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Instantaneous local heat transfer coefficients on the wall surface of combustion chamber were estimated experimentally using a four cycle, L-type, single cylinder, spark-ignition engine. The effects of gas flow and flame propagation on the heat transfer coefficients were investigated. Local heat flux was measured at twenty four positions on the cylinder head using a fast-response heat flux sensor developed by the authors, and the pressure in the combustion chamber was measured simultaneously. The burned- and unburned gas temperatures were calculated from a two-zone model. The flame arrival time at a position of cylinder head surface was also measured and flame velocity was calculated. The results showed that the maximum heat flux decreases as the flame arrival time increases. An empirical correlation between Nusselt number based on the local heat transfer coefficient and Reynolds number based on the flame velocity is derived from the experimental investigation of spark-ignition engine.

The influence of elevated temperature forming on local mechanical properties of AZ31B magnesium (Mg) sheet material was investigated. The Mg sheet was formed into a closure component with high temperature gas pressure at 485°C. Miniature tensile testing specimens were cut from selected areas of the component where different levels of thinning occurred. The specimens were strained in tension to fracture using a miniature tensile stage. The two-dimensional strain distribution in the necking region along with true stress-true strain curves were computed using a digital image correlation technique to assess the influence of the forming-induced thinning on tensile strength and percent elongation at fracture.

Over the years, internal combustion engines have been researched and improved in the search for more power and for lower fuel consumption. An automotive subsystem that directly affects the performance of the engine is the valve train system. This system allows for the control of the admittance and release of gases from the combustion chamber. This system operates in all phases, ensuring that the valves open and close properly and ensuring the sealing of the cylinder. Several researchers have studied the kinematics and dynamics of the valve actuation system to improve engine performance. As the actuation of the valves occurs usually by cams, every movement and timing of the system is dictated by the design characteristics of the profile of the cams: it has a predominant action on the dynamics of the system.

In autonomous driving, variations in tire vertical load, tire slip angle, road conditions, tire pressure and tire friction all contribute to uncertainty in tire cornering stiffness. Even the same tire may vary slightly during the manufacturing process. Therefore, the uncertainty of tire cornering stiffness has an important influence for autonomous driving path planning and control strategies. In this paper, the Chebyshev interval method is used to represent the uncertainty of tire cornering stiffness and is combined with a model predictive control algorithm to obtain the trajectory interval bands under local path planning and tracking control. The accuracy of the tire cornering stiffness model and the path tracking efficiency are verified by comparing with the path planning and control results without considering the corner stiffness uncertainties.

Local path planning for obstacle avoidance is one of the core topics of intelligent vehicle. A novel method based on dubins curve and tentacle algorithm is proposed in this article, with the consideration of obstacle avoidance and vehicle motion constraints. First, the preview distance of the vehicle is given according to the current speed, so that the preview point can be found with the information of global path. Then dubins curve is adopted to find a path with appropriate turning radius, between the current position and preview point, satisfying the constraints of current direction and target direction, considering handling and ride comfort of the vehicle. In order to avoid obstacle, tentacle algorithm is adopted. 20 tentacle points are given by moving the original preview point, and then 21 local paths can be given by using dubins curve. Cost function is used to find out the best option of the 21 paths.

Dense depth estimation is a critical application in the field of robotics and machine vision where the depth perception is essential. Unlike traditional approaches which use expensive sensors such as LiDAR (Light Detection and Ranging) devices or stereo camera setup, the proposed approach for depth estimation uses a single camera mounted on a rotating platform. This proposed setup is an effective replacement to usage of multiple cameras, which provide around view information required for some operations in the domain of autonomous vehicles and robots. Dense depth estimation of local scene is performed using the proposed setup. This is a novel, however challenging task because baseline distance between camera positions inversely affect common regions between images. The proposed work involves dense two view reconstruction and depth map merging to obtain a reliable large dense depth map.

Local strain measurement based on digital image correlation at both macroscopic and microscopic scales is presented. A speckle pattern was used for the macroscopic strain mapping to reveal the inhomogeneous deformation processes occurring during tensile deformation of a strip cast automotive aluminum sheet. Moreover, a novel microscopic strain mapping technique based on scanning electron microscopic (SEM) topography image correlation was introduced for strain mapping down to the grain level. The SEM images taken from an in-situ tensile sample of the same material within a field emission SEM chamber are used to demonstrate the validity of the method. The results clearly reveal the evolution of local strain of order of one as well as the formation of shear band in the material.

In this paper, the local stress intensity factors for kinked cracks in spot weld cup specimens are investigated by finite element analyses. Based on the experimental observations of kinked crack growth mechanisms in square-cup specimens under cyclic loading conditions, axisymmetric finite element models are established to investigate the local stress intensity factor solutions for kinked cracks emanating from the main crack. Both circular and rectangular shaped notch tip and a sharp crack tip are considered for the main crack. Various kink lengths are considered. The local stress intensity factor solutions for kinked cracks are obtained. The results show that the local stress intensity factors for kinked cracks with finite kink lengths are much higher than those based on the closed-form solutions for kinked cracks with vanishing kink length. Finally, the implications of the local stress intensity factor solutions for kinked cracks on fatigue life prediction are discussed.

Limited room temperature formability hinders the wide-spread use of high strength aluminum alloys in body parts. Forming at warm temperatures or from softer tempers are the current solutions. In this work, our approach is to start with age-hardened sheets from 7xxx and 6xxx family of alloys and improve their formability using local thermomechanical processing only in the regions demanding highest ductility in the forming processes. We achieved local formability improvements with friction stir processing and introduce another process named roller bending-unbending as a concept and showed its feasibility through finite element simulations. Initial results from FSP indicated significant deformation in the processed zones with minimal sheet distortion. FSP also resulted in dynamically recrystallized, fine grained (d < 5 μm) microstructures in the processed regions with textures significantly different from the base material.

Intelligent driving is an important research direction in the field of artificial intelligence. The fourth industrial revolution represented by the Internet of things provides more prospects for the development of intelligent vehicles. Trajectory planning and tracking control is one of the key technologies of intelligent driving vehicle. This paper takes intelligent driving vehicle as the starting point and establishes a research method of intelligent vehicle trajectory planning based on particle swarm optimization, based on the vehicle kinematics and dynamics model, a model predictive control algorithm is built for trajectory tracking control, the simulation scene is built by Prescan, the vehicle dynamics parameters are set in Carsim, and then the joint simulation is carried out with Simulink.

The objective of this study was to investigate the local change of PV value on the end faces of rocker pins driven by a high-performance chain under transmitting torque conditions. A test bench system was prepared to evaluate the behavior of the chain belt under driven state. Local contact force of the pin was measured by strain gauges attached to a specific modified pin for which the thickness was partly reduced by machine work. Change of PV value on the end face of the pin was also calculated by considering the change of pressure generated by contact force and sliding velocity of rocker pin. Autorotation angles of the rocker pins in the groove of driving and driven sheaves were investigated by replacing the normal pulleys with visibly transparent sheaves made with acrylic resin. The representative loading points were also calculated assuming that the pin was regarded as a simple beam where an eccentric compressive load was applied.

In the multi-link mechanism of a variable compression ratio engine, the stiffness of the end of the housing increase by adopting the slit structure, this eventually led to an increase in pressure concentrate locally at a certain contact point at the end of the sliding surface of the lower link bearing. As a design solution, this is a report of how to disperses/reduces the generated axial pressure by optimizing the shape of the sliding surface based on FEM/EHD, which are estimated by considering the deformation characteristics of lower link mechanism.

Valve covers are a primary source of radiated engine noise. In this paper, we discuss an analytical approach that captures the complicated nonlinear response of the cam cover gaskets and grommets without the need for a prohibitively large finite-element model of the cam cover system. We utilize a detailed local analysis of the gasket and grommet components and abstract their isolation characteristics for later use in a global NVH (Noise-Vibration-Harshness) system analysis.

This paper presents the design and experimental validation of a localization method for autonomous driving. The investigated method proposes and compares the application of the Extended Kalman Filter (EKF) and Unscented Kalman Filter (UKF) to the sensor fusion of onboard data streaming from a Global Positioning System (GPS) sensor and an Inertial Navigation System (INS). In the paper, the design of the hardware layout and the proposed software architecture is presented. The method is experimentally validated in real time by using a properly instrumented all-wheel-drive electric racing vehicle and a compact Sport Utility Vehicle (SUV). The proposed algorithm is deployed on a high-performance computing platform with an embedded Graphical Processing Unit that is mounted on board the considered vehicles.

Future SAE Level 4 and Level 5 autonomous vehicles will require novel applications of localization, perception, control and artificial intelligence technology in order to offer innovative and disruptive solutions to current mobility problems. This paper concentrates on low speed autonomous shuttles that are transitioning from being tested in limited traffic, dedicated routes to being deployed as SAE Level 4 automated driving vehicles in urban environments like college campuses and outdoor shopping centers within smart cities. The Ohio State University has designated a small segment in an underserved area of campus as an initial autonomous vehicle (AV) pilot test route for the deployment of low speed autonomous shuttles. This paper presents initial results of ongoing work on developing solutions to the localization and perception challenges of this planned pilot deployment.

A three-dimensional (3D) sound intensity probe is used to identify the trim components generating buzz, squeak, and rattle (BSR) noise in a vehicle interior. The 3D intensity probe has the advantages of compact overall size, small number of microphones, and low-frequency detection capability. Although the 3D sound intensimetry has been not popularly applied in practical problems due to various bias errors, a new error compensation method is adopted in this work, substantially improving the estimate’s precision. Linearization of the phase function of the cross-spectral density function between a set of two microphones is used to calculate the intensity avoiding spectral bias error, and an error map for spatial angles is used to compensate for the difference in directivity index around the microphone array. An intensity probe with an even microphone spacing of 30 mm in tetrahedral arrangement is used for the source localization.

The recent research on location approaches of the intelligent vehicle based on Light Detection and Ranging (LiDAR) is analyzed in this paper. According to the features of these approaches, it can be divided into three categories: simultaneous localization and mapping (SLAM), offline mapping and online localization (OMOL) and fusion localization (FL). Past research and applications of the main algorithms and critical research scenarios in each localization approaches are reviewed. Three aspects of the current trend in location approaches of the intelligent vehicle based on LiDAR are discussed. Based on object detection, object recognition and object analysis algorithms in the field of deep learning, semantic SLAM and real-time three-dimensional reconstruction are important research trends for SLAM. The performance of robustness and real-time performance of localization algorithm of intelligent vehicles based on LiDAR need to be improved.

The exploitation of full load capabilities of DI gasoline engines requires at least the same degree of effort as in MPFI engine development. An optics based sensor and sensing technique is presented, which together with conventional pressure indicating provides identification of self ignition centers as the engine is operated under knock or borderline knock conditions. The knock location sensor is configured as a spark plug providing the relevant spark plug properties together with the multichannel optical access into the upper part of the combustion chamber. Functionality and sensitivity of this sensing technique are demonstrated and results for combustion system development are shown.

Structure-born vibrations are often required to be localized in a complex structure, but in such dispersive medium, the vibration wave propagates with speed dependent on frequency. This property of solid materials causes an adverse effect for localization of vibrational events. The cause behind such phenomenon is that the propagating wave envelope changes its phase delay and amplitude in time and space as it travels in dispersive medium. This problem was previously approached by filtering a signal to focus on frequencies of the wave propagating with a similar speed, with improved accuracy of cross-correlation results. However, application of this technique has not been researched for localization of vibrational sources. In this work we take advantage of filtering prior to cross-correlation calculation while using multiple sensors to indicate an approximate location of vibration sources.

Acoustic beamforming was used to visualize the sound radiation of trucks under test track passby and actual highway operating conditions. The purpose of these measurements was to obtain an understanding of which sources contribute to the overall passby noise level and to determine the vertical distribution of noise sources. For trucks, drive axle tires were found to be the major contributor to passby noise at highway speeds, followed by powertrain noise to a much less degree, and very occasionally, exhaust stack outlet noise. For medium and heavy trucks, the acoustic mean source height was found to be about 0.5m and about 0.3m for light vehicles.