Medium Trucks Research Articles

Stepping Surface Testing Method for Medium and Heavy Duty Vocational Trucks

Stepping Surface Testing Method for Medium and Heavy Duty Vocational Trucks

Simulation on Entrainment Process of Suction Mouth under Negative Pressure in the Medium Dry Sanitation Trucks

Since twentieth Century 40's, some foreign enterprises in developed countries began to study and produce sweeper [1-2]. Research on China's sweeping car began in twentieth Century 60 years, but until the 80 time end when china had been reforming and opening that it began to rapidly develope [3-4].But the study of mouth has the same general trend at home and abroad. Due to the different design of suction mouth, circulation type pneumatic conveying systems in general can be divided into open pneumatic conveying system using pure suction type suction mouth [5] and the use of reverse blowing type suction mouth delivery system [6]. Now most of the sweeper adopts the latter, but if the back blowing type suction mouth design improperly ,it can not achieve the ideal effect of absorbing dust, and may lead to strong fugitive dust [7-9].Today although road sweeper have been studied for decades at home and aboard, but these studies mainly is through the enterprise using engineering practice means to complete ,there are two situations occurring as follows: a number of technical on research and development need to rely on our own to explore; The engineering practice have greater demand for human, material and financial resources, and it is difficult to achieve better expected. In order to solve the problems of the above two points, according to the fluid mechanics analysis, this paper mainly research and analyze the sweeper suction mouth's flow field pickup role of entrainment process for particulate contamination by negative pressure suction, which can provide a foundation for the research and optimization of sweeper pneumatic conveying system.

Vehicle Security System Design Based on Material Internet Technology

With the increasing quantity and position of vehicles in people’s daily life, the security problems of vehicles have been paid more and more attention. At present, the medium and low-end cars and truck positioning, monitoring and anti-theft function have not been popular. Facing the imperfect function and unfriendly software design interface problems, it can not meet the users’ need. This paper adopts C/S structure to design a vehicle security system. It can realize the remote monitoring, vehicle carrier talk, fatigue driving monitoring, remote fortification and call alarm functions, ensuring the vehicles for 24 hours in the monitoring state, improving the vehicle usage safety coefficient. The system can have stable and reliable operation, and the data can conduct uninterruptedly transmission, and the interface is friendly and the operation is strong.

Estimation of Expressway O/D Matrices from TCS data by Using Video Survey Data for Vehicle Classification: Focused on Truck

Truck demand analysis based on TCS data has limitation in that TCS data can not provide truck O/D data for each type of truck vehicle. This study conducted video survey for classifying truck vehicle types. By using TCS data and vehicle ratio by region/cities type, truck O/D data on expressway were estimated. It was found that average travel distances of small truck, medium truck and large truck were 52km/veh, 56km/veh and 97km/veh, respectively by analysing truck O/D data estimated in this study. The reliability analysis showed that check points where error rate is lower than 30% comprise of 87.3%. It is considered that estimated O/D data by truck vehicle types would be useful for the analysis of truck demand of expressway.

Research into the costs of vehicle exhaust gases from the standpoint of using natural gas-powered buses

This paper aims at analysing the costs of motor vehicle exhaust gases with particular reference to natural gas-powered buses in intercity passenger transport in the territory of the Republic of Serbia. For defining and forecasting transport demands, expressed in the number of vehicles per day at each section of the created multimodal transport network, Transtools application is used, specially adapted for the territory of the Republic of Serbia. By applying the Highway Design and Maintenance (HDM) model and regression analysis, the functional dependency between the speed of a vehicle and fuel consumption is established for each of the following categories: passenger car, bus, light truck, medium truck, heavy truck, articulated truck, according to the type of the terrain and International Roughness Indicator (IRI) of the road. By estimating the unit costs of NOx, NMVOC, SOx, PM, CO, CO2 and CH4 pollutants and by estimating the average factors of exhaust emissions expressed in a gram of pollutant/gram of burnt fuel, according to all vehicle categories, the analysis of exhaust gas emission costs is conducted for three different scenarios. Key words: Exhaust gas emissions, compressed natural gas (CNG) bus, diesel bus, emission cost, transport network.

Impact of Trucks on Signalized Intersection Capacity

The most common method used for the analysis of signalized intersections in the United States is contained in the Highway Capacity Manual (HCM). In this method, the base saturation flow rate of the signalized intersection is defined in units of passenger cars per hour green per lane (pc/hg/ln). To account for the presence of large trucks in the traffic stream, the HCM includes a Passenger Car Equivalency (PCE) value. In the current edition of the HCM, a PCE value of 2.0 is applied for all large trucks, with no distinction between different sizes of trucks. The HCM also recommends a single value of 2.0 seconds for startup lost time, regardless of queue composition. Many transportation professionals have questioned the validity of the PCE value and startup lost time recommended by the HCM. They are concerned that the impact of trucks at signalized intersections is being underestimated. If this is the case, then capacity is being overestimated and intersections are not being adequately designed. The objective of this study was to identify appropriate truck PCE values and a relationship for startup lost time as a function of truck percentage in the traffic stream. To accomplish this objective, a custom simulation tool was developed based on the modified Pitt car-following model, calibrated with field data, and applied to a comprehensive experimental design. The PCE values determined from this study are 1.8, 2.2, and 2.8 for small, medium, and large trucks, respectively. A model for estimating startup lost time based on the same small, medium, and large truck classifications was also developed.

Hydraulic Hybrid Propulsion for Heavy Vehicles: Combining the Simulation and Engine-In-the-Loop Techniques to Maximize the Fuel Economy and Emission Benefits

The global energy situation, the dependence of the transportation sector on fossil fuels, and a need for a rapid response to the global warming challenge, provide a strong impetus for development of fuel efficient vehicle propulsion. The task is particularly challenging in the case of trucks due to severe weight/size constraints. Hybridization is the only approach offering significant breakthroughs in near and mid-term. In particular, the series configuration decouples the engine from the wheels and allows full flexibility in controlling the engine operation, while the hydraulic energy conversion and storage provides exceptional power density and efficiency. The challenge stems from a relatively low energy density of the hydraulic accumulator. This places particular emphasis on development of the supervisory controller. The conventional wisdom is to operate the engine at the “sweet spot”, but the aggressive pursuit of engine efficiency as the sole objective can lead to frequent and rapid diesel engine transients, thus causing an adverse affect on the soot emissions and driver feel. Therefore, we propose a comprehensive methodology for considering a combined hybrid system fuel-economy and emissions objective. The fuel economy is addressed with the simulation-based approach, while investigating the impact of engine transients on particulate emission relies on the Engine-In-the-loop (EIL) capability. The EIL study confirms advantages of a modulated state-of-charge control over the thermostatic approach, and demonstrates the ability of the Series Hydraulic Hybrid to improve the fuel economy of the medium truck by 72%, while reducing the particulate emission by 74% compared to the conventional baseline over the city driving schedule.

Measurement of Vertical Distribution of Truck Noise Sources during Highway Cruise Pass-Bys by Acoustic Beam Forming

A measurement program was completed to determine the vertical distribution of heavy-truck noise sources for pass-by events on an in-service highway for vehicles operating under cruise conditions. In addition to data on heavy trucks, some data were obtained for medium trucks and light-duty vehicles. The measurements were performed with acoustic beam forming, which provided visualization of the sound radiation of passing vehicles as well as means for calculating the vertical distribution of noise source level. The data set includes pass-by events for 125 heavy trucks, 30 medium trucks, and nine light vehicles operating nominally at 55 mph on two asphalt surfaces. The purposes of the research were to compare the source height splits assumed in the FHWA traffic noise model (TNM) to the results of this work, examine the acoustic benefit of sound walls designed to block the line of site of truck exhaust outlets, and obtain a better understanding of truck noise sources. For heavy trucks, the pass-by noise is dominated by tire noise produced by the drive axles, with other secondary sources related to the power train occurring in some cases. Noise from elevated exhaust outlets was not observed except in one or two special cases. For all vehicle types, ground level sources (tire noise) produced the highest noise levels. Furthermore, the vertical source distributions were found to be virtually identical for heavy and medium trucks. For truck and light vehicles, it appeared that the current source height splits assumed in TNM may be biased toward higher upper-source strength.

Noise benefits of asphalt pavements—Trends at ages up to 52 months

The U.S. DOT Volpe Center Acoustics Facility, in support of the California Department of Transportation, is participating in a long-term study to assess several types of pavement for the purpose of noise abatement. On a 6.4-km (4-mi) stretch of a 2-lane highway in Southern California, several asphalt pavement overlays are being examined. Acoustical, meteorological, and traffic data are collected in each pavement overlay section, where microphones are deployed at multiple distances and heights. Single vehicle pass-by events are recorded primarily for three vehicle types: automobiles, medium trucks, and heavy trucks. Data are analyzed to determine the noise benefit of each pavement as compared to the reference dense-graded asphalt pavement; this includes a modified Statistical Pass-By Index as well as average A-weighted maximum sound levels for each vehicle type. In addition, 1/3-octave band data are examined.

ASTM Radial Medium Truck Tire Operating Temperatures—Curved versus Flat Surfaces

Abstract This paper reports the results of an extensive design of experiment (DOE) conducted on radial medium truck tires by the ASTM Committee F09.30 Task Group on Truck/Bus Tire Test Development. These results are from Phase I of the task group’s work, operational (“real world”) tire temperature benchmarking. DOE variables were tire inflation, load, and speed. Response temperatures from embedded thermocouples were measured at apex/ply ending, no. 2/no. 3 belt ending, and shoulder and centerline ribs. Steady-state temperatures for steer, drive, and trailer tires from three different test venues are compared, i.e., flat belt lab machine, road/track, and 1.7 m diam laboratory roadwheel. Results from temperature regression modeling are discussed. Examples of the effects of a curved test surface on tire operating temperatures as well as on tire strain levels are provided. Model predictions are used to compare temperatures and strains of tires running at current Federal Motor Vehicle Safety Standard (FMVSS) 119 test conditions versus a severe service long-haul truck operating condition. The concept of “highway speed equivalency” for laboratory endurance testing is proposed.

Successful surgical treatment of chronic inferior vena caval thrombosis following blunt trauma

Posttraumatic inferior vena cava (IVC) thrombosis is extremely rare. We report a case of surgical treatment for chronic inferior vena caval thrombosis 4 years after blunt trauma. A 22-year-old man was referred to our hospital for investigation of an inferior vena caval thrombosis. He had a history of blunt abdominal trauma at age 18 while dismantling a medium truck and had undergone pancreaticojejunostomy for a pancreatic laceration. Computed tomography (CT) scans revealed an inferior vena caval thrombosis extending into the right atrium. Lung perfusion scintigraphy was unremarkable. We performed thrombectomy through a median sternotomy under deep hypothermic circulatory arrest, which gave adequate visualization in a bloodless field. A fiberscope was used intraoperatively for detailed IVC inspection. Postoperative recovery was uneventful, and he was discharged on the 14th postoperative day. Postoperative CT and echocardiography showed no recurrence of the thrombosis.

MAN’s new light and medium trucks TGL/TGM

The new MAN Nutzfahrzeuge AG light and medium TGL/TGM series completely replaced the successful L/M2000 series within only 18 months and sets new standards in the respective segments. The September edition of the ATZ introduced the MAN TGL/M truck series, focussing on the development goals, concept, driver’s cab, chassis, engine and engine peripheral equipment. The present part 2 below describes the axles, electronics structure, brakes and drive line.

The TerraMax autonomous vehicle

The TerraMax vehicle is based on Oshkosh Truck's Medium Tactical Vehicle Replacement truck platform and was one of the five vehicles able to successfully reach the finish line of the 132 miles DARP...

MAN’s new light and medium truck TGL and TGM

The new MAN Nutzfahrzeuge AG light and medium TGL/TGM series completely replaced the successful L/M2000 series within only 18 months and sets new standards in the respective segments. Trade journalists have already singled out the TGL for the “Truck of the Year 2006” award, in which it was clearly points ahead of the competition. This article describes concept, cab, chassis and engine of the new series. Axles, the electronic system, brakes and driveline are described in the October edition of ATZ.

Variability of pavement noise benefit by vehicle type

The Volpe Center Acoustics Facility, in support of the California Department of Transportation (Caltrans), is participating in a long-term study to assess several types of pavement for the purpose of noise abatement. On a four-mile stretch of a two-lane highway in Southern California, several asphalt pavement overlays are being examined. Acoustical, meteorological, and traffic data are collected in each pavement overlay section, where microphones are deployed at multiple distances and heights. Single vehicle pass-by events are recorded primarily for three vehicle types: automobiles, medium trucks, and heavy trucks. Data are analyzed to determine the noise benefit of each pavement as compared to the reference dense-graded asphaltic concrete (DGAC); this includes a modified Statistical Pass-By Index as well as average Lmax values for each vehicle type. In addition, 1/3-octave band data are examined. Automobiles and heavy trucks are the focus of this paper, where benefits due to pavement will be presented for three pavement types: open-graded asphaltic concrete (OGAC) of 75 mm thickness, open-graded asphaltic concrete (OGAC) of 30 mm thickness, and rubberized asphaltic concrete, Type O (open) (RAC) of 30 mm thickness. Average Lmax values and spectral data show that noise benefits due to pavement can vary by vehicle type.

Computational Fracture Mechanics Analysis of Truck Tire Durability

Abstract A three-dimensional fracture mechanics model is formulated to study fatigue crack growth and durability in tires. The application of this model in a radial medium truck tire reveals fracture characteristics of belt edge cracks and helps to explain mechanical and material changes in the tire subject to indoor accelerated durability tests. Along with a proprietary fatigue crack growth law, a fracture mechanics based durability analysis methodology is developed and successfully applied to rank durability of tires with different constructions or different rubber materials.

Combined optimisation of design and power management of the hydraulic hybrid propulsion system for the 6 ? 6 medium truck

Hybrid propulsion systems are one of the critical technologies on the roadmap to future ultra-efficient trucks. While there is a significant body of work related to hybrid passenger cars and light commercial trucks, there are many open issues related to hybridisation of heavier trucks intended for both on- and off-road use. This work addresses those questions through a systematic analysis of the proposed parallel hydraulic hybrid powertrain for the Family of Medium Tactical Vehicles (FMTV). A representative duty cycle for the FMTV is generated based on information about the typical vehicle mission. A methodology for sequential optimisation of hybrid propulsion and power management systems is applied to a hydraulic hybrid configuration with post-transmission motor location. This analysis is critical in evaluating the fuel economy and mobility potential of the hybrid propulsion system, as well as enhancing our understanding of the phenomena leading to predicted fuel economy values.

Modelling and control of a medium-duty hybrid electric truck

The main contributions of this paper are the development of a forward-looking hybrid vehicle simulation tool, and its application to the design of a power management control algorithm. The hybrid electric vehicle simulation tool (HE-VESIM) was developed at the Automotive Research Center of the University of Michigan to study the potential fuel economy and emission benefits of the parallel hybrid propulsion system for a medium truck. The fundamental architecture of the feed-forward simulation tool and the dynamic equations of its sub-system modules are first described. A power management control algorithm is then designed and evaluated, which is based on mimicking the behaviour of a dynamic-programming optimisation scheme. Simulation results over an urban driving cycle demonstrate that the hybrid control algorithm is able to improve vehicle fuel economy significantly, compared with the original vehicle, powered only by a diesel engine.

Acoustic–seismic detection and classification of military vehicles—developing tools for disarmament and peace-keeping

Acoustic and seismic signals of military vehicles passing between two newly-developed sensor stations separated by about 100 m distance have been measured. Five tracked and five wheeled vehicles drove with seven speeds in both directions on four lanes. Rms values rose above background at distances of several 100 m for tanks, 60–80 m for a medium truck, and 40–50 m for a light van. By processing the acoustic and seismic maxima together, tracked and wheeled vehicles were separated correctly in 94% of the passes. An algorithm for detecting lines and harmonic series in acoustic spectra worked for eight vehicles. For vehicle-type recognition, learning-vector quantisation was used, working on the relative powers of the first 15 harmonics. This was successful in 95–98% of the tracked-vehicle passes and 69–95% of the wheeled-vehicle passes. These experiences and results suggest that sensor monitoring of control lines is feasible.

Estimating the contributions of mobile sources of PAH to urban air using real-time PAH monitoring

Motor vehicles are a significant source of airborne polycyclic aromatic hydrocarbons (PAH) in many urban areas. Traditional approaches used in determining the relative contributions of individual vehicle types to the total amount of PAH in air have been based on the analysis of integrated samples of airborne particles and gases for the presence of chemical tracers indicative of the vehicles from which the chemicals derived. As an alternative, we have used a photoelectric aerosol sensor (PAS) capable of measuring PAH levels in real-time in the emissions plumes from motor vehicles. We placed the PAS near a traffic-light in Kenmore Square, a busy crossroads in downtown Boston (MA, USA). A video camera co-located at the site recorded the vehicles passing the sensor, and this record was correlated with the PAS data. During a 5-day monitoring period (∼59 h) in the summer of 1998, over 34 000 motor vehicles were counted and classified and over 24 000 PAS readings were recorded (frequency=1/8.6 s). The composition of the vehicle population was 94% passenger vehicles, 1.4% buses, 2.6% small trucks, 1.3% medium trucks, 0.35% large trucks, and 0.45% garbage and construction trucks. In analyzing the PAS data, it was assumed that the highest PAS measurements — those that exceeded the 95% critical level of the 5-min moving average of all the PAS measurements — were indicative of primary vehicular emissions. We found that ∼46% of the mass of particle-bound PAH (i.e. ∼46% of the integrated area under the PAS signal vs. time plots) was attributable to primary emissions from motor vehicles passing the sensor. Of this, 35–61% was attributable to passenger vehicles (cars, pickup trucks, and sports utility vehicles) and 39–65% was attributable to non-passenger vehicles [buses (14–23%), small trucks (12–20%), medium trucks (8.4–14%), large trucks (2.9–4.8%) and garbage and construction trucks (1.9–3.2%)]. Our results suggest that on a per vehicle basis, buses and trucks — the majority of which run on diesel fuel — emitted greater amounts of particle-bound PAH than passenger vehicles. Overall, we found that real-time photoelectric aerosol sensing (in combination with video photography) is useful for estimating the contributions of airborne PAH from different vehicle types. Due to the physical constraints of our monitoring site and the high volumes of traffic, however, it was not possible to uniquely attribute PAS signals to individual vehicles.