In any aerospace mission, after the vehicle has taken off, the visual is lost and the information about its current state is only through the sensor data telemetered in real-time. Very often, this data is difficult to perceive and analyze. In such cases, a 3D, near to real representation of the data can immensely improve the understanding of the current state of mission and can aid in real-time decision making if possible. Generally, any aerospace vehicle carries onboard an inertial system along with other sensors, which measures the position and attitude of the vehicle. This data is communicated to ground station. The received telemetry data is encoded as bytes and sent as packets through the network using the Universal Datagram Protocol (UDP). The transmitted data is often available in a very low frequency, which is not desirable for a smooth display. It is therefore necessary to interpolate the data between intervals based on the time elapsed since last rendered frame.
The hood closing characteristic in gas strut condition is different than in the stay rod condition. In stay rod condition, the hood closes once it is dropped from a minimum closing height and opening the hood requires effort. The gas strut in turn aids in hood opening but for hood closing it requires effort. In sports utility vehicles, due to bigger sizes of hood and architectural requirements dual latches and gas strut are employed on hood. In this condition, the hood can be closed either by dynamic single stroke or by quasi static two stroke conditions. In dynamic case, the hood is closed at higher velocity whereas in quasi static case force is applied first for secondary latching position and then for primary latching position. In this study, both the dynamic and quasi static closing conditions are compared in terms of closing force and velocity and hood over travel.
A crucial component utilized in the trunk space is the luggage board. Positioned at the bottom of the trunk, the luggage board separates the vehicle body from the interior and provides support for luggage.The luggage board serves multiple functions, including load-bearing stiffness for luggage, partition structure functionality, noise insulation, and thermal insulation. To meet the increasing demand for luggage boards in response to the changing market environment, there is a need for a competitive new luggage board manufacturing method. To address this, the "integrated sandwich molding method" is required. The integrated sandwich molding method utilizes three key methodologies: grouping processes to integrate similar functions, analyzing materials to replace them with suitable alternatives, and overcoming any lacking functionality through integrated design structures.
Side doors are pivotal components of any vehicle, not only for their aesthetic and safety aspects but also due to their direct interaction with customers. Therefore, ensuring good structural performance of side doors is crucial, especially under various loading conditions during vehicle use. Among the vital performance criteria for door design, torsional stiffness plays an important role in ensuring an adequate life cycle. This paper focuses on investigating the impact of several door structural parameters on the torsional stiffness of side doors. These parameters include the positioning of the latch, the number of hinge mounting points on doors (single or double bolt), and the design of inner panel with or without Tailor Welded Blank (TWB) construction.
In the early stages of vehicle development, it is critical to establish performance goals for the major systems necessary for NVH. The fundamental modes of BIW and chassis frames are typically assessed using FE models, discretized using 3D shell elements. However, the use of the 3D shell-based FE method is problematic in terms of fast analysis and quick decision-making, especially during the concept phase of a vehicle design because it takes much time and effort for detailed modeling. To overcome these weaknesses, a 1D method based on beam elements has been extensively studied over several decades, but it was not successful because of low analysis accuracy for thin-walled beam structures. This investigation proposes a 1D method based on thin-walled beam theory for fast analysis of vehicle structures with comparable accuracy to 3D shell models.
The Time-Sensitive Networking (TSN) working group has introduced a comprehensive set of standards to enable reliable communication in time-critical systems. The TSN standards set encompasses several shaping mechanisms that aim to provide bounded transmission latency for streams in the network. Among these shaping mechanisms, Cyclic Queuing and Forwarding (CQF) and frame preemption provide deterministic guarantees for frame transmission. However, despite some current studies on the performance analysis of CQF and frame preemption, they also need to consider the potential effects of their combined usage on frame transmission. Furthermore, there is a need for more research that addresses the impact of parameter configuration on frame transmission under different situations and shaping mechanisms, especially in the case of mechanism combination.
The need for accuracy in element design and manufacturing is greater now than ever before in engineering industries. In order to increase accuracy, the part design and function must be clearly communicated between the design engineer and the manufacturing technicians, especially in automotive industry and feeder industries. Geometric Dimensions and Tolerances (GD&T) is an engineering symbolic language that clearly discusses a part function, priority and quality. The GD&T system of elements determines the quality, importance and price of the designed product. The standard used in the United States to define GD&T methodology is ASME Y14.5-2009 while the standard used in Europe is ISO 1101-2017. This article discussed the importance of using GD&T system including the types of geometrical features, limitations and accuracy, feature control frame, datum references frame to handle these symbols seamlessly.
Automotive body structures are being increasingly made in multi-material system consisting of steel, aluminum (Al) and fiber-reinforced plastics (FRP). Therefore, many joining tech-niques such as self-piercing riveting (SPR) and adhesive bonding have been developed. On the other hand, OEMs want to minimize the number of joining techniques to reduce the manufacturing complexity. Amount all joining methods, resistance Spot welding (RSW) is the most advanced and cost-effective one for body-in-white. However, RSW cannot be applied for joining dissimilar materials. Therefore, a novel Rivet Resistance Spot Welding method (RRSW) was developed in which Al or FRP Components can be directly welded to steel structures with existing welding systems. RRSW uses rivet-like steel elements as a welding adapter which are formed into Al or FRP components dur-ing their forming process. After that, they are welded to the steel components by RSW. This paper shows at first the results on Steel – Al RRSW.
Tradespace exploration (TSE) describes the activity occurring early in the design process through which stakeholders explore a broad solution space in search of more-optimal alternatives. In doing so, these stakeholders attempt to maximize the utility inherent in the chosen solution while understanding the tradeoffs and compromises that may be required to find an acceptable solution. In the field of vehicle design, tradespaces are often comprised of vast amounts of alternatives which increases the complexity of the decision-making process. Additionally, the number of stakeholders has grown, as decision-makers seek to include more variety in both perspectives and expertise. As such, decision-making stakeholders can often find themselves working at odds and attempting to maximize vastly different objectives in the process. One way to rectify these contrasting viewpoints can be to intentionally introduce a group framing prior to the start of decision making.
This paper analyzes the mechanism of vibrational energy propagation and panel vibration generation at the point joints between frame and panel which can be applied to reduce the vehicle interior noise. In this study, we focused on the traveling wave in the early stage of propagation before the mode is formed, and investigated the mechanism of panel vibration generation due to wave energy propagation and its reduction method. First, we show theoretically that the out-of-plane component of the transmitted power at the point junction between frame and panel that contributes to panel vibration is associated with frame deformation. Then, we show through numerical verification that panel vibration can be reduced by reducing the transferred power of the out-of-plane component, and explain the effectiveness of the frame-to-panel joint design guidelines based on energy propagation analysis. Next, This analysis technique is applied to the vehicle body model.
For the design optimization of the electric bus body frame orienting frontal crash, considering the uncertainties may impact the crashworthiness performance, a robust optimization scheme considering tolerance design is proposed, which maps the given acceptable objective and feasibility variations into the parameter space to analyze the robustness. Two contribution analysis methods those are the entropy weight and TOPSIS method and the grey correlation calculations method are adopted to screen all the design variables, and 15 shape design variables with relatively high effect are chosen for design optimization. A symmetric tolerance and interval model is used to describe the uncertainty of 15 shape design variables of the key components of the bus body skeleton to form an uncertainty optimization problem in the form of an interval, and a triple-objective robust optimization model is developed to optimize the shape design variables and tolerances simultaneously.
The paper presents a trajectory tracking method for an unmanned bicycle in its local body-fixed coordinate frame. A bicycle is regarded as a multibody system consisting of four rigid bodies which are named front wheel, front fork, body frame, and rear wheel. Unlike many studies before, the interaction between tire and road is regarded as tire force instead of a nonholonomic constraint. The body frame has six degrees of freedom and the rear wheel and front fork have one degree of freedom relative to the body frame respectively. The front wheel has one degree of freedom relative to the front fork. Thus, a bike has nine degrees of freedom in total. The kinetic energy of a bike is expressed using quasi-coordinates in the local body-fixed coordinate frame which has a simpler form than using absolute coordinates in the global frame. The dynamic model can be acquired by submitting the expression of kinetic energy into the Lagrange equation.
Hood insulators are widely used in automotive industry to improve noise insulation, pedestrian impact protection and to provide aesthetic appeal. They are mounted below the hood panel and are often complex in shape and size. Pedestrian head impacts are highly dynamic events with a compressive strain rate experienced by the insulator exceeding 300/s. The energy generated by the impact is partly absorbed by the hood insulators thus reducing the injury to the pedestrian. During this process, the insulator experiences multi-axial stress states. The insulators are usually made of soft multi-layered materials, such as polyurethane or fiberglass, and have a thin scrim layer on either side. These materials are foamed to their nominal thickness and are compression molded to take the required shape of the hood. During this process they undergo thickness reduction varying based on the shape of the hood, thereby increasing their density.
For safe driving function, signs must be visible. Sign luminance is one of the primary factors that determine the visibility of a sign. In daytime conditions, sign luminance is a function of the ambient lighting. In night-time conditions however, sign luminance is a function of the retro-reflectivity of the sign material, the illumination provided by the vehicle headlamps, and the relative locations of the vehicle, sign, and driver. Traffic sign visibility at night is largely determined by sign luminance. Virtual simulation approach is used for analyzing the sign board visibility. Among several factors which affect the visibility of traffic signs at night, headlamp installation position from ground, distance between two lamps & eye position of driver are considered for analyzing the sign board visibility.
The side door check arm is one of the primary components that determine the operating characteristics of a vehicle door. The profile of the check arm has a significant impact on the closing effort of side doors. The side-door closing effort is vital to the customer, as it reflects the overall build quality of the vehicle. In this study, the check arm profiles are analyzed virtually in relation to the side door's closing velocity using ADAMS. A virtual model was developed to simulate the side door closing and opening in Adams. The study involves a check arm that guides the ball spring mechanism unit. The ball spring mechanism unit is attached to the door while the check arm is attached to the body. Typically, a check-arm profile has two or three indents at a specific location which serves to maintain the door open in those positions. When a door enters an indent, the user must exert efforts to traverse it.
The increasing importance of minimizing drag and the absence of an exhaust system result in battery electric vehicles (BEVs) commonly having a very streamlined underbody. Although this shape of underbody is typically characterized by a low acoustic interference potential, significant flow resonance can be observed for certain vehicle configurations and frequencies below 30 Hz. Since the interior of the vehicle is excited as a Helmholtz resonator, these low-frequency fluctuations result in reduced comfort for the passengers. As preliminary studies have shown, the flow around the front wheel spoilers significantly influences this flow phenomenon. Flow separation occurs at the front-wheel spoilers and at the front wheels. This leads to the generation of vortices which are growing significantly while being transported downstream with the flow. Even small geometric changes to add-on components on the underbody significantly influence both aerodynamics and aeroacoustics.