Browse Topic: Mirrors
Researchers at the Max Planck Institute for Extraterrestrial Physics have developed a new way to produce and shape large, high-quality mirrors that are much thinner than conventional space-telescope mirrors. The final product is even flexible enough to be rolled up and stored compactly inside a launch vehicle
The global market for automotive LIDAR is expected to grow from $332 million in 2022 to more than $4.5 billion by 2028. That’s solid market growth, particularly given the decades-old challenges of commercializing LIDAR that would be affordable for automotive designs. We interviewed Eric Aguilar, co-founder and CEO of Omnitron Sensors, Los Angeles, CA, to learn about a new MEMS scanning mirror that could accelerate the market adoption of LIDAR
The design and location of rear-viewing mirrors or systems, and the presentation of the rear view to the driver can best be achieved if the designer and the engineer have adequate references available on the physiological functions of head and eye movements and on the perceptual capabilities of the human visual system. The following information and charts are provided for this purpose. For more complete information of the relationship of vision to forward vision, see SAE SP-279
This SAE Recommended Practice describes methods for determining total and specular reflectance for mirrors with flat and curved surfaces and a method for determining diffuse reflectance and haze for mirrors with flat surfaces
Optical parametric oscillator (OPO) lasers test optical fibers and components to characterize the spectral response of optical components. OPO lasers are common in sophisticated test and measurement applications such as mass spectrometry, photoacoustic imaging, and spectroscopy. Now, these tunable pulsed lasers are being used to facilitate a range of tests at different wavelengths to qualify and quantify the performance of optical components such as fiber optic strands, filters, lenses, and coated mirrors
The James Webb Space Telescope’s stunning images showing previously unseen corners of the universe are possible because of the telescope’s 21-foot segmented mirror that had to unfurl on its own after launch and assemble itself in space
Light detection and ranging (LiDAR) provides the type of velocity data about objects and vehicles that are necessary to enable the type of decision-making necessary for navigation systems in autonomous vehicles. However, most LiDAR sensors that have been used in automotive and other mobility applications have been fragile, expensive and unreliable
Enriched ventilation and driver assistance systems which plays vital role in human thermal comfort and safety, are now necessities for the whole automotive sector. For faster cabin thermal comfort, air circulation around occupant’s body reveals higher cabin comfort index. In India natural and forced ventilation system is predominantly used in commercial vehicles as an economical solution for achieving interim cabin comfort over air conditioning system. Presently used forced ventilation system consist of electrically driven blower motor to remove stale air around human body which is adding alternator load and thus affects fuel economy. Remarkably, 22% of such auxiliary electrical load is taken by electrical components from engine generated power. In order to enhance cabin thermal comfort and conceivably reduce power usage, an effective air flow control system is need of hour. In the proposed new technology, the ORVM (Outside Rear View Mirror) based air cooling technique is used for
Numerical methodologies for aeroacoustic analyses are increasingly crucial for car manufacturers to optimize the effectiveness of vehicle development. In the present work, a hybrid numerical tool based on the combination of a delayed detached-eddy simulation and a finite element model, which relies on the Lighthill’s acoustic analogy and the acoustic perturbation equations, is presented. The computational aeroacoustics is performed by the software OpenFOAM and Actran, concerning respectively the CFD and the FEM. The aeroacoustic behavior of the SUV Lamborghini Urus at a cruising speed of 140 km/h has been investigated. The main aerodynamic noise phenomena occurring in the side mirror region in a frequency range up to 5 kHz are discussed. The numerical simulations have been verified against the measurements performed in the aeroacoustic wind tunnel of the University of Stuttgart, operated by FKFS. The predicted exterior noise propagation into the far field has been validated by
Thermal control coatings, i.e. coatings with different visible versus infrared emission, have been used by NASA on the Orbiter and Hubble Telescope to reflect sunlight, while allowing heat rejection via infrared emission. However, these coatings absorb at least 6 percent of the Sun’s irradiant power, limiting the minimum temperature that can be reached to about 200 K. NASA needs better solar reflectors to keep cryogenic fuel and oxidizers cold enough to be maintained passively in deep space for future missions
A gigantic furnace slowly started spinning underneath the stands of Arizona Stadium at the University of Arizona in March 2021. Fire-engine red, massive in size and resembling a sci-fi version of a Dutch oven, the furnace is the only one of its kind, and its sole purpose is to produce the world’s biggest and most advanced telescope mirrors
The investigation of vehicle soiling by improvement of vehicle parts to optimize the surrounding airflow is of great importance not only because of the visibility through windows and at mirrors but also the functionality of different types of sensors (camera, lidar, radars, etc.) for the driver assistance systems and especially for autonomous driving vehicles has to be guaranteed. These investigations and corresponding developments ideally take place in the early vehicle development process since later changes are difficult to apply in the vehicle production process for many reasons. Vehicle soiling is divided into foreign soiling and self-soiling with respect to the source of the soiling water, e.g., direct rain impact, swirled (dirty) water of other road users and own rotating wheels. The investigations of the soiling behavior of vehicles were performed experimentally in a wind tunnel and street tests. The investigations of self-soiling are assisted numerically by computational fluid
Conventional dental photography technology has had a limitation in using inconvenient tools such as mirrors and cheek retractors. Dentists require basic teeth images from various angles, such as right/left buccal and maxillary/mandibular occlusal, for dental health inspection. To acquire these images, patients feel discomfort because dentists must put a mirror into the mouth to capture the reflected teeth image through a handheld camera. Information such as tooth arrangement and the location of tooth decay can be obtained through this process. A compact intraoral dental camera can overcome the discomfort and scan the condition of teeth. However, due to the restricted depth of field and field of view, the conventional device has limitations in close-up imaging for observing tooth decay in detail and wide-angle imaging for capturing the entire arrangement of teeth
The commercial vehicle development process needs to consider the vehicle aerodynamics not only in ideal flow conditions, but also in the turbulent real world environment. The turbulent real world environment includes not only atmospheric turbulence, but also the vehicle to vehicle interactions that happen when driving around other vehicles or into and out of the wake of in/on coming vehicles. A vehicle driving into the wake of an oncoming vehicle not only experiences an increase in the total aerodynamic forces, it also experiences unsteady transient loads over the vehicle components such as windshield, mirror, sunvisor, door and side fairing. To properly design specific components, designers need to understand the magnitude of unsteady forces on various vehicle components, otherwise these components may fail which imposes warranty and safety risks. In this paper, we attempt to understand the various forces acting on the primary vehicle during a passing maneuver. The main purpose is to
The James Webb Space Telescope is set to show us some of the first stars in the universe, with its enormous and powerful mirrors capturing bits of light from more than 13 billion years ago. Meanwhile, technology developed as part of the decades-long effort to build Webb has already improved the vision of millions back on Earth by driving major improvements to LASIK eye surgery
This SAE Standard defines the safety and performance requirements for low-speed vehicles (LSVs). The safety specifications in this document apply to any powered vehicle with a minimum of four wheels, a maximum level ground speed of more than 32 km/h (20 mph) but not more than 40 km/h (25 mph), and a maximum gross vehicle weight of 1361 kg (3000 pounds), that is intended for operating on designated roadways where permitted by law
This SAE Standard defines requirements relating to the elements of design, operation, and maintenance of light utility vehicles (LUVs). The safety specifications in this document apply to any self-propelled, operator-controlled, off-highway vehicle 1829 mm (72 inches) or less in overall width, exclusive of added accessories and attachments, operable on three or more wheels or tracks, primarily intended to transport material loads or people, with a gross vehicle weight of 2500 kg (5500 pounds) or less, and a maximum design speed less than or equal to 40.23 km/h (25 mph). This document is not intended to cover go-karts (ASTM F2007-07a), fun-karts (ASTM F2011-02e1), dune buggies, and all terrain-vehicles (ATVs) complying with ANSI/SVIA 1
In this article, the method based on the combination of the acoustic perturbation equations and the statistical energy analysis has been used to simulate and optimize the interior aerodynamic noise of a large sport utility vehicle model. The reliability of the method was verified by comparing the analysis results with the wind tunnel test. Influenced by the main noise sources such as A-pillar, exterior rearview mirror, and front sidewindow, the wind noise of the model was significantly greater than that of the same class. To improve the wind noise performance, the side mirror was optimized with the method, including the minimum distance between the rearview mirror and the triangle trim cover, the angle between the rearview mirror and the front sidewindow, and the shell groove of the rearview mirror. The simulation results show that the overall sound pressure level in the car decreases by 2.12 dBA and the articulation index increases by 4.04% after optimization. The development target
The tow vehicle should be designed for towbarless push-back and/or maintenance towing of regional type aircraft as specified in 1.3. The design will ensure that the unit will safely secure the aircraft nose landing gear within the coupling system for any operational mode. The purpose of this towing procedure is to achieve a safer and faster operation than is possible with conventional towing equipment
This SAE Recommended Practice establishes boundaries for shade bands on glazed surfaces in class "A" vehicles. These boundaries are located so that the shade band can provide occupant comfort and driver vision protection from glare, with respect to solar radiation, under some lighting and driving conditions. Since shade bands transmit less visible light than adjacent glazed surfaces, the shade band boundaries establish boundaries for the driver's field of view
In partly autonomous driving such as level 2 or level 3 automatic driving from SAE international classification, the switching of the driving right between the human driver and the machine plays an important role in the driving process of vehicle [1]. In this paper, the data collected from vehicle states and the driving behavior of drivers is completed via a simulator and self-report questionnaires. A fuzzy analytic network process (Fuzzy-ANP) model is developed to evaluate the driving capability of the drivers in real time from vehicle states due to its direct inherent link to the change of the driving state of drivers Moreover, in this model, the idea of group decision and multi-index fusion is adopted. The questionnaire is required to identify the experimental results from the simulator. The results show that the proposed Fuzzy-ANP model can evaluate the driving capability of the participants in real time accurately. As a real and objective driving state from vehicle, it is a good
When it comes to long range multi-spectral optical systems, large mirrors play an integral role. Such optical systems are used for defense applications, surveillance and monitoring, as well as for certain commercial applications. For example, large mirrors may be integrated into the optical systems of aircraft like large UAVs. An interesting commercial application is the long-distance aerial monitoring of agricultural field temperature using infrared. The most commonly recognized applications for large mirrors are in the aerospace industry for satellites and telescopes
Automotive millimeter-wave radar is used extensively in vehicle active safety. The Radar Cross Section (RCS) is one of the main parameters used by the automotive radar system to detect and identify surrounding vehicles. The RCS describes the electromagnetic scattering properties of objects. This paper describes a method and equipment to measure the RCS. An automobile-grade radar is used to measure the RCS of typical vehicles. A representative distance between the radar and the vehicle was chosen based on the analysis of the RCS of passenger vehicles in different distances in the near field. A cost-effective rotating platform was developed to rotate the passenger vehicles for RCS measurement in different azimuth angles. The RCS generated by the rotating platform was analyzed and mitigated. The measurement system can record the synchronized azimuth angle and RCS measurement. Different radar types, antenna response variations, and waveforms are eliminated by a calibration method using
The SAE Recommended Practice is intended for use in measuring the radius of curvature (ROC) of spherical convex mirrors
This document specifies the minimum recommendations for Blind Spot Monitoring System (BSMS) operational characteristics and elements of the user interface. A visual BSMS indicator is recommended. BSMS detects and conveys to the driver via a visual indicator the presence of a target (e.g., a vehicle), adjacent to the subject vehicle in the “traditional” Adjacent Blind Spot Zone (ABSZ). The BSMS is not intended to replace the need for interior and exterior rear-view mirrors or to reduce mirror size. BSMS is only intended as a supplement to these mirrors and will not take any automatic vehicle control action to prevent possible collisions. While the BSMS will assist drivers in detecting the presence of vehicles in their ABSZ, the absence of a visual indicator will not guarantee that the driver can safely make a lane change maneuver (e.g., vehicles may be approaching rapidly outside the ABSZ area). This document applies to original equipment and aftermarket BSMS systems for passenger
This SAE Recommended Practice establishes limits for electrical circuits on motor vehicle safety glazing materials
This test method specifies the operating procedures for using a solar fresnel reflector apparatus for the accelerated exposure of various automotive materials
The use of sensors in advanced driver-assistance systems (ADAS) and autonomous vehicles has been accelerating over the past few years largely driven by regulatory and consumer interest in safety applications. These sensors help to prevent accidents and protect drivers by assisting with the monitoring, warning, braking, and steering tasks. As several unfortunate examples have highlighted these valuable systems can reduce safety if the sensors are not operating un-impaired. Planning for harsh weather environments is critical to the success of these systems. This study presents a fully automated workflow for an industrial side mirror geometry optimization for improved sensor performance under soiling conditions. The methodology includes CAD parametrization, multiphase simulation setup, intelligent design optimization and a detailed result analysis. All relevant aspects like external flow, geometrical fidelity and multiphase interaction are considered. A source term is applied to a fluid
Connected and automated technologies poised to change the way vehicles operate are starting to enter the mainstream market. Methods to accurately evaluate these technologies, in particular for their impact on safety and energy, are complex due to the influence of static and environmental factors, such as road environment and traffic scenarios. Therefore, it is important to develop modeling and testing frameworks that can support the development of complex vehicle functionalities in a realistic environment. Microscopic traffic simulations have been increasingly used to assess the performance of connected and automated vehicle technologies in traffic networks. In this paper, we propose and apply an evaluation method based on a combination of microscopic traffic simulation (AIMSUN) and a chassis dynamometer-based vehicle-in-the-loop environment, developed at Argonne National Laboratory. This method is applied to analyze the impact of surrounding traffic on an eco-driving vehicle
Aerodynamic technologies for light-duty vehicles were evaluated through full-scale testing in a large low-blockage closed-circuit wind tunnel equipped with a rolling road, wheel rollers, boundary-layer suction and a system to generate road-representative turbulent flow. This work was part of a multi-year, multi-vehicle study commissioned by Transport Canada and Environment and Climate Change Canada, and carried out in cooperation with the US EPA, to support the evaluation of light-duty-vehicle greenhouse-gas-emission regulations. A 2016 paper reported drag-reduction measurements for technologies such as active grille shutters, production and custom underbody treatments, air dams, ride height control and combinations of these. This paper describes an extension to that work and addresses vehicle aerodynamics in three ways. First, whole vehicle body-shaping changes were evaluated by adding older or newer generation models, representing distinct body style redesigns, of select vehicles of
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