Mark T. Smith

Robust lane detection and tracking with ransac and Kalman filter

In a previous paper, a simple approach to lane detection using the Hough transform and iterated matched filters was described [1]. This paper extends this work by incorporating an inverse perspective mapping to create a birds-eye view of the road, applying random sample consensus to help eliminate outliers due to noise and artifacts in the road, and a Kalman filter to help smooth the output of the lane tracker.

A layered approach to robust lane detection at night

A layered approach is designed to address many of the real-world problems that an inexpensive lane detection system would encounter. A region of interest is first extracted from the image followed by an enhancement procedure to manipulate the shape of the lane markers. The extracted region is then converted to binary using an adaptive threshold. A model based line detection system hypothesizes lane position. Finally, an iterated matched filtering scheme estimates the final lane position. The developed system shows good performance when tested on real-world data that contains fluctuating illumination and a variety of traffic conditions.

Using location and environment awareness in mobile communications

We are investigating the use of badge based wearable computers to create highly mobile location and environment aware systems. When coupled to intelligent servers the badges provide an unparalleled platform for human centred information environments. This paper describes the architecture of the badge, its distributed computing environment, and presents initial results of application development trials conducted by a class of telecommunications students at KTH.

Interacting with audio streams for entertainment and communication

We present a new model of interactive audio for entertainment and communication. A new device called the DJammer and its associated technologies are described. The DJammer introduces the idea of provisioning mobile users to interact cooperatively with digital audio streams. Users can augment the audio in real time and communicate the result in several ways resulting in a new form of multimedia communication across diverse devices and multiple networks. This paper describes the technologies incorporated into the DJammer, and discusses the actual implementation of the prototype DJammer. Future enhancements are also described.

MINT-a mobile Internet router

The mobility of portable computers and workstations is not transparent to users. They adjust to reduced services as long as they have no connection to a supporting infrastructure. The goal of the Walkstation project is to realize a user transparent mobile IP router (MINT) for wireless links (infrared and radio) operating at 1-10 Mbit/sec. For the study of user behavior and system characteristics, a campuswide testbed (ERIC) with 50-100 stations is planned to demonstrate the new solutions found in the Walkstation II project.Today, mobility of portable computers and workstations is not transparent to users. They adjust to reduced services as long as they have no connection to a supporting infrastructure. The goal of the Walkstation project is to realize a user transparent mobile IP router (MINT) for wireless links (infrared and radio) operating at 1-10 Mbit/sec. For the study of user behavior and system characteristics a campus wide testbed (ERIC) with 50-100 stations is planned to demonstrate the new solutions found in the Walkstation II project.<<ETX>>

Advances in roll-to-roll imprint lithography for display applications

A solution to the problems of roll-to-roll lithography on flexible substrates is presented. We have developed a roll-toroll imprint lithography technique to fabricate active matrix transistor backplanes on flexible webs of polyimide that have a blanket material stack of metals, dielectrics, and semiconductors. Imprint lithography produces a multi-level 3- dimensional mask that is then successively etched to pattern the underlying layers into the desired structures. This process, Self-Aligned Imprint Lithography (SAIL), solves the layer-to-layer alignment problem because all masking levels are created with one imprint step. The processes and equipment required for complete roll-to-roll SAIL fabrication will be described. Emphasis will be placed on the advances in the roll-to-roll imprint process which have enabled us to produce working transistor arrays.

Parallel boxing in B-spline intersection

A modified formulation of oriented boxing called oriented slab boxing is presented. It almost doubles the speed of the oriented boxing component in B-spline intersection. The method used to accelerate B-spline intersection includes algorithmic improvements and parallelization of the algorithm at different levels of granularity to find an optimum solution on a network of parallel processors. The software testbed is linked to a B-spline-based library, which is a prototype of what may be used in an actual engineering design environment. A parallel implementation of the algorithm on a network of three processors achieves an additional twofold improvement in speed.<<ETX>>

A multiport mobile internet-router

In the Swedish Walkstation project a device for mobile hosts and base stations is realized by the same kind of hardware but with different kinds of communication software. This device, called MINT (Mobile IP Router), consists mainly of three parts, one for the connection to the host or backbone net (Ethernet), one for connecting to wireless LANs (radio or infrared), and a processing part for computing the communication protocols. This device serves as more than a mobile modem, i.e., it actually routes packets over potentially multiple paths with varying connectivity and quality. By using Ethernet as an input channel, it should not be necessary to install special purpose wiring dedicated to mobile communication. Instead the existing network, which normally is globally available, is used to select suitable sites for base stations. To realize a large scale field trial the new router must be low cost, small in size, and have a low power consumption while offering high performance. The current phase of the project involves building a 68030 based router with multiple interfaces, including as host interfaces: SCSI, Ethernet, serial, parallel; and as wireless interfaces: IR, microwave-radio, or a-second Ethernet (supported for software development).<<ETX>>

Smart cards: integrating for portable complexity

The decreasing cost of embedded chips is one of many factors that have spurred growing interest in smart cards. Today, typical markets for smart cards fall into three broad areas: electronic currency, an application in which smart cards replace cash or traditional credit cards in pay phone, transit, and toll collection systems; electronic identification, which permits controlled access to buildings or systems (like computers or cash registers); and data warehousing, applications that must opportunistically store and retrieve data, such as medical records, object tracking information, or process verification information. Such applications are only the beginning-future applications could make smart cards an integral and almost transparent part of our daily lives. Two factors seem to be converging to make this possible. First, as the world we live in becomes increasingly complex, smart cards offer a way to integrate that complexity into a compact and portable package. Second, the increasing functionality developers can integrate into a smart card opens new avenues for application development.

An efficient method to generate ground truth for evaluating lane detection systems

In this document, a new and efficient method to specify the ground truth locations of lane markers is presented. The method comprises of a novel process called Time-Slicing that provided the user with a unique visualization of the video. Coupled with automation via spline interpolation, the quick generation of necessary ground truth information is achieved. Videos recorded from a vehicle while driving on local city roads and highways are marked with ground truth information for use in testing. The performance of a variety of lane detection systems is compared to the ground truth and the error is computed for each system. Finally, quantitative analysis shows that the reference lane detection system presented in [1] produces the most accurate lane detections which is depicted by the smallest error.