Furthermore, injection of charge carriers at the electrode/active layer interface and electrochemical metalization mechanisms drove the formation of a nanoscale conductive filament in the device A and B. On the other hand, we attributed the conduction mechanism of device C to hopping conduction. Our results demonstrate the behaviour of MoS2 embedded PVP composite-based ReRAM has a strong dependence on the amount of MoS2 and that both the switching and conduction mechanism can be exploited by controlling the amount of MoS2 in the composite.

Electroforming-Free Bipolar Resistive Switching Memory Based on Magnesium Fluoride

Electroforming-free resistive switching random access memory (RRAM) devices employing magnesium fluoride (MgFx) as the resistive switching layer are reported. The electroforming-free MgFx based RRAM devices exhibit bipolar SET/RESET operational characteristics with an on/off ratio higher than 102 and good data retention of >104 s. The resistive switching mechanism in the Ti/MgFx/Pt devices combines two processes as well as trap-controlled space charge limited conduction (SCLC), which is governed by pre-existing defects of fluoride vacancies in the bulk MgFx layer. In addition, filamentary switching mode at the interface between the MgFx and Ti layers is assisted by O–H group-related defects on the surface of the active layer.

The Impact of Highly Paramagnetic Dy3+ Cations On Magnetic and Electrical Behaviour of Nanocrystalline Mnfe2o4

In this paper, the detailed study of magnetic properties of Dy3+ substituted soft manganese ferrite (MnFe2O4) nanoparticles with varied contents of Dy3+ ions (0.00 ≤ x ≤ 0.16) was carried out by vibrating sample magnetometery (VSM) at room temperature. The synthesis of reported magnetic materials was carried out via facile wet chemical route. Structural characterization was investigated via X-ray diffraction and infra-red spectroscopy. Exploration of magnetic measurements revealed an irregular behavior in the values of saturation magnetization (Ms), remanent magnetization (Mr), and coercivity (Hc) depending upon the concentration of rare-earth ions (Dy3+). The fluctuations in the values of Ms, Mr, and Hc may be associated with the modifications in the spin-exchange interactions caused by structural changes due to the substitution of rare-earth ions (Dy3+). DC electrical resistivity values were recorded and were found to be increased with increased Dy3+ contents. The soft magnetic nature of Dy3+ substituted MnFe2O4 spinel ferrites nanoparticles suggested their possible utilization in switching mode power supplies, recording media, spintronics, and many other advanced technological devices.