Counterfeit Good Detection Using Radar

Radar, such as frequency-modulated continuous wave (FMCW), can be used to analyze characteristics of an item. The radar can be emitted by a mobile device, such as a smartphone, that has radar technology incorporated as part of it. The radar backscatter of various portions of an item can be analyzed to determine whether the item is likely counterfeit or authentic

A framework for cooperative localization in ultra-wideband wireless networks

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.Includes bibliographical references (p. 89-93).Location-aware technologies have the potential to revolutionize computing, cellular services, sensor networks, and many other commercial, military, and social applications. In wireless networks, accurate information about an agent's location can give meaning to observed data and facilitate the agent's interactions with its surroundings and neighbors. Determining the location of one or more agents, known as localization or positioning, is a fundamental challenge. Most existing localization methods rely on existing infrastructure and hence lack the flexibility and robustness necessary for large ad-hoc networks. In this thesis, we describe a framework for localization that overcomes these limitations by utilizing cooperation: the agents in the network work together to determine their individual locations. We derive a practical algorithm for cooperative localization by formulating the problem as a factor graph and applying the sum-product algorithm. Each agent uses relative positioning measurements and probabilistic location information from its neighbors to iteratively update its location estimate. We investigate the performance of this algorithm in a network of ultra-wideband (UWB) nodes, which are well-suited for localization due to their potential to measure inter-node distances with high accuracy. Realistic models of UWB ranging error, based on an extensive measurement campaign in several indoor environments, are incorporated into the localization algorithm. Using the experimental data and simulations, we quantify the benefits that cooperation brings to localization.by Jaime Lien.M.Eng

A Comparison of Parametric and Sample-Based Message Representation in Cooperative Localization

Location awareness is a key enabling feature and fundamental challenge in present and future wireless networks. Most existing localization methods rely on existing infrastructure and thus lack the flexibility and robustness necessary for large ad hoc networks. In this paper, we build upon SPAWN (sum-product algorithm over a wireless network), which determines node locations through iterative message passing, but does so at a high computational cost. We compare different message representations for SPAWN in terms of performance and complexity and investigate several types of cooperation based on censoring. Our results, based on experimental data with ultra-wideband (UWB) nodes, indicate that parametric message representation combined with simple censoring can give excellent performance at relatively low complexity

Closed-Loop Manufacturing System Using Radar

A closed-loop manufacturing system is designed to use small, low-cost radar to observe a manufacturing process and measure characteristics of a build product. The build data measured by the radar includes geometry, reflection characteristics, material density, and high resolution maps. A controller processes the build data to detect errors. Example errors include mistakes in geometry, delamination, curling, shrinkage, lack of material uniformity, air bubbles, inclusions, and contaminations in the build product. Based on the detected errors, the controller determines build corrections and reports the build corrections to the manufacturing process. Using radar, the closed-loop manufacturing system automatically detects and corrects errors, saving time and resources in additive and subtractive manufacturing

Embedding Radars in Robots for Safety and Obstacle Detection

A safety system is designed to use small, low-cost radars embedded in joints and end effectors of a robot to monitor an environment for potential safety hazards. In this way, the radars directly detect obstacles with respect to the moving parts of the robot. A safety controller analyzes the obstacle data provided by the radars and determines an appropriate operating state of the robot based on predefined safety requirements

Embedding Radars in Robots to Accurately Measure Motion

A motion correction system is designed to use small, low-cost radars embedded in joints and end effectors of a robot to measure motion of the robot. In this way, the radars directly measure the robot’s motion and relative position and velocity with respect to a target. A motion correction controller analyzes the motion data provided by the radars and determines an amount of motion correction required to accurately position the robot

Estimation of Distributed Fermat-Point Location for Wireless Sensor Networking

This work presents a localization scheme for use in wireless sensor networks (WSNs) that is based on a proposed connectivity-based RF localization strategy called the distributed Fermat-point location estimation algorithm (DFPLE). DFPLE applies triangle area of location estimation formed by intersections of three neighboring beacon nodes. The Fermat point is determined as the shortest path from three vertices of the triangle. The area of estimated location then refined using Fermat point to achieve minimum error in estimating sensor nodes location. DFPLE solves problems of large errors and poor performance encountered by localization schemes that are based on a bounding box algorithm. Performance analysis of a 200-node development environment reveals that, when the number of sensor nodes is below 150, the mean error decreases rapidly as the node density increases, and when the number of sensor nodes exceeds 170, the mean error remains below 1% as the node density increases. Second, when the number of beacon nodes is less than 60, normal nodes lack sufficient beacon nodes to enable their locations to be estimated. However, the mean error changes slightly as the number of beacon nodes increases above 60. Simulation results revealed that the proposed algorithm for estimating sensor positions is more accurate than existing algorithms, and improves upon conventional bounding box strategies

Standard Radar API: Proposal Version 0.1

This publication describes a radar API that enables different radar options to be used without changing higher level software layers. The radar API supports frequency-modulated continuous-wave (FMCW) radar and other radar types. The radar API also supports interleaved radar configurations, so that different features may use different burst configurations simultaneously. For example, the radar API may support a dual burst configuration, where a first configuration is optimized for the longest range and a second configuration uses a wider bandwidth optimized for better range resolution. Together, the burst configurations may run simultaneously so that the algorithms supporting different features may consume their optimal input stream

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie