Browse Topic: Measurements
This SAE Recommended Practice establishes the test procedure, environment, instrumentation, and data analyses for comparing interior sound level of passenger cars, multipurpose vehicles, and light trucks having gross vehicle weight rating (GVWR) of 4540 kg (10 000 lb) or less. The test procedure is characterized by having fixed initial conditions (specified initial vehicle speed and gear selection at the starting point on the test site) to obtain vehicle interior sound measurement during road load operation over various road surfaces at specified constant speeds. The measurement data so derived is useful for vehicle engineering development and analysis
This SAE Recommended Practice is intended for use in testing and evaluating the approximate performance of engine-driven cooling fans. This performance would include flow, pressure, and power. This flow and pressure information is used to estimate the engine cooling performance. This power consumption is used to estimate net engine power per SAE J1349. The procedure also provides a general description of equipment necessary to measure the approximate fan performance. The test conditions in the procedure generally will not match those of the installation for which cooling and fuel consumption information is desired. The performance of a given fan depends on the geometric details of the installation, including the shroud and its clearance. These details should be duplicated in the test setup if accurate performance measurement is expected. The performance at a given air density and speed also depends on the volumetric flow rate, or the pressure rise across the fan, since these two
Vehicle chassis design can take great advantage from a virtual design approach, as it helps tackle the complexity of modern machines, bringing benefits in performance, development cost, and lead-time. For specific applications such as construction or defense vehicles, the simulation design chain may lack significant input model bricks due to the physical limitations of existing test equipment which limit their ability to characterize the large components and extreme loading conditions (high loads, large torques, extreme slip angles. etc.). Michelin SIMIX proposes / develops an innovative solution to fill the gap by combining physical real world measured data with virtual measurements, allowing the creation of digital models relevant to the full usage perimeter
A research team at The University of Texas at Austin created a noninvasive electroencephalogram (EEG) sensor that was installed in a Meta VR headset that can be worn comfortably for long periods. The EEG measures the brain’s electrical activity during the immersive VR interactions
A wearable health monitor can reliably measure levels of important biochemicals in sweat during physical exercise. The 3D-printed monitor could someday provide a simple and non-invasive way to track health conditions and diagnose common diseases, such as diabetes, gout, kidney disease or heart disease
New Scale Technologies Victor, NY
Light measurement devices called optical frequency combs have revolutionized metrology, spectroscopy, atomic clocks, and other applications. Yet challenges with developing frequency comb generators at a microchip scale have limited their use in everyday technologies such as handheld electronics
If an external force with changing amplitude acts on an elastic medium such as a gas, a liquid or a solid, an undulating propagation of pressure and density fluctuation occurs in space and time, starting from the point where the force is applied. This is known as sound. The frequency of sound waves ranges from a few hertz (Hz) up to several gigahertz (see Figure 1). Infrasound, the sound humans cannot hear, lies at frequencies below 16 Hz. It is followed by the hearing range, which reaches up to 20 kHz. Ultrasonic waves, which cannot be heard, lie in the frequency range from 20 kHz to 1.6 GHz, which equals 16 billion cycles per second. A prominent application example in medical technology is the use of ultrasound for diagnostic imaging techniques. In industry and research, ultrasound is mainly used in measurement technology, where sound waves with low power are used. The intensity of the sound describes the power that hits a certain surface. If it exceeds 10 W/cm2, we speak of power
This recommended practice contains dimensions and tolerances for spindles in the interface area. Interfacing components include axle spindle, bearing cones, bearing spacer, and seal. This recommended practice is intended for axles commonly used on Class 7 and 8 commercial vehicles. Included are SAE axle configurations FF, FL, I80, L, N, P, R, U, and W
The optimization and further development of automated driving functions offers great potential to relieve the driver in various driving situations and increase road safety. Simulative testing in particular is an indispensable tool in this process, allowing conclusions to be drawn about the design of automated driving functions at a very early stage of development. In this context, the use of driving simulators provides support so that the driving functions of tomorrow can be experienced in a very safe and reproducible environment. The focus of the acceptance and optimization of automated driving functions is particularly on vehicle lateral control functions. As part of this paper, a test person study was carried out regarding manual vehicle lateral control on the dynamic vehicle road simulator at the Institute of Automotive Engineering. The basis for this is the route generation as a result of the evaluation of curve radii from several hundred thousand kilometers of real measurement
This SAE Aerospace Recommended Practice (ARP) provides guidance on the engine performance parameters that may be selected by airframe and engine manufacturers, and used by a pilot or operator, to monitor the thermodynamic health of a turboshaft engine installed in a rotorcraft and the measurement system accuracies desired. Different accuracies may be required for in-flight operations such as engine control
When dealing with the structural behavior of a car body, analyzing the dynamic distortion in all body closure openings in a complete vehicle, provides a better understanding of the body characteristics compared to traditional static load cases such as static torsional body stiffness. This is particularly relevant for non-traditional vehicle layouts and electric vehicle architectures where mass distribution and in particular battery mass and stiffness play a completely different effect with respect to the internal combustion engine vehicles. A methodology typically adopted to measure the body response, e.g. when driving a vehicle on a rough pavé road, is the so-called Multi Stethoscope (MSS). The MSS is measuring the distortion in each body closure opening in two diagonals. During the virtual development, the distortion is described by the relative displacement in diagonal direction in time domain using a modal transient analysis. The results are shown as Opening Distortion Fingerprint
When traveling in an open-jet wind tunnel, the path of an acoustic wave is affected by the flow causing a shift of source positions in acoustical maps of phased arrays outside the flow. The well-known approach of Amiet attempts to correct for this effect by computing travel times between microphones and map points based on the assumption that the boundary layer of the flow, the so-called shear layer, is infinitely thin and refracts the acoustical ray in a conceptually analogy to optics. However, in reality, the turbulent nature of both the not-so-thin shear layer and the acoustic emission process itself causes an additional smearing of sources in acoustic maps, which in turn causes deconvolution methods based on these maps – the most prominent example being CLEAN-SC – to produce certain ring effects, so-called halos, around sources. In this paper, we intend to cast some light on this effect by describing our path of analyzing/circumventing these halos and how they are linked to the
With the increasing importance of electrified powertrains, electric motors and gear boxes become an important Noise Vibration & Harshness (NVH) source especially regarding whining noises in the high frequency range. Engine encapsulation noise treatments become often necessary and present some implementation, modeling as well as optimization issues due to complex environments with contact uncertainties, pass-throughs and critical uncovered areas. Relying purely on mass spring systems is often a too massive and relatively unefficient solution whenever the uncovered areas are dominant. Coverage is key and often a combination of hybrid backfoamed porous stiff shells with integral foams for highly complex shapes offer an optimized trade-off between acoustic performance, weight and costs. A dedicated experimental set-up has been designed in order to measure both structureborne and airborne NVH performances of engine encapsulation insulators applied on an engine casing placed in a coupled
While conventional methods like classical Transfer Path Analysis (TPA), Multiple Coherence Analysis (MCA), Operational Deflection Shape (ODS), and Modal Analysis have been widely used for road noise reduction, component-TPA from Model Based System Engineering (MBSE) is gaining attention for its ability to efficiently develop complex mobility systems. In this research, we propose a method to achieve road noise targets in the early stage of vehicle development using component-level TPA based on the blocked force method. An important point is to ensure convergence of measured test results (e.g. sound pressure at driver ear) and simulation results from component TPA. To conduct component-TPA, it is essential to have an independent tire model consisting of wheel-tire blocked force and tire Frequency Response Function (FRF), as well as full vehicle FRF and vehicle hub FRF. In this study, the FRF of the full vehicle and wheel-tire blocked force are obtained using an in-situ method with a
Though modal analysis is a common tool to evaluate the dynamic properties of a structure, there are still many individual decisions to be made during the process which are often based on experience and make it difficult for occasional users to gain reliable and correct results. One of those experience-based choices is the correct number and placement of reference points. This decision is especially important, because it must be made right in the beginning of the process and a wrong choice is only noticeable by chance in the very end of the process. Picking the wrong reference points could result in incomplete modal analysis outcomes, as it might make certain modes undetectable, compounded by the user's lack of awareness about these missing modes. In the paper an innovative approach will be presented to choose the minimal number of mandatory reference points and their placement. While other approaches use results of numerical simulations or rely on a visual evaluation of measurement
The photochemical etching (PCE) process is distinguished by its capacity to fabricate metal parts with unparalleled accuracy. This process sidesteps the typical stresses and deformations linked to conventional metal-working, like stamping or laser cutting, which can compromise material integrity. Such fidelity is crucial in the manufacture of components for thermal management systems, where material integrity and component precision are non-negotiable for ensuring effective heat creation or dissipation. PCE’s ability to craft parts with smooth, burr-free edges and exact dimensions means heat management components work more effectively, bolstering the reliability and extending the service life of micro electronic devices
For decades, people with diabetes have relied on finger pricks to withdraw blood or adhesive microneedles to measure and manage their glucose levels. In addition to being painful, these methods can cause itching, inflammation and infection
Severe problem of aerodynamic heating and drag force are inherent with any hypersonic space vehicle like space shuttle, missiles etc. For proper design of vehicle, the drag force measurement become very crucial. Ground based test facilities are employed for these estimates along with any suitable force balance as well as sensors. There are many sensors (Accelerometer, Strain gauge and Piezofilm) reported in the literature that is used for evaluating the actual aerodynamic forces over test model in high speed flow. As per previous study, the piezofilm also become an alternative sensor over the strain gauges due to its simple instrumentation. For current investigation, the piezofilm and strain gauge sensors have mounted on same stress force balance to evaluate the response time as well as accuracy of predicted force at the same instant. However, these force balance need to be calibrated for inverse prediction of the force from recorded responses. A reliable multi point calibration
This AIR was prepared to inform the aerospace industry about the electromagnetic interference measurement capability of spectrum analyzers. The spectrum analyzers considered are of the wide dispersion type which are electronically tuned over an octave or wider frequency range. The reason for limiting the AIR to this type of spectrum analyzer is that several manufacturers produce them as general-purpose instruments, and their use for EMI measurement will give significant time and cost savings. The objective of the AIR is to give a description of the spectrum analyzers, consider the analyzer parameters, and describe how the analyzers are usable for collection of EMI data. The operator of a spectrum analyzer should be thoroughly familiar with the analyzer and the technical concepts reviewed in this AIR before performing EMI measurements
Most heavy trucks should be fully electric, using a combination of batteries and catenary electrification, but heavy trucks requiring very long unsupported range will need chemical fuels. Hydrogen is the key to storing renewably generated electricity chemically. At the scale of heavy trucks, compressed hydrogen can match the specific energy of diesel, but its energy density is five times lower, limiting the range to around 2,000 km. Scaling green hydrogen production and addressing leakage must be priorities. Hydrogen-derived electrofuels—or “e-fuels”—have the potential to scale, and while the economic comparison currently has unknowns, clean air considerations have gained new importance. The limited supply of bioenergy should be reserved for critical applications, such as bioenergy with carbon capture and storage (BECCS), aviation, shipping, and road freight in the most remote locations. Additionally, there are some reasons to prefer ethanol or methanol to diesel-type fuels as they are
Items per page:
50
1 – 50 of 1213