Browse Topic: Visibility

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MAVEN: A Multimodal Deep Learning Framework for In-Flight Long-Range Visibility EstimationF-0082-2026-03035/5/2026
Deep learning (DL) models have attained state-of-the-art performance in numerous fields. Nevertheless, for certain real-world applications, existing models encounter diverse challenges, ranging from a lack of generability to new data to issues of scalability and overfitting. In this context, integrating information extracted from different modalities holds promise as a potential solution to alleviate these challenges. This paper introduces MAVEN, a multimodal deep-learning framework for long-range atmospheric visibility estimation. Using multimodal deep learning, MAVEN fuses various modalities to estimate long-range atmospheric visibility. These modalities include RGB imagery, Edge Map, Entropy Map, Depth Map, and Normal Surface Map. Results show that in contrast to single-modality RGB, which achieves only 87.92% accuracy, multimodal deep learning models achieve an accuracy of over 96%. This significant improvement highlights the potential of multimodal approaches to enhance the accuracy and reliability of atmospheric visibility estimation, which is crucial for improving safety in applications such as aviation, maritime navigation, and autonomous vehicles. By addressing challenges such as data variability, environmental factors, and the inherent complexity of atmospheric conditions, MAVEN contributes to more reliable and robust visibility estimation systems, thereby enhancing safety and operational efficiency in critical environments.
Khelifi, Amine, Johnson, Charles, Bouaynaya, Nidhal, Carannante, Giuseppina, Bouhsine, Taha
Abstraction of a Flight Test Maneuver to Evaluate Handling Qualities for Helicopter Air-to-Air RefuelingF-0081-2025-03195/20/2025
Several efforts have been made to develop Flight Test Maneuvers for Handling Qualities evaluations, aimed at quantifying the effects of vehicle characteristics and assistance systems on a Helicopter Air-to-Air Refueling mission profile. However, these Flight Test Maneuvers have not achieved widespread adoption, likely due to the substantial logistical challenges associated with tanker deployment. Depending on a tanker aircraft not only incurs significant costs but also requires extensive organizational effort and prior testing, before Handling Qualities can be evaluated for the aerial refueling capabilities of a new rotorcraft design. Additionally, these available Flight Test Maneuver setups are not standardized or widely applied to the same degree as Mission Task Elements of the Aeronautical Design Standard, which limits repeatability and comparability. A new approach is proposed to address these limitations by introducing a repeatable, standardized method to reveal Handling Qualities deficiencies considering a worst-case situation of Helicopter Air-to-Air Refueling. This approach involves analyzing drogue motion to create a synthetic, deterministic target forcing function, based on the summation of several sine waves. Resulting laws of motion are applied to a target tracking task replicating a drogue chasing scenario by projecting all required references into the pilots' field of view. Piloted simulator studies conducted at the Air Vehicle Simulator (AVES) of the German Aerospace Center (DLR) demonstrate a high degree of similarity in pilot control behavior between the proposed Flight Test Maneuver and actual simulated Helicopter Air-to-Air Refueling.
Schmidt, Sven, Jusko, Tim
A Review of Proposed Enhancements to the Broken Wheel Vertiport Marking & SymbologyF-0081-2025-01575/20/2025
Electric Vertical Takeoff and Landing (eVTOL) aircraft present a series of challenges to traditional aviation infrastructure that was designed for conventional rotorcraft. Questions have arisen within the vertical flight community as to the validity and applicability of applying current heliport markings and symbology to vertiports. Several of these questions were addressed in a previous paper from VFS Forum 80: "A Comparison of Proposed Concepts for Vertiport Markings and Symbology" (Ref. 6). In contrast, this paper extends that work and presents the results of additional research to enhance the visibility of the Federal Aviation Administration’s (FAA) “Broken Wheel” symbology. These notional enhancements to the "Broken Wheel" symbology were evaluated over the course of an experimental study using helicopter-rated pilots in the FAA William J. Hughes Technical Center’s S76-D and Loft Dynamics H125 and R22 rotorcraft flight simulators.
Johnson, Charles, Thompson, Lacey, Morfitt, Grant
Application of BOS Velocimetry to Full-scale Helicopter Flight TestsF-0080-2024-10605/7/2024
Time-resolved background-oriented schlieren (BOS) data are used to calculate the two-dimensional velocity field in the wake of free-flying full-scale helicopters in ground effect. The calculation is performed based on the density gradient pattern of the helicopter engine exhaust gas passing the BOS field of view. A classical BOS evaluation allows the visualization of density gradients such as vortices and the exhaust plume. The result is the BOS displacement field. Applying the two-dimensional divergence to this data results in a pattern that is constant in shape across multiple BOS images, but convects downstream with the outwash velocity of the helicopter. Using this data as input to a second, timeresolved evaluation, quantitative two-dimensional velocity fields are calculated. Choosing an appropriate strategy for preparing and evaluating the data is critical to reliable velocity estimation. Another important aspect is to distinguish between reliable velocity data and erroneous results in areas of reduced signal intensity due to a lack of thermal structures. The velocity data obtained are compared with an analytical outwash model and constant temperature anemometry data acquired simultaneously with the BOS images. The data show good quantitative agreement in areas of sufficient thermal structures within the field of view.
Braukmann, Johannes N., Gardner, Anthony D., Wolf, C. Christian
Virtual Reality on a Motion Platform for Rotorcraft Shipboard SimulationF-0080-2024-11895/7/2024
Piloted simulation has been used for decades to support flight test activities at the Naval Air Warfare Center Aircraft Division located at Naval Air Station Patuxent River, MD. Conventional lab stations at the Manned Flight Simulator facility have been used effectively to support a wide range of flight test requirements. However, there were limitations with these conventional lab stations when the purpose was to assess handling qualities and pilot workload while landing rotorcraft aboard a ship. Two critical simulation elements were determined to be necessary: (1) an expanded field of view so the pilot could see the ship deck below the aircraft and (2) a motion system to provide the pilot with vital proprioceptive cueing in the turbulent ship environment. A new Virtual Reality Lab was developed at Patuxent River that included these key features. The primary components of the lab included virtual reality headsets, an Unreal Engine image generator, ocean and ship visual models, a six degree-of-freedom motion platform, and a generic cockpit. This paper describes development of the lab, various issues that were encountered, and plans for future improvements.
Gaublomme, Donald P., Zinchiak, Andrew G., Meyers, Kyle J., Smith, Zachary F., Calvillo, Robert V.
TERMINALS, LUG AND SPLICES, CONDUCTOR, CRIMP STYLE, COPPER TERMINAL, LUG, CRIMP STYLE, COPPER, INSULATED, RING TONGUE, FOR THIN WALL WIRE, TYPE II CLASS 1 FOR 105 °C TOTAL CONDUCTOR TEMPERATUREAS7928/1E (Current)9/21/2021
AE-8C2 Terminating Devices and Tooling Committee
TERMINALS, LUG AND SPLICES, CONDUCTOR, CRIMP STYLE, COPPER, INSULATED, RECTANGULAR TONGUE, FOR THIN WALL WIRE, TYPE III, CLASS 1, FOR 105 °C TOTAL CONDUCTOR TEMPERATUREAS7928/2E (Current)8/26/2021
AE-8C2 Terminating Devices and Tooling Committee
Validating an Approach to Assess Sensor Perception Reliabilities Without Ground Truth2021-01-00804/6/2021
A reliable environment perception is a requirement for safe automated driving. For evaluating and demonstrating the reliability of the vehicle’s environment perception, field tests offer testing conditions that come closest to the vehicle’s driving environment. However, establishing a reference ground truth in field tests is time-consuming. This motivates the development of a procedure for learning the vehicle’s perception reliability from fleet data without the need for a ground truth, which would allow learning the perception reliability from fleet data. In Berk et al. (2019), a method based on Bayesian inference to determine the perception reliability of individual sensors without the need for a ground truth was proposed. The model utilizes the redundancy of sensors to learn the sensor’s perception reliability. The method was tested with simulated data. In this contribution, we further explore and validate the method by utilizing real data, including ground truth data based on high-resolution LIDAR and human labeling. An area with overlapping field of view from five sensors is selected for the analysis. A basic association method is used to compare the object data obtained from the different sensors. Finally, we compare the sensor perception reliabilities learned from the Bayesian inference model with the sensor perception reliabilities determined from the labeled ground truth. In this paper, it is shown that the model introduced in Berk et al. (2019) can approximate the reference data based on the provided ground truth. The estimated parameters of the model do not perfectly correspond to the sensor reliabilities but are of the same order of magnitude as when derived from the ground truth.
Kryda, Marco, Berk, Mario, Buschardt, Boris, Straub, Daniel
Impact of Fog Particles on 1.55 μm Automotive LiDAR Sensor Performance: An Experimental Study in an Enclosed Chamber2021-01-00814/6/2021
To achieve full automation in self-driving vehicles, environmental perception sensing accuracy is critically important. However, ambient particles in adverse weather like foggy, rainy, or snowy conditions can significantly scatter the incident laser beam, and therefore contaminate the intensity and accuracy of light detection and ranging (LiDAR) sensors. Especially compared to the rapidity of technology development in self-driving vehicles, there is a significant lack of documented research on LiDAR systems with wavelength longer than 1 μm for application in Advanced Driver-Assistance Systems. In this work, experimental studies were performed with a state-of-the-art 1.55 μm wavelength automotive-grade LiDAR system in a controlled laboratory fog chamber. The goal of the research is to correlate laser attenuation and the optical properties of fog particles. In this work, a thorough multistep procedure for LiDAR data analysis is presented including spatial averaging of the object measurement and characterizing the temperature effect on a LiDAR intensity parameter. Fog particle density is measured by a commercial visibility sensor instrument. Assuming a constant extinction coefficient and backscatter coefficient, a simple analytical model is derived that correlates LiDAR reflectance and extinction coefficient measured by visibility sensor. Results show that the correlation coefficient between LiDAR and visibility sensor data is 0.98 and the R-squared value of linear fitting is 0.96. By comparing the LiDAR original signal and the model, the Root-Mean-Squared Deviation is 0.007, meaning the model performs very well for predicting LiDAR reflectance in the controlled environment. Furthermore, although the returned signal strength is attenuated, the LiDAR can measure the target with a visibility range lower than six meters.
Zhan, Lu, Northrop, William F.
Object Detection and Tracking for Autonomous Vehicles in Adverse Weather Conditions2021-01-00794/6/2021
Object detection and tracking is a central aspect of perception for autonomous vehicles. While there has been significant development in this field in recent years, many perception algorithms still struggle to provide reliable information in challenging weather conditions which include night-time, direct sunlight, glare, fog, etc. To achieve full autonomy, there is a need for a robust perception system capable of handling such challenging conditions. In this paper, we attempt to bridge this gap by proposing an algorithm that combines the strength of automotive radars and infra-red thermal cameras. We show that these sensors complement each other well and provide reliable data in poor visibility conditions. We demonstrate the advantages of a thermal camera over a visible-range camera in these situations and employ YOLOv3 for object detection. The proposed system utilizes a modified Track-Oriented Multiple Hypothesis Tracking (MHT) algorithm which uses data from these sensors to keep track of the surrounding vehicles. The modifications in the well-known MHT algorithm were introduced in order to curb the exponential growth of possible hypotheses and consequently reduce the computational time without loss of any critical information. To validate the system, we provide a real-time implementation on an urban dataset collected at the Texas A&M University.
Bhadoriya, Abhay Singh, Vegamoor, Vamsi Krishna, Rathinam, Sivakumar
V2X Connectivity with ROS for AD Applications2021-01-00604/6/2021
Increased levels of autonomy requires an increasing amount of sensory data for the vehicle to make appropriate decisions. Sensors like camera, Lidar and Radar will help to perceive the surroundings, exposing nearby objects and blind spots within the line of sight. With V2X connectivity, vehicles communicate to other vehicles and infrastructure using wireless communications even in non-line of sight conditions. This paper presents an approach to utilize a V2X system to develop Automated Driving (AD) features in a Robot Operating System (ROS) environment. This was achieved by developing ROS drivers and creating custom messages to enable the communication between the V2X system and vehicle sensors. The developed algorithms were tested on FEV’s Smart Vehicle Demonstrator. The test results show that the proposed V2X automated driving approach has increased reliability compared to that of camera, Radar and Lidar based autonomous driving.
Yedida, Siddhartha, Paudyal, Ajay, Matta, Sherif, Tasky, Tom
TERMINALS, LUG AND SPLICES, CONDUCTOR, CRIMP STYLE, COPPER, INSULATED, RECTANGULAR TONGUE, FOR THIN WALL WIRE, TYPE II, CLASS 1 FOR 105 °C TOTAL CONDUCTOR TEMPERATUREAS7928/2D (Historical)2/19/2021
AE-8C2 Terminating Devices and Tooling Committee
TERMINALS, LUG AND SPLICES, CONDUCTOR, CRIMP STYLE, COPPER TERMINAL, LUG, INSULATED, RING TONGUE, BELL-MOUTHED, TYPE II, CLASS 1 (FOR 150 °C TOTAL CONDUCTOR TEMPERATURE)AS7928/4C (Current)11/13/2020
AE-8C2 Terminating Devices and Tooling Committee
Occupant Restraint Dynamic System Evaluation - Frontal Impact Heavy TrucksJ2418_202011 (Current)11/9/2020
This SAE Recommended Practice describes the test procedures for conducting frontal impact restraint tests for heavy truck applications. Its purpose is to establish recommended test procedures that will standardize restraint system testing for heavy trucks. Descriptions of the test set-up, test instrumentation, photographic/video coverage, and the test fixtures are included.
Truck Crashworthiness Committee
Restoring Practical Single Engine IFR to the MarketplaceF-0076-2020-1634310/5/2020
Attempting to pick through bad weather - becoming disoriented in diminished visibility or striking a wire or obstacle at low altitude - remains one of the major causes of fatal helicopter accidents. It is more common than engine failure, more common than mechanical failures, and more common than systems failures. While some feel the answer involves more tools to enable low-flying helicopters to avoid terrain and obstacles, a better solution is to keep helicopters safely away from terrain and obstacles using instrument flight rules (IFR) when weather conditions demand. For single engine helicopters, which form the largest population of helicopters, this means finding cost effective ways to provide them with safe and practical IFR capability. IFR capability is commonplace in airplanes, even among entry-level and training aircraft. An IFR rating is typically the first rating sought after an airplane pilot receives their license. For helicopters, there is currently not a parallel culture of shifting to the safety of IFR operations when weather demands. The reasons are complex, but a significant factor affecting this culture today is that the entryl evel IFR rotorcraft is generally a twin-turbine-engine helicopter. By the time a helicopter pilot gets to this level of machine, he or she is typically well versed in the "alternate" methods of weather avoidance. Unfortunately, even IFR rated helicopter pilots tend to default to a practice of attempting to fly below the weather using visual flight rules (VFR). Increasing the availability of IFR-capable helicopters by restoring practical, low-cost IFR solutions to single engine rotorcraft is the first step in a process intended to change the rotorcraft safety culture. This paper describes a 5-year effort by associations, industry, and regulators to remove the obstacles to certifying low-cost IFR helicopters. By mid-year 2019, two single-engine helicopters were certified for IFR operations, ending an absence of more than 20 years from the marketplace, but these were newly-manufactured aircraft. The remaining challenge is to apply what has been done in order to allow cost-effective retrofits of IFR capability to the existing fleet of VFR helicopters. The hope is that, with the trail now blazed, others will follow, and we will see even more single-engine rotorcraft with IFR capability and fewer weather-related accidents.
Oltheten, Erik
Intention-aware Lane Changing Assistance Strategy Basing on Traffic Situation Assessment2020-01-01274/14/2020
Traffic accidents avoidance is one of the main advantages for automated vehicles. As one of the main causes of vehicle collision accidents, lane changing of the ego vehicle in case that the obstacle vehicles appear in the blind spot with uncertain motion intentions is one of the main goals for the automated vehicle. An intention-aware lane changing collision assistance strategy basing on traffic situation assessment in the complex traffic scenarios is proposed in this paper. Typical Regions of Interest (ROI) within the detection range of the blind spots are selected basing on the road topology structures and state space consisting of the ego vehicle and the obstacle vehicles. Then the motion intentions of the obstacle vehicles in ROI are identified basing on Gaussian Mixture Models (GMM) and the corresponding motion trajectories are predicted basing on the state equation. Traffic situation is assessed according to the index of the motion intentions and the coupling tendency between the ego vehicle and the obstacle vehicles and the risk level is graded basing on the map with collision time. Lane keeping assist is carried out according to the assessment result of the traffic situation. Testing scenarios with the straight road and T-junction are designed and a co-simulation environment consisting of CarMaker and Mathwork Simulink is established to verify the proposed strategy in complex traffic scenes. Simulation results present an adaptive ROI and a high identification accuracy for motion intentions of the obstacle vehicles. What’s more, it shows that the traffic situation can be accurately evaluated and the ego vehicle can be effectively controlled with the appearance of the high-risk vehicles.
Wu, Jian, Liu, Sihan, He, Rui, Sun, Bohua
A Stability-Guaranteed Time-Delay Range for Feedback Control of Autonomous Vehicles2020-01-00904/14/2020
The vehicles with level-5 autonomy (L5AVs) that have no human driver in the loop are also known as self-driving cars. L5AVs are assumed the next generation of ground transportation, which have growing attention from both industry and academia in most recent years. Most of the work related to feedback strategies of L5AVs are on developing mapping systems through a variety of sensors. These systems can be considered as an analogue to the perception and central nervous system of human drivers. For instance, innovative visualization systems are more powerful when compared to the visual perception system of a person, yet, mapping demands high computation loads. This burden causes delay in the feedback loop and thus, it might have an unfavorable influence on proper and safe control action. This study investigates the effect of time delay occurring in mapping systems on the stability of the controlled vehicle. An algorithm entitled as “Cluster Treatment of Characteristic Roots - CTCR” is used to calculate a safe delay range as a remedy for the time delay caused by mapping systems. The CTCR analysis is applied to a linearized two degree-of-freedom bicycle model for different velocities. The critical time delay values, which determines the boundary between the stability and instability of the controlled vehicle, are calculated based on the vehicle dynamics. Finally, results are drawn for a regular weave test by computer simulations, in which a non-linear vehicle model is used. The proposed approach is validated by exhibiting that a delay value outside the safe range leads the vehicle instability.
Kirli, Ahmet, Arslan, Mehmet Selçuk
A Novel Velocity Planner for Autonomous Vehicle Considering Human Driver’s Habits2020-01-01334/14/2020
In automatic driving application, the velocity planner can be considered as a key factor to ensure the safety and comfort. One of the most important tasks of the velocity planner is to simulate the velocity characteristics of human drivers. In this paper, two Driver In-the-Loop (DIL) experiments are designed to explain velocity characteristics of human drivers. In the first experiment, static obstacles are placed on both sides of the straight road to shorten the cross range that vehicles can driver across. Moreover, different cross ranges are set to study the influence of the steering wheel error. In the second experiment, velocity characteristics are investigated under the condition of different road widths and curvatures in a U-turn road contour. In both tests, different drivers’ preview behavior is analyzed through the operation of throttle, braking, and steering. From the results we could see the change of vehicle speed depends largely on the traffic environment at the driver’s preview point. On this basis, a novel velocity planner is proposed. Firstly, a target velocity in preview terminal point is calculated. The calculation of the velocity is based on two indicators-the driver’s driving & operating ability, and the degree of visual restriction. The former refers to the ability of the driver to maintain the driveway as well as the control ability of the vehicle stability, and the latter is related to the uncertainty of the environment. Subsequently, the smooth velocity profiles that connect the initial point and the preview terminal point are generated based on the convex optimization. Finally, the simulation results show that this velocity planner possesses good human-like performance, considering the human-vehicle-road coordination. This study is useful to customize velocity planning for autonomous vehicle so as to improve the acceptability of the specific human driver.
Cui, Zongwei, Guo, Xuexun, Pei, Xiaofei
Analysis of Dashcam Video for Determination of Vehicle Speed2020-01-08774/14/2020
Using dashcam video footage to extract reliable vehicle speed data can be challenging when the only available image stream comes from a camera whose optical parameters are unknown. One means of overcoming such difficulties uses visible landmarks and features within the video frame whose dimensions can be independently measured. While good results have been obtained by others using a Total Station or LiDAR to physically measure locations for such purposes, this approach could prove difficult if a site of interest is inaccessible (e.g. on a busy highway that cannot be shut down) or if relevent features of the target location have changed (e.g. due to construction or even restriping of lanes lines). As an alternative to direct scene measurement, it is proposed that measurement of features visible in overhead satellite images be used to dimension relevant features visible in the video. In this work, videos from individual dashcams and phone-based cameras were used to calculate average vehicle speed by tracking individual features as they pass through and then exit the image frame. Because the features used herein are limited to periodically-occurring markings such as lane lines, average vehicle speed is calculated based solely on distances referenced to these features as well as video frame rate. Although limited in scope, a major advantage of this approach is that it eliminates the need for camera calibration, because only one small patch of the image frame is used for the average speed calculation. In this study, selected video sequences were used to calculate vehicle speed at speeds ranging from 16 - 65 mph, with results corresponding to the vehicle’s speedometer display for all but the lowest frame rates.
Leifer, Jack, Marquez, Alvaro
Prevention of Snow Accretion on Camera Lenses of Autonomous Vehicles2020-01-01054/14/2020
With the rapid development of artificial intelligence, the autonomous vehicles (AV) have attracted considerable attention in the automotive industry. However, different factors negatively impact the adoption of the AVs, delaying their successful commercialization. Accretion of atmospheric icing, especially wet snow, on AV sensors causes blockage on their lenses, making them prone to lose their sight, in turn, increasing potential chances of accidents. In this study, two different designs are proposed in order to prevent snow accretion on the lenses of AVs via air flow across the lens surface. In both designs, lenses made of plain glass and superhydrophobic coated glass surfaces are tested. While some researchers have shown promise of water repellency on superhydrophobic surfaces, more snow accretion is observed on the superhydrophobic surfaces, when compared to the plain glass lenses. In the experiments, snow is formed using a novel snow gun inside a walk-in cold room connected to a wind tunnel that can reach wind speeds of up to 40 mph. It is observed that the air flow over the lens significantly reduces the accretion of snow on the lens and could maintain the lens clean for up to 20 mph wind velocities. However, at LWC values of approximately 28%, the stickiness of the snowflakes increases, enhancing snow accretion on the lenses and translating to significant loss of sight. The high stickiness of the snowflakes along with high wind speeds leads to increased blockage of the AV lenses.
Mohammadian, Behrouz, Sarayloo, Mehdi, Heil, Jamie, Sojoudi, Hossein, Robertson, Michael, Hong, Haiping, Tran, Tommy, Patil, Sunil, Krishnan, Venkatesh
SUV Kinematics during a Steer-Induced Rollover Resolved Using Consumer-Grade Video, Laser Scans and Match-Moving Techniques2020-01-06424/14/2020
Rollover crashes are complex events that generate motions in all six degrees of freedom (6DOF). Directly quantifying the angular rotations from video can be difficult and vehicle orientation as a function of time is often not reported for staged rollover crashes. Our goal was to evaluate the ability of using a match-moving technique and consumer-grade video cameras to quantify the roll, pitch and yaw angles and angular velocities of a rollover crash. We staged a steer-induced rollover of an SUV at 106 km/h. The vehicle was fitted with tri-axial accelerometers and angular rate sensors, and five consumer-grade video cameras (2 on tripods, 2 on drones, 1 handheld, ~30 fps) captured the event. Roll, pitch and yaw angles were determined from the video using specialized software. We then compared the vehicle orientation angles from the video data to the integrated angular rate data measured by onboard sensors, and also compared the angular rates from the differentiated video data to the angular rates measured directly by the sensors. We found that both methods of measuring the 3D angles and angular rates generated similar results. The integrated sensor data drifted a maximum of 13° relative to the video-based angles, with RMS differences of ±2.7° or less when the drift was removed. The differentiated video data did not drift relative to the sensor data, with RMS differences of ±0.22 rad/s or less. These findings indicate that both methods generate similar results and are suitable for reconstructing rollovers. Given the drift we observed in the integrated sensor data, we recommend using angle measurements from the video to quantify the amount of drift in integrated sensor data if accurate knowledge of the vehicle’s orientation as a function of time is important.
Young, Cole R., King, David J., Siegmund, Gunter P.
Requirements for Road Weather ApplicationsJ2945/3_202003 (Historical)3/24/2020
Inclement weather can have a significant impact on surface transportation systems. It can result in hazardous conditions for travelers due to poor visibility, or wet or icy roadways. Weather applications have the potential to provide additional data to surface transportation infrastructure owners and operators, allowing them to better assess the impacts of the weather environment on or around the roadway and to better manage the surface transportation system. Such weather applications can: Collect road weather data from connected vehicles and mobile devices, increasing the number of data sources available. Provide road weather related traveler information to travelers via connected vehicles and devices, such as when and where a hazardous condition exists. Provide the ability to manage road weather response on specific roadways. This SAE Standard specifies interface requirements between vehicles and infrastructure for weather applications, including detailed systems engineering documentation (needs and requirements mapped to appropriate message exchanges). The purpose of this SAE Standard is to enable interoperability supporting these weather applications over a communications technology agnostic interface.
Infrastructure Applications Technical Committee
Color-Coded Incandescent Flange Base T-1 and T-1 3/4 Lamps for Voltage IdentificationAS4156C (Current)3/12/2020
This document specifies that black is the only color that can be used for the insulator at the bottom of the base of T-1 and T-1 ¾ Flanged Base lamps.
A-20A Crew Station Lighting Committee
Good Design Controls Are Critical to Avoiding FDA IssuesTBMG-357831/1/2020
Medical device companies recognize that having an emphasis on design controls helps to assure good design and engineering practices that yield high-quality solutions. This is critical when considering FDA validation and design compliance. But to accomplish this, first know what key elements should be incorporated in design controls before implementing formalized plans for their creation.
CONTI SUITS UP19AUTP10_0110/1/2019
A team of young innovators aims to transform a critical piece of safety equipment - and create new business - through collaboration. Few colors shock the human brain into attention more than high-visibility Yellow. “Hi-viz” as it's known in the safety-apparel industry, is an on-the-job requirement for first responders, road workers, tow-truck drivers, linesmen, loggers, couriers, coast guard deck crews - any all-weather vocation for which being seen in low-visibility situations can make the difference between life and death. Included are overnight package-delivery drivers who must sprint across busy city streets - at night, in the fog and rain - to deliver the goods. But hi-viz, even when combined with reflective fabrics, is often not sufficient for wearers to be seen.
Brooke, Lindsay
How HMI displays impact operator productivity in industrial vehicles19TOFHP10_1110/1/2019
The latest research indicates that well-integrated HMI (human-machine interface) systems lead to more attentive users that better retain task-related information and stay focused for longer with less reported effort. These systems also fit into the wider development trends in off-highway machines that affect operator fatigue in day-to-day tasks. Operator comfort includes more than just the cushioning in their seats; it is everything that surrounds a driver as they operate a vehicle-steering wheel height, pedal positioning, seat support, harnessing and control interface. Research from Norway and Italy as part of an overall European Union study looking into HMI in heavy machines has shown the importance of ergonomics in reducing operator fatigue. Research from Markus Wallmyr, head of UX at CrossControl and a researcher with Mälardalen University in Sweden, has demonstrated the importance of display placement in improving information detection and the effectiveness of operator aids.
Wallmyr, Markus
Improving Lidar - or Defeating It19AVEP09_089/1/2019
The buzz at Sensors Expo pitted lidar-tech optimism against the reality of an impending shakeout. For more than a decade, the lidar market has been led by Velodyne and its spinning towers of 64 or 128 laser beams. But the relatively high cost, delicate architecture, and beefy form factor have made it a competitive target. The growing ranks of competitors fall roughly into two camps. There are the fledgling lidar-makers with novel approaches to distance measurement, laser wavelength, and beam steering. And there are those with radar and vision systems promising lidar-level sensing capabilities at a lower cost. The jockeying for position was on full display at the 2019 Sensors Expo and Conference, held in San Jose, Calif. “The greatest amount of discussion is about lidar right now because there are a lot of startups in that space,” observed Jim Hines, an independent consultant working on semiconductor and sensor technologies for connected and autonomous vehicles.
Berman, Bradley
Robot “Eye” Provides 360° Field of ViewTBMG-351599/1/2019
The production of precision products depends on robot control systems knowing the location of the adhesive bonding head or welding head to the nearest millimeter at all times. This means the robot needs some sort of eye. Specialized sensors can perform this function, most of which operate on the principle of laser triangulation. A laser diode projects a line of red light onto the workpiece, from which the light is reflected at a specific angle before being detected by a camera. From the position of the light striking the camera chip, the position and distance of the sensor with respect to the workpiece within the coordinate system can be calculated.
Ice-Crystal Icing Accretion Studies at the NASA Propulsion Systems Laboratory2019-01-19216/10/2019
This paper describes an ice-crystal icing experiment conducted at the NASA Propulsion System Laboratory during June 2018. This test produced ice shape data on an airfoil for different test conditions similar to those inside the compressor region of a turbo-fan jet engine. Mixed-phase icing conditions were generated by partially freezing out a water spray using the relative humidity of flow as the primary parameter to control freeze-out. The paper presents the ice shape data and associated conditions which include pressure, velocity, temperature, humidity, total water content, melt ratio, and particle size distribution. The test featured a new instrument traversing system which allowed surveys of the flow and cloud. The purpose of this work was to provide experimental ice shape data and associated conditions to help develop and validate ice-crystal icing accretion models. The results support previous experimental observations of a minimum melt-ratio threshold for accretion to occur as well as the existence of a plateau region where the icing severity is high for a range of melt ratios. However, a maximum limit for melt ratio, which is suggested in the ice crystal icing literature, was not observed perhaps complicated by the potential for some supercooling of the water at these conditions.
Struk, Peter M., Agui, Juan, Ratvasky, Thomas, King, Michael, Bartkus, Tadas, Tsao, Jen-Ching
Analysis and Automated Detection of Ice Crystal Icing Conditions Using Geostationary Satellite Datasets and In Situ Ice Water Content Measurements2019-01-19536/10/2019
Recent studies have found that high mass concentrations of ice particles in regions of deep convective storms can adversely impact aircraft engine and air probe (e.g. pitot tube and air temperature) performance. Radar reflectivity in these regions suggests that they are safe for aircraft penetration, yet high ice water content (HIWC) is still encountered. The aviation weather community seeks additional remote sensing methods for delineating where ice particle (or crystal) icing conditions are likely to occur, including products derived from geostationary (GEO) satellite imagery that is now available in near-real time at increasingly high spatio-temporal detail from the global GEO satellite constellation. A recent study using a large sample of co-located GEO satellite and in-situ isokinetic evaporator probe (IKP-2) total water content (TWC) datasets found that optically thick clouds with tops near to or above the tropopause in close proximity (≤ 40 km) to convective updrafts were most likely to contain high TWC (TWC ≥ 1 g m-3). These parameters are detected using automated algorithms and combined to generate a HIWC probability (PHIWC) product at the NASA Langley Research Center (LaRC). Seven NASA DC-8 aircraft flights were conducted in August 2018 over the Gulf of Mexico and the tropical Pacific Ocean during the HIWC Radar II field campaign. The convection sampled during four flights was observed by GOES-16 at 1- or 5-minute intervals, providing the first opportunity to analyze product performance from this new satellite. This paper will (1) present initial comparisons between GOES-16 and IKP-2 datasets during HIWC Radar II, (2) demonstrate GOES-16 products for select periods when high TWC was encountered with an emphasis on three flights with 1-minute imagery, (3) compare GOES observations and derived products from the HIWC Radar I and II campaigns.
Bedka, Kristopher, Yost, Christopher, Nguyen, Louis, Strapp, J. Walter, Ratvasky, Thomas, Khlopenkov, Konstantin, Scarino, Benjamin, Bhatt, Rajendra, Spangenberg, Douglas, Palikonda, Rabindra
Vision Sensors in Factory AutomationTBMG-345776/1/2019
There are a number of ways to extract data from a production line. In factory automation, sensors are used in work cells to gather data for inspection or to trigger other devices. These sensors fall into multiple categories – photoelectric, fiber optic, proximity, ultrasonic, and vision are the most common.
New Performance Metrics for Lidar19AVEP05_075/1/2019
Frame-rate measurement is so yesterday. Object-revisit rate and instantaneous resolution are more relevant metrics, and indicative of what a lidar system can and should do, argues a revolutionary in the artificial-perception space. How do you measure the effectiveness of an intelligent, lidar-based perception system for autonomous vehicles? Conventional evaluation metrics favor frame rate and resolution as the ideal criteria. However, experts at Pleasanton, Calif.-based artificial perception company AEye believe that these criteria are inadequate for measuring the unique capabilities of more advanced lidar systems, nor do they explicitly address real-world problems facing autonomous driving, such as hazard detection and tracking. “Makers of automotive lidar systems are frequently asked about their frame rate, and whether or not their technology has the ability to detect objects with 10% reflectivity at a specified range, frame rate and resolution,” said the company's co-founder and senior VP of engineering, Dr. Barry Behnken. “These metrics were established back in 2004 during the first DARPA Grand Challenge and haven't been altered since. Unfortunately, they fail to adequately rate a perception system's ability to perform safely on public roads, as the AVs back then were not being built for widespread use.”
Vijayan, Indu
AV ‘Goiters’ Be Gone!19AVEP05_125/1/2019
Magneti Marelli's ‘Smart Corner’ technology aims to reduce cost, complexity and mass by integrating key vehicle sensors seamlessly into a vehicle's lighting modules. Warts. Bumps. Blisters. Protuberances. These and other less-flattering terms are used by vehicle designers and engineers to describe the bulging, non-integrated sensor placement that has become the unfortunate visual signature for automated vehicles (AVs). “We actually call them ‘goiters,’” said Bill Grabowski, head of innovation and technology for Automotive Lighting division at Magneti Marelli. “While they're [sensors] primarily for function, the OEM and the end customer don't want to see these protrusions littering the vehicle exterior in production. Packaging up to 25 sensors that handle all levels of ADAS and autonomous driving has become a major problem for the automakers.”
Brooke, Lindsay
Monitoring a Nearshore Beneficial Use Site: Application of a Benthic Sled and Video Annotation19AERP05_075/1/2019
Passive survey method provides less labor and resource intensive system for monitoring the effects of dredging on aquatic life in nearshore beneficial use sites. Army Engineer Research & Development Center, Portland, Oregon The U.S. Army Corps of Engineers (USACE) Portland Districts (NWP) maintains safe and navigable waterways in Oregon through a variety of dredging projects, including channel deepening, and dredging sandbars. Placement of dredged sediment occurs at preselected, specific geographic areas categorized as nearshore beneficial use sites. Beneficial use sites are commonly monitored before, during, and after disposal, to evaluate dredge management practices and to avoid potentially adverse effects to the marine environment. Ecological monitoring focuses on the survey of fish and epibenthic invertebrate species distribution and abundance. Surveys are conducted within, and outside the disposal area to assess changes in population or community structure, and to establish diversity indices for comparisons over time. A commonly used survey method to accomplish this goal is a bottom trawl survey, whereby a net is dragged along a preselected part of the ocean floor for a specific time and distance. The net is then retrieved onto the boat where the aquatic life can be more closely examined and the taxa are sorted. Traditional trawl surveys are labor and resource intensive, highlighting the opportunity to improve alternative “passive” survey methods.
Monitoring a Nearshore Beneficial Use Site: Application of a Benthic Sled and Video AnnotationTBMG-343365/1/2019
The U.S. Army Corps of Engineers (USACE) Portland Districts (NWP) maintains safe and navigable waterways in Oregon through a variety of dredging projects, including channel deepening, and dredging sandbars. Placement of dredged sediment occurs at preselected, specific geographic areas categorized as nearshore beneficial use sites. Beneficial use sites are commonly monitored before, during, and after disposal, to evaluate dredge management practices and to avoid potentially adverse effects to the marine environment.
An Introduction to Time of Flight ImagingTBMG-344165/1/2019
Three-dimensional (3D) imaging applications are used in many different industries ranging from industrial pick and place, palletization/depalletization, warehouse, robotics, and metrology to consumer-based products such as drones, safety and security, and patient monitoring. No one specific type of 3D technology can address all of these different types of applications — the features of each must be compared as to their suitability.
Numerical Investigation of Wiper Drawback2019-01-06404/2/2019
Windscreen wipers are an integral component of the windscreen cleaning systems of most vehicles, trains, cars, trucks, boats and some planes. Wipers are used to clear rain, snow, and dirt from the windscreen pushing the water from the wiped surface. Under certain conditions however, water which has been driven to the edge of the windscreen by the wiper can be drawn back into the driver’s field of view by aerodynamic forces introduced by the wiper motion. This is wiper drawback, an undesirable phenomenon as the water which is drawn back on to the windscreen can reduce driver’s vision and makes the wiper less effective. The phenomena of wiper drawback can be tested for in climatic tunnels using sprayer systems to wet the windscreen. However, these tests require a bespoke test property or prototype vehicle, which means that the tests are done fairly late in the development of the vehicle. Furthermore, these results do not provide significant insight into the mechanisms driving the wiper drawback. In order to better understand wiper drawback a numerical simulation is presented of a configuration known to exhibit this phenomenon. This requires the inclusion into an aerodynamics solver of: moving wipers, a surface film model, and a representation of airborne spray. Using the results of this simulation, the forces causing the drawback of the water film, along with the mechanism for introducing these forces are studied. Through understanding the driving factors in wiper drawback, it can be avoided earlier in the development cycle.
Jilesen, Jonathan, Gaylard, Adrian, Linden, Tom
Enhancing Contrast-Sensitivity Charts for Validating Visual Representations of Low-Illumination Scenes2019-01-10094/2/2019
This aim of this study was to introduce and test three different design enhancements to the contrast-sensitivity charts developed by Ayers and Kubose [1]. Contrast-sensitivity charts are the current, critical instrument for generating photographic representations of low-illumination scenes. However, their range of applicability is limited to a specific range of lighting conditions for any given scene, and a limited set of testing and perceptual conditions for observers. A total of four contrast charts were presented to ten dark-adapted observers in nine different lighting conditions that changed in ascending order from low to high levels of illumination. For each lighting condition, the order and orientation of the charts was randomized. Observations related to the number of detected contrast levels were then compared to find the utilization ranges for each chart. In addition, observers were asked to report the directionality of the detected center light wedges for the two enhanced chart designs. The non-linear contrast functions minimized floor and ceiling effects, specifically at the lower tested frequencies of 3.5 and 7.0 c/d. Additionally, the wedge orientation of each visual target added a layer of testability for the perception of contrast and the validation of visual representations. The inclusion of non-linear contrast functions, randomized contrast levels, and a re-orientable layout extended the usefulness and range of lighting in which contrast-sensitivity charts can be used. The described enhanced contrast-sensitivity charts provide testable means to validate photographic representations of low-illumination scenes for an extended range of lighting and testing conditions.
Sprague, James, Meza-Arroyo, Manuel, Shibata, Peggy, Auflick, Jack
Multiplexing of Wireless Surface Acoustic Wave SensorsTBMG-341584/1/2019
The traditional approach for wireless sensors involves interrogators that communicate with each other (i.e., the two boxes “talk” to each other). In contrast, surface acoustic wave (SAW) sensors allow for a single box that can communicate with multiple sensors. One of the biggest advantages of SAW sensors over competing wireless sensors is that the SAW sensors do not require a power source.
Key Human Factors Drive Design for Disposables, Test Kits and IFUsTBMG-3344512/1/2018
Bring to mind your last straight-out-of-the-box experience with a disposable medical device of any kind. Without a doubt, everyone has experienced the same frustrations: ambiguous instructions printed too small to read easily, and difficult assemblies that simply don't match up with human capabilities. As an industry and a profession, medical product developers have vast knowledge on how human beings perceive and process information and on how human hands work. Surprisingly, not much of that knowledge manages to inform the design of medical disposables, test kits, and instructions for use (IFUs). With an eye toward higher functionality and usability in disposables, test kits, and IFUs, this article reviews fundamental factors critical to successful design plus common oversights that lead to design disasters.
Portable Acousto-Optic SpectrometersTBMG-3339812/1/2018
Spectrometers are widely used for applications such as chemical analysis, remote sensing, quality control, environmental monitoring, spaceborne measurements, and optical measurements. Most spectrometers are based on using dispersive elements such as prisms, gratings, or etalons. These spectrometers typically have moving parts that induce spurious readings due to vibrations, and have limited use due to their limited spectral range and resolution capabilities, which in turn limit their use when needed for portable field applications.
MR Coil for High-Quality ImagingTBMG-3306510/1/2018
Researchers have developed and tested an MR coil for high-quality imaging of the whole mouse. Such coils are required for preclinical studies of drugs, as well as for targeted examination of various body systems. Due to the design features, the new coil provides three times higher image quality than a commercial volume MR coil, usually used in such studies. The coil is low cost, and the manufacturing technology can be adapted for different studies.
Technique Allows Mobile Robots to Navigate AutonomouslyTBMG-3307710/1/2018
A technique was developed to quickly teach robots novel traversal behaviors with minimal human oversight. The technique allows mobile robot platforms to navigate autonomously in environments while carrying out actions a human would expect of the robot in a given situation.
A Novel Barricade Warning Light System Using Wireless Communications2018-01-50369/12/2018
Workers in construction and transportation sectors are at increased risk for work-related injuries and fatalities by nearby traffic. Barricade-mounted warning lights meeting current specifications do not always provide consistent and adequate visual guidance to drivers and can contribute to glare and reduced safety. Through an implementation of sensors and wireless communications, a novel, intelligent set of warning lights and a tablet-based interface were developed. The lights modulate between 100% and 10% of maximum intensity rather than between 100% and off in order to improve visual guidance and adjust their overall intensity based on ambient conditions. The lights can be synchronized or operated in sequential flash patterns at any frequency between 1 and 4 Hz, and sequential patterns automatically update based on global positioning satellite (GPS) locations displayed in the control interface. A successful field demonstration of the system verified that its functions were viewed favorably by transportation safety personnel.
Rea, Mark S., Skinner, Nicholas P., Bullough, John D.
Ultrathin Endoscope Captures Neurons Firing Deep in the BrainTBMG-297497/1/2018
Researchers have developed an endoscope as thin as a human hair that can image the activity of neurons in the brains of living mice. Because it is so thin, the endoscope can reach deep into the brain, giving researchers access to areas that cannot be seen with microscopes or other types of endoscopes.
Lens-Free Fluorescent MicroscopeTBMG-297417/1/2018
Rice engineers have developed a wide-field microscope thinner than a credit card, small enough to sit on a fingertip and capable of micrometer resolution over a volume of several cubic millimeters.
Guidance on Mitigation Strategies Against Laser Illumination EffectsARP6378 (Current)6/2/2018
This document is intended to give guidance to users, regulators and persons in the aviation field who may be affected by the potential visual interference effects of lasers aimed at aircraft by the general public. The potential effects include startle (distraction, disruption, disorientation, and operational incapacitation), glare, and flashblindness. This document provides mitigation strategies against such effects, including operational procedures, pilot education, and the use of Laser Glare Protection. Prevention of harm from laser eye injuries is discussed but is not a focus of this document, due to the extremely low likelihood of injurious levels of laser light in typical aircraft illumination scenarios. Devices for detecting and reporting hazardous laser illuminations are briefly described in Appendix D, but are not a focus of this document. Some information in this document may also be useful for non-aviation users, such as persons driving vehicles. Additional information can be found in ANSI Z136.6, “Safe Use of Lasers Outdoors”.
G10-OL Operational Laser Committee
Studying Pilot Cognition in Ship-Based Helicopter Landing Maneuvers1F-0074-2018-127435/14/2018
ABSTRACT Shipboard-landing maneuvers in rotorcraft piloting involve a number of unique challenges. Such maneuvers can be cognitively demanding even for experienced rotorcraft pilots. To minimize risk, these maneuvers are conducted within well-defined boundaries related to weather and visibility. In order to expand this envelope, technological aids are being proposed to augment decision making capabilities and reduce pilot workload without compromising safety. Our paper reports a cognitive task analysis, which involved interviews with four rotorcraft pilots, who were experienced in shipboard-landing maneuvers. Our results reveal points of high cognitive load, where expertise plays a critical role. We have articulated our understanding on why pilots are faced with difficulties during these critical points, which led us towards design recommendations and system requirements for technological aids. We have also identified a number of system limitations and quantities of interest, which may be useful in defining safety thresholds.
Minotra, Dev, Feigh, Karen
Tip Vortex Measurements on a Cycloidal Rotor Blade at Ultralow Reynolds Numbers - Lichten Award Runner-Up PaperF-0074-2018-126805/14/2018
ABSTRACT This study provides the first in-depth analysis of the formation, strength, and convection of cycloidal rotor tip vortices. The blade force and PIV-based tip-vortex measurements were conducted for different blade aspect ratios and pitch kinematics in water at a chord Reynolds number of 18,000. Two phase-locked PIV configurations were utilized to investigate the flow field induced by the cyclorotor blade: (1) a laboratory-fixed field of view to enable investigation of vortex development at increasing vortex ages, and (2) a blade-fixed field of view to investigate the early development of the wingtip vortex at fixed 2° vortex age for varying azimuthal locations. The instantaneous blade force measurements on the cycloidal rotor showed a decrease in lift coefficient with decreasing blade aspect ratio. This is due to the higher peak swirl velocity of the tip vortex produced by the low AR blade, thereby resulting in higher induced downwash along the blade span. The aspect ratio of the blade did not affect the shape of the vortex convection trajectory, however, the rate of downward convection increased with increasing aspect ratio due to the higher thrust produced. The tip vortices showed self-similarity in both the velocity and the circulation profiles. The measurements indicate that the core-radius of the vortex experiences a logarithmic growth and the swirl velocity experiences a logarithmic decay, with vortex age due to viscous diffusion. When compared to previous helicopter rotor studies, the observed vortex dynamics from the present study exhibit increased viscous diffusion, likely due to the significantly lower Reynolds number. The tip vortex strength varied cyclically with blade azimuthal location due to the cyclic variation of blade pitch angle and the dynamic virtual camber effects. The periodic variation in tip vortex strength leads to a periodic variation in the induced flow velocity on the blade.
McElreath, James, Benedict, Moble, Tichenor, Nathan
Multimodal Cueing and Assessment of Pilot Engagement During Low Level FlightF-0074-2018-127475/14/2018
ABSTRACT Low-level flight missions can be complex, at times requiring any or all of the following: maneuvering and navigating over challenging terrain, scanning for hostile or friendly units, operation in degraded visibility, radio communications, and decision-making in uncertain and dynamics environments. These conditions, and time, will affect mental workload (MWL) and performance. While direct performance measurements are normally available, information on pilot workload must either be obtained through (intrusive) subjective measures directly from the pilot, or inferred using indirect measurements. Performance can affect MWL, and MWL can affect performance - as the pilot generally perceives and responds to task performance through display interfaces, these displays can be used to manage and balance the tradeoff between MWL and performance. This paper presents the work of a collaborative project between US and Israel whose objectives are to develop a multimodal integrated cueing environment for near-earth helicopter operations, and to validate measures for assessing pilot workload for real-time and post-mission applications. A first simulation experiment was conducted that examined 1) visual cueing depicting both predicted terrain slope and aircraft height-above-ground, and 2) spatial (3D) auditory cueing for depicting predicted deviation from desired height-above-ground and impending collision with terrain. Collected Measures included altitude error, control rate and Bedford rating. Initial results indicate that synergistic visual and auditory cueing can enhance performance, therefore could be used to reduce pilot workload while sustaining performance. A second simulation experiment was designed to assess MWL and task engagement under different workload levels encountered during a low-level mission that included the following conditions: unlimited vs. degraded visibility, presence or absence of obstacles and/or targets and terrain difficulty. Two local measures of workload were favored over a global measure: (1) oculomotor behavior, including the Index of Cognitive Activity (ICA) and (2) pilot's momentary behavior (micro-performance). Preliminary results show promise for using some of these measures as real-time indicators of pilot workload and engagement. The results of these two experiments will provide a framework for the development and evaluation of future workload-adaptive multimodal display concepts for helicopter operations during low-level flight.
Bachelder, E., Godfroy-Cooper, M., Kahana, A., Rottem-Hovev, M., Miller, J.D.
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