Bus Network Research Articles

A Reflection-Based Channel Fingerprint to Locate Physically Intrusive Devices in ICS

It is hard to conduct cyber attacks in industrial control systems (ICSs) because most underlying networks of ICS like the field bus network are isolated from the Internet. However, attackers can physically connect the intrusive device into the target network to launch various attacks, which bypasses the security protection mechanisms between the ICS and the Internet. Currently, no effective measures could defend against such unauthorized physical access attacks. In this paper, a reflection-based channel fingerprint is proposed to detect and locate these physically intrusive devices in the field bus network. We theoretically analyze the signal reflection characteristics and utilize inevitable changes in the channel fingerprint to detect the intrusive device. Besides, the detected anomaly features could be used to accurately estimate the intrusive device's location. In the end, the proposed method's effectiveness is validated through extensive simulation experiments.

Smart Intrusion Detection System for CAN Network Implemented using LSTM Strategy

In today's cars, communication between electronic control units is managed via the Controller Area Network (CAN) bus system. Nevertheless, the CAN bus system lacks means for authentication and authorisation, making it susceptible to attacks like denial-of-service, fuzzing, and spoofing. To identify and counteract CAN bus network intrusions, this study suggests an intrusion detection system based on a Long Short-Term Memory (LSTM) model. Extraction of attack-free data and attack injection produced the dataset used for testing and training. Findings show that the suggested LSTM model has a greater detection rate than the Survival Analysis approach and is efficient in defending current automobiles from assaults on the CAN bus network. The ability to identify these sorts of assaults is limited by the constraints of conventional intrusion detection systems (IDS) for CAN bus networks, such as statistical analysis, frequency-based analysis, and Hidden Markov Model (HMM). Using a Long Short-Term Memory (LSTM) based strategy, the objective of this article is to build a reliable IDS that can efficiently identify and counteract these assaults on the CAN bus network.

Transmission of Power and Signal Multiplex for Electric Vehicles Using Cascaded Multilevel Inverters

Abstract: P&SMT, or power and signal multiplex transmission, is a method for transmitting communication signals using power electronic circuits. A three-phase cascaded multilevel inverter-based P&S MT system is recommended in this investigation. By allowing communication signals to be transmitted without utilizing a Controller Area Network bus, the proposed solution can lower the wiring expense of the existing electric vehicle (EV) communication system. The system's architecture enables battery balancing discharge and motor speed management for EVs. In a simulation system proposed in MATLAB/Simulink, both power and communication signals are effectively conveyed using the combined pulse width modulation scheme and frequency shift keying approach. The maximum signal rate of the proposed system is established at 600 bits per second by analyzing the bit error rate of the sent signal.

Intrusion Detection in Vehicle Controller Area Network (CAN) Bus Using Machine Learning: A Comparative Performance Study.

Electronic Control Units (ECUs) have been increasingly used in modern vehicles to control the operations of the vehicle, improve driving comfort, and safety. For the operation of the vehicle, these ECUs communicate using a Controller Area Network (CAN) protocol that has many security vulnerabilities. According to the report of Upstream 2022, more than 900 automotive cybersecurity incidents were reported in 2021 only. In addition to developing a more secure CAN protocol, intrusion detection can provide a path to mitigate cyberattacks on the vehicle. This paper proposes a machine learning-based intrusion detection system (IDS) using a Support Vector Machine (SVM), Decision Tree (DT), and K-Nearest Neighbor (KNN) and investigates the effectiveness of the IDS using multiple real-world datasets. The novelty of our developed IDS is that it has been trained and tested on multiple vehicular datasets (Kia Soul and a Chevrolet Spark) to detect and classify intrusion. Our IDS has achieved accuracy up to 99.9% with a high true positive and a low false negative rate. Finally, the comparison of our performance evaluation outcomes demonstrates that the proposed IDS outperforms the existing works in terms of its liability and efficiency to detect cyber-attacks with a minimal error rate.

Modelling of Electric Bus Operation and Charging Process: Potential Contribution of Local Photovoltaic Production

The transition from diesel to electric buses allows the reduction of greenhouse gas emissions. However, the impacts of charging strategies on the quality of bus services and the utility grid must be assessed to ensure the feasibility of the energy transition in the public transportation sector. This study investigates the performances of different locations and sizes of charging infrastructures by presenting the comprehensive modelling of a bus network. It also estimates the potential benefits of a local photovoltaic (PV) production to reduce negative impacts on the utility grid. The presented approach is used for modelling one urban bus line in Compiègne, France, and simulations are performed for various case studies. The results demonstrate that the proposed method allows analysing the impact of the charging process on the quality of bus services by determining the delays of arrivals. The simulations also show the impacts of charger placement on bus on-board battery capacity, total peak power demand of battery charging, and PV self-consumption ratio. The amount of PV energy used directly to charge buses remains low, although it varies between scenarios. PV energy during winter is not sufficient to fully charge buses; however, it can be enough with additional stationary storage in the summer.

Evaluation Methods and Optimization Strategies for Low-Carbon-Oriented Urban Road Network Structures: A Case Study of Shanghai

It is generally believed that the development of mass transportation is an effective and practical path by which to promote low-carbon development. As a form of infrastructure for the development of bus transits, urban road networks directly affect the planning and operation of a bus network. Existing studies have shown that urban road networks affect the layout effect of bus transit from aspects such as the topological network structure characteristics. Based on the existing foundation of research, this study aims to address evaluation methods for quantitative research on the topological structure of road networks, emphasizing that the topological structure characteristics are an important attribute affecting the morphological characteristics of the road network and also a key attribute affecting low-carbonization orientation. Furthermore, this study proposes an evaluation method for the low-carbon friendliness of urban road network structures and constructed a numerical comparison matrix. On this basis, the actual case of the central urban area of Shanghai was selected to conduct an empirical analysis of the evaluation of the low-carbon friendliness of the road network structure. Based on the street (township) as the regional unit scale, four types of evaluation results were obtained, corresponding to different levels of low-carbon friendliness. Based on the above analysis results, a low-carbon-oriented road network structure optimization strategy in Shanghai’s central urban area was further proposed to (1) develop countermeasures for low-carbon transportation development according to local conditions; (2) emphasize the key role of intersection forms in optimizing topology; (3) improve the connectivity level of important road sections; (4) encrypt the road network density in high-density development areas; (5) and combine this with other form of green transportation development to improve low-carbonization levels.

Integrated optimization of bus bridging service design and passenger assignment in response to urban rail transit disruptions

As the urban rail transit (URT) system plays an increasingly important role in supporting large cities’ mobility around the world, service disruptions have become more prevalent, potentially resulting in severe economic losses and passenger safety issues. It is imperative to investigate effective response strategies to mitigate the effects of such disruptions. In response to URT service disruptions, this paper systematically investigates the bus bridging service design (BBSD) problem, which concerns the integration of bus bridging route design, frequency determination, and passenger assignment in the integrated URT and bus network. The problem is formulated as a path-based integer linear programming (ILP) model with the goal of simultaneously minimizing operator-oriented and passenger-oriented costs. A column generation-based approach is proposed to solve this model efficiently, allowing nonintuitive bus routes to be freely generated on the network dynamically. Our method has been tested with two different case studies based on real data from the Hong Kong Mass Transit Railway (MTR). Experiments demonstrate that our proposed approach can assist public transit (PT) operators in developing efficient emergency response plans for various potential disruption situations in advance. Even in the face of unexpected disruptions that necessitate a quick response, our approach can generate high-quality solutions in a matter of minutes.

Quantifying bus route service disruptions under interdependent cascading failures of a multimodal public transit system based on an improved coupled map lattice model

The coupled map lattice (CML) model can present rich spatiotemporal dynamic behaviors of complex systems, e.g., it has been observed to have good adaptability in the cascading failure modeling of subway networks (SNs). However, most studies rarely considered an interdependency between an SN and a bus network (BN), which reveals an open problem concerning the CML model's adaptability to a multimodal public transit system (MPTS). This paper develops an improved CML model to simulate interdependent cascading failures of an MPTS and quantify bus route service disruptions for amplifying severe consequences of failures. Remarkably, an interdependency integrating operational and nonlinear geographical interdependencies is proposed to modify the node state evolutionary function and model cascading failures across layers. Moreover, an estimation method for the node initial state is proposed to accommodate the initial value-sensitive dependence due to a logistic chaotic map involved in the evolutionary function. Finally, a case is simulated to verify the model's adaptability and enlighten operation management. Results indicate that (i) the neglect of interdependency causes an overestimation of the severity of cascading failures of an SN while a severe underestimation of those of a BN; (ii) the management and engineering measures to adjust transfers both have a phase transition point on the controllability of cascading failures, and the latter exhibits more a direct and comprehensive effect.

Maximizing synchronous transfer between metro and buses considering connection level

Transfer between the metro (underground railway system) and buses is standard in many cities, and the simultaneous arrival of these two modes can provide passengers with a smoother transfer experience. However, previous synchronous transfer studies rarely consider different public transport modes simultaneously. This paper presents an optimization model that maximizes the number of metro and bus network synchronizations considering the connection level. An improved algorithm that combines simulated annealing (SA) and artificial bee colony (ABC) is proposed. The best nectar source position in history is combined with the SA operation. The ABC and simulated annealing and improved artificial bee colony (SA–IABC) algorithms are used to solve the model using the Nanmendou metro station and the bus stations within 1.2 km around it in Fuzhou City, China. The results show that ABC and improved SA–IABC algorithms increase the synchronization times of the metro and bus network by 17% and 24% on average, respectively, without expanding the departure frequency.

A Two-Stage Multi-Agent EV Charging Coordination Scheme for Maximizing Grid Performance and Customer Satisfaction

Advancements in technology and awareness of energy conservation and environmental protection have increased the adoption rate of electric vehicles (EVs). The rapidly increasing adoption of EVs may affect grid operation adversely. However, the increased integration of EVs, if managed appropriately, can positively impact the performance of the electrical network in terms of power losses, voltage deviations and transformer overloads. This paper presents a two-stage multi-agent-based scheme for the coordinated charging scheduling of EVs. The first stage uses particle swarm optimization (PSO) at the distribution network operator (DNO) level to determine the optimal power allocation among the participating EV aggregator agents to minimize power losses and voltage deviations, whereas the second stage at the EV aggregator agents level employs a genetic algorithm (GA) to align the charging activities to achieve customers' charging satisfaction in terms of minimum charging cost and waiting time. The proposed method is implemented on the IEEE-33 bus network connected with low-voltage nodes. The coordinated charging plan is executed with the time of use (ToU) and real-time pricing (RTP) schemes, considering EVs' random arrival and departure with two penetration levels. The simulations show promising results in terms of network performance and overall customer charging satisfaction.

Optimal design method of public transit network considering transfer efficiency

AbstractImproving the sharing rate of public transport and reducing operation costs are key factors affecting the sustainable development of the public transport system. After quantifying the impact of transfer, this study proposes a multi‐objective optimization model of bus networks considering the integral transfer efficiency and operation costs, whose optimal solution is hard to find. Since the heuristic algorithm has great global searchability, a non‐dominated sorted genetic algorithm (NSGA‐II) is adopted to solve this NP‐hard problem. Also, an adaptive mutation mode selection algorithm is proposed to enhance the solution efficiency. The optimization framework is applied to the benchmark case of the Swiss public transit network. The results show that the method significantly improves the transfer efficiency of the designed network when compared to existing studies. After calculation, it is found that enhancing the direct rate can improve transfer efficiency, but with high costs. Moreover, the proposed method can design an efficient and economic network to balance the benefits of passengers and operators in practice.

Optimal variable vehicle scheduling strategy for a network of electric buses with fast opportunity charging

The introduction of battery-powered electric buses (EBs) presents promising prospects for greener and more sustainable public transit. However, recharging activities of EBs to extend the total daily operation range, enabled by fast opportunity charging approach, create a significant challenge for attaining better, or equivalent, operational efficiency than conventional diesel buses. We propose a novel variable vehicle scheduling strategy of a transit EB network with multiple depots to meet this challenge by right shifting trip departure times. A numerical example is used as an expository device to illustrate the variable EB-scheduling methodology, followed by an empirical case study in the city of Dalian, China. The results show how the optimised variable EB scheduling strategy can reduce the impact of recharging activities on the operation’s efficiency. It has been found that by inserting a small schedule delay it is possible to save operational costs, especially through a reduction of the fleet size.

Electrification of a citywide bus network: A data-driven micro-simulation approach

Electrification of a citywide bus network: A data-driven micro-simulation approach

An intelligent energy management system for optimum design and real-time operation

<span lang="EN-US">Planning and management of distribution networks has become a very difficult task, especially with the strong expansion of renewable energy sources (RES) which are intermittent in nature. Maintaining fluidity and reliability of real-time decisions while taking into consideration uncertainties related to production and increasing the profit of distribution network operators is the objective of the system proposed in this work. It is an intelligent energy management system dedicated to the management of grid-integrated RES and battery energy storage systems (BESS), composed of: i) a real-time control and data acquisition model, ii) a model for forecasting the intermittent parameters of RES based on neural networks, iii) a long-term planning model based on the optimal placement and size of RES and BESS, and iv) an hourly planning model for scheduling the energy distribution between energy sources. The non-dominated sorting genetic algorithm and the entropy-TOPSIS method (technique for order of preference by similarity to ideal solution) form the basic block of this model. To evaluate it, a modified IEEE 33 bus network was used for testing and the results, for short-term scheduling, proved that the system succeeds in maximizing profits and significantly minimizing CO<sub>2</sub> emissions, in addition to power losses and voltage drops.</span>

Research of In-Vehicle Ethernet Information Fault Detection Based on IEEE 802.1Qci

With features such as the high data transfer rate of 1G/bps and strong compatibility, in-vehicle Ethernet can become the backbone network of next-generation in-vehicle bus network systems. Currently, in-vehicle Ethernet is mainly used in audio and video entertainment systems, to further improve the network security performance of in-vehicle Ethernet, the information security of the data layer and physical layer in the in-vehicle bus network system must be ensured. Based on the characteristics of in-vehicle Ethernet data frame structure, this paper introduces IEEE 802.1 Qci protocol, proposes an information fault detection method through data shifting, detection, and policing, and verifies it by simulation with OMNET++ simulation system. The experimental results show that the accuracy rate of in-vehicle Ethernet data during transmission can reach 99.61%, which further improves the network security performance of in-vehicle Ethernet.

Electric bus charging station location optimization considering queues

The transition to new forms of urban transport, which are environment friendly, efficient, and cost-effective has become a pressing issue of modern times. Battery electric buses are being deployed worldwide, marking a change in public transport planning and operations. The emergence of fast and ultra-fast wireless charging for electric buses has brought about the need for new planning processes and associated decision-support models for their deployment. The objective of this paper is the development of a model for optimally locating fast wireless chargers in an electric bus network, which considers delays of buses queuing for opportunity charging at charger locations. An integer linear programming model is formulated for that purpose: the model minimizes the investment cost for deploying opportunity charging facilities. An M/M/1 queuing model is employed to incorporate bus queuing considerations at terminal charging locations. The proposed model is demonstrated to a benchmark instance and results are discussed.

DpGuard: A Lightweight Attack Detection Method for an Industrial Bus Network

In industrial control systems (ICSs), the PROFIBUS-DP (decentralized peripherals) protocol is widely used for communication between devices. Because PROFIBUS-DP is an unencrypted and insecure bus protocol, attackers can connect to the PROFIBUS-DP system and arbitrarily manipulate I/O process values, which may interrupt the normal operation of industrial equipment, or have more serious consequences. However, due to the complex structures of bus networks and the large number of attack areas, the existing scheme does not monitor all the messages in the industrial head office network and cannot effectively detect semantic attacks. To solve this problem, we propose a novel attack detection system DpGuard. DpGuard automatically builds a finite-state machine model of normal ICS behavior through a large number of historical ICS traffic data. The model includes state events, state transitions, state transition probability, and other normal behavior information. In addition, DpGuard records the execution status of the context data package, uses the real-time captured data package as the input of the model, and judges whether the state event and state transition probability conform to the constraints of the finite-state machine model, so as to identify the legitimate normal behavior of the ICS. Our proposal was evaluated using two Siemens PLCs (programmable logic controllers) deployed on the PROFIBUS-DP system. The experimental results demonstrated that the scheme could accurately detect fault injection and semantic attacks. Compared with other detection models, our scheme presented an improved detection performance, with a detection accuracy of 99.80%.

ANALYSIS OF ELECTROMAGNETIC TRANSIENTS IN THE LOW-VOLTAGE DISTRIBUTION NETWORK OF AN INDUSTRIAL ENTERPRISE

Analysis of a short circuit in the distribution network with a voltage of up to 1 kV of the power supply system of an industrial enterprise. The procedure for calculating the short-circuit current in accordance with the recommendations of the ANSI/IEEE standard C37 series, which regulates the calculation of the short-circuit current for the selection and verification of switchgear and protective devices according to the short circuit current rating, was used to calculate the short-circuit current in the low-voltage distribution network of an industrial enterprise. The need to automate the process of calculating short-circuit currents in the power supply system of an industrial enterprise was substantiated. The Electrical Transient Analyzer Program (ETAP) software was used as an analysis tool. The design of the low-voltage distribution network was carried out in the ETAP software environment. The Short Circuit package of the ETAP software was used to calculate the short-circuit current on any bus of the distribution network. The result of the analysis is the determination of the short circuit current values and the verification of the compliance of the characteristics of the installed electrical equipment with the short-circuit currents. The effectiveness of using ETAP software for short-circuit analysis in order to select and verify the electrical equipment of the low-voltage distribution network of an industrial enterprise according to the level of short-circuit current was proven. The results of the analysis of the short-circuit current using the ETAP software provided an opportunity to verify the correctness of the decisions made regarding the selection of low-voltage switchgear of the distribution network of the facility’s power supply system. Analysis of short-circuit current using ETAP software provides the possibility of selecting switchgear and protective devices according to the level of short-circuit current, which contributes to the design of a reliable power supply system for the facility.

Visions of public and private mobility: the Kowloon railway terminus in Hong Kong

Abstract This article explores and complicates notions of public and private urban mobility through the exploration of one site of transport, the Kowloon railway terminus in Hung Hom, Hong Kong. It considers the question: how did the conflicts and tensions between public and private forms of mobility affect policies for the urban environment in colonial Hong Kong? This article explores the Hung Hom railway terminus and its tensions and interactions with automobility and other forms of transport, most pertinently the bus network. Hong Kong's imperial and colonial context further throws into question seemingly straightforward divisions of public and private mobility.

Development and performance evaluation of an automatic section control system for corn precision planters

Overlap- planted area (OPA) tends to appear when large precision planters with more row units were employed in planting corn for the operator would typically need to drive the planter into the already planted area and decide when to stop planting to ensure complete coverage. This will lead to an increase in the cost of seeds and potential yield losses. In this paper, an automatic section control (ASC) system for corn precision planters was proposed to address above problems, the working principle of the system is to build a database of planted areas (DAPA) by collecting coordinates of the planted area during planting, and constantly query whether the coordinates of the seed tube egress point (STC) of each row unit is in DAPA, finally control the start-stop state of the corresponding brushless DC motors (BLDCM) according to the query results. A mathematical model calculating STC of each row unit in real-time according to coordinates acquired by GPS receivers is established. In addition, the system adopts controller area network (CAN) bus distributed control mode, which makes independent control of the row unit possible and offers good extensibility. Algorithms including Geohash algorithm, algorithm of discarding the same prefix, and dynamic trie data structure for improving the efficiency and performance of the ASC systems were proposed. Laboratory experiments were conducted at five Geohash string quantities (7410, 37040, 74070, 111110, and 148,150 Geohash strings), the results demonstrate that the proposed algorithms have high efficiency and are basically not affected by the increase of DAPA scale: time consumed (t) of retrieving and inserting a Geohash string from the dynamic trie is less than 36.51 ms and 62.99 ms, respectively, and there is no significant difference in t under various Geohash string quantities (P greater than 0.05). Field experiments were conducted at three positioning frequencies (fGPS) (2, 5, and 10 Hz) and three field shape complexity (pa) (0.08, 0.10, and 0.12). The results showed that the dp value could be decreased immensely when the ASC function was turned on: under the ASC function turned off, the corresponding dp values under the pa values of 0.08, 0.1, and 0.12 are 9.17 %, 7.71 %, and 10.74 %, respectively, while once the ASC function is enabled, the dp values under all experiments conditions do not exceed 1.63 %, and the change of pa has no significant effect on the dp. As the fGPS increases from 2 Hz to 5 Hz, dp value of field 1–3 decreased significantly by 0.56, 0.39, and 0.52 percentage points, respectively. Due to the influence of processor performance, the fluctuation of dp value is not obvious when fGPS increases from 5 Hz to 10 Hz. In conclusion, the proposed ASC system has a good performance in reducing OPA and can be employed on corn precision planters to save seeds and improve yield.