Semi-trailer Truck Research Articles

Разработка системы автоматической парковки грузовика с полуприцепом

Разработка системы автоматической парковки грузовика с полуприцепом

An empirical study of DSRC V2V performance in truck platooning scenarios

Among many safety applications enabled by Dedicated Short Range Communication (DSRC), truck platooning provides many incentives to commercial companies. This paper studies DSRC Vehicle-to-Vehicle (V2V) performance in truck platooning scenarios through real-world experiments. Commercial DSRC equipments and semi-trailer trucks are used in this study. We mount one DSRC antenna on each side of the truck. One set of dynamic tests and a few sets of static tests are conducted to explore DSRC behaviors under different situations. From the test results, we verified some of our speculations. For example, hilly roads can affect delivery ratio and antennas mounted on opposite sides of a truck can suffer from low delivery ratio at curved roads. In addition, we also found that antennas can sometimes suffer from low delivery ratio even when the trucks are on straight roads, possibly due to reflections from the nearby terrain. Fortunately, the delivery ratio can be greatly improved by using the two side antennas alternately.

Проверка адекватности математической модели криволинейного движения автопоезда

Проверка адекватности математической модели криволинейного движения автопоезда

Sticking to cars and the call came from inside

Sticking to cars Pedestrians struck by cars might find themselves glued to their automobile assailants in a few years, if a patent recently awarded to Google turns into a real product. The concept described in U.S. Patent No. 9340178 is for an adhesive layer to be applied to the front end of a vehicle, which might include a conventional or self-driving automobile or “a truck, bus, van, semi-trailer truck, motorcycle, golf cart, ATV, off-road vehicle, or farm vehicle, as well as a carrier that rides on a track such as a rollercoaster, trolley, tram, or train car.” The adhesive layer would be covered by a coating that would break on impact to expose the adhesive. Whatever broke the coating would then stick to the front of the vehicle. The goal is to protect pedestrians from injuries they might sustain in additional impacts with the road or other objects if thrown

Comparison of Acceleration Acting on Cargo in Front and in Rear Part of Semi-Trailer during Braking with and without Using the Systems ABS/EBS

This article deals with braking tests of semi-trailer truck in forward and rear driving direction. It compares the accelerations and angular velocities in the front and rear part of the semi-trailer and their influence on forces in lashing points when using front lashing. The paper also contains a comparison between forces reached in the lashing points at the rate of cargo weight between the braking tests of semi-trailer and similar braking tests of a van. The first part of the paper contains also possibilities of using tracking devices for detecting accelerations acting on cargo in semi-trailer during transport.

Impact of farm equipment loading on low-volume concrete road structural response and performance

The rapid increase in farm equipment size in the United States of America agricultural industry has raised significant concerns regarding its impact on the low-volume road infrastructure. The study described in this paper investigated the impact of heavy farm equipment (or agricultural vehicle) on the structural behaviour of rigid pavement system. A series of full-scale traffic tests were conducted at the Minnesota’s Cold Weather Pavement Testing Facility (more commonly known as MnROAD) on two existing low-volume rigid pavement sections: (1) to study the effects of agricultural vehicle and weights, traffic wander pattern, pavement structure, and environmental factors on rigid pavement responses (deflections, strains and stresses), and (2) to compare these responses with those of a standard 356 kN (80 kips) five-axle, semi-trailer truck for assessing relative rigid pavement damage caused by heavy farm equipment. Numerical analyses were also carried out for rigid pavement fatigue damage estimations by simulating field test conditions. The Finite Element Model was able to predict rigid pavement responses under complicated heavy agricultural farm equipment loading. The study findings revealed that seasonal change, traffic wander, vehicle loading/configurations, pavement thickness, slab length and modulus of subgrade support are all important factors to be considered in designing rigid pavement subjected to heavy farm equipment loading. The use of tandem or tridem axles is recommended for all farm equipment because those axles help to distribute the load and minimize rigid pavement damage.

Possibilities of Finding out the Braking Parameters with Using GPS Equipment and Cameras

This article deals with results of testing, what level of reliability and accuracy can be reached by GPS devices and cameras when using them for purposes of detection of extreme braking and determination of its parameters. Braking tests with a van and with semi-trailer truck were done for purposes of this research. The main aim is to find out, whether this equipment can be used for detection of extreme braking as a situation, which can cause hidden damages on transported cargo. The article contains evaluation of differences between data measured by GPS equipment and those measured by equipment with accelerometer. Here are also stated examples of runs of braking deceleration as there were recorded by particular types of equipment.

Highway Network Expansion in Andean Patagonia: a Warning Notice From Rufous-legged Owls

As part of the economic and population growth of Patagonia, several dust/gravel roads crossing well preserved Andean forests are being converted into paved highways. The potential effects of these changes on forest wildlife have been little studied. The Rufous-legged Owl (Strix rufipes) was dominant among road-killed birds in our survey of a 27-km section of highway running through forests of Nahuel Huapi National Park, in Argentine Patagonia. Fatalities were not evenly distributed along the surveyed length of the road, so we investigated whether landscape features, roadside slope on both sides of the highway, demography, and/or season explained the aggregation pattern. Patterns of distribution of the road-killed owls were explained by owl abundance and age-class, time of year, and hour, and were weakly related to canopy closure; roadside slope on both sides was unrelated to abundance of fatalities. Traffic-related deaths were likely the primary cause of non-natural mortality of Rufous-legged Owls (especially for young individuals) in the study area. Examination of carcasses indicated that most owls were killed by turbulence behind large vehicles and that deaths occurred early in the night. Semitrailer trucks capable of carrying large loads, which peak in numbers between dusk and midnight, likely caused most fatalities. A way to reduce owl mortality could be to schedule truck traffic outside the hours when owls are most active at hunting around paved roads crossing natural forests, at least during late winter and spring seasons. Because transportation networks encourage future development that will affect the environment in a variety of ways, it is critical to retain roadless and near-roadless (i.e., having only dirt or gravel roads with slow-moving traffic) portions of the southern Andes to preserve their natural landscapes.

Dispatches

Dispatches

Real-Time Dynamic Simulations of Large Road Vehicles Using Dense, Sparse, and Parallelization Techniques

This article presents three multibody formulations with improved efficiency in order to achieve real-time simulations for the forward dynamic of two real-life road vehicles. The bigger is a semitrailer truck with 40 degrees of freedom (DOF). Two topological and semirecursive formulations are used as well as a global formulation based on the use of Euler parameters and flexible joints. The first semirecursive formulation carries out a double velocity transformation and the integration is done by means of the explicit fourth order Runge–Kutta method. The second semirecursive formulation and the global one use a penalty scheme at position level and orthogonal projections at velocity and acceleration levels. In both cases the integrator was the implicit Hilbert–Huges–Taylor (HHT) method. The double velocity transformation method involves the coordinate partitioning of the constraint Jacobian matrix which leads to the costly solution of a redundant but consistent with the constraints linear system of equations. The choice of a unique set of independent coordinates may not be valid for a complete simulation and additional repartitioning would be required. Based on previous experience and as the examples show in this article, a careful initial choice of the independent coordinates can remain valid for complete simulations involving common maneuvers. This represents a numerical advantage for dense matrix methods and can be further exploited if sparse matrix techniques are employed. This has been the case for both of the vehicles used, reaching real-time simulations even with the semitrailer truck. The implicit semirecursive formulation involves the numerical evaluation of the stiffness and damping matrices, which hamper obtaining real-time simulations. For the semitrailer truck, this computation represents the 76% of the total simulation time. The numerical computation of these matrices is carried out by columns and its algorithm is straightforwardly parallelizable. Using a quad-core processor and with a simple and efficient OpenMP implementation, it has been possible to achieve a speedup of 3.25 reducing the simulation times under the real-time limit. The sparse matrices of Euler parameters formulation show very different sparsity degrees, difference that grows with the size of the multibody model. This poses a challenge to sparse matrix implementations in order to be able to efficiently perform matrix operations without increasing fillings or handling zero entries. This has been successfully accomplished using a new sparse matrix representation. This one is not a feature of general purpose sparse software, requiring at some stages the implementation of our own algorithms. Reductions in time of three orders of magnitude have led to real-time simulations even with the semitrailer truck.

A multibody dynamics model to assess the impact of road unevenness on the efficiency of a semitrailer truck

An open source multibody model of a semi-trailer truck with 331 degrees of freedom was built and within it a dynamic tyre model has been implemented. The truck model was calibrated and validated by an on-road experimental campaign of coastdown tests. The signal from a photodetector and ten accelerometers, the weight distribution, meteorological data, and the longitudinal profile have been collected. The purpose of the model is to obtain the relationships between the longitudinal road profile and fuel consumption, vehicle wear, passenger health, and safety. A subsequent study demonstrated the capacity of the model to fulfil its purpose.

An overview of various new road profile quality evaluation criteria: part 2

This is the second part of an article which correlates road-induced impacts on vehicle to a selection of road assessment criteria. The impacts on tyre, suspension and radiator wear are studied by running a multibody semi-trailer truck model on 270 road profiles. The model accurateness is assessed by comparing international roughness index (IRI)–impact relationships to those published in the literature. A new profile rating method uses wavelength content to predict the impacts of a specific profile on driver and passenger health and safety, truck wear and fuel consumption. It is concluded that (1) medium wavelengths severely impact fuel consumption, component wear and safety; (2) simple, two-point and four-point indices yield similar results, but the more the points the better the correlation; (3) the IRI is good at predicting general trends in road-induced vehicular impact but is weak for specific impacts and (4) tyre wear correlates linearly while component wear requires quadratic correlations.

A Study on Aerodynamic Drag of a Semi-trailer Truck

The primary objective of this study is to determine the aerodynamic impact of various fuel saving devices used in a commercial vehicle (i.e., semi-trailer truck). To measure the aerodynamic drag produced by the vehicle, a wind tunnel study was undertaken using a 1/10th scale model truck. The aerodynamic drags on the baseline vehicle including different external attachments (i.e., front faring, side skirting and gap filling) were measured for a range of vehicle operating speeds and yaw angles, and with different combinations. The results show that these external attachments (fairing and covering) have notable impact on aerodynamic drag as they can reduce up to around 26% aerodynamic drag over the baseline model depending on cross wind effects. The full-skirting (using the front fairing, side skirting and gap filling) has maximum impact whereas only front fairing has minimum impact on aerodynamic drag reduction.

Integration and road tests of a self-sensing CNT concrete pavement system for traffic detection

In this paper, a self-sensing carbon nanotube (CNT) concrete pavement system for traffic detection is proposed and tested in a roadway. Pre-cast and cast-in-place self-sensing CNT concrete sensors were simultaneously integrated into a controlled pavement test section at the Minnesota Road Research Facility (MnROAD), USA. Road tests of the system were conducted by using an MnROAD five-axle semi-trailer tractor truck and a van, respectively, both in the winter and summer. Test results show that the proposed self-sensing pavement system can accurately detect the passing of different vehicles under different vehicular speeds and test environments. These findings indicate that the developed self-sensing CNT concrete pavement system can achieve real-time vehicle flow detection with a high detection rate and a low false-alarm rate.

The crash at Kerang: Investigating systemic and psychological factors leading to unintentional non-compliance at rail level crossings

In 2007 a loaded semi-trailer truck struck a passenger train on a railway level crossing in Northern Victoria, Australia, killing eleven train passengers. Although the incident was formally investigated, why the truck driver proceeded through the crossing in the presence of a train remains unexplained. This article uses two juxtaposed Human Factors approaches to provide insight into the contributory factors underlying the incident. A systems analysis framework is used to examine the rail level crossing system in which the incident occurred and an individual psychological schema theory account is used to examine the failures which led the truck driver to proceed through the crossing in the presence of a train. The findings suggest that the primary cause of the incident was a looked-but-failed-to-see error driven by a faulty activation of schema error, leading the truck driver to assume initially that the crossing was in fact in a non-activated state with no train present. Moreover, various system-wide factors that shaped the rail level crossing ‘system’ and thus the incident are identified.

Implementación eficiente de una formulación semirrecursiva para la dinámica de sistemas multicuerpo de gran tamaño

This article shows an efficient implementation of a dynamic semi-recursive formulation for large and complex multibody system simulations, with interesting applications in the automotive field and especially with industrial vehicles. These systems tend to have a huge amount of kinematic constraints, becoming usual the presence of redundant but compatible systems of equations. The maths involved in the solution of these problems have a high computational cost, making very challenging to achieve real-time simulations.In this article, two implementations to increase the efficiency of these computations will be shown. The difference between them is the way they consider the Jacobian matrix of the constraint equations. The first one treats this matrix as a dense one, using the BLAS functions to solve the system of equations. The second one takes into account the sparse pattern of the Jacobian matrix, introducing the sparse function MA48 from Harwell.Both methodologies have been applied on two multibody system models with different sizes. The first model is a vehicle IVECO DAILY 35C15 with 17 degrees of freedom. The second one is a semi-trailer truck with 40 degrees of freedom. Taking as a reference the standard C/C++ implementation, the efficiency improvements that have been achieved using dense matrices (BLAS) have been of 15% and 50% respectively. The results in the first model have not improved significantly by using sparse matrices, but in the second one, the times with sparse matrices have been reduced 8% with respect to the BLAS ones.

Fuel consumption and life cycle GHG emissions by China’s on-road trucks: Future trends through 2050 and evaluation of mitigation measures

We established a bottom-up model to deliver the future trends of fuel consumption and life cycle greenhouse gas (GHG) emissions by China's on-road trucks. The mitigation measures of mileage utilization rate (MUR) improvement, fuel consumption rate (FCR) improvement, and penetration of liquefied natural gas (LNG) fueled trucks were evaluated. With no mitigation measures implemented, in the year 2050, the total fuel consumption and life cycle GHG emissions by China's on-road trucks were projected to reach 498 million toe and 2125 million tons, respectively, approximately 5.2 times the level in 2010. If the MUR of trucks in China is increased from the current status as those of the developed countries, a 13% reduction of total fuel consumption can be achieved after 2020. If the FCR of trucks is reduced by 10% in 2011, 2016, 2021, and 2026, a 30% reduction of total fuel consumption can be achieved after 2030. Moreover, if the share of LNG fueled trucks in all newly registered semi-trailer towing trucks and heavy-duty trucks is increased to 20% in 2030, an estimate of 7.9% and 10.9% of the total diesel consumption by trucks will be replaced by LNG in 2030 and 2050, respectively.

Evaluating the potential of the Otto® Wildlife GPS device to record roadside moose and deer locations for use in wildlife vehicle collision mitigation planning

Wildlife vehicle collisions present a serious challenge to road safety. Although spatially accurate wildlife collision data is necessary to identify areas where wildlife vehicle collisions are recurrent, global positioning system technology has seldom been operationally used to mark roadkilled carcass or roadside live animal points of interest. We modified an existing global positioning system based device (Otto-Driving Companion®) to record roadside live sightings and carcass locations of deer (Odocoileus spp.) and moose (Alces alces) in northern British Columbia, Canada and assess the operational feasibility of the device to quickly and reliably collect data. Ten modified Otto-Driving Companion® units were installed in commercial semi-trailer trucks and roadside points of interest were recorded between July 2006 and May 2007. The device was straightforward to install and operate, and functioned proficiently for data collection. Data transfers from the units to the researchers were simple and fast. Maps showing live sighting and carcass points of interest were easily created from the data. While methodologies remain to be developed to normalise the data and minimise temporal biases arising from non systematic data collection, the modified Otto-Driving Companion® demonstrated it is well suited to the collection of roadside wildlife points of interest for a variety of operational and research purposes.

Fictional Safety [Electrical Safety

Skies were sunny with no wind. A long semitrailer truck's cab was crossing a major intersection headed south, and at the same time, a large dump truck was northbound. Both were moving legally in their lanes at a modest speed. Without warning, a small dark sedan arrived from the east and sped through its red light. The sedan attempted to dodge and weave the narrow space between the trucks, as if in a movie where the action takes place with digital precision.

A wavelet interpretation of vehicle-pavement interaction

This paper utilizes a wavelet approach to interpret the interaction between truck dynamic axle loads and pavement roughness profile. The experimental data used was obtained from an instrumented 5-axle semi-trailer truck equipped with an air and a rubber suspension in the drive and trailer axles, respectively. Wavelet decomposes the original signal into a number of sub-band levels depending on its characteristics. The size of the dataset used allowed 11 levels of wavelet decomposition with test speed dependent frequencies ranging up to 4 cy/m. For dynamic load, the extent of variation in each of these wavelength sub-bands, was summarized through an energy metric effectively computed as the sum of the squares of the wavelet coefficients in each sub-band. Total energy was computed as the sum of the energy of all sub-bands and was normalized by dividing by the length of the test section. Relative energy was computed as the percent of total energy in each sub-band. The results were summarized through 3D plots of relative energy versus load frequency versus profile frequency. The profile frequencies mostly affecting dynamic loads depend on speed and range from 0.65 to 3.76 cy/m.