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Accurately predicting the future trajectories of surrounding traffic agents is important for ensuring the safety of autonomous vehicles. To address the scenario of frequent interactions among traffic agents in the highway merging area, this paper proposes a trajectory prediction method based on interactive graph attention mechanism. Our approach integrates an interactive graph model to capture the complex interactions among traffic agents as well as the interactions between these agents and the contextual map of the highway merging area. By leveraging this interactive graph model, we establish an agent-agent interactive graph and an agent-map interactive graph. Moreover, we employ Graph Attention Network (GAT) to extract spatial interactions among trajectories, enhancing our predictions. To capture temporal dependencies within trajectories, we employ a Transformer-based multi-head self-attention mechanism.

Vacuum cleaning vehicle is the necessary equipment for the Municipal Sanitation Department to keep the road surface clean and the dust subsidence system is the heart unit for the proper function of the cleaning vehicle. The reasonable design of this system could increase the load capacity of the vehicle and be convenient for the garbage collecting and dumping. Meanwhile, the engine power could be relatively reduced and the influence on the environment duo to the dusty air in the outlet could be also effectively improved. In the study, the gravity dedusting principle is used firstly for structure design to reduce the flow rate of dust particles inside the lower part of the dust subsidence system. The ruleless collision loss among dust particles is reduced and thereby the fan power is saved. By means of a reasonable separated chamber design and the use of inertia baffle, the sort management for dust particles is developed and the work stress of the export filter is released observably.

The vehicle engine exhaust wastes heat. For the conventional scheme, the hot-end of the thermoelectric module is connected with the exhaust pipe, while the cold-end is cooled through the vehicle engine cooling cycle. The variation of vehicle engine operating conditions brings the instability of the hot-end temperature, which affects the power generation performance of thermoelectric materials and increases the damage risk to the thermoelectric materials caused by the high temperature. This research adopts the heat transfer oil circulation as the intermediate fluid to absorb the dynamic heat flux of the vehicle engine exhaust so as to release the heat steadily to the hot-end of the thermoelectric module. The thermal characteristics of the target diesel vehicle engine exhaust gas are evaluated based on the experimental data firstly.

This paper combines fluid software STAR-CCM+ and finite element software ABAQUS to solve the temperature field of this Gasoline engine exhaust manifold based on loose coupling method. Through the simulation of car parking cooling - full load condition at full speed, we estimate thermal fatigue life of the exhaust manifold with the plastic strain increment as the evaluation parameters. It can guide the direction of optimal design of the exhaust manifold. Here we also revealed how the bolt force affects the manifold elastic and plastic behavior.

Vehicle exhaust waste-heat recovery with thermoelectric power generators can improve energy efficiency, as well as vehicle fuel economy. In the conventional structure, the hot-end of thermoelectric module is directly connected with the outer wall of the exhaust pipe, while the cold-end is connected with the water pipe’s outer wall of the vehicle engine cooling cycle. However, the variety of vehicle engine operating conditions leads to the instability of the hot-end temperature, which will reduce the generating efficiency of the thermoelectric modules and also shorten its service life. This research is on the basis of constructing a heat transfer oil circulation, and to study the action principles and implementation methods of it.

While the car ownership increasing all over the world, the unutilized thermal energy in automobile exhaust system is gradually being realized and valued by researchers around the world for better driving energy efficiency. For the unexpected urban traffic, the frequent start and stop processes as well as the acceleration and deceleration lead to the temperature fluctuation of the exhaust gas, which means the unstable hot-end temperature of the thermoelectric module generator (TEG). By arranging the heat conduction oil circulation at the hot end, the hot-end temperature’s fluctuation of the TEG can be effectively reduced, at the expense of larger system size and additional energy supply for the circulation. This research improves the TEG hot-end temperature stability by installing solid heat capacity material(SHCM) to the area between the outer wall of the exhaust pipe and the TEG, which has the merits of simple structure, none energy consumption and light weight.

It’s not easy to start the engine in winter, especially in frigid highlands, because the low temperature increases the fuel’s viscosity, decreasing the lubricating oil flow ability and the storage performance of battery. Current electrical heating method can improve the engine starting performance in low temperature condition, but this method adds an external power to the engine, leading to the engine cannot maintain an efficient energy utilization. A warming device using the solar energy is designed to conserve the energy during the daytime, and directly warm up the engine at the time when the engine turns off for a long time, especially during the night. A solar collector installed on the top of the vehicle is used to convert the solar energy to the thermal energy, which is then transferred to the heat accumulator that contain the phase-change medium which can increase the heat storage performance.

The automobile exhaust energy can be recovered by the thermoelectric module generator(TEG). Owing to the complex urban traffic, the exhaust gas’s temperature fluctuations are resulted, which means the unstable hot-end temperature of the TEG. By installing solid heat capacity material(SHCM) to the area between the outer wall of the exhaust pipe and the TEG, it is possible to appropriately reduce the temperature fluctuation, but there is still a fluctuation of the TEG’s power output. Then by adding voltage filter circuit (VFC) after the TEG, the power output stability can be improved. This research uses SHCM and VFC to improve the stability of the exhaust gas generation. Firstly, the three-dimensional heat transfer model of the exhaust pipe thermoelectric power generation system is established. The heat capacity materials with low thermal resistance and high heat capacity were selected as the research object based on previous research.

In order to meet the Euro IV HD diesel engine emission standard legislation limits, an efficient SCR system is adopted for PM optimized YC6L350-40 HD diesel engine serving in China. This paper presents tests made on the engine. The engine had base NOx emission of 8.8g/kwh over the ESC and 8.7g/kwh over the ETC. Outfitted with a 24.7 liter 300cpsi SCR catalyst, the engine NOx emission dropped to 3.2g/kwh over the ESC and 3.5g/kwh over the ETC.

In order to predict the thermal fatigue life of the internal combustion engine exhaust manifold effectively, it was necessary to accurately obtain the unsteady heat transfer process between hot streams and exhaust manifold all the time. This paper began with the establishment of unsteady coupled heat transfer model by using serial coupling method of CFD and FEA numerical simulations, then the bidirectional thermal coupling analysis between fluid and structure was realized, as a result, the difficulty that the transient thermal boundary conditions were applied to the solid boundary was solved. What's more, the specific coupling mode, the physical quantities delivery method on the coupling interface and the surface mesh match were studied. On this basis, the differences between strong coupling method and portioned treatment for solving steady thermal stress numerical analysis were compared, and a more convenient and rapid method for solving static thermal stress was found.

To study the mechanism of the effect of low-viscosity oils on engine friction loss reduction so as to improve the vehicle fuel economy of the Worldwide harmonized Light vehicles Test Cycle (WLTC) by upgrading the Society of Automotive Engineers (SAE) viscosity grade of the factory fill oil from 5W30 to 0W20, eight 0W20 oil samples were blended with different doses of base oil, viscosity modifier (VM), and friction modifier (FM). Theoretical analysis by AVL-EXCITE simulation of the key friction pairs combined with practical engine friction torque test and vehicle WLTC fuel consumption tests were carried out. The results showed that 0W20 oils can effectively reduce the engine friction torque by 5.64 Nm and the friction loss by 11.95% with the throttle fully opened; while with the throttle closed, the friction torque decreased by 3.53 Nm and the friction loss by 11.26%, resulting to the improvement of the vehicle WLTC fuel economy by 2.08%.

This paper mainly researches transmission efficiency (TE) of mechanical transmission in relation to the temperature of lubricating oil. Firstly the formula of TE is calculated about the kinematic viscosity of lubricating oil, then analyze the relationship between kinematic viscosity and temperature of lubricating oil, and finally the formula of TE which is related to the oil temperature is put forward. In order to verify the theoretical formula, the test bench for mechanical transmission is designed, which is used to research the N109 transmission of one mini car. The bench can be used to measure the curve of TE under different speed , load and lubricating oil temperature. The optimum operating temperature of the transmission is obtained by analyzing the measured data and theoretical calculation results. The test bench adopts 2 AC asynchronous motors to respectively simulate the driving and load performance of a vehicle.

The aerodynamic noise of the reactive muffler is generated inside the muffler and mixed with the noise of the muffler body, which is difficult to be measured in the exhaust system. Based on two-microphone transfer function method and transmission loss of mufflers in the absence of airflow, this paper proposes a method for measuring the aerodynamic noise of the muffler. On the built-in muffler aerodynamic noise test bench, a special sampling tube was designed to measure the aerodynamic noise of the muffler at different flow velocity. For the sound absorption end with large reflection coefficient, the test and simulation data have large error at low frequency, and a correction formula that can eliminate the reflection of sound waves at the end of the test pipeline and form multiple reflections in the upstream and downstream is derived.

In order to make full use of engine exhaust heat, the thermoelectric module been used to contribute to thermoelectric power generation in the automotive. At present, the thermoelectric generators (TEGs) have been developing with continuously advances in thermoelectric technology. And almost all of the existing thermoelectric technologies are adding a gas tank to the vehicle exhaust system which increases the exhaust back pressure and occupying excessive space of the vehicle chassis. In this study, a new TEG integrated with a front silencer muffler (FMTEG) is proposed. The muffler is reshaped as the heat exchanger which has a hexagon cross-section. The water tank and clamping mechanism have been redesigned for the new heat exchanger. The FMTEG system’s dimensions are small that can well meet the installation requirements and has a good compatibility with the vehicle exhaust system.

With great development of thermoelectric exhaust heat recovery technology, more and more attention has been paid to optimization of automotive thermoelectric generators (ATEGs). A lot of work has been done on optimization of flow field and thermal analysis. However, investigation on acoustic optimization is rather limited. In this paper, efforts have been paid to study the acoustic performance of a flat-plate TEG, and the feasibility of integration of automotive exhaust thermoelectric generator with muffler was discussed. The internal configuration of heat exchanger looks like “fishbone”. Four factors have been taken into consideration: the spacing of two fins, angle of the fins, the diameter of inlet and outlet of exchanger; and filling sound absorbing material in heat exchanger chamber. Based on these four factors, acoustic analysis was carried out.

In order to study the influence of low-viscosity oil on automobile pollutant emissions reduction, three different 0W20 oil samples were prepared with oil 5W30 as the base oil. Parameters such as the oil viscosity, ash, and element content were tested at different stages, speeds, and accelerations of the Worldwide Harmonized Light Vehicles Test Cycle (WLTC). The results showed the effects of low-viscosity oil on exhaust emissions reduction were mainly concentrated in the low-speed and extra high-speed segment. At the low-speed segment, especially in the starting stage, carbon monoxide (CO), total hydrocarbon (THC), and non-methane hydrocarbon (NMHC) emissions can be reduced. The use of low ash oil can reduce nitrogen oxides (NOx) emissions; the methane (CH4) emissions can be reduced by increasing the Zinc (Zn) content in engine oil moderately.

In vehicles with urea-SCR system, normal operation of the urea-SCR system and engine will be influenced if there are deposits appearing on exhaust pipe wall. In this paper, a commercial vehicle is employed to study the influence factors of deposits through the vehicle road test. The results show that, urea injection rate, temperature and flow field have impacts on the formation of deposits. When decreasing the urea injection rate of calibration status by 20%, the deposit yield would reduce by 32%. If the ambient temperature decreased from 36 °C to 26 °C, the deposit yield would increase by 95%. After optimizing the exhaust pipe downstream of the urea injector by removing the step surface, only a few flow marks of urea droplets are observed on the pipe wall, and no lumps of deposits existing.

For fracture cracks that occurred in the tight coupling exhaust manifold durability test of a four-cylinder gasoline engine with EGR channel, causes and solutions for fracture failure were found with the help of CFD and FEA numerical simulations. Wall temperature and heat transfer coefficient of the exhaust manifold inside wall were first accurately obtained through the thermal-fluid coupling analysis, then thermal modal and thermoplastic analysis were acquired by using the finite element method, on account of the bolt pretightening force and the contact relationship between flange face and cylinder head. Results showed that the first-order natural frequency did not meet the design requirements, which was the main reason of fatigue fracture. However, when the first-order natural frequency was rising, the delta equivalent plastic strain was increasing quickly as well.

To make full use of engine exhaust heat and further improve the utilization of the energy efficiency of the heavy truck, thermoelectric module is used to contribute to thermoelectric power generation. The hot-end temperature of the module varies with the engine operating condition because it is connected with the exhaust pipe. The cold-end of the thermoelectric module is mainly cooled by engine cooling system. Increasing the temperature difference between the hot-end and cold-end of the thermoelectric module is a good way to improve the thermoelectric conversion efficiency. For the poor controllability of the hot-end temperature of the thermoelectric module, this study puts forward by lowering the cold-end temperature of the thermoelectric module so as to ensure the improvement of the thermoelectric conversion efficiency. The cooling circle for the cold-end of the thermoelectric module which is independent of the engine cooling system is built.

A 3-D numerical analysis model of transient heat transfer among the multi-component coupling system in combustion chamber of internal combustion engine has been developed successfully in the paper. The model includes almost all solid components in combustion chamber, such as piston assembly, cylinder liner, cylinder head gasket, cylinder head, intake valves and exhaust valves, etc. With two different coupling heat transfer modes, one is the lubricant film heat conduction between two moving components, another is the contact heat conduction between two immovable solid components, and with the direct coupled-field analysis method of FEM, the heat transfer relation among the components is established. The simulation result dedicates the transient heat transfer process among the components such as moving piston assembly and cylinder liner, moving valves and cylinder head. The effect of cylinder head gasket on heat transfer among the components is also studied.