Fossil fuels are currently the most convenient on-board energy sources for vehicles in terms of energy density and refueling time. However, the increase in global temperature together with the increase in transported people and goods in recent years has forced regulatory authorities around the world to establish strict regulations on pollutant and CO2 emissions. These scenarios are challenging for vehicle manufacturers, but they also create opportunities for the development of new technologies and concepts. For example, automotive companies and researchers are currently exploring hybrid powertrains with either advanced internal combustion engine technologies and low levels of electrification, or with high levels of electrification combined with simpler internal combustion engines. While these hybridization approaches can provide significant improvements in efficiency and emissions. There is also a global movement at the, consumer, manufacturing and government level to accelerate the adoption of zero tailpipe emitting vehicles (e.g., battery electric vehicles and fuel cell electric vehicles). This paper reviews the current state of powertrain technologies, analyzing first the evolution of emissions regulations in major markets and emphasizing the future tighter measures that will be adopted in Europe and the US. After that, an analysis of current global vehicle sales considering the COVID situation is performed, followed by a forecast of future powertrain technology market share trends. Finally, reviews of internal combustion engine, hybrid, and battery electric vehicle technologies announced in 2020 are carried out.

A review of current and future powertrain technologies and trends in 2020

A method has been developed to estimate the environmental impact of wheel loaders used in earthmoving operations. The impact is evaluated in terms of energy use and emissions of air pollutants (CO2...

https://www.tandfonline.com/doi/pdf/10.1080/10962247.2019.1640805

Determining the environmental impact of material hauling with wheel loaders during earthmoving operations.

To overcome the difficulty of collecting the working resistance and working trajectory of a wheel loader, this paper constructs a statics model of the bucket working resistance and a kinematics model of the working trajectory in the shoveling process and analyzes the key parameters of measuring the working resistance and working trajectory. Based on this, a working resistance and working trajectory acquisition strategy is proposed. To verify the effectiveness of the acquisition strategy, the in-service operation data of fine sand and loose soil shoveled by the wheel loader are collected and analyzed. Then, the test-fitted working resistance and working trajectory are obtained, and the working trajectory is input into the RecurDyn–EDEM co-simulation model to obtain the simulation-fitted working resistance. Considering the complex working conditions of the wheel loader, it is difficult to obtain accurate working resistance, and the actual working resistance is also a relative value. Therefore, a strong correlation between the two curves indicates that the acquisition strategy of the wheel loader’s working trajectory and working resistance proposed in this paper is feasible.

/pdf/modeling-and-verification-of-an-acquisition-strategy-for-17t3tql7.pdf

Modeling and Verification of an Acquisition Strategy for Wheel Loader’s Working Trajectories and Resistance

In construction projects, wheel loader is widely used for transporting building materials. The operations of wheel loader contain extensively repetitive tasks that could be optimized and automated for sustainable construction. This paper proposes, according to optimal control theory, an optimization approach for the loading cycle concerning fuel efficiency and environmental impacts. Based on a 2D space discretization and a detailed wheel loader model, a dynamic programming approach is formulated for optimal path search. The method is effective for integrating the system models with the path planning algorithm and for handling objective functions and constraints. A case study was carried out to demonstrate the application of the proposed algorithm for the loading cycle with spatial constraints.

Path planning for wheel loaders: A discrete optimization approach

Energy carried by engine exhaust pulses is critical to the performance of a turbine or any other exhaust energy recovery system. Enthalpy and exergy are commonly used concepts to describe the energy transport by the flow based on the first and second laws of thermodynamics. However, in order to investigate the crank-angle-resolved exhaust flow enthalpy and exergy, the significance of the flow parameters (pressure, velocity, and temperature) and their demand for high resolution need to be ascertained. In this study, local and global sensitivity analyses were performed on a one-dimensional (1D) heavy-duty diesel engine model to quantify the significance of each flow parameter in the determination of exhaust enthalpy and exergy. The effects of parameter sweeps were analyzed by local sensitivity, and Sobol indices from the global sensitivity showed the correlations between each flow parameter and the computed enthalpy and exergy. The analysis indicated that when considering the specific enthalpy and exergy, flow temperature is the dominant parameter and requires high resolution of the temperature pulse. It was found that a 5% sweep over the temperature pulse leads to maximum deviations of 31% and 27% when resolving the crank angle-based specific enthalpy and specific exergy, respectively. However, when considering the total enthalpy and exergy rates, flow velocity is the most significant parameter, requiring high resolution with a maximum deviation of 23% for the enthalpy rate and 12% for the exergy rate over a 5% sweep of the flow velocity pulse. This study will help to quantify and prioritize fast measurements of pulsating flow parameters in the context of turbocharger turbine inlet flow enthalpy and exergy analysis.

Numerical Analysis of Engine Exhaust Flow Parameters for Resolving Pre-Turbine Pulsating Flow Enthalpy and Exergy

Large bore marine engines are a major source of fossil fuel consumption in the transport sector. The development of more efficient and cleaner marine engine systems are always required. Exergy anal ...

Quantification of Losses and Irreversibilities in a Marine Engine for Gas and Diesel Fuelled Operation Using an Exergy Analysis Approach

Wheel loader is one of the most widely used heavyduty vehicles for transporting building materials in construction site. Improvement of its efficiency is important for sustainable transport and construction operations. This paper proposes a path optimization approach that allows us to plan loader trajectory and corresponding vehicle motions in construction site when the topological relief information is available. Vehicle dynamics is modeled for 3D motions considering the power bal- ance of vehicle propulsion. The path planning problem is then formulated using a framework of constrained optimal control where vehicle dynamics is incorporated as system constraints. In order to solve the problem, a discrete search method is de- veloped based on the principle of dynamic programming (DP), in which the states of the forward and backward movement paths of wheel loader are explored in parallel. A numerical study is then presented to demonstrate the application of the proposed approach for optimizing the loader path using terrain information.

Path optimization for a wheel loader considering construction site terrain

Earthwork, an essential activity in most construction projects, consumes large quantities of fossil fuel and produces substantial air pollution with adverse environmental impacts. To achieve more sustainable construction processes, novel methodologies to evaluate and improve the performance of earthwork operations are required. This study quantifies the real-world emissions and fuel consumption of construction equipment within an earthwork project in China. Two wheel loaders and two dump trucks are examined through on-board measurements and in-lab engine tests. The duty cycles of construction equipment are categorized with respect to their power efficiency and working patterns. Moreover, the power-specific and time-based emission factors for these duty cycles are computed and compared with relevant legislative emission limits. Significant emission variations among different duty cycles were found, and the real-world emission measurements exceeded the results from the in-lab test required for emission certification. In addition, a discrete-event simulation (DES) framework was developed, validated, and integrated with the computed emission factors to analyze the environmental and energy impacts of the earthwork project. Furthermore, the equipment fleet schedule was optimized in the DES framework to reduce greenhouse gas emissions and fuel consumption by 8.1% and 6.6%, respectively.

/pdf/assessment-of-emissions-and-energy-consumption-for-21ebrpes.pdf

Assessment of Emissions and Energy Consumption for Construction Machinery in Earthwork Activities by Incorporating Real-World Measurement and Discrete-Event Simulation

Beichuan Hong

Papers

Path planning for wheel loaders: A discrete optimization approach

Quantification of Losses and Irreversibilities in a Marine Engine for Gas and Diesel Fuelled Operation Using an Exergy Analysis Approach

Numerical Analysis of Engine Exhaust Flow Parameters for Resolving Pre-Turbine Pulsating Flow Enthalpy and Exergy

Path optimization for a wheel loader considering construction site terrain

Assessment of Emissions and Energy Consumption for Construction Machinery in Earthwork Activities by Incorporating Real-World Measurement and Discrete-Event Simulation