Hisayoshi Sugiyama

Collaborative movement of rescue robots for reliable and effective networking in disaster area

We investigated a collaboration scheme for rescue robots for reliable and effective operation of rescue systems using robots. The investigation focused on the collaborative movement of robots to maintain their wireless network. We propose classifying the robots into search robots and relay robots and using a behavior algorithm for their collaborative movement. According to the algorithm, search robots explore the disaster area and search for victims, whereas relay robots act as relay terminals within the network. Each robot classifies itself autonomously and repeatedly as the system operation progresses. We evaluated the performance of the victim detection system (a rescue system introduced in our previous paper) based on the proposed scheme by computer simulation. Its performance was improved compared with the case where every robot walked randomly in the disaster area and no classification occurred

Pulsed Power Network Based On Decentralized Intelligence For Reliable And Lowloss Electrical Power Distribution

Abstract Pulsed power network is proposed for reliable and low loss electrical power distribution among various type of power sources and consumers. The proposed scheme is a derivative of power packet network so far investigated that has affinity with dispersion type power sources and has manageability of energy coloring in the process of power distribution. In addition to these advantages, the proposed scheme has system reliability and low loss property because of its intelligent operation performed by individual nodes and direct relaying by power routers. In the proposed scheme, power transmission is decomposed into a series of electrical pulses placed at specified power slots in continuous time frames that are synchronized over the network. The power slots are pre-reserved based on information exchanges among neighboring nodes following inherent algorithm of the proposed scheme. Because of this power slots reservation based on decentralized intelligence, power pulses are directly transmitted from various power sources to consumers with the least power dissipation even though a partial failure occurs in the network. The network operations with the proposed scheme is simulated to confirm the algorithms for the power slots reservation and to evaluate the power network capacity.

Direct relayed power packet network with decentralized control for reliable and low loss electrical power distribution

Direct relayed power packet network is proposed for reliable and low loss electrical power distribution to consumers. Differing from the power packet networks so far proposed, in this scheme, power packets are not stored at routers but a direct path is established to the destination at each packet transmission. Each path is reserved before the packet transmission following the reservation protocol based on the synchronized QoS routing in data packet networking. Therefore, power losses do no occur by packet processing at routers nor by packet discards caused by packet collisions or overflows at routers. In addition, because of the pure decentralized scheme of the network operation, system reliability of the electrical power distribution is obtained against a partial failure of the network. This reliability is especially desirable from the view point of disaster prevention in urban areas. In this paper, besides the description of the proposed power packet network, its performances are evaluated by computer simulations including the network capacity, and its reliability against a partial network failure.

Real-time exploration of a multi-robot rescue system in disaster areas

Abstract A system procedure is proposed for a multi-robot rescue system that performs real-time exploration over disaster areas. Real-time exploration means that every robot exploring the area always has a communication path to human operators standing by at a base station and that the communication path is configured by ad hoc wireless networking. Real-time exploration is essential in multi-robot systems for USAR (urban search and rescue) because operators must communicate with every robot to support the victim detection process and ad hoc networking is suitable to configure a communication path among obstacles. The proposed system procedure consists of the autonomous classification of robots into search and relay types and behavior algorithms for each class of robot. Search robots explore the areas and relay robots act as relay terminals between search robots and the base station. The rule of the classification and the behavior algorithm refer to the forwarding table of each robot constructed for ad hoc networking. The table construction is based on DSDV (destination-sequenced distance vector) routing that informs each robot of its topological position in the network and other essentials. Computer simulations are executed with a specific exploration strategy of search robots. The results show that a multi-robot rescue system can perform real-time exploration with the proposed system procedure and reduce exploration time in comparison with the case where the proposed scheme is not adopted. Graphical Abstract

A protocol for energy transmission in packetized energy networks with sources and consumers

A protocol is proposed for energy transmission in packetized energy distribution networks with power sources and consumers. According to the proposed scheme, energy packets are transmitted simultaneously among multiple nodes. Each power source decides its energy transmission target depending on consumer demands and distances to them. The energy transmission procedure is triggered by an occurring of a consumer demand. The performance of the packtized energy distribution network is confirmed by computer simulations.

Simultaneous power transmissions among specified sources and consumers through shared power lines

An example system of pulsed power network is demonstrated. This scheme is already proposed in our papers. In the proposed network, simultaneous power transmissions among specified power sources and consumers with different intensities are possible through shared power lines. This advantage is demonstrated with two power sources and two consumers operating in the pulsed power network.

Power distribution protocol among power plants and consumers in power packet networks

Power distribution protocol among power plants and consumers in power packet networks is proposed. According to this protocol, power packets are transmitted multipoint-to-multipoint simultaneously. Each power plant decides its power transmission destination depending on consumer demands and distances to them. The power transmission procedure is triggered by an occurring of a consumer demand. The power network performance is confirmed by computer simulations.

Pulsed power network with power sources and consumers operated on exhibition table

A mini-scaled pulsed power network operation is demonstrated. This scheme of smart grid was proposed in my previous papers and the basic operation was already demonstrated. In this exhibition, an advanced performance of the pulsed power network is demonstrated where electric pulses are autonomously transmitted among users according to current demands of consumers through pre-reserved transmission paths. Reliability of the decentralized control is also demonstrated against power router failures.

Mutual cancellation among electric pulse flows for advanced performance of pulsed power network

An algorithm is proposed for mutual cancellation among electric pulse flows in pulsed power networks. The pulsed power network is already proposed as one of the neo-futuristic schemes for smart grids. This scheme has advantages including low loss property in power transmissions, affinity with distributed power generations, availability of energy coloring, and reliablity against partial network failures. However, with the original proposal, power suppliers and consumers cannot utilize the entire capacity the power network essentially has. In this paper, as a method to improve the network capacity of pulsed power network, mutual cancellation among electric pulse flows is investigated. This method cancels present and intended bidirectional pulse flows and changes them into virtual ones that makes actual pulse flows coexist and consequently the network capacity improves. The algorithm for this process is designed and network capacity improvement is confirmed by simulations.

Virtual networking method for multi-robot navigation

Virtual networking method for multi-robot navigation is proposed. This method is suitable for the collaboration of the robots that supports human workers in offices, factories, or disaster areas. In this method, virtual nodes and their forwarding tables are constructed on each robot according to DSDV routing protocol. These virtual information navigates the robot to its destination. The data volume is reasonable and is shareable with other robots through wireless channels. Simulations on a maze like environment is executed to confirm the performance of the proposed method.