Digital Speedometers Research Articles

Speedometer-reading performance of senior drivers with cognitive impairment: a comparison of analogue and digital speedometers.

With the deterioration of cognitive functions, the capability to obtain information with speed, one of the essential elements needed to perform safe driving, may be impacted. We aimed to compare the legibility of analogue and digital speedometers for senior drivers with cognitive impairment, and examined the demographic, cognitive, and driving-related variables that predict their speedometer-reading performance. A total of 50 senior drivers with cognitive impairment were investigated and asked to complete an office-based speedometer-reading test using an iPad. Two general types of speedometers (analogue and digital) were tested in this study. The age of the participants ranged from 61 to 92 years (mean (SD), 79.10 (6.973)), and 29 were male. The mean (SD) score of the Mini-Mental State Examination was 22.48 (6.089). The median (QL , QU ) scores of the analogue and digital speedometer-reading tests were 4 (4, 5.25) and 6 (6), respectively. Based on the result of the Wilcoxon signed-rank test, the score of the digital speedometer-reading test was significantly higher than that of the analogue one (Z=4.399, P < 0.001). The results of multiple linear regression analyses show that the scores of the Mini-Mental State Examination (β=0.358, P=0.025), and the trail-making test-A (β=-0.443, P=0.006) predicted the digital speedometer-reading performance, and they together explain 54.7% of the total variance. A digital speedometer was found to be easier for absolute value reading for senior drivers with cognitive impairment, compared to an analogue speedometer. Senior drivers with subjective cognitive decline may also have impairments in obtaining the speed information through an analogue speedometer. General cognitive function and attention may influence the speed-reading performance on the digital speedometer.

Performance control of root piles using a digital odometer

Root piles are injected and installed during mortar shaft construction, using pressures of up to 500 kPa. The executive control is typically done through static load testing, an expensive and time-consuming method. Static load tests on eight controlled piles (diameters between 310 mm and 410 mm) were performed, aiming at evaluating pile ultimate load. This study suggests an innovative, non-destructive approach to validate root pile field performance, using a digital speedometer connected to the drilling rig’s rotating head. The proposed method monitors variables related to bearing capacity during pile installation and proposes an empirical equation to estimate the ultimate bearing capacity of root piles. For the assessed piles, the predictions obtained with the proposed equations agreed fairly well with results from static load tests, proving it as a feasible and helpful option for the executive control of root piles, especially when load tests are not available.

Reading of the speedometer value in elderly drivers with cognitive impairments: A comparison of analog and digital speedometer

AbstractBackgroundWith cognitive functions deteriorated, the capability to get the information of speed, one of the essential element needed to perform safe driving1, may be influenced. We aim to investigate the reading of the speedometer (SM) values in elderly driver with cognitive impairments by comparing the recognition of analog and digital SM values, and examine its correlation with cognitive functions.MethodsElderly subjects with driving experience who visited the outpatient neurology clinic in the Kyoto university hospital for cognitive complaints from July 2018 to December 2019 were investigated. Cognitive tests were carried out, as well as a test asking participants to read the speed values of analog SM and digital SM presented on the iPad within the time limit.ResultsAmong 48 participants slightly more than half of them returned their driving licenses (retired drivers) whereas 22 still hold a valid driving license (current drivers). Based on the result of Wilcoxon test, among all participants the result of reading test of digital SM had significant higher scores than analog SM (Z=‐3.996, p&lt;0.0001). According to the Mann‐Whitney U test, there was no significantly different about their reading ability of both analog and digital SM values between current drivers and retired drivers. Additionally, the reading ability of digital SM was significantly correlated with the score of Mini‐mental state examination, block design test and clock drawing test.ConclusionsAmong elderly drivers with cognitive impairments, it was shown that digital SM was easier to read than analog SM. This newly gained information provides an innovative insight to the design of SM. Reference: Francois M, Osiurak F, Fort A, Crave P, Navarro J. Analogue versus digital speedometer: effects on distraction and usability for truck driving. European Conference on Human Centred Design for Intelligent Transport Systems; 2016‐06‐30, 2016; Loughborough, France.

Information technology for remote forced vehi-cle speed limits to improve road safety

Problems. Overcoming the consequences of traffic accidents places a heavy burden on the country's health and social services. The International Transport Forum has developed the report “Striving for Zero: High Tasks and a Systematic Approach to Traffic Safety”. Forum experts consider non-compliance with the high-speed regime on roads to be a key problem in the growth of road accidents, and the use of information technologies is one of the ways to reduce accidents. Goal. Based on the analysis, we formulated the goal of the study, which consists in creating a method and device for remote forced speed limits (RFSL) of vehicles on roads in the city and outside it in accordance with the speed limit adopted at this place. The task of this article is to formulate a concept for improving road safety in Ukraine in terms of bringing vehicle speeds to the maximum allowable values for these roads (the concept is outlined and justified), as well as developing a functional diagram of a device for remote forced vehicle speed limitation. Methodology . The analytical method is research of existing systems that can remote forced speed to limit. The method of synthesis is creation the structural scheme of a new system, based on the advantages and disadvantages of analyzed systems. Results . A method of improving road safety by remote forced speed limits of cars on roads within the city and outside them in accordance with the accepted speed limit in this place is the constant transmission over mobile networks or any other communication signal carrying information about the restrictions speed in a specific place on a specific highway. This signal after reception is processed in the microprocessor control system of fuel supply to the car engine according to a certain algorithm for the purpose of maintenance of a car speed, which does not exceed the value of restriction. Moreover, the driver of the vehicle could not, even if he wanted to, compromise such a restriction. Originality . The method of remote forced speed limitation of the car works as follows. The GSM receiver (possibly another radio receiver) constantly receives a signal that carries the value of the speed allowed on this road. In a microprocessor control unit (MCU), this value is compared to a signal from a digital speedometer or speed sensor, which is the current value of the vehicle speed. The inconsistency of these two signals or exceeding the speed of the car over the allowable speed on this road is the basis for recalculation (reduction) according to the programmed algorithm by the MCU unit of the amount of fuel required to feed the injector, as well as to reduce the duration of injectors. Reducing the fuel supply to the engine cylinders lowers the speed of the car to the acceptable values. Practical value . Functional schemes of devices for realization of the offered way on the basic types of control systems of the engine in modern cars are developed. As an example, a generalized universal functional diagram of a device for remote forced limitation of vehicle speed is given. Key words . traffic safety, speeding, remote forced vehicle speed limit, microprocessor, controller.

Digital Speedometer using Arduino Board for Formula Student Cars

Digital Speedometer using Arduino Board for Formula Student Cars

Speckle Observations and Orbits of Multiple Stars

Abstract We report results of speckle-interferometric monitoring of visual hierarchical systems using the newly commissioned instrument NN-EXPLORE Exoplanet and Stellar Speckle Imager at the 3.5 m WIYN telescope. During one year, 390 measurements of 129 resolved subsystems were made, while some targets were unresolved. Using our astrometry and archival data, we computed 36 orbits (27 for the first time). Spectro-interferometric orbits of seven pairs are determined by combining positional measurements with radial velocities measured, mostly, with the Center for Astrophysics digital speedometers. For the hierarchical systems HIP 65026 (periods 49 and 1.23 yr) and HIP 85209 (periods 34 and 1.23 yr) we determined both the inner and the outer orbits using astrometry and radial velocities and measured the mutual orbit inclinations of 11.°3 ± 1.°0 and 12.°0 ± 3.°0, respectively. Four bright stars are resolved for the first time; two of those are triple systems. Several visual subsystems announced in the literature are shown to be spurious. We note that subsystems in compact hierarchies with outer separations less than 100 au tend to have less eccentric orbits compared to wider hierarchies.

Digital Speedometers and Wireless Indicator Lights on Cyclist Jackets

Abstract – Bicycles has become the best solution to be able to reduce the level of congestion for the citizens of the world. Cycling is an activity carried out by someone to be able to go from place to destination and cycling has also become a hobby for some people. Even so, bicycles also experience infrastructure problems, namely bicycle lanes which are still rarely available. Some countries in the world have not fully provide special lanes for bicycle users. This causes bicycle users to use highways that are more often used by other vehicles. And it can cause accidents for bicycle users. Therefore, in the implementation of the wireless indicator lights on this jacket, the author wants to provide a better solution to overcome this problem, that is by combining indicator lights with jackets so that it can function to signal to other road users. In Addition, the author also designed a digital speedometer that can later appear on the LCD screen (liquid crystal display). For this speedometer, by placing a magnetic sensor on the forks as a magnetic speed reader placed on the bicycle spokes. For indicator lights on this jacket, the input uses a touch sensor and brake levers will be attached to the front of the bike through the bluetooth master transmission system and the bluetooth slave on the jacket, so the indicator light on the jacket will light up and form the right, left or stop direction and will be displayed on the LCD with the digital speedometer.Keyword : Speedometer, Bluetooth, Bicycle, Indicator Light, Wireless

Digital, analogue, or redundant speedometers for truck driving: Impact on visual distraction, efficiency and usability

Existing literature does not draw conclusions as to which speedometer type is better for truck driving. A digital speedometer would be more beneficial when obtaining absolute and relative readings, while an analogue speedometer would be more efficient and less distracting when detecting dynamic speed changes. Redundant speedometers, which simultaneously present digital and analogue speedometers, appear increasingly in vehicles, but no information is available on their ergonomic qualities. This study compared three speedometers: digital speedometers, analogue speedometers, and redundant speedometers. This study compared the efficiency, usability and visual distraction measures for all three types of speedometers in a simulated truck driving setting. The task-dependant results were confirmed for the digital and analogue speedometer. The redundant speedometer combined the benefits of each type presented separately, which highlights interesting theoretical and applied implications.

Biomechanical Analysis at the Start of Bobsleigh Run in Preparation for the 2018 Pyeongchang Winter Olympics

Objective: The bobsleigh shoes used in the start section are one of the most important equipment for improving the competition. Despite the importance of the start section, there are no shoes that are specific for bobsleigh athletes in Korea and Korean athletes have to wear sprint spike shoes and practice the start instead of wearing bobsleigh shoes. The objective of the present study was to provide data for improving the performance of Korean bobsleigh athletes by investigating the differences in their split time, plantar pressure, and forefoot bending angle based on skill levels at the start of a run under the same conditions as training conditions. Method: Six Korean bobsleigh athletes were divided into two groups, superior (n=3) and non-superior (n=3). A digital speedometer measured the split time at the start; the Pedar-X system (Novel, Germany) measured plantar pressure. Plantar pressures and split times were measured as the athletes pushed a bobsleigh and sprinted at full speed from the start line to the 10-m mark on the bobsleigh track. An ultra-high-speed camera was used to measure the forefoot bending angle during the start phase. Results: Significant between-group differences were found in split times (p<.000; superior = 2.38 s, non-superior = 2.52 s). The superior group had a larger rearfoot (p<.05) contact area, maximum rearfoot force (p<.01), and a larger change in angles 3 and 4 (p<.05). Conclusion: At the start of a bobsleigh run, proper use of the rearfoot for achieving effective driving force and increasing frictional resistance through a wider frictional force can shorten start time.

ADVANCED CONTROL SYSTEMS IN TWO WHEELER AND FINDING THE COLLISION SITE OF THE VEHICLE USING GSM

In the earlier days, vehicles such as Motorbikes hardly had Mechanical support in all concerns, in the recent past the development in Electronic devices in Motorbikes are evolving, with components such as E-breaks, Digital speedometers, etc. and most interesting from an engineering point of view, dealing with motorcycle dynamics is more complex than it is for four wheeled vehicles. In fourwheeled vehicles, electronic stability control (ESC) was introduced in the recent past to improve passengers’ safety in critical driving conditions and it is now part of most commercial cars. For two-wheeled vehicles, the design of such a control system is an open problem, and it constitutes quite a challenging task due to the complexity of two-wheeled vehicles dynamics and to the strong interaction between the vehicle and the driver, so to encourage this scheme I am Designing an advanced electronic active stability control system with ABS assistance for e-bikes providing the much needed vehicle roll stability control in situations such as high speed cornering etc. Designing a system that, in any case of emergency situation such as crashing, will send the bicycle accident location to nearby hospitals/emergency services with the assistance of GSM

위험운전판단장치를 이용한 사업용자동차(버스)의 운전행태분석

운전자의 인적요인분석을 위한 기초자료를 제공하는 디지털 운행기록계에서는 GPS 속도, 방위각, RPM정보 등 극히 제한된 운행정보만을 기록하여 실제 운전자의 운전행태를 분석하는 데는 많은 한계가 있다. 또한, 현재 상업화가 활발히 이루어지고 있는 차량용 블랙박스는 운전자의 운전행동보다는 차량에 대한 위험사항을 기록하고 있는 방식으로서 운전자의 실제 운전행태를 분석하기에는 많은 문제점을 보이고 있다. 따라서 기존의 교통안전관련 연구들을 살펴보면 인적요인분석에 필요한 운전자의 위험운전분석이 극히 제한적으로 이루어져 있는 현실이다. 이에 본 연구에서는 사업용자동차의 위험운전유형과 각 운전유형을 결정하는 임계치를 이용하여 버스운전자의 운전행태를 분석하였다. 또한, 버스운전자에게 위험운전에 대해 단말기를 통해 실시간으로 경고정보를 자동 제공하여 실시간경고정보에 따른 효과분석을 실시하였다. 운전자들의 행태분석에 대한 해석은 차량의 가속도 센서와 회전 각속도 센서의 종방향 가속도(Ax), 횡방향 가속도(Ay), 회전 각속도(Yaw rate) 등에 대한 분석을 통해 이루어졌다. Digital speedometer which is supposed to provide the basic data for analyzing human factors of drivers has a limitation for human behavior studies of drivers, because it records limited driving information including GPS velocities. Besides, Black Box, which is currently being actively commercialized in the market, records mostly vehicles' risky patterns rather than drivers' behaviors. As a result, it also shows a limit to analyze dangerous driving patterns. This study performed a risky driving study for human factor analysis. This study conducted before and after comparisons for real time warning study using a risky driving judgment device. The analysis was conducted based on Longitudinal acceleration, Lateral acceleration, and Yaw rate of vehicles.

Absolute dimensions of eclipsing binaries

CONTEXT: Accurate physical properties of eclipsing stars provide important constraints on models of stellar structure and evolution, especially when combined with spectroscopic information on their chemical composition. Empirical calibrations of the data also lead to accurate mass and radius estimates for exoplanet host stars. Finally, accurate data for unusual stellar subtypes, such as Am stars, also help to unravel the cause(s) of their peculiarities. AIMS: We aim to determine the masses, radii, effective temperatures, detailed chemical composition and rotational speeds for the Am-type eclipsing binaries SW CMa (A4-5m) and HW CMa (A6m) and compare them with similar normal stars. METHODS: Accurate radial velocities from the Digital Speedometers of the Harvard-Smithsonian Center for Astrophysics were combined with previously published uvby photometry to determine precise physical parameters for the four stars. A detailed abundance analysis was performed from high-resolution spectra obtained with the Nordic Optical Telescope (La Palma). RESULTS: We find the masses of the (relatively evolved) stars in SW CMa to be 2.10 and 2.24 solar masses, with radii of 2.50 and 3.01 solar radii, while the (essentially zero-age) stars in HW CMa have masses of 1.72 and 1.78 solar masses, radii of 1.64 and 1.66 solar radii -- all with errors well below 2%. Detailed atmospheric abundances for one or both components were determined for 14 elements in SW CMa ([Fe/H] = +0.49/+0.61 dex) and 16 in HW CMa ([Fe/H] = +0.33/+0.32 dex); both abundance patterns are characteristic of metallic-line stars. Both systems are well fit by current stellar evolution models for assumed bulk abundances of [Fe/H] = +0.05 and +0.23, respectively ([alpha/Fe] = 0.0), and ages of about 700 Myr and 160 Myr.

Studies of multiple stellar systems — III. Modulation of orbital elements in the triple-lined system HD 109648

The triple-lined spectroscopic triple system HD 109648 has one of the shortest periods known for the outer orbit in a late-type triple, 120.5 days, and the ratio between the periods of the outer and inner orbits is small, 22:1. With such extreme values, this system should show orbital element variations over a timescale of about a decade. We have monitored the radial velocities of HD 109648 with the CfA Digital Speedometers for eight years, and have found evidence for modulation of some orbital elements. While we see no definite evidence for modulation of the inner binary eccentricity, we clearly observe variations in the inner and outer longitudes of periastron, as well as in the radial velocity amplitudes of the three components. The observational results, combined with numerical simulations, allow us to put constraints on the orientation of the orbits.

Absolute Dimensions of Eclipsing Binaries. XXIII. The F-Type System EI Cephei

We report new radial velocity measurements made with the Harvard-Smithsonian Center for Astrophysics Digital Speedometers of the F-type double-lined eclipsing binary EI Cep (P = 8.4 days), in which the secondary is a metallic-line star. Using these and previous measurements from the literature, we redetermine the masses of the components to a precision of 0.4%, 4 to 5 times better than previously achieved. We also reanalyze UBV light curves for the system from the literature with modern methods to determine the radii and the effective temperatures. The resulting stellar parameters are MA = 1.7716 ± 0.0066 M⊙, MB = 1.6801 ± 0.0062 M⊙, RA = 2.896 ± 0.048 R⊙, RB = 2.329 ± 0.044 R⊙, T = 6750 ± 100 K, and T = 6950 ± 100 K. Further properties of the system are given in this paper. Both components are near the end of their main-sequence evolution, and a comparison of the observational results with theoretical evolutionary models gives excellent agreement with models using two somewhat different treatments of overshooting from the convective cores (but not with standard models). An age of 1.4 Gyr is derived for the roughly solar metallicity indicated by our low signal-to-noise ratio spectra. A precise spectroscopic determination of the metallicity of EI Cep would be very useful to place even tighter constraints on the models. The measured projected rotational velocities of the stars (13 and 17 km s-1 for EI Cep A and B, respectively) are very close to, but not quite synchronized with, the orbital motion. This is in agreement with predictions from current tidal theories, which, however, also predict that orbital circularization has not yet occurred, although we detect no significant eccentricity.

The Low-Mass Double-lined Eclipsing Binary CM Draconis: A Test of the Primordial Helium Abundance and the Mass-Radius Relation near the Bottom of the Main Sequence

view Abstract Citations (130) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Low-Mass Double-lined Eclipsing Binary CM Draconis: A Test of the Primordial Helium Abundance and the Mass-Radius Relation near the Bottom of the Main Sequence Metcalfe, Travis S. ; Mathieu, Robert D. ; Latham, David W. ; Torres, Guillermo Abstract CM Dra is the least massive main-sequence eclipsing double-lined spectroscopic binary currently known. Consequently, this system offers a unique opportunity to test stellar structure models near the bottom of the main sequence. The orbital solution of Lacy (1977) established the masses and radii of the two components with uncertainties of a few percent, but these errors are too large to distinguish between competing models. We present a new double-lined orbital solution based on 233 echelle spectra obtained with the CfA Digital Speedometers over the past 10 yr. Radial velocities for both components were determined using TODCOR, a two-dimensional correlation technique. Using Lacy's (1977) value for orbital inclination, we derive individual masses of MA = 0.2307±0.0010 and MB = 0.2136±0.0010 Msun and a mass ratio of q = 0.9260±0.0026. Using Lacy's light-curve solution and our spectroscopic orbit we derive individual radii of RA = 0.2516±0.0020 and RB = 0.2347±0.0019 Rsun. When plotted on a mass-radius diagram, the slope defined by the two components of CM Dra agrees well with the predictions of recent models. The ability to distinguish between models is limited by the uncertainties in the radii and the metal abundance. Following the analysis of Paczynski & Sienkiewicz (1984), we derive bulk helium abundances for the two components of YA = 0.32 and YB = 0.31. The uncertainty in the difference of these two helium abundances, YA - YB, is ±0.02 and depends only on the uncertainty in the ratios of the masses and radii. The uncertainty in the absolute value of these helium abundances set by the uncertainties in the luminosity (including parallax and bolometric correction), radii, ages, and masses is ±0.04. CM Dra, appears to be a member of Population II. Thus there is some promise that it will be able to provide a useful test of the primordial helium abundance. Publication: The Astrophysical Journal Pub Date: January 1996 DOI: 10.1086/176657 Bibcode: 1996ApJ...456..356M Keywords: STARS: BINARIES: ECLIPSING; STARS: BINARIES: SPECTROSCOPIC; STARS: ABUNDANCES; STARS: INDIVIDUAL CONSTELLATION NAME: CM DRACONIS; STARS: POPULATION II full text sources ADS | data products SIMBAD (2)

Can Evolution in Close Binaries Account for the Blue Stragglers in M67?

For the past 9 years we have been monitoring the radial velocities of 13 blue stragglers in the old open cluster M67. For the 9 blue stragglers with rotational velocities no larger than about 100 km s−1 we have used the CfA digital speedometers to measure more than 500 radial velocities. To get reliable velocity correlations we use synthetic rotating templates computed from a grid of Kurucz model atmospheres. Four of the blue stragglers rotate too rapidly to allow successful velocity correlations with the CfA instruments. For three of these we have used a CCD spectrograph at Kitt Peak and similar reduction procedures (Morse et al. 1991.

Surveys of Spectroscopic Binaries at the Center for Astrophysics

Abstract For more than a decade we have been measuring stellar radial velocities with three almost identical digital speedometers on telescopes in Arizona and Massachusetts. By now we have accumulated nearly 100,000 measurements with a typical precision of better than 1 km s-1. One of the main scientific applications has been surveys of binaries in several different stellar environments, to study the frequency and orbital characteristics of binaries in a variety of stellar populations. A main goal is to confront theories of binary formation and evolution with observational results. With various collaborators we have investigated the binary populations among pre-main-sequence stars, in the Hyades and M67 open clusters, and in the Carney-Latham proper-motion sample. Thus, we have data for coeval samples of binaries covering a wide range of ages. One result is clear evidence for evolution of binary orbits. The orbital period at which there is a transition from circular to eccentric orbits gets longer for older samples of binaries, presumably due to tidal circularization. Another result is that the frequency of binaries does not seem to depend on the stellar population. Binaries are just as common among the oldest stars in the halo of our Galaxy as among the younger stars in the disk.

The Effects of a Simulated Head-Up Display Speedometer on Perceptual Task Performance

This study compared the effects of simulated head-up display (HUD) and dashboard-mounted digital speedometers on key perceptual driving tasks in a simulated driving environment. Subjects were 20 male and female volunteers ranging in age from 19 to 51 years. A videotape, taken from the driver's perspective, of a car traveling along a memorized route served as the test scene. While viewing the test scene subjects performed tasks related to navigation, speed monitoring, and salient cue detection. The simulated HUD speedometer produced generally superior performance on the experimental tasks; most important, it enabled subjects to respond significantly more quickly to the salient cues. Implications for the effects of HUDs on automobile safety are discussed.