Showing papers on "Bus network published in 2011"

Method for routing information over a network employing centralized control

Abstract: A method and apparatus for centralized control of a network is described. The network includes a number of nodes. The method includes creating a database and storing the database on a master node of the network. The database contains topology information regarding a topology of the network. Each of the nodes is coupled to at least one other of the nodes, with the master node being one of the nodes.

Bus Selection in Multibus DC Microgrids

Abstract: DC power systems can be made more reliable by using multiple buses for redundancy. Multiple buses provide multiple configuration options for supplying power to the load. Diode OR'ing with auctioneering diodes is perhaps the most common method to connect a load to multiple buses. Although the diode action is automatic and fault-tolerant, it results in ill-defined bus currents when the bus voltages are similar and the potential for uncontrolled switching in a faulted high-impedance system-operating scenarios not often included in a discussion on auctioneering diodes. Active switching and bus converters with auctioneering diodes are control techniques that overcome these limitations by providing full control over the bus selection process. Using local information in the form of the bus voltage, these techniques do not rely on a centralized controller, which improves system reliability. Dwell time is proposed as a technique to stabilize the state-dependent switching in the bus selector.

Intelligent Agent Optimization of Urban Bus Transit System Design

Abstract: The transit route network design (TRND) problem seeks a set of bus routes and schedules that is optimal in the sense that it maximizes the utility of an urban bus system for passengers while minimizing operator cost. Because of the computational intractability of the problem, finding an optimal solution for most systems is not possible. Instead, a wide variety of heuristic and meta-heuristic approaches have been applied to the problem to attempt to find near-optimal solutions. This paper presents an optimization system that synthesizes aspects of previous approaches into a scalable, flexible, intelligent agent architecture. This architecture has successfully been applied to other transportation and logistics problems in both research studies and commercial applications. This study shows that this intelligent agent system outperforms previous solutions for both a benchmark Swiss bus network system and the very large bus system in Delhi, India. Moreover, the system produces in a single run a set of Pareto equivalent solutions that allow a transit operator to evaluate the trade-offs between operator costs and passenger costs.

An Empirical Investigation of Passenger Wait Time Perceptions Using Hazard-Based Duration Models

Abstract: Waiting time in bus stops heavily affects traveler attitude towards public transportation and therefore is an important element for consideration when planning and operating a bus system. Furthermore, what passengers perceive as waiting time is often quite different from their actual waiting time at a bus stop. In this context, we present an empirical investigation of actual and perceived waiting times at bus stops for the case of a large bus network, using hazard-based duration models. The analysis is based on a questionnaire survey undertaken at bus stops of the Athens, Greece, bus network. Results indicate that age, trip purpose, and trip time period seem to have an impact on that perception, with older individuals, work, and education trips being factors that increase perceived waiting time and lead to an overestimation of actual waiting, while perceived waiting time decreases during morning time periods.

Methods and apparatus for configuring multiple logical networks of devices on a single physical network

Abstract: Methods and apparatus for configuring multiple logical networks that share a common transmission medium are presented According to an exemplary embodiment, an apparatus for configuring multiple logical networks of devices on a single physical network includes a transceiver configured to exchange information with devices connected to a shared bus of the physical network The apparatus includes logic configured to assign a network number to a new logical network when the apparatus is first activated on the shared bus, the assigned network number being different from network numbers associated with other logical networks using the shared bus

Quantitative Comparison of the Error-Containment Capabilities of a Bus and a Star Topology in CAN Networks

Abstract: There has been an increasing interest in using star topologies in field-bus communications, e.g., in Time Triggered Protocol for SAE classC applications (TTP/C), FlexRay, or controller area network (CAN), due to increased fault resilience and potential error-containment advantages. In this context, an innovative CAN-compliant star topology, CANcentrate, has been developed, whose hub includes enhanced fault-treatment mechanisms. However, despite this interest toward stars, it is still necessary to quantify their real dependability benefits. For this purpose and for the particular case of CAN, this paper presents models for the dependability features of CAN and CANcentrate using Stochastic Activity Networks (SANs). It quantitatively compares their reliability and error-containment capabilities under permanent hardware faults. These models rely on assumptions that ensure that results are not biased toward CANcentrate, which, in some cases, is too detrimental for it. Thus, despite not reflecting the full CANcentrate potential, results quantitatively confirm the improvement of error-containment it achieves over CAN. Additionally, the way in which the nodes' ability to contain their own errors affects the relevance of using a star topology has been quantified. Although this paper refers to the case of CAN, conclusions regarding the justification of using a star topology depending on this ability can be extrapolated to other field-bus technologies.

Implementation and Testing of Directional Comparison Bus Protection Based on IEC61850 Process Bus

Abstract: A directional comparison bus protection unit (DCBPU) can provide a high speed bus fault clearing in the IEC61850 process-bus environment. This technique is based on superimposed fault direction for each circuit connected to the protected bus. In this paper, the implementation and testing of a superimposed directional comparison technique for bus protection based on an IEC61850 process bus is investigated. Design, hardware implementation, and related issues of DCBPU are described. A unique test setup is proposed and developed for testing DCBPU, including merging unit simulator, traffic generator, prototype DCBPU, and Ethernet switches to simulate the real IEC 61850-based substation automation process bus. Test results are reported.

Logic cell array and bus system

Abstract: A logic cell array having a number of logic cells and a segmented bus system for logic cell communication, the bus system including different segment lines having shorter and longer segments for connecting two points in order to be able to minimize the number of bus elements traversed between separate communication start and end points.

Adaptive bus profiler

Abstract: An adaptive bus profiler is described. In embodiment(s), data traffic that is communicated on an adaptive bus can be monitored, and projected data traffic that is scheduled for communication via the adaptive bus can be determined. An adaptive bus profile can be determined based on the data traffic and the projected data traffic. A reconfiguration of a bus width of the adaptive bus can be initiated based on the adaptive bus profile.

Bus transport network model with ideal n-depth clique network topology

Abstract: We propose an ideal n -depth clique network model. In this model, the original network is composed of cliques (maximal complete subgraphs) that overlap with each other. The network expands continuously by the addition of new cliques. The final diameter of the network can be set in advance, namely, it is controllable. Assuming that the diameter of the network is n , the network exhibits a logistic structure with ( n + 1 ) layers. In this structure, the 0th layer represents the original network and each node of the ( m ) th layer ( 1 ≤ m ≤ n ) corresponds to a clique in the ( m − 1 ) th layer. In the growth process of the network, we ensure that any ( m ) th layer network is composed of overlapping cliques. Any node in an ( m ) th layer network corresponds to an m -depth community in the original network, and the diameter of an m -depth community is m . Therefore, the ( n − 1 ) th layer network will contain only one clique, the ( n ) th layer network will contain only one node, and the diameter of the corresponding original network is n . Then an ideal n -depth clique network will be obtained. Based on the ideal n -depth clique network model, we construct a bus transport network model with an ideal n -depth clique network topology (ICNBTN). Moreover, our study compares this model with the real bus transport network (RealBTN) of three major cities in China and a recently introduced bus transport network model (BTN) whose network properties correspond well with those of real BTNs. The network properties of the ICNBTN are much closer to those of the RealBTN than those of the BTN are. At the same time, the ICNBTN has higher clustering extent of bus routes, smaller network diameter, which corresponds to shorter maximum transfer times in a bus network, and lower average shortest path time coefficient than the BTN and the RealBTN. Therefore, the ICNBTN can achieve higher transfer efficiency for a bus transport system.

Communication with lighting units over a power bus

Abstract: A first entity communicates with a second entity over a shared power bus by switching the bus to a high-impedance state and modifying the voltage on the power bus, in accordance with an outgoing communication, such that the modified voltage is detected by the second entity and the communication is received thereto.

Priority division: A high-speed shared-memory bus arbitration with bounded latency

Abstract: In state-of-the-art multi-processor systems-on-chip (MPSoC), interconnect of processing elements has a major impact on the system's overall average-case and worst-case performance. Moreover, in real-time applications predictability of inter-chip communication latency is imperative for bounding the response time of the overall system. In shared-memory MPSoCs buses are still the prevalent means of on-chip communication for small to medium size chip-multi-processors (CMPs). Still, bus arbitration schemes employed in current architectures either deliver good average-case performance (i.e. maximize bus utilization) or enable tight bounding of worst-case-execution time. This paper presents a shared bus arbitration approach allowing high bus utilization while guaranteeing a fixed bandwidth per time frame to each master. Thus it provides high-performance to both realtime and any-time applications or even a mixture of both. The paper includes performance results obtained while executing random traffic on a shared bus implemented on a FPGA. The results show that our approach provides bus utilization close to static priority based arbitration, a fairer bandwidth distribution than Round Robin and latency guarantees identical to TDMA. With this it combines the best properties of these schemes.

Optical Fiber Bus Protection Network to Multiplex Sensors: Self-Diagnostic Operation

Abstract: We present a mathematical model for a wavelength- division multiplexed self-healing optical fiber bus network to interconnect an array of sensors. The network uses protection switching to reestablish service after the failure of one or more of its constituent elements. Our model is a matrix-vector formalism that divides the network into blocks. It predicts which wavelengths arrive at the receiver node when damage has occurred in one or more places. We study single and multiple failures within one block, categorizing and tabulating all combinations of surviving wavelengths. In this way, we correlate the received wavelengths with the failure location(s). The network thus provides “self-diagnosis,” which we define to be the determination of its own sites of failure from network management information, without requiring external resources.

Dispatching management system and method for event emergency response of urban bus passenger transport

Abstract: The invention relates to a dispatching management system and a method for event emergency response of urban bus passenger transport. Methods of combining actual measurement data, event prediction model and algorithm as well as event real-time dispatching model and algorithm are comprehensively applied; geographical information technology, locating technology and modern communication technology are scientifically integrated; bus emergency dispatching technology developed through bus network intellectualization and multi-way coordinative dispatching technology of an urban bus passenger transport system are utilized; and an emergency coordinative dispatching model and the method are established by taking the networked bus passenger transport vehicle dispatching and operation dispatching management as a core and based on the key theories and methods for multi-way and multi-line intelligent coordinative dispatching of a urban bus and passenger transport system. The invention provides excellent theory, methods and technique supports for the real-time dispatching of urban bus events, effectively reduces the event recognition time, generates a quick real-time dispatching strategy, effectively eliminates the influences generated by the events, and resumes the driving plan so as to effectively improve the running efficiency and safety of buses.

Method and apparatus for effective utilization of energy storage components within a microgid

Abstract: A method for effectively utilizing energy storage components within a microgrid may include the steps of connecting a first plurality of energy storage components to a DC bus through switches, connecting a second plurality of energy storage components to an AC bus through inverters, connecting controllers to the energy storage components, connecting a first plurality of the controllers to the DC bus to regulate bidirectional flow of energy between the DC bus and the first plurality of energy storage components and connecting a second plurality of the controllers to the AC bus to regulate bidirectional flow of energy between the AC bus and the second plurality of energy storage components. The controllers may be interconnected with a local energy storage system bus and controlled via a master microgrid controller connected to the local energy storage system bus. The controllers may have a state of charge and a state of health algorithm adapted to measure the state of charge and the state of health of the energy storage components under dynamic charge or discharge conditions.

Reducing simultaneous switching outputs using data bus inversion signaling

Abstract: An apparatus includes a plurality of data lines defining a data bus for communicating data. A controller is operable to communicate a plurality of data transfers over the data bus using a plurality of data time slots, wherein for at least a subset of the data time slots the controller is operable to communicate an associated data bus inversion indicator indicating that bits communicated during the associated data time slot are inverted, the data bus inversion indicators for the subset of the data transfers are grouped into a data bus inversion vector, and the controller is operable to communicate a global data bus inversion indicator indicating an inversion of the data bus inversion vector.

Customized diagrammatic view of a network topology

Abstract: A method includes receiving a request for network topology information for a network. The request includes an identifier for a requesting entity and an identifier for the network. The method also includes accessing network topology information for the network based on the identifier for the network. The network topology information identifies a plurality of network elements in the network and defines a relationship between the network elements. A diagrammatic view of the network topology is determined based on the network topology information for the network. The method includes determining one or more aspects of at least one network element based on the identifier for the requesting entity. The method further includes associating the one or more aspects to the at least one network element to form a customized diagrammatic view of the network topology. The method also includes providing the customized diagrammatic view of the network topology.

Secure message filtering to vehicle electronic control units with secure provisioning of message filtering rules

Abstract: A method according to one embodiment includes the operations of configuring a host processor to receive a message filtering rule, the host processor associated with a vehicle; configuring a bus controller to verify authenticity of the message filtering rule, wherein the bus controller is programmed through an interface, the interface inaccessible from the host processor; filtering messages from the host processor using the verified message filtering rule, wherein the filtering is performed by the bus controller; and transmitting the filtered messages from the bus controller over a bus to one or more electronic control units (ECUs), the ECUs communicatively coupled to the bus.

Interaction between Bus Stops Location and Traffic on Bus Operation

Abstract: In bus networks there are many stations used for boarding and alighting passengers along the bus route. In designing bus stop location three sides approach to be considered; the big picture, street side and curb side. Apiece of three sides have directly affects in the bus scheduling. The effectiveness of bus operation will depend on number of bus stops and its spacing. Basically, bus stations have two kinds: bus stop, use to service passengers in one bus line and bus interchange (terminal) use to share station between some bus lines. This article described a survey on bus stop location efficiency in bus operation where study on bus stop location in three points: near-side, far-side and mid-block were considered. It has been highlighted bus stop location in situation mid-block has higher efficiency than others situations.

Communication system, master node, and slave node

Abstract: In a communication system, a bus allows information to be communicated thereon as signals. Each of the signals has an electrical dominant level thereon and an electrical recessive level thereon. The electrical dominant level is asserted on the bus in priority to the electrical recessive level. Each of a master node and at least one autonomous communicating slave node detects that the bus is in an idle state when the electrical recessive level on the bus is continued for a predetermined period or more, transmits a corresponding header via the bus after detection of the bus being in the idle state, and performs arbitration on the bus based on the corresponding header.

Automatic under-frequency load shedding in New Zealand power system — A systematic review

Abstract: Automatic Under-Frequency Load Shedding (AUFLS) is the last resort for New Zealand (NZ) power system to prevent widespread blackout following severe system contingency. This paper provides a systematic review of existing AUFLS in New Zealand power system and assesses future potentials that can be enabled through emerging Smart Grid technology investments in distribution networks. A new AUFLS scheme is proposed that can be implemented for effective and improved AUFLS. The proposed scheme is analyzed through realistic simulations on a 5 bus network and IEEE-39 bus test system. This is compared with existing New Zealand AUFLS scheme applied to these test systems.

Double on-site bus interface converter

Abstract: The invention relates to a multi-field bus interface converter, with the technical scheme that: one end of a CAN bus transceiver (1) is connected with the can bus network, and other end is connected with a CAN controller (10) through a first optical coupling isolation circuit (2); one end of a SPC3 protocol controller (4) is connected with a SoC microcontroller (9), and the other end is connectedwith an RS deliver (6) through a second optical coupling isolation circuit (5); an RS 485 driver (6) is connected with the Profibus-DP bus network; a serial field device or an instrument (13) is connected with the SoC microcontroller (9) through a serial communucation interface module (11); a bus selecting switch module (8) is connected with a Soc microcontroller (1). The protocol converting program between the serial port and the CAN and Profibus-DP bus interface is stored in the SoC microcontroller (9). The invention is characterized by strong flexibility and low hardware complexity and thelike, thereby realizing the monitoring management and resource sharing on the same serial device by the two field bus networks, reach interconnection of heterogeneous network.

An Ant System application to the Bus Network Design Problem: an algorithm and a case study

Abstract: Bus system design is a difficult problem, and hence is usually decomposed into a series of sub-problems solved sequentially. Bus network design is foremost in this series of problems. The bus network design problem in this study is the problem of choosing a subset of interconnected bus routes from among a given set of such routes, which minimizes the total travel time of the users of the network, while being feasible in fleet requirements. The Ant System concept has been exploited to solve this problem. The algorithm has been applied to the problem and calibrated based on the network of Sioux Falls. For this purpose, several fleet assignment routines have been tested, some sensitivity analyses are made to estimate suitable parameter values, and alternative ways of laying pheromone on bus routes have been examined. Experiments are conducted to investigate the performance of the solution algorithm when the number of routes, or bus fleet size, increases. Moreover, other experiments help to determine the number of algorithmic iterations. These experiments prepared the algorithm to be applied to design the bus network of the City of Mashhad, with a population of over 2 million. The results have been compared with those of another solution to the same problem, obtained by another meta-heuristic, namely a Genetic Algorithm.

Network control method of dual-redundancy CAN bus

Abstract: The invention provides a network control method of a dual-redundancy CAN bus, which comprises five major steps: step 1: switching on a system and carrying out node initialization; step 2: detecting the initialization of the system; step 3: carrying out normal work and cycle detection; step 4: carrying out treatment of abnormality during the operation of the system; and step 5: carrying out the treatment after switching over a main channel and a standby channel. The method fully utilizes a mature CAN device for constructing a dual-redundancy bus network, carries out error detection and specifies control authorities of different nodes through application software, realizes a network control strategy of distributed monitoring and centralized management, simultaneously provides a detailed fault detection method of the CAN bus system and carries out classification on different errors, thereby being easy to realize programming and having strong universality. The network control method improves the fault-tolerant capacity of the CAN bus system and fully utilizes the redundancy mechanism to ensure the reliability of the system; and the network control method has wide practical value and application prospect in the field of mechanical and electrical control.

Timely data delivery in a realistic bus network

Abstract: WiFi-enabled buses and stops may form the backbone of a metropolitan delay tolerant network, that exploits nearby communications, temporary storage at stops, and predictable bus mobility to deliver non-real time information. This paper studies the problem of how to route data from its source to its destination in order to maximize the delivery probability by a given deadline. We assume to know the bus schedule, but we take into account that randomness, due to road traffic conditions or passengers boarding and alighting, affects bus mobility. We propose a simple stochastic model for bus arrivals at stops, supported by a study of real-life traces collected in a large urban network. A succinct graph representation of this model allows us to devise an optimal (under our model) single-copy routing algorithm and then extend it to cases where several copies of the same data are permitted. Through an extensive simulation study, we compare the optimal routing algorithm with three other approaches: minimizing the expected traversal time over our graph, minimizing the number of hops a packet can travel, and a recently-proposed heuristic based on bus frequencies. Our optimal algorithm outperforms all of them, but most of the times it essentially reduces to minimizing the expected traversal time. For values of deadlines close to the expected delivery time, the multi-copy extension requires only 10 copies to reach almost the performance of the costly flooding approach.

Distributed Computing Bus

Abstract: A distributed computing bus that provides both data transport and ambient computing power is provided. Contemplated buses comprise a network fabric of interconnected networking infrastructure nodes capable of being programmed before or after installation in the field. A fabric manager organizes the fabric into a bus topology communicatively coupling computing elements that exchange payload data using a bus protocol. Nodes within the bus topology operate on the payload data as the data passes through the node on route to its destination.

Arbitrating bus transactions on a communications bus based on bus device health information and related power management

Abstract: Devices, systems, methods, and computer-readable mediums for arbitrating bus transactions on a communications bus based on health information are disclosed. Health information of master devices can be used to adjust priorities of bus transactions from master devices to meet quality of service requirements of the master devices. In one embodiment, a bus interconnect is provided and configured to communicate bus transactions from any of a plurality of master devices to slave device(s) coupled the bus interconnect. The bus interconnect is further configured to map health information for each of the plurality of master devices into virtual priority space. The bus interconnect is further configured to translate the virtual priority space into a physical priority level for each of the plurality of master devices. The bus interconnect is further configured to arbitrate bus transactions for the plurality of master devices based on physical priority level for the plurality of master devices.

Central Bus Guardian (CBG) and method for operating CBG

Abstract: Central bus guardians (CBGs) and methods for operating a CBG are described. In one embodiment, a method for operating a CBG includes performing race arbitration among the buses connected to the CBG to select a winner bus for a time slot, and selectively forwarding data received at the CBG from the winner bus to a destination bus in the time slot based on whether the winner bus or the destination bus has a connection to an external network with respect to the application network and whether a communications device connected to the winner bus or the destination bus performs a critical function. Other embodiments are also described.

Application of passive optical network with optimized bus topology for local backbone data network

Abstract: This paper proposes an innovative application of passive optical networks with optimized bus topology for local backbone data networks. Passive optical networks represent a promising solution for modern access networks to meet the increasing demands on transmission rate for demanding multimedia services. As these networks rely exclusively on passive components implemented in their entire infrastructure, it is necessary to consider their certain specific features and optimize properly necessary parameters, especially an attenuation balance. Considering the possibility of such optimization, the passive optical network with optimized bus topology provides several interesting opportunities for specific applications. Its potential application is, for example, a high-speed local backbone infrastructure connecting local data switches and routers. For that purpose, the passive optical splitter with adjustable power splitting ratio at its outputs can be used for the optimization process of attenuation balance. This paper presents a mathematical apparatus for calculating the maximum number of splits and the number of bridge taps in the passive optical network with the bus topology and an example of obtained results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2351–2355, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26291