M. Brackstone - Profile on Academia.edu (original) (raw)

Papers by M. Brackstone

Data Fusion for Urban Traffic Network State

Proceedings of the IEEE Intelligent Vehicles Symposium 2000 (Cat. No.00TH8511), 2000

Advanced Vehicle Control and Safety Systems (AVCSS) are rapidly evolving around the globe, allowi... more Advanced Vehicle Control and Safety Systems (AVCSS) are rapidly evolving around the globe, allowing the testing of convoying systems, for example, which may benefit road capacity by increasing throughput and decreasing emissions. A key element in such systems is the production of a reliable vehicle-to-vehicle communication (comms.) link, capable of robust operation in a range of operating environments. This paper reports on a modelling study of one such system conducted as part of the Road Traffic Advisor project within the U.K., based on a comms. link in the millimetric waveband (approximately 60 GHz). The likely outage is examined for a basic inter-vehicle data link. This is used in conjunction with a simulation of convoy behaviour based on a control model to examine the effect of such outages on convoy operation. The paper concludes that the impact of the comms. protocol and the comms. outages on the control dynamics of an automated convoy would not degrade its performance.

IEEE IV2003 Intelligent Vehicles Symposium. Proceedings (Cat. No.03TH8683), 2003

Although much attention has been given to the simulation and modeling of driver behaviour, and co... more Although much attention has been given to the simulation and modeling of driver behaviour, and comparison and testing of differing algorithms (such as car following) is now performed, there are several assumptions in use regarding

Ninth International Conference on Road Transport Information and Control, 1998

In attempting to formulate models of traffic flow on motorways in the last thirty to forty years,... more In attempting to formulate models of traffic flow on motorways in the last thirty to forty years, a great deal of work has been performed in the investigation of the microscopic processes governing the longitudinal motion of vehicles (car following). However, there has been comparatively little investigation of the microscopic basis of the lane changing process, which affects the distribution of vehicles across lanes. This has important implications as it is this process which affects the number of vehicles in any lane (and hence the number of vehicles participating in following). Also, there is evidence that this manoeuvre is the cause of the largest number of motorway accidents (Jeffcoate et. al ). A more detailed understanding of the factors affecting the process is vital.

Proceedings of Conference on Intelligent Transportation Systems, 1997

This paper will report on progress in the development of a new microscopic model of interurban tr... more This paper will report on progress in the development of a new microscopic model of interurban traffic, which uses fuzzy modelling techniques to describe behavioural processes. Emphasis will be placed on recent work undertaken in establishing, implementing and calibrating a new set of driving rules for both car following and lane changing, using both 'traditional' and new methods, such as the use of an instrumented vehicle.

FLOWSIM and Its Applications for Convoy Driving System Stability Study

Traffic And Transportation Studies (2002), 2002

Validity of microscopic modelling of motorway traffic

Proceedings of the Intelligent Vehicles '94 Symposium, 1994

Abstract Developments have recently been made in increasing the quality of data available for the... more Abstract Developments have recently been made in increasing the quality of data available for the calibration of microscopic simulation models, and several techniques devised for high accuracy collection. Little consideration has been given however to the acceptability of the ...

Transportation Research Part C: Emerging Technologies, 2015

Use of traffic simulation has increased in recent decades; and this high-fidelity modelling, alon... more Use of traffic simulation has increased in recent decades; and this high-fidelity modelling, along with moving vehicle animation, has allowed transportation decisions to be made with better confidence. During this time, traffic engineers have been encouraged to embrace the process of calibration, in which steps are taken to reconcile simulated and field-observed performance. According to international surveys, experts, and conventional wisdom, existing (non-automated) methods of calibration have been difficult or inadequate. There has been extensive research on improved calibration methods, but many of these efforts have not produced the flexibility and practicality required by real-world engineers. With this in mind, a patent-pending (US 61/859,819) architecture for softwareassisted calibration was developed to maximize practicality, flexibility, and ease-of-use. This architecture is called SASCO (i.e. Sensitivity Analysis, Self-Calibration, and Optimization). The original optimization method within SASCO was based on ''directed brute force'' (DBF) searching; performing exhaustive evaluation of alternatives in a discrete, userdefined search space. Simultaneous Perturbation Stochastic Approximation (SPSA) has also gained favor as an efficient method for optimizing computationally expensive, ''black-box'' traffic simulations, and was also implemented within SASCO. This paper uses synthetic and real-world case studies to assess the qualities of DBF and SPSA, so they can be applied in the right situations. SPSA was found to be the fastest method, which is important when calibrating numerous inputs, but DBF was more reliable. Additionally DBF was better than SPSA for sensitivity analysis, and for calibrating complex inputs. Regardless of which optimization method is selected, the SASCO architecture appears to offer a new and practiceready level of calibration efficiency.

Vehicle to vehicle communication based convoy driving and potential applications of GPS

The 2nd International Workshop on Autonomous Decentralized System, 2002., 2002

Traffic congestion is forecasted to continue gowing. Simply building more roads is believed not a... more Traffic congestion is forecasted to continue gowing. Simply building more roads is believed not a solution. Many studies have been made to investigate the application of convoy driving or Automated Highway System (MIS) to release increasingly congested motorway, smooth motorway ...

Transportation Research Part F: Traffic Psychology and Behaviour, 1999

In recent years, the topic of car-following has become of increased importance in trac engineerin... more In recent years, the topic of car-following has become of increased importance in trac engineering and safety research. Models of this phenomenon, which describe the interaction between (typically) adjacent vehicles in the same lane, now form the cornerstone for many important areas of research including (a) simulation modelling, where the car-following model (amongst others) controls the motion of the vehicles in the network, and (b) the functional de®nition of advanced vehicle control and safety systems (AVCSS), which are being introduced as a driver safety aid in an eort to mimic driver behaviour but remove human error. Despite the importance of this area however, no overview of the models availability and validity exists. It is the intent of this paper therefore to brie¯y assess the range of options available in the choice of car-following model, and assess just how far work has proceeded in our understanding of what, at times, would appear to be a simple process. Ó

Data requirements and sources for the calibration of microscopic motorway simulation models

Proceedings of VNIS'94 - 1994 Vehicle Navigation and Information Systems Conference, 1994

ABSTRACT At higher levels of demand, the flow of traffic on motorways can become unstable with fl... more ABSTRACT At higher levels of demand, the flow of traffic on motorways can become unstable with flow breakdowns and an increase in accident risk. Improvements in capacity and stability may be achieved by modifying behaviour or control, and this process is the target of research into preventative IVHS measures. However, to understand the effects it is necessary to develop and use appropriate microscopic simulation models. To calibrate a microscopic simulation model, a large amount of checking should be performed to ensure that the model behaves correctly, at both a microscopic and a macroscopic scale. This procedure is not straightforward as microscopic data is complex to obtain and interpret, due to the diversity of the information required, and because many parameters used in model formulation are not directly related to easily observable quantities

Hyperspectral imaging of tissue mimicking phantoms: principle component analysis

Optical Interactions with Tissue and Cells XXIV, 2013

ABSTRACT Angular domain spectroscopic imaging (ADSI) is a hyperspectral imaging technology that c... more ABSTRACT Angular domain spectroscopic imaging (ADSI) is a hyperspectral imaging technology that combines both optical spectroscopy and optical imaging into a single platform. The technique employs an array of micro-channels to perform angular filtration, whereby quasi-ballistic photons traversing a turbid sample are accepted, and scattered photons (imagedegrading) are rejected. The aim of the work reported here was to evaluate the effectiveness of an ADSI system at identifying targets buried within tissue-mimicking phantoms. Principal component analysis (PCA) was applied to spectral data-cubes to extract the main spectral features from the images. Targets of various absorption levels (indocyanine green), depths beneath the phantom surface, and background scattering levels were evaluated. Principal components were analyzed with k-means clustering. The extracted features were grouped and classified. Then, the sensitivity and specificity of the ADSI system were estimated. Angular domain spectroscopic imaging with PCA provided clear separation of targets of different absorber concentration and depth. The results led us to conclude that the technique holds potential for characterizing tissue specimens obtained during surgery.

Index of Authors (With the Titles of Papers)

Application of guidelines for microsimulation modelling in the EU

Interurban Att: Some Deployment Options for the Uk

A Collision Model for the Assessment of the Safety Benefits of AVCSS

This paper reports on the progress of the 'Platform Grant in Motorway Operations' project in the ... more This paper reports on the progress of the 'Platform Grant in Motorway Operations' project in the U.K, which addresses problems in the use of in-vehicle systems to aid motorway congestion and safety. The project is undertaking a number of scoping studies in order to: i) Develop and extend understandings of the fundamental processes governing traffic flow on motorways, through measurement and modelling, ii) Apply the understandings to assess strategies to alleviate identified problems in a range of scenarios, through the use of ITS technologies, such as ACC (Adaptive Cruise Control) and Convoy driving, iii) Raise the awareness of the fundamental traffic processes, behaviour and opportunities for change with highway authorities, network operators and manufacturers. The five scoping studies will provide an in-depth understanding of motorway operations and include Driver Reactions to Congested Condition, Behaviour in an Emergency, Junction Operations, 'Next Generation' Advanced Vehicle Control and Safety Systems (AVCSS) and Implications to Flow Modelling and Theory.

Instrumented vehicle studies of traffic flow models

The Microscopic Modelling of Traffic Flow: Weaknesses and Potential Developments

Special Issue on Emerging Techniques for the Management of Uncertainty in Computational Traffic Models