Minimizing position uncertainty for under-ice autonomous underwater vehicles

Localization underwater has been known to be challenging due to the limited accessibility of the Global Positioning System (GPS) to obtain absolute positions. This becomes more severe in the under-ice environment since the ocean surface is covered with ice, making it more difficult to access GPS or to deploy localization infrastructure. In this paper, a novel solution that minimizes localization uncertainty and communication overhead of under-ice Autonomous Underwater Vehicles (AUVs) is proposed. Existing underwater localization solutions generally rely on reference nodes at ocean surface or on localization infrastructure to calculate positions, and they are not able to estimate the localization uncertainty, which may lead to the increase of localization error. In contrast, using the notion of external uncertainty (i.e., the position uncertainty as seen by others), our solution can characterize an AUV’s position with a probability model. This model is further used to estimate the uncertainty associated with our proposed localization techniques. Based on this uncertainty estimate, we further propose algorithms to minimize localization uncertainty and communication overhead. Our solution is emulated and compared against existing solutions, showing improved performance.     

Lateral control of autonomous vehicles based on fuzzy logic

Autonomous vehicles have attracted considerable attention in the research community and industry. This paper addresses a problem in designing lateral control law and develops a strategy to determine the given speed of autonomous vehicles. An improved method for calculating the lateral offset and heading angle error is proposed to reduce the impact of reference path data noise. Multiple fuzzy inference engines are used to design the steering controller and determine the given driving speed, including the forward and backward directions. The stability condition is given to guide the design of fuzzy inference engines. Satisfactory simulation and experimental results have been obtained from different reference paths.     

自主水面货船研究现状与展望

船舶智能化、自主化是水路载运工具的重要发展趋势,与此同时,船舶设计、制造、运营、维护等相关领域也迎来了新一轮的挑战。基于国际海事组织（international maritime organization,IMO）提出的海事自主水面船舶（maritime autonomous surface ships,MASS）概念,对其中自主水面货船进行阐述。首先对水路载运工具进行详细分类,分析了当前自主水面货船的特点及当前的研究现状。之后提出自主水面货运船舶系统组成,思考自主水面货船在实船试验、推进方式与能源、智能航行、通信系统、航行规则等方面中面临的挑战,并直面挑战对海事自主航行水面货船未来发展及应用的多样性做出展望。     

Investigating user activities and the corresponding requirements for information and functions in autonomous vehicles of the future

The potential benefits of autonomous vehicles, including safety, convenience, fuel economy, and low emissions can only be achieved when consumers are comfortable with the vehicle design. There are only a limited number of user studies in the design of future autonomous vehicles, owing to the difficulties of shifting focus “from the present to the future.” An integrated method of simulator study and user enactment was applied in the research to bridge the gap between the current and the future. Thirty drivers participated in the study to experience enacted driving scenarios in an autonomous vehicle simulator. The participants were divided into two groups, i.e., driving-alone drivers and driving-with-a-passenger drivers, to investigate the effect of passenger presence. Rich data were elicited about possible in-vehicle activities, the corresponding requirements of information and functions to support any such activities. Also identified were the preferred methods of interacting with the information and functions. Passenger presence was found to have an influence on the attributes of activities undertaken as well as the preferences for in-vehicle information and functions. Dominant themes were identified in future autonomous vehicle designs, including a more flexible and adaptive design language, concerns of trust and safety, and trade-offs between safety and convenience and between privacy and social connection. Based on the findings, design implications for future autonomous vehicles are discussed.     

A systematic review of agent-based models for autonomous vehicles in urban mobility and logistics: Possibilities for integrated simulation models

This paper provides a systematic review of studies that model future autonomous vehicles (AVs) in urban mobility and logistics using an agent-based model (ABM). Eighty relevant papers published between 2015–2020 are included. This review evaluates the quality of each model through the newly developed AAODD (Autonomous vehicle Agent-based Overview, Design concepts and Details) protocol in four perspectives: model transparency, research questions, network + agent behaviour and model execution. Then, similarities and particularities of the papers are summarised based on whether AVs are used for passenger mobility or for freight logistics.The reviewed mobility papers exhibit the ABMs’ applicability and flexibility for studying different AV operational patterns. We summarise the respective modelling specifications in research questions, data collections, model platforms, model executions, and scenario variations. Overall, by combining AVs with different technical possibilities and operational strategies, the simulation results illustrate that AVs would bring vast benefits to urban mobility networks.Unlike AVs’ usage in passenger mobility, it is still unclear how AVs will serve future urban logistics demands. Many operational patterns, including unmanned aerial vehicles, autonomous robots, autonomous trucks, and autonomous cargo-hatching vehicles coexist in the research community. The number of relevant papers remains low due to the early stage of AV technology deployment. However, ABMs also prove their applicability for analysing the macro and mesoscopic impacts of freight AV transportation on urban network. The reviewed papers suggest that implementing AVs for urban logistics is more efficient and environmentally friendly than conventional delivery vehicles.Overall, ABMs are a powerful tool for simulating future urban scenarios with AVs. By calculating the average score of reviewed papers obtained via AAODD annually, we find that studies simulating AV systems in ABMs are getting more complex by combing diverse technological possibilities, supporting the simulation of more realistic future scenarios. The outcomes of reviewed ABM research reveals that AVs are a promising solution for solving current urban transport problems. Lastly, as nearly all current reviewed studies focus on AVs’ usages in either mobility or logistics, research on an integrated simulation that combines AVs for both purposes has been scarcely addressed. We discuss its necessities, possibilities, and opportunities in this paper, to steer future research in this direction.     

Investigating mobile wireless technology adoption: An extension of the technology acceptance model

This research represents a theoretical extension of the Technology Acceptance Model (TAM), which IS researchers have used to explain technologies’ perceived usefulness and individuals intention to use it. The authors developed a model, referred to as the Mobile Wireless Technology Acceptance Model (MWTAM), to test the relationship between theoretical constructs spanning technological influence processes (Perceived Ubiquity, and Perceived Reachability) and cognitive influence processes (Job Relevance, Perceived Usefulness, and Perceived Ease of Use) and their impact on Behavioral Intention. MWTAM is assessed using data collected from an online survey and analyzed using AMOS 5.0. Results provide evidence to support MWTAM as both the technological and cognitive influence processes accounted for 58.7% of the variance explained in an individual’s Behavioral Intention toward using mobile wireless technology. Additionally, the path coefficients between constructs ranged from 0.241 to 0.572 providing further evidence to support the theoretical extension of TAM.

Wearable fitness technology: A structural investigation into acceptance and perceived fitness outcomes

Wearable fitness technologies (WFT) track physical activity, such as steps taken, calories burned and workout intensity, through a device that is typically worn at all times. While the market for WFT devices continues to grow, current theoretical understanding of adoption is lacking. Thus, in an attempt to extend the Technology Acceptance Model (TAM), the current study employs a structural equation model to increase current understanding of wearable technology use. Further, to better understand the outcome of WFT use, the current study examines the relationship among health related outcomes of WFT use such as overall exercise behavior and perceptions of health. Results support the TAM and WFT use was significantly related to perceived health outcomes.     

Lateral control strategy for autonomous steering of Ackerman-like vehicles

This paper presents the results of a lateral control strategy that has been applied to the problem of steering an autonomous vehicle using vision. The lateral control law has been designed for any kind of vehicle presenting the Ackerman kinematic model, accounting for the vehicle velocity as a crucial parameter for adapting the steering control response. This makes the control strategy suitable for either low or high speed vehicles. The stability of the control law has been analytically proved, and experimentally tested by autonomously steering Babieca, a Citro n Berlingo prototype vehicle.     

Optimal position and velocity navigation filters for autonomous vehicles

This paper presents the design and performance evaluation of a set of globally asymptotically stable time-varying kinematic filters with application to the estimation of linear motion quantities of mobile platforms (position, linear velocity, and acceleration) in three dimensions. The proposed techniques are based on the Kalman and H_∞ optimal filters for linear time-varying systems and the explicit optimal filtering solutions are obtained through the use of an appropriate coordinate transformation, whereas the design employs frequency weights to achieve adequate disturbance rejection and attenuation of the measurement noise on the state estimates. Two examples of application in the field of ocean robotics are presented that demonstrate the potential and usefulness of the proposed design methodology. In the first the proposed filtering solutions allow for the design of a complementary navigation filter for the estimation of unknown constant ocean currents, while the second addresses the problem of estimation of the velocity of an underwater vehicle, as well as the acceleration of gravity. Simulation results are included that illustrate the filtering achievable performance in the presence of both extreme environmental disturbances and realistic measurement noise.     

The acceptance and diffusion of the innovative smart phone use: A case study of a delivery service company in logistics

Technology adoption has been the topic of several theories. We empirically assessed and integrated four models to help in predicting smart phone adoption. The varying factors were combined and a survey was conducted in five sales branches of a delivery service company. Results of the analysis of the collected data show that the relationships amongst constructs were similar. Self-efficacy was a strong predictor of behavioral intention through attitude; after innovation, diffusion theory was added. Attitude towards smart phone adoption was found to be affected mainly by testability and organizational and environmental factors. We decided that an iterative approach to implementing smart phone adoption was effective. Managerial implications are discussed.     

Mission design for a group of autonomous guided vehicles

In this paper, a generic approach for the integration of vehicle routing and scheduling and motion planning for a group of autonomous guided vehicles (AGVs) is proposed. The AGVs are requested to serve all the work stations in a two-dimensional environment while taking into account kinematics constraints and the environment’s geometry during their motion. The problem objective is the simultaneous determination of time-optimum and collision-free paths for all AGVs. The proposed method is investigated and discussed through a number of simulated experiments using a variety of environments and different initial conditions.     

Uses and gratifications and acceptance of Web-based information services: An integrated model

This study combines the technology acceptance model (TAM) and uses and gratifications theory (U&G) to create an integrated model that predicts usage and satisfaction with Web-based information services (WIS). Two pilot studies and three laboratory experiments were conducted to test and develop the concepts, measurements, and the integrated model. The results support the proposed integrated model. Behavioral intention and entertainment motive collectively predicted behavioral usage. Satisfaction was positively associated with the level of usage. The good structure fit with the merge model and data showed that the model explained more than 30% variance of behavioral usage. Although both theories are solid acceptance theories, U&G provides specific information and a more complete understanding of usage, whereas TAM constructs are easily used with Web-based applications. This study gives researchers and practitioners an interdisciplinary perspective for investigating the phenomenon of technology acceptance. In addition, it merges the strengths from the fields of information systems and communications.     

Fuzzy logic steering control of autonomous vehicles inside roundabouts

The expansion of roads and the development of new road infrastructures have increased in recent years, linked to the population growing in large cities. In the last two decades, roundabouts have largely replaced traditional intersections in many countries. They have the advantage of allowing drivers continuous flow when traffic is clear, without the usual delay caused by traffic lights. Although roundabouts with and without traffic-signal control have been widely used and considered in the literature, driverless control on roundabouts has not been studied in depth yet. The behavior of autonomous vehicles in roundabouts can be divided into three stages: entrance, inside, and exit. The first and last may be handled as an extension of intersections. However, autonomous driving on the roundabout requires special attention. In this paper, the design and implementation of a fuzzy logic system for the steering control of autonomous vehicles inside the roundabout is proposed. Cascade architecture for lateral control and parametric trajectory generation are used. Fuzzy control has proved to be easy to define using expert knowledge. Experiments with a real prototype have been carried out, taking into account different speed profiles and lane change maneuvers inside the roundabout, with very satisfactory results.     

The impact of use context on mobile services acceptance: The case of mobile ticketing

The most important factor in the decision to adopt mobile systems is user perception of their value. However, behavioral theory suggests that context affects user attitude and therefore influences acceptance. We therefore hypothesized that the benefits of mobile systems should be evaluated against users’ contextual needs and that reduced dependence on time and place required providing service at any time and place needed by the user. Mental costs or costs of learning to use the system, however, may not be evaluated in the same way, because system use and learning about it are acts with different contexts. Our findings advance knowledge of IT adoption and suggest that we should start to identify the contexts of both the benefits of use and in learning to use the system.     

主-从自治海上航行器有限时间同步运动控制

研究主-从自治海上航行器有限时间同步运动问题, 提出一种可实现主-从自治海上航行器的位置、姿态、线速度、角速度、线加速度和角加速度等运动状态有限时间同步的连续状态反馈控制方法. 首先, 通过建立主、从自治海上航行器的动力学模型, 给出了主-从同步运动控制方案; 然后, 采用齐次系统有限时间稳定性理论, 为从自治海上航行器设计了一种连续状态反馈控制器, 以及在该控制器下实现主-从自治海上航行器有限时间同步运动的充分性判据, 并通过实例仿真进行了验证.     

The acceptance of information technology innovations in hospitals: differences between early and late adopters

The increasing maturity of information technologies (IT) in hospitals and their infrastructure development is improving the quality and efficiency of healthcare services. In these circumstances, an investigation of the diffusion of IT in this context would provide some insight into adopters’ behaviours and further the diffusion of IT in the near future. The purpose of this paper is to conduct an investigation of the diffusion of IT’s innovations in hospitals. Technology acceptance model and innovation diffusion theory have been applied in this research trying to find factors that permit an effective discrimination between early and late adopters. The differences in characteristics between these two categories are assessed and implications based on the research findings are discussed.     

Learning control in spatial coordinates for the path-following of autonomous vehicles

We prove the existence of a P-type (proportional-type) space-learning control, which, on the basis of a kinematic third order nonlinear model of an autonomous nonholonomic vehicle and by a proper choice of the proportional control gain, guarantees asymptotic tracking of planar curves whose uncertain curvature is L$L$-periodic in the curvilinear abscissa. The behavior of a human driver, who repetitively learns the correct action from the past experience in the space, is mathematically reproduced. A stability analysis is presented while simulation results demonstrate the effectiveness of the presented approach.     

Determinants of customer acceptance of multi-service network: An implication for IP-based technologies

Using a modified TAM as a conceptual framework and SEM for analysis, we determined the factors influencing the adoption of Internet Protocol Television by surveying 320 consumers. The modifications involved new constructs that incorporated user-perceived control and security in the model. The perceived quality of the content and system were found to have a significant effect on perceived usefulness and perceived playfulness. In addition, perceived control was found to have a significant effect on both extrinsic and intrinsic motivation. A significant relationship was also found between consumer-perceived security and intention. Also consumers regarded price as a main driver for switching TV services. We discuss the significance of this observation in the context of the emerging trend of technology convergence and importance in acquiring customer preference and other strategies.     

A novel fused neural network controller for lateral control of autonomous vehicles

We present a novel fused feed-forward neural network controller inspired by the notion of task decomposition principle. The controller is structurally simple and can be applied to a class of control systems that their control requires manipulation of two input variables. The benchmark problem of inverted pendulum is such example that its control requires availability of the angle as well as the displacement. We demonstrate that the lateral control of autonomous vehicles belongs to this class of systems and successfully apply the proposed controller to this problem. The parameters of the controller are encoded into real value chromosomes for genetic algorithm (GA) optimization. The neural network controller contains three neurons and six connection weights implying a small search space implying faster optimization time due to few controller parameters. The controller is also tested on two benchmark control problems of inverted pendulum and the ball-and-beam system. In particular, we apply the controller to lateral control of a prototype semi-autonomous vehicle. Simulation results suggest a good performance for all the tested systems. To demonstrate the robustness of the controller, we conduct Monte-Carlo evaluations when the system is subjected to random parameter uncertainty. Finally experimental studies on the lateral control of a prototype autonomous vehicle with different speed of operation are included. The simulation and experimental studies suggest the feasibility of this controller for numerous applications.     

Synchronization of multiple autonomous underwater vehicles without velocity measurements

In this paper,we investigate the synchronization control of multiple autonomous underwater vehicles (AUVs),considering both state feedback and output feedback cases.Treating multiple AUVs as a graph,we define the tracking error of each AUV with both its own tracking error and the relative position errors with respect to its neighbors taken into account.Lyapunov analysis is used to derive the control law for each AUV.For the output feedback case,a passive filter is used to compensate for the unknown relative velocity errors among AUVs,and an observer is employed to estimate the velocity of the AUV itself.Rigid mathematical proof is provided for the proposed algorithms for both state feedback and output feedback cases.Simulations are provided to demonstrate the effectiveness of the proposed approach.It is shown that,the synchronization error is smaller in the case of considering the relative errors between AUVs than in the case of considering the tracking error of the single AUV only.