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The National Renewable Energy Laboratory's (NREL's) Fleet Test and Evaluations team recently conducted chassis dynamometer tests of a class 8 conventional regional delivery truck over the Heavy Heavy-Duty Diesel Truck (HHDDT), West Virginia University City (WVU City), and Composite International Truck Local and Commuter Cycle (CILCC) drive cycles. A quantitative study analyzed the impacts of various factors on fuel consumption (FC) and fuel economy (FE) by modeling and simulating the truck using NREL's Future Automotive Systems Technology Simulator (FASTSim). Factors included vehicle weight and the coefficients of rolling resistance and aerodynamic drag. Simulation results from a single parametric study revealed that FC was approximately a linear function of the weight, coefficient of aerodynamic drag, and rolling resistance over various drive cycles.

The emerging trends in commercial vehicle technology have increased the necessity for critical attribute engineering refinements. Drivability is emerging as one of the most significant attributes in the automotive sector. The degree of smoothness in a vehicle's response to the driver's input is termed as drivability. This attribute has to be rigorously refined in order to achieve brand specific vehicle characteristics, which will ensure a thorough product differentiation. In order to calibrate for a positive drivability feel, a methodology for evaluation of drivability is a prerequisite. The scope of this paper is aimed at describing the methodology for subjective and objective evaluation of drivability attributes in commercial vehicles. Drivability is a highly subjectively perceived attribute, therefore a subjective assessment technique to assess drivability attributes and sub-attributes are essential.

Steering pull during high speed braking of heavy commercial vehicles possesses a potential danger to the occupants. Even with negligible wheel-to-wheel brake torque variation, steering pull during the high speed braking has been observed. If the steering pull (i.e. steering rotation) is forcibly held at zero degree during high speed braking, the phenomena called axle twist, wheel turn and shock absorber deflection arise. In this work the data have been collected on the mentioned measures with an intention to develop a mathematical model which uses real time data, coming from feedback mechanism to predict the values of the measures in coming moments in order to aid steering system to ‘auto-correct’. Driven by the intention, ‘Time Series Analysis’, a well-known statistical methodology, has been explored to see how suitable it is in building the kind of model.

To properly respond to demands to reduce national energy consumption and meet greenhouse gas emission targets based on environment policy, the Ministry of Trade, Industry, and Energy of Korea formed a research consortium consisting of government agencies and academic and research institutions to establish the first fuel efficiency standards for medium- and heavy-duty (MHD) commercial vehicles. The standards are expected to be introduced in 2017 as Phase 1 of the plan and will regulate trucks with a gross vehicle weight in excess of 3.5 tons and buses with a carrying capacity of more than 16 persons. Most MHD commercial vehicles are custom-made and manufactured in diversified small-quantity batch production systems for commercial or public use, resulting in difficulties in utilizing mandatory vehicle tests for fuel efficiency evaluations.

This paper presents an integrated chassis controller with multiple hierarchical layers for 4WID/4WIS electric vehicle. The proposed systematic design consists of the following four parts: 1) a reference model is in the driver control layer, which maps the relationship between the driver's inputs and the desired vehicle motion. 2) a sliding mode controller is in the vehicle motion control layer, whose objective is to keep the vehicle following the desired motion commands generated in the driver control layer. 3) By considering the tire adhesive limits, a tire force allocator is in the control allocation layer, which optimally distributes the generalized forces/moments to the four wheels so as to minimize the tire workloads during normal driving. 4) an actuator controller is in the executive layer, which calculates the driving torques of the in-wheel motors and steering angles of the four wheels in order to finally achieve the distributed tire forces.

This paper presents simple but comprehensive modeling of the loads on the rubber sandwich-type mounts that often suspend the drum(s) in vibratory compactors or asphalt rollers. The goal of the modeling is to predict the overall performance of the rubber mount system. The modeling includes calculations to 1) identify and quantify all predictable low-frequency loads on the rubber mounts during normal vehicle operations, 2) predict the steady-state high-frequency vibration response of the drum, rubber mounts, and vehicle frame during compaction operations, 3) predict the heat generation in the rubber mounts from their hysteretic damping, and 4) predict the fatigue life and life distribution of the rubber mounts. Some typical results of the modeling are provided along with some brief criteria to assess suspension performance. Other, unpredictable suspension loads are discussed but not modeled.

Steering wheel being the most used tactile point in a vehicle, its feel and response is an important factor based on which the vehicle quality is judged. Engineering the right feel and response into the system requires knowledge of the objective parameters that relate to the driver perception. Extensive correlation work has been done in the past pertaining to passenger cars, but the driver requirements for commercial vehicles vary significantly. Often it becomes difficult to match the right parameters to the steering feel experienced by the drivers, since most of the standard ISO weave test units used to describe them are of zero or first order parameters. Analyzing the second order parameters gave a better method to reason driver related feel. Also, each subjective attribute was fragmented into sub-attributes to identify the reason for such a rating resulting in the identification of the major subjective parameters affecting driver ratings.

A cabin on an agricultural tractor is meant to protect the operator from harsh environment, dust and provide an air conditioned space. As it is an enclosed space, cabin structure should be a crashworthiness structure and should not cause serious injury to operator in case of tractor roll over. There are International standard like OECD Code 4, SAE J2194 which regulates the crashworthiness of this protective structure. The roll-over protective structure (ROPS) is characterized by the provision of space for a clearance zone large enough to protect the operator in case of tractor overturn. None of the cabin parts should enter into the clearance zone for operator safety. In addition to meeting ROPS test criteria, the cabin structural strength should be optimized for the required tractor life. In this paper, simulation process has been established to design an agricultural tractor cabin structure and its mountings to meet the above requirements.

This paper discusses the off-road performance prediction of military application mini UGVs using terramechanics work deals with the development of performance simulation model for mini UGV in the Matlab/Simulink Software. Transient forward vehicle propulsion model and soil terrain interaction model have been built in the Simulink® software. It is a semi-empirical mobility model which predicts mini UGV performance on given terrain. The interaction between vehicle and the terrain causes resistances to vehicle propulsion. The model calculates these resistances, compares them to both the power limitations of the vehicle and the tractive limitations of the soil/terrain, to determine if the vehicle is immobilized. If not, then the vehicle speed is calculated based on available drawbar pull. The terrain is defined in terms of the soil parameters measured by the Bevameter. Semi-empirical equations suggested by Bekker have been used to model the soil terrain interaction.

Developing countries like India is now highly relying on the alternate source of power generation to have uninterrupted power supply for their economic development. Diesel Power generator is one of the solutions in meeting the uninterrupted power requirement. In India, Power generating sets are having stringent emission norms and also the present government policies of removing subsides from Diesel fuel adding the additional burden on operating cost. As such researcher has a tough task to design the product considering the stringent requirement of legislation and performance. The main focus of this research work is to address performance necessities and the noise legislation. The detail methodology has been laid down to analyze and optimize performance and noise of Diesel Generator with respect to cooling system. Cooling fan with drive arrangement has been selected to study the canopied Diesel Generator performance and overall noise emission.

The objective of this project is “Bringing Field to Lab”. Normally in field, tractors are utilized for various applications like harvesting and threshing operation in a dusty environment which consists of paddy, sand, straw etc. These dusts would affect the tractor performance and often cause problem like engine choking at severe condition. Field data on threshing acquired from north Indian places like Jaitsar, Jalandhar where threshing done in summer at a temperature around 50°C. Also during threshing full tractor power is used through (PTO) power take off and this load fluctuates according to manual loading of paddy in thresher.

Fuel economy is an important customer requirement which determines the position of earth-movers such as backhoe loaders in the market. Earth-movers are heavy duty machines that are used for construction works. Currently fuel consumption in earth-movers is quantified as fuel consumed per unit time (Liters per hour). Similarly, conventional measure of productivity of the earth-movers is in terms of volume of soil trenched per hour. Measurements using the above scales showed wide variations in measured fuel consumption and productivity, For the same equipment between measurements Two equipment of same make at different trench locations and Against the competitor equipment This inconsistency and lack of a proper measuring system made logical decision making extremely difficult. This paper describes the step by step procedures involved in deriving the methodology for robust fuel consumption measurement of earth-mover vehicles.

A feature of the present state of the Russian agricultural industry is that productive resources (tractor pool, arable land area and number of workers involved) are diminishing and the reduction does not have a quantified value. In the prevailing conditions of limited resources, agricultural enterprises are forced to operate tractors beyond their amortization periods on a massive scale, which results in an unpredictable service life. This situation calls for an assessment of the optimal composition of the tractor pool in terms of number and age. By way of a solution to this problem, the given article presents a methodological approach as to the analysis of two opposing factors. On the one hand, it takes into account the fact that the use of tractors beyond their depreciation periods leads to increased costs of their operation and further yield losses related to the poor technical condition factor, which is proportional to the number of tractors with expired depreciation periods.

Special purpose, high payload carrying capacity, live gooseneck, multi axles, hydraulic suspension semi trailer is abinitio designed for transportation and tilting of heavy cargo from horizontal to vertical by hydraulically actuated mechanism integrated on the trailer. The chassis is levelled on hydraulic jacks followed by tilting of cargo. Hence the chassis experiences variable forces during tilting and estimated from kinematic model of tilting mechanism. These forces are input for finite element based structural design of chassis. Structural deflection of a step is made as initial condition for certain load cases of the analysis. Live gooseneck of this semi-trailer consists of hydraulically actuated mechanism, interconnected with multiple hydraulic suspensions in appropriate ratios. Estimation of Axles and fifth wheel force distributions of such trailer is complex. Mathematical modelling made to estimate these forces and applied as inputs for finite element analysis.

Globally, road traffic crashes kill about 1.24 million people each year. Pedestrians constitute 22% of all road deaths, and in some countries this is as high as 60%. The capacity to respond to pedestrian safety is an important component of efforts to prevent road traffic injuries. Pedestrian collisions, like other road traffic crashes, should not be accepted as inevitable because they are, in fact, both predictable and preventable. Examination of pedestrian injury distribution reveals that given an impact speed, the probability of fatal injuries is substantially greater when the striking vehicle is a pick-up rather than a passenger car. Given their utility areas, pickup vehicles require negotiating rough terrains and are therefore engineered with higher ground clearance and larger approach angle. The challenge is to optimize these design parameters and also style the vehicle for pedestrian safety while maintaining a low design cost at the same time.

This paper discusses various fruitful iterations / experiments performed to reduce air flow induced noise without compromising on total air flow requirement for thermal comfort and ways to avoid heat ingress inside the bus. Also the paper discusses the devised process for noise reduction through front loading of computer aided engineering and computational fluid dynamics analysis. Air conditioning buses in light commercial vehicle (LCV) segment is growing market in India, especially for applications like staff pick-up and drop, school applications and private fleet owners. The air-conditioning system is typically mounted on bus roof top and located laterally and longitudinally at center. It is an easiest and most feasible way to package air conditioning system to cater the large passenger space (32 to 40 seats) with the conditioned air. This makes air conditioning duct design simple and commercially viable.

The main emphasis for a commercial vehicle design which was focused on fuel-economy and durability does not fulfill the increasing customer expectations anymore. Commercial vehicle designers need to focus on other vehicle aspects such as steering, ride comfort, NVH, braking, ergonomics and aesthetics in order to provide car like perception to truck, bus drivers and passengers during long distance drives. Powertrain mounting system must perform many functions. First and foremost, the mounting system must maintain & control the overall motion of the powertrain, to restrict its envelope reasonably, thereby avoiding damage to any vehicle component from the potential impact. This requires the mount to be stiff. Second the mount must provide good vibration isolation to have a comfortable ride to the vehicle occupant. This requires the mount to be soft.

The Euro IV legislation for heavy-duty on-road vehicles enforces emissions limits on the tailpipe NOx levels during both transient and modal testing, typically paired with additional limitations on, for example, ammonia emissions. There are several possible strategies for complying with the legislation, including engine management measures as well as after-treatment in the form of catalytic removal of NOx with ammonia as the reducing agent. Based on experimental data, a range of important aspects are presented and discussed, with both overall system performance and the installation and operational costs in mind. Factors relevant for future legislations, in the form of EU V and beyond, are also discussed. Operating the engine with high levels of Exhaust Gas Recirculation (EGR) is a possible path to EU IV compliance with no or little catalytic NOx reducing after-treatment. Here, it is contrasted against an SCR-only solution based on a non-EGR engine calibration.

Engines of commercial vehicles deliver significant amount of power (more than 25% of propulsive power) for non-propulsive loads such as air-conditioner, alternator, air compressor, radiator fan, steering oil pump, lights etc. Use of these auxiliaries cause sub-optimal utilization of engine power resulting in increased fuel consumption and emissions. A fuel cell powered auxiliary power unit (FC-APU) is proposed to isolate the auxiliaries from the engine. Use of FC-APU shall help improve load carrying capacity, gradeability, fuel efficiency and emissions of the vehicle. This paper describes a mathematical system level model developed using MATLAB-SIMULINK to estimate auxiliary power consumption and simulate FC-APU system. A statistical analysis is performed on the power consumed by various auxiliaries during different duty cycles. The data is used to propose a FC- APU system. Fuel cell is the most expensive component in the system.

For zero tail pipe emission transportation, fuel cell technology is the best available option for replacing commercial IC engines. Worldwide lot of research work is going on in development of fuel cell vehicles. This work deals with the virtual development of system architecture for hybrid electric - fuel cell light commercial vehicle. The goal of this research work is to virtually design, model and convert an existing LCV model in to a hybrid electric fuel cell vehicle for the same performance and better efficiencies with zero tail pipe emissions. A unique fuel cell management system is developed and used for obtaining better efficiencies. A mathematical model of the vehicle is developed using GT-Drive which tracks the energy flow and fuel usage within the vehicle drivetrain. The vehicle is tested on chassis dynamometer to provide data for validation of the mathematical model. Model results and vehicle data show good correlation when validated.