695 research outputs found

    Benchmarking LiDAR Sensors for Development and Evaluation of Automotive Perception

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    Environment perception and representation are some of the most critical tasks in automated driving. To meet the stringent needs of safety standards such as ISO 26262 there is a need for efficient quantitative evaluation of the perceived information. However, to use typical methods of evaluation, such as comparing using annotated data, is not scalable due to the manual effort involved. There is thus a need to automate the process of data annotation. This paper focuses on the LiDAR sensor and aims to identify the limitations of the sensor and provides a methodology to generate annotated data of a measurable quality. The limitations with the sensor are analysed in a Systematic Literature Review on available academic texts and refined by unstructured interviews with experts. The main contributions are 1) the SLR with related interviews to identify LiDAR sensor limitations and 2) the associated methodology which allows us to generate world representations

    Obstacle detection for autonomous navigation : an LDRD final report.

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    ELECTRIC FIELD INDUCED DROPLET MANIPULATION

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    In this thesis, we explore several droplet manipulation concepts on different length scales for a surface cleaning application. The design evolution to transfer these techniques from laboratory conditions to a chaotic environment, such as on the road, is an evolving engineering challenge where reliability and performance are equally important. Electrowetting and liquid dielectrophoresis are techniques by which an electromechanical response from an applied electric field enables precise droplet manipulation. This thesis presents several contributions to these technologies, focusing primarily on scalability, simplicity, and reliability. The control of surface wettability using the electric methods attracts much attention due to their fast response (milliseconds), exceptional durability (hundreds of thousands of switching cycles) and low energy consumption (hundreds of microwatts). Furthermore, their superior performance and reliable nature have prompted a vast amount of literature to expand their application. They are widely used in several scientific and industrial fields, including microfluidics, optical devices, inject printing, energy harvesting, display technologies, and microfabrication. Droplet actuation using electric methods has been a long-standing interest in microfluidics, and most often, it is limited by high operating voltages. The first actuation method explored in this thesis is based on interdigitated electrodes to generate a dielectrophoretic response. In order to apply an effective electrostatic force for droplet manipulation, the geometry of the electrodes must be optimised, which similarly leads to a lower operating voltage (as low as 30 V). Furthermore, microscale electrodes can be iteratively combined to realise larger arrays to move larger droplets. The iterative approach was developed for a large-scale device to manipulate droplets of varying sizes while keeping the actuation process simple. In the second actuation method, a pair of microelectrodes separated by a variable gap distance generated an electrostatic gradient to produce a continuous droplet motion along the length of the electrode pad. The novel actuation method transported droplets of different sizes without active control. The droplet actuation was demonstrated on a larger scale using several platforms, including radial-symmetric, linear, and bilateral-symmetric droplet motion. An automated self-cleaning platform was tested in laboratory conditions and on the road. The technology has significant potential in the automotive sector to clean body parts, camera covers, and scanning sensors. The electrostatic force applied across the droplet was calculated by placing a continuously moving droplet on a tilted platform and measuring the critical angle at which the droplet’s gravity overcomes the opposing applied electric force. Several electrode designs were also considered to evaluate the effect of electrode geometry on the actuation force. The droplet actuation was also modelled using an analytical approach to estimate the critical signal frequency, maximum electrostatic energy, and maximum electrostatic force. Lastly, a tilting micromirror platform investigated the dielectrophoretic response without measuring the droplet contact angle. The mirror platform is also suitable for other optical applications as it provides three axes of movement for beam steering. The tilting platform enabled an angular coverage of up to 0.9° (± 0.02°), with a maximum displacement of 120 μm. We also explored the feasibility of using a microhydraulic actuator based on liquid dielectrophoresis for a microfluidic application. The actuation method opens new possibilities for positioning and manipulating particles and components. These could be hazardous medical materials or even radioactive substances, where direct contact should be avoided

    A Proposal for a Three Detector Short-Baseline Neutrino Oscillation Program in the Fermilab Booster Neutrino Beam

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    A Short-Baseline Neutrino (SBN) physics program of three LAr-TPC detectors located along the Booster Neutrino Beam (BNB) at Fermilab is presented. This new SBN Program will deliver a rich and compelling physics opportunity, including the ability to resolve a class of experimental anomalies in neutrino physics and to perform the most sensitive search to date for sterile neutrinos at the eV mass-scale through both appearance and disappearance oscillation channels. Using data sets of 6.6e20 protons on target (P.O.T.) in the LAr1-ND and ICARUS T600 detectors plus 13.2e20 P.O.T. in the MicroBooNE detector, we estimate that a search for muon neutrino to electron neutrino appearance can be performed with ~5 sigma sensitivity for the LSND allowed (99% C.L.) parameter region. In this proposal for the SBN Program, we describe the physics analysis, the conceptual design of the LAr1-ND detector, the design and refurbishment of the T600 detector, the necessary infrastructure required to execute the program, and a possible reconfiguration of the BNB target and horn system to improve its performance for oscillation searches.Comment: 209 pages, 129 figure

    Channel rehabilitation to increase aquatic habitat and reestablish floodplain connectivity on the Upper Gila River

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    Stream restoration is an opportunity to recover a substantial amount of lost ecosystem structure and function. This may be particularly beneficial for perennial streams in semi-arid regions because of the striking differences in productivity and biodiversity between the riparian corridor and surrounding uplands. We develop a plan to restore floodplain connectivity along a channelized reach of the unregulated Upper Gila River in southwestern New Mexico, and evaluate its potential to provide additional aquatic habitat. To identify the extent of historical channelization, primary and secondary documents are examined. Signs of current geomorphic processes are also considered to formulate a restoration design. A high-resolution elevation model of the channel and floodplain is built from Light Detection and Ranging (LIDAR) and channel survey data, and an additional elevation model is created that includes the restoration plan. The plan consists of a new overflow channel in the disconnected floodplain, and is evaluated using a hydraulic model of open channel flow built with stream geometry information from the georeferenced elevation model. Flow levels for the study are chosen and characterized based on the 83-year record of daily mean discharge measured at the gaging station immediately upstream of the study site. The hydraulic simulation estimates for total area, total volume, and patterns of inundation in the study reach are used to evaluate the change in aquatic habitat availability and floodplain connectivity for the restoration plan. Results show that the reconfigured channel pattern would provide unique backwater habitat in the reach, and it also would increase total flooded area and floodplain connectivity throughout the entire range of modeled discharges

    Simulation of a cylindrical glass dome negative impact on a 360o field of view 2D laser scanner performance and a method for correction

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    Although laser scanning ideas and hardware solutions are well-known to experts in the field, there is still a large area for optimization. Especially, if long-range and high-resolution scanning is considered, the smallest defects in optical quality should be perfected. On the other hand, the simplicity, reliability, and finally the cost of the solution plays an important role, too. In this paper, a very simple but efficient method of optical correction is presented. It is dedicated to laser scanners operating from inside cylindrical glass domes. Such covers normally introduce aberrations into both the laser beam and receiving optics. If these effects are uncorrected, the laser scanner performance is degraded both in terms of angular resolution and maximum range of operation. It may not be critical for short-range scanning applications; however, if more challenging concepts are considered, this issue becomes crucial. The proposed method does not require sophisticated optical solutions based on aspheric or freeform components, which are frequently used for similar purposes in imaging-through-dome correction but is based on a simple cylindrical refractive correction plate

    Optical Speed Measurement and Applications

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    Photonic integrated components for optical coherence tomography

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