On-board Devices Research Articles

On-board diagnostic system for vehicle state assessment

The paper presents a concept of an on-board diagnostic system for the assessment of vehicle state in critical situation. A vehicle state assessment is done by an analysis of given signals recorded by on-board devices. A vehicle state is described by providing its position, velocities, accelerations, rotations and also powetrain data related to engine and other vehicle parts in operation. The first prototype of this device has already been developed. It registers signals taken from inertial modules such as linear and angular accelerometers (gyroscopes) and geographical coordinates from GPS. The data from GPS together with the data from inertial modules are written into a text file and can then be visualized by geo-information software. Accelerometers will be used for detection of engine malfunctions using vibroacoustic signals analysis and for vehicle position identification and the support of GPS.

Stratospheric communication platforms as an alternative for space program

PurposeThe purpose of this paper is to examine the potential applications of stratospheric communication platforms (SCP), which have been recently introduced as an alternative for satellite communications.Design/methodology/approachVarious applications, solutions and services are planned by using aircraft or airship SCP, which could be classified as digital narrowband or broadband, depending on the broadband required. The platforms as base stations can provide service for fixed and mobile applications, with commercial and military solutions. Subscribers will use uplink to the platform for transmitting and receiving information, where onboard SCP switching devices will downlink to the ground station and route traffic directly to other subscribers within the same platform coverage, to another platform via optical inter‐platform links, trough heterogeneous networks including satellite or to the terrestrial telecommunications network. Each SCP can deploy an antenna for large coverage area or a multibeam antenna capable of projecting numerous spot beams within its potential coverage area.FindingsThis paper outlines the findings of fixed and mobile applications, features, testing and some specific development programs of SCP using aircraft solutions, such as SkyTower and airship solutions, such as CRL/TAO/NAL.Research limitations/implicationsParticular consideration is given to the use of SCP for delivery of future broadband, broadcast and multimedia wireless communications including research for new communication, navigation and surveillance (CNS) implications.Practical implicationsSCP will provide communication facilities that can exploit the best features for both terrestrial and satellite schemes.Originality/valueEmerging solutions of voice, data and video over IP are offered by SCPs operating in the stratosphere at altitudes of up to 25 km.

The challenges and opportunities of technological approaches to fatigue management

There are a number of different strategies to mitigate the effects of fatigue in transportation and other occupational settings. Many are centered on regulatory or organizational approaches, such as work scheduling restriction and employer screening practices. While these generally benefit safety and productivity, there are clearly limitations to these approaches. Technologies that objectively detect or predict operator fatigue may be used to effectively complement or even supplant organizational or regulatory approaches. Over the past decade and a half, there have been considerable advances in relevant technologies, including onboard devices that monitor drivers’ state or level of performance as well as devices that predict fatigue in advance of a work cycle or trip. In this paper, we discuss the challenges and opportunities for technological approaches to fatigue management, beginning with a discussion of the “ideal” system, followed by some of the general issues and limitations of current technologies. We also discuss some of the critical and outstanding issues related to the human interaction with these systems, including user acceptance and compliance. Finally, we discuss future directions in next generation technology for fatigue management.

Determination of the surface-averaged composition of the regolith of phobos by measurements of the secondary ion flux during the Phobos-Grunt mission in the MANAGA-F experiment

The onboard time-of-flight mass reflectron MANAGA-F is described which is aimed at measuring the elemental and isotopic composition of the secondary ion fluxes generated under the influence of solar wind. It is shown that by using this apparatus, the composition of the surface regolith layer averaged over a considerable area can be determined while approaching Phobos. After the landing of the spacecraft on the surface of Phobos, the measurements will be aimed at examining the local characteristics of the regolith and a new mechanism for water synthesis in the process of ion collisions. The apparatus allows for the mass of the secondary molecular ions to be detected and determined, including organic ones which arise during the bombardment of the regolith by ions of different origins. The main scientific problems to be solved using the given apparatus are considered in the paper. The working principle of the apparatus together with its analytical and technical characteristics and design particularities are presented. Information concerning the range of its applications for solving a number of challenging tasks of contemporary science is given. The MANAGA-F apparatus is shown to be the first realization of an original new-generation onboard device that has been invented, developed, and produced at the Space Research Institute of the Russian Academy of Sciences (SRI RAS).

The Influence of Noise Environment upon Voice and Data Transmission in the RF-CBTC System

The RF-CBTC (Radio Frequency-Communication Based Train Control) System is a communication system in railroad systems. The communication method of RF-CBTC system is the wireless between the wayside device and on-board device. The wayside device collects its location and speed from each train and transmits the distance from the forwarding train to the speed-limit position to it. The on-board device controlling device controls the speed optimum for the train. In the case of the RF-CBTC system used in Korea, transmission frequency is 2.4 [㎓]. It is the range of ISM(Industrial Scientific and Medical equipment) band and transmission of voice and data is performed by CDMA (Code Division Multiple Access) method. So noises are made in the AWGN (Additive White Gaussian Noise) and fading environment. Currently, the SNR (Signal to Noise Ratio) is about 20 [㏈], so due to bit errors made by noises, transmission of reliable information to the train is not easy. Also, in the case that two tracks are put to a single direction, it is needed that two trains transmit reliable voice and data to a wayside device. But, by noises, it is not easy that just a train transmits reliable information. In this paper, we estimated the BER (Bit Error Rate) related to the SNR of voice and data transmission in the environment such as AWGN and fading from the RF-CBTC system using the CDMA method. Also, we supposed the SNR which is required to meet the BER standard for voice and data transmission. By increasing the processing gain that is a ratio of chip transmission to voice and data transmission, we made possible voice and data transmission from maximally two trains to a wayside device, and demonstrated it by using Matlab program.

A Study on the Magnetic Field Intensity and BER from Wayside Device to On-board Device about the Train Speed in ATP System

Electric railway system consists of rolling stock, track, signal and catenary system. ATP system in railway signaling system is the important one grasping the position and velocity of a train. The wayside device of ATP system is installed between rails. Recently, the research about increasing train speed has been developed in total departments of the railroad systems. The study on the information transmission between on-board device and wayside device is required for increasing the train speed in the ATP system. When the train speed is increased as to same transmission distance, the problem on information transmission occurs because the transmission time is decreased. In case that the transmission distance is extended, the transmission time is decreased with respect to the train speed. Therefore, we have to define the standard magnetic field intensity as to the train speed in order to transmit correctly telegram. In this paper, the transmission distance for the telegram is suggested on the basis of the train speed. Also, the standard magnetic field intensity from the wayside device to on-board device is proposed by using transmission distance regarding the train speed in the ERTMS/ETCS system by using Matlab program. Also, BER according to the train speed is presented by calculating electric field intensity from the magnetic field intensity.

Selected Accelerations and Orbital Elements of the Goce Satellite in the Time Domain

Selected Accelerations and Orbital Elements of the Goce Satellite in the Time Domain

Orthogonal Frequency Coded SAW Sensors for Aerospace SHM Applications

National Aeronautics and Space Administration (NASA) aeronautical programs require structural health monitoring (SHM) to ensure the safety of the crew and the vehicles. Future SHM sensors need to be small, lightweight, inexpensive, and wireless. Orthogonal frequency coded (OFC) surface acoustic wave (SAW) reflectors and transducers have been recently introduced for use in communication, as well as in sensor and radio-frequency identification (RFID) tag applications (Malocha , 2004, Puccio , 2004). The OFC SAW technology approach has been investigated by NASA for possible inclusion in ground, space flight, and space exploration sensor applications. In general, SAW technology has advantages over other potentially competitive technologies, because the devices can operate in ranges from cryogenic to furnace temperature. SAW devices can also be small, rugged, passive, wireless, and radiation hard and can operate with variable frequency and bandwidth. SAW sensor embodiments can provide onboard device sensor integration or can provide integration with an external sensor that uses the SAW device for encoding the sensor information and transmission to the receiver. SAW OFC device technology can provide RFID tags and sensors with low loss, large operating temperatures, and a multiuse sensor platform. This paper will discuss the key parameters for OFC device design, which includes reflector and transducer design, coding diversity approaches, and insertion loss considerations. Examples of several OFC device sensors and RFID tags are presented to show the current state-of-the-art performance for several NASA applications. Projections for future sensor and RFID tag platform performance are discussed, along with some of the current challenges and issues of the technology.

Satellite image compression by post-transforms in the wavelet domain

This paper proposes a novel compression scheme with a tunable complexity-rate-distortion trade-off. As images increase in size and resolution, more efficient compression schemes with low complexity are required on-board Earth observation satellites. The standard of the Consultative Committee for Space Data Systems (CCSDS) defines a strip-based compression scheme with the advantages of a low complexity and an easy rate control [CCSDS, Image Data Compression Recommended Standard CCSDS 122.0-B-1 Blue Book, November 2005]. However, future mission specifications expect higher performance in terms of rate-distortion. The scheme proposed in this paper intends to perform better than the CCSDS standard while preserving low complexity and easy rate control. Moreover, to comply with existing on-board devices, the proposed core compression engine still uses the wavelet transform but in association with a linear post-processing inspired from the bandelet transform. The post-transform decomposes a small block of wavelet coefficients on a particular basis. This basis is adaptively selected within a predefined dictionary by rate-distortion optimization. The computational complexity depends upon the dictionary size and of the basis structure. An extremely simple dictionary, reduced to the Hadamard basis, is proposed. The post-transform efficiency is illustrated by experiments on various Earth observation images provided by the French Space Agency (CNES).

Onboard motorcycle plasma-assisted catalysis system – Role of plasma and operating strategy

Abstract Hydrogen as a supplementary fuel can be blended with gasoline/diesel to improve engine performance and reduce pollutant emission. A compact plasma-assisted catalysis (PAC) reformer designed as an onboard device for motorcycle was used to convert methane into a hydrogen-rich gas which then mixed with gasoline to fuel motorcycle engine. Performance of the PAC reformer for motorcycle operated in the cold start, normal idle and normal cruising periods were evaluated experimentally. In the cold start period, the catalyst-bed temperature can rise from 25 °C to >500 °C in 14 s with the assistance of plasma. In the normal operation mode, the goal is to achieve either a high power output in the cruising mode or a low energy consumption in the idle mode. With the power consumption of 32.4 W for plasma, the reforming efficiency was increased by 2%–16% at given conditions. Engine test results showed that the PAC reformer not only reduced CO and HC concentrations by 42% and 21%, respectively, but also enhanced the engine performance, e.g., the brake power increased by 14% and the gasoline consumption by 33%. This study confirmed that in the idle mode, the plasma can be turned off without sacrificing the PAC's performance. Overall speaking, the plasma plays a great role in the cold start, be minor in the cruising mode, and trivial in the idle mode.

Extension of Thru de-embedding technique for asymmetrical and differential devices

Accurate radiofrequency (RF) characterisation of on-chip or on-board devices often requires de-embedding to account for parallel and serial parasitics associated with bonding pads and interconnects. It is usually performed by well-known techniques such as Open-Short, Pad-Open-Short or Thru. However, these approaches or alternative techniques employing more standards assume a specific lumped-element model of bonding structures. This reduces de-embedding accuracy at higher frequencies. The Thru de-embedding technique is analysed in this paper and it is shown that under certain conditions de-embedding can be performed without modelling of the internal structure of the thru standard. The possibility to obtain the parameters of an error network by using a single test structure reduces significantly the costs of manufacturing standards and saves the measurement time. Further, an extension of the Thru technique is introduced. It is shown that at the expense of one more measurement, it is possible to characterise the system without additional assumptions. The presented method can be applied, for example, for de-embedding of fixtures with different connectors on either side. Additionally, the extension of Thru technique for de-embedding of differential devices is proposed. The paper verifies the extension for asymmetrical structures by simulation performed using Sonnet electromagnetic field solver in the frequency range 1-40-GHz. Finally, the extension for differential devices is verified by measurement in the frequency range 1-20-GHz and comparison of the results with Open-Short de-embedding technique.

Estimation of dynamic characteristics of the International Space Station from measurements of microaccelerations

We describe the results of determining the mass of the International Space Station using the data of MAMS accelerometer taken during correction of the station orbit on August 20, 2004. The correction was made by approach and attitude control engines (ACE) of the Progress transporting spacecraft. The engines were preliminary calibrated in an autonomous flight using the onboard device for measuring apparent velocity increment. The method of calibration is described and its results are presented. The error in station mass determination is about 1%. The same data of MAMS and similar data obtained during the orbit correction on August 26, 2004 were used for the analysis of high-frequency vibrations of the station mainframe caused by operation of the ACE of Progress. Natural frequencies of the ACE are determined. They lie in the frequency band 0.024–0.11 Hz. ACE operation is demonstrated to result in a substantial increase of microaccelerations onboard the station in the frequency range 0–1 Hz. The frequencies are indicated at which disturbances increase by more than an order of magnitude. The study described was carried out as a part of the Tensor technological experiment.

Simultaneous interaction with in-vehicle systems while turning left: comparison among three groups of drivers

The growing introduction of new technologies inside vehicles represents a set of extra information sources. Its use can interfere with the driving activity and induce performance decrements. An on-road experiment was conducted to investigate how drivers reacted to the simultaneous interaction with in-vehicle systems. Forty-eight subjects (elderly, reference and novice) participated in the tests. They were asked to interact with one (road guidance system) or two (road guidance system and mobile phone) on-board devices. Their performance was evaluated for the turn left manoeuvres and main effects of system conditions were revealed. The simultaneous interaction with both in-vehicle systems induced participants to some performance decrements on the driving task: higher number of late activations of the turning indicator; lower mean speeds before the intersection; lower values of instant speed at the beginning of the turn manoeuvre; higher steering wheel variability; activations of the braking pedal with less pressure, later, and performing a higher number of strokes; and also less glances towards important areas of the environment. No significant difference was observed for the guidance task. The comparison between driver groups' performance did not reveal enough significant differences in order to draw a general conclusion.

Energy Use and Emissions of Idling-Reduction Options for Heavy-Duty Diesel Trucks

Pollution and energy analyses of different idling-reduction (IR) technologies have been limited to localized vehicle emissions and have neglected upstream energy use and regional emissions. In light of increasing regulation and government incentives for IR, this research analyzed the full fuel cycle effects of contemporary approaches. It compared emissions, energy use, and proximity to urban populations for nine alternatives, including idling, electrified parking spaces, auxiliary power units, and several combinations of these. It also compared effects for the United States and seven states: California, Florida, Illinois, New York, Texas, Virginia, and West Virginia. U.S. average emissions impacts from all onboard IR options were found to be lower than those from a 2007-compliant idling truck. Total particulate emissions from electrified parking spaces were found to be greater than those from a 2007 truck, but such emissions generally occurred in areas with low population density. The lowest energy use, carbon dioxide emissions, and nitrogen oxide emissions are seen with a direct-fired heater combined with electrified parking spaces for cooling, and the lowest particulate-matter emissions were found with a direct-fired heater combined with an onboard device for cooling. As expected, state-to-state variations in the climate and grid fuel mix influence the impacts of the full fuel cycle from IR technologies, and the most effective choice for one location may be less effective elsewhere.

MODIS On-Orbit Spatial Characterization Using Ground Targets

The Moderate Resolution Imaging Spectroradiometer (MODIS) sensor is currently being operated on both Terra and Aqua spacecrafts. MODIS uses 36 bands arranged in four focal plane assemblies (FPAs) - visible, near infrared, short- and middle-wavelength infrared, and long-wavelength infrared. Misregistrations between spectral bands and FPAs and changes of spatial characterization on-orbit could impact the quality of science data products generated with multiple bands located on different FPAs. In this paper, an approach is presented to compute the MODIS band-to-band registration (BBR) using ground measurements. A special ground scene with unique features is selected to calculate the spatial registration along-scan and along-track. The monthly and yearly spatial deviations are calculated for the bands of both Terra and Aqua MODIS except for some ocean bands, cloud bands, and the Aqua MODIS band 6. The comparison with results derived from the spectroradiometric calibration assembly, a device operated on-orbit to track the BBR shift between any two of the spectral bands, generally shows good agreement. The measured differences between these two approaches are typically less than 100 m in the scan direction and 200 m in the track direction. This approach can provide more frequent characterization of the MODIS BBR and is extremely useful for other sensors that do not have an onboard spatial characterization device.

Visual cognitive performance of elderly people: effects on reading time of age, character size and visual distance

In this study, we conducted two experiments on visual cognitive performance in reading an on-board information device. Experiment 1: The relation between the gazing time needed for reading and the number of Kanji characters displayed was investigated, as the number of characters was changed in three steps. The gazing time was divided into preparation time and information processing time. The unit information processing speed was calculated from the amount of information read divided by the information processing time. Experiment 2: The character size was changed between three conditions (large, middle and small), and visual distance was changed between two conditions (700 and 2000 mm). The gazing time was similar to that in experiment 1. The results from these experiments are applicable to the design of user-friendly information devices, taking into account the user's age.

Information in motion: road vehicles as wireless relay stations for an ad hoc communications network

There is growing interest among automobile engineers and wireless communications researchers in the concept of a Vehicular Ad-hoc NETwork (VANET). Each motor vehicle on the road today provides a natural platform for mobile communications. When equipped with suitable on-board device, the population of vehicles in a busy area becomes a wireless network capable of relaying signals across considerable distances, without the need for a central transmitter. Among the applications so far suggested are the propagation of safety warnings such as icy road conditions, crime prevention, surveillance aimed at public security, together with less urgent passenger services, and even congestion management. To determine whether and how such a system would function, it is necessary to model two distinct kinds of network simultaneously—the road system and the wireless network. The challenge is signi-cant, not least because of the many factors involved. The authors have adapted a cellular automaton (CA) approach, which is used to investigate the relationship between communication, contention/interference and mobility. The results show how mobility a-ects network performance and how the processing gain G can be used to design e-ective coverage areas which maximize the total network throughput. Most important for safety-critical applications, a VANET can break down under congested road traffic conditions because of radio interference among the vehicles.

Identification of hydro-acoustic waves emitted from floating units during mooring tests

Identification of hydro-acoustic waves emitted from floating units during mooring tests Measurements of hydro-acoustic noise emitted from vessels are a.o. a subject of the tests carried out in the control measurement ranges of the Navy. The measurements are performed both on anchored and floating vessels. Acoustic field of vessels is changing along with their speed changing and is associated with acoustic activity of wave sources installed in vessel's hull (main engines, electric generating sets, reduction gears, pumps, shaft-lines, piping, ventilating ducts etc) as well as hydro-dynamic sources such as screw propellers and water flow around the hull [5, 7]. Vibration energy generated by the onboard devices is transferred through ship structural elements to water where it propagates in the form of hydro-acoustic waves of a wide frequency band.

Integrated Microreactor System for Gas-Phase Catalytic Reactions. 1. Scale-up Microreactor Design and Fabrication

The design and fabrication of a gas-phase microreactor that is based upon a multilayer laminate microelectronics structure is described. The reactor is a key component in an integrated system whose platform utilizes a commercial computer chassis with modular boards to perform the required process functions. The design combines knowledge from earlier laminate microstructures with new prototyping concepts for incorporation of various on-board devices. A 3-D finite element simulation model was used to identify various design improvements. The final device contains two parallel reaction channels on a chiplike die in which a 1 μm platinum film catalyst is deposited on the underside of a silicon nitride membrane. Seven platinum heaters and temperature sensors are evenly distributed along the top side of the silicon nitride membrane. Electrical contacts for the on-board control and sensing devices are achieved through various pins that are distributed around the reactor die. The experience and knowledge gained i...

Real-time multi-body formulation for virtual-reality-based design and evaluation of automobile controllers

Nowadays, modelling and simulation of vehicle dynamics play a great role in the design and evaluation of vehicle control systems, as they reduce costly and time-consuming construction of prototypes and experimentation. Multi-body simulation can be used for controller design, tuning and testing of electronic control units, optimum control, or onboard devices providing driver advice and/or actuation. This article reports on the application of a robust real-time formulation to the development of a low-cost and efficient computational framework for the design and evaluation of automobile motion controllers. The core elements of the tool are the real-time formalism for the dynamics of multi-body systems, a virtual-reality (VR) interface for human-in-the-loop simulation, and Matlab for the controllers. A detailed model of an existing prototype car has been implemented in the Fortran language, and controllers have been designed for several purposes, in order to test the developed framework. It has been demonstrated that the dynamic formalism is fast enough to enable human-in-the-loop simulation, that the VR interface is of great help for both control design and evaluation, and that Matlab algorithms can be efficiently connected to the Fortran computational model of the car.