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In this paper, an improved grey Euclidean relational analysis method based on Euclidean distance was proposed, which was based on the traditional grey relational analysis method. This method was applied to the material-structure integrated design of the backrest skeleton of a car seat. Firstly, the steel backrest skeleton of a car seat was replaced by carbon fiber reinforced plastics (CFRP), and the backrest skeleton was designed as an integrated structure. Its weight was reduced by 1.69 kg (39.12 %) while still meeting various seat performance test requirements. Then, the effect of the ply design on the performance of car seats with CFRP was studied, and the optimal layer scheme of CFRP backrest skeleton of car seats was obtained by combining the grey Euclidean relational analysis method. Finally, the method proposed in this paper was compared with the widely used method. The results showed that the optimization schemes obtained by the two methods greatly improved performance indicators, especially L_R_2 which had an improvement rate of 13.31 %. Additionally, the proposed method reduced computing resources by 95 %, indicating its ability to effectively balance optimization results and calculation efficiency. [ABSTRACT FROM AUTHOR]

The increase in the size of the city and the increase in population mobility have greatly increased the number of vehicles on the road, and at the same time brought considerable challenges to the traffic management department. In recent years, more and more experts and scholars have devoted themselves to applying sensors, network communication and dynamic adaptive technologies to road traffic management systems. At present, people have not completely overcome all kinds of complex problems in traffic supervision. The complexity of traffic information and the defects of identification algorithms have brought great challenges to intelligent traffic management. This article has launched a research on the intelligent Internet of Things traffic management system, with the detection and recognition of stationary vehicles and seat belts as the key analysis targets. When monitoring stationary vehicles, this paper replaces the background difference algorithm commonly used in dynamic vehicle detection with a new recognition algorithm. From the experimental results, the average detection accuracy of the new algorithm is 96.77% higher than the previous 87.56%. When studying the driver's seat belt detection, this paper combines the YOLOv3 target detection algorithm and the lightweight network structure, and proposes a driver-oriented positioning algorithm. With the increase in the number of lightweight templates, the accuracy of the positioning algorithm has increased from 80.57 to 99.98%. But on the other hand, the detection speed has also changed from 78 to 69 frames/s. [ABSTRACT FROM AUTHOR]

Work presented in this article concerns an industrial example of a mass optimization problem, performed on automotive suspension components. Due to the fact, that the considered element, i.e. spring seat is a part of the vehicle suspension module, analyses are performed on the shock absorber assembly level with the mutual interaction of each body. To solve constrained optimization task, a combination of genetic and gradient-based algorithms are used, involving nonlinear static strength problem, represented by finite element method analysis. Parametric representation of considered component geometry is used, incorporating manufacturing restrictions and design assembly requirements. The final, optimized form of the spring seat is then compared with its initial shape, i.e. "working space", especially under constraints fulfillment, which are specified by the customer. Performance comparison of used methods (or combination of such) is the aim of this paper, focusing on practical aspects of work, i.e. final mass decrease, number of function calls, or design space exploration capabilities. The optimization method presented hereby is universal and can be adapted to many fields of industry, wherever efficient mass reduction must be achieved incorporating the feasibility of the component. The hybrid optimization approach presented in the paper allows effective mass reduction and works well for multimodal objective functions typically found in industrial applications. [ABSTRACT FROM AUTHOR]

The main goal of this paper is to analyze flow loss of the ventilated seats by seating position for driver. Also, this work includes the method of analysis as to body pressure distribution, ventilation performance, subjective valuation, and flow loss. The experiment is conducted with a male who is 75 kg of weight and 177 cm of height corresponding AM 50 % (American model) and the evaluation of the vehicle seat is conducted through the regular inspections after mass production system. As far as the seating positions as experimenter preference is concerned, it is verified to stress the load at cushion and back from the body pressure. The trend of ventilation performance is shown to be highly at internal temperature sensors attached to face of the vehicle seat without working ventilation. Consequently, the temperature range of cushion and back of vehicle seat is increased in order of lay down < lean(rest) < normal conditions. [ABSTRACT FROM AUTHOR]

The examination of seated occupants' ride comfort under whole-body vibration is a complex topic that involves multiple factors. Whole-body vibration refers to the mechanical vibration that is transmitted to the entire body through a supporting surface, such as a vehicle seat, when traveling on rough or uneven surfaces. There are several methods to assess ride comfort under whole-body vibration, such as subjective assessments, objective measurements, and mathematical models. Subjective assessments involve asking participants to rate their perceived level of discomfort or satisfaction during the vibration exposure, typically using a numerical scale or questionnaire. Objective measurements include accelerometers or vibration meters that record the actual physical vibrations transmitted to the body during the exposure. Mathematical models use various physiological and biomechanical parameters to predict the level of discomfort based on the vibration data. The examination of seated occupants ride comfort under whole-body vibration has been of great interest for many years. In this paper, a multi-body biomechanical model of a seated occupant with a backrest is proposed to perform ride comfort analysis. The novelty of the present model is that it represents complete passenger by including thighs, legs, and foot which were neglected in the past research. A multi-objective firefly algorithm is developed to evaluate the biomechanical parameters (mass, stiffness and damping) of the proposed model. Based on the optimized parameters, segmental transmissibilities are calculated and compared with experimental readings. The proposed model is then combined with a 7-dofs commercial car model to perform a ride comfort study. The ISO 2631-1:1997 ride comfort standards are used to compare the simulated segmental accelerations. Additionally, the influence of biomechanical parameters on most critical organs is analyzed to improve ride comfort. The outcomes of the analysis reveal that seated occupants perceive maximum vibration in the 3–6 Hz frequency range. To improve seated occupants' ride comfort, automotive designers must concentrate on the pelvis region. The adopted methodology and outcomes are helpful to evaluate protective measures in automobile industries. Furthermore, these procedures may be used to reduce the musculoskeletal disorders in seated occupants. [ABSTRACT FROM AUTHOR]

Failure mode and effects analysis (FMEA) is one of the typical structured, systematic and proactive approaches for product or system failure analysis. A critical step in FMEA is identifying potential failure modes for product sub-systems, components, and processes, for which component-failure mode (CF) knowledge is necessarily needed as an important source of knowledge. However, this knowledge is usually acquired manually based on historical documents such as bills of material and failure analysis reports, which is a labor-intensive and time-consuming task, incurring inefficiency and plenty of mistakes. Nevertheless, few existing studies have developed an effective and intelligent approach to acquiring accurate CF knowledge automatically. To fill the gap, this paper proposes a method to construct the CF matrix automatically by mining unstructured and short quality problem texts and mapping as well as representing them as CF knowledge. Starting with mining the frequent itemsets of failure modes through Apriori algorithm, the method uses the semantic dictionary WordNet to find synonyms in the set of failure modes, based on which the standard set of failure modes is finally built. Subsequently, upon the previous work and components set, we design the component-failure mode matrix mining (CFMM) algorithm and apply it to establish the CF matrix from unstructured quality problem texts. Lastly, we examine the quality data of the seat module of an automobile company as a case study in order to validate the proposed method. The result shows that the failure mode extraction method with standardized features can extract failure modes more effectively than the FP-growth and K-means clustering methods. Meanwhile, the devised CFMM algorithm can extract more combinations of CF than the FP-growth method and build a richer CF matrix. Although different industries have distinct domain characteristics, our proposed method can be applicable not only to manufacturing but also to other fields needing FMEA to enhance product and system reliability. [ABSTRACT FROM AUTHOR]

With the reduction of vehicle interior noise, the Buzz, Squeak and Rattle (BSR) noises have become an intractable problem that needs to be tackled urgently. Seat system rattle noises have a large contribution to the passengers' complaints, due to the close distance between the passengers and seats. The seat structure and its components can be sources of rattle noise based on their physical characteristics. The aim of the present paper is to characterize the sound quality property of rattle noise in seat system, and subsequently, use the characteristics of the rattle noises to assess the subjective responses to the noise. In this study, sound metrics are computed for the signals recorded at different points in the seat system. To be more specific, the signals are recorded before and after the durability test in different loading states. Consequently, the characteristics of the rattle noises were compared and analyzed, and the jury test was performed. On this basis, a rattle index and evaluation models were developed. It is expected that the developed rattle evaluation system and sound quality index can be used to reduce the automotive interior rattle noise in terms of subjective levels as well as objective levels. [ABSTRACT FROM AUTHOR]

Neck injuries caused by low-speed rear-end collisions are a worldwide problem. The reasonable design of car seat can effectively prevent or reduce the passenger neck injuries. In this paper, the finite element analysis (FEA) and whiplash test are combined to optimize the seat structure parameters to enhance the safety. The whiplash test results of the existing car seats according to C-NCAP (2015) were matched with FEA, and the optimization scheme was developed by computer simulation. For the improvement of seat safety, the optimizations are applied to determine backrest stiffness, backrest rotational stiffness, headrest rotational stiffness and headrest stiffness. The retest results of optimized seat show that its safety performance is greatly improved. Furthermore, it shows that the combination of finite element analysis and whiplash test can optimize seat structure to improve safety performance. [ABSTRACT FROM AUTHOR]

To achieve the secondary production in multistage fracturing wells of tight oil, milling tools are usually used to remove the multistage fracturing ball seats to achieve production with a large diameter in later. In this paper, first of all, the working mechanism of milling tools for multistage fracturing ball seats was studied and a mechanical analysis model of single abrasive grain was established. Then, an experimental system for milling tools was developed, and the experimental tests of the flat, the blade, and the slope milling tool were conducted in order. Besides, the morphology of chips and the surface morphology of the workpiece after the experiment were analyzed. Also, the working performance of milling tools was evaluated from the perspectives of working safety, working efficiency, and wear resistance of the milling tool. The results show that the torque of the milling tool increases nonlinearly with the increase in the cutting depth of the abrasive grain and increases linearly with the increase in the cutting width. Also, the chips are irregular particles and the size is mainly from 10 to 50 μm. So, the chips should be pumped up with a small pump pressure and a large displacement. Besides this, the cutting depths of the abrasive grains are from 216.20 to 635.47 μm and the bottom surface of the milling tool should be eccentric to avoid the zero point of cutting speed. Furthermore, the torque of the slope milling tool is 23.8% larger than that of the flat milling tool, which is also 30.4% smaller than that of the blade milling tool. Compared with the flat milling tool, the working efficiency of the blade milling tool improves by 79.9% and the slope milling tool improves by 111.1%. Also, the wear resistance of the blade milling tool decreases by 102.7%, while the slope milling tool declines by 32.6% when compared with the flat milling tool. Therefore, the slope milling tool has the characteristics of moderate torque, stable working conditions, the highest working efficiency, and fine wear resistance, which is preferably used to mill multistage fracturing ball seats. This study provides a theoretical basis and guidance for milling multistage fracturing ball seats on-site and realizing production with a large diameter in later stages of multistage fracturing wells. [ABSTRACT FROM AUTHOR]

The paper deals with the parameter sensitivity analysis of a passenger/seat model that can be used for ride comfort assessments. The final aim is to produce a comprehensive framework for enabling vehicle seat designers to develop comfortable (and healthy) seats, especially for those people who spend their lives while working on vehicles. In this paper a seated passenger proprietary model has been proposed and validated either by comparing it with a mathematical model derived by means of commercial software, either by experimental activities. On the basis of the validated model a sensitivity analysis has been performed, aiming to identify the key parameters affecting the ride comfort. A total of 47 parameters were accounted for. Many parameters seem relevant to describe the ride comfort of a seated road vehicle passenger. The most important conclusion of the research is that the parameters referring to posture have proved to influence ride comfort to a great extent. Other relevant but less important parameters are: the stiffness and damping of the seat, the geometry of the seat, the size and inertia properties of the body segments, and the stiffness and damping of the different parts of the human body. Different running conditions have been considered, i.e. vehicle passing over cleats or running on a randomly profiled road. Different running conditions influence differently the ride comfort, so care has to be used when performing either experimental or numerical simulations. [ABSTRACT FROM AUTHOR]

This document is a personal account of Jerry Ericksen's family perspectives, as told by his daughter Lynn Cadmus and son Randy Ericksen. Lynn recalls fond memories of her father teaching her about nature, swimming, and making meal times fun. Randy reflects on their father's diverse range of interests, including mathematics, mechanics, smoking a pipe, watching television, and collecting various items. Both Lynn and Randy express admiration for their father's accomplishments and the impact he had on others in his field. [Extracted from the article]

In this paper, an application of speaker identification in automobile industry is proposed. The work is divided into two main categories. The first part deals with the task of speaker identification where a system is trained and tested for multiple users using a database of isolated Hindi digits and Hindi sentences. A hybrid new algorithm is used for speaker identification which captures the benefits of both LPC and MFCC feature extraction technique. The new proposed technique shows an improvement of 2.05% over conventional MFCC features for isolated Hindi digits and 12.41% for Hindi sentences. It also shows an improvement of 53.26 over LPC for Hindi sentence and 32.51% for isolated Hindi digit over LPC. The proposed features were also tested for real time noisy environment by adding speech and F16 noise to test voice samples with varying degree of distortion starting from 0 to 20 dB. The second part describes the interfacing techniques and design of the hardware configuration for seat adjustment. The proposed model is designed using MATLAB. Speech samples from users are recorded through a microphone. Different features of this wav file are evaluated and fed into the model generated during testing phase. Depending on outcome from the classifier, a user is identified. Once the user is successfully identified, signals are sent to the servo motor through arduino microcontroller interfaced through MATLAB to automatically adjust the driver's seat. [ABSTRACT FROM AUTHOR]

Metallic reinforcing titanium is added to the magnesium matrix to improve the mechanical properties without losing ductility. Titanium has negligible solid solubility in magnesium below 500°C therefore it does not form a tertiary hard phase with Mg. Therefore, when titanium is added to magnesium, both strength and ductility are improved. However, due to the low solid solubility of Ti in Mg, the bonding between matrix and reinforcement is poor. Therefore, a small amount of metallic reinforcement Cu is added to fabricate Mg/Ti/Cu hybrid composites by powder metallurgy technique to enhance the bonding between Mg and Ti. Cu is selected as a binding agent because it has significant solid solubility with Ti and Mg. In the present work, the effect of Cu on the physical, mechanical, and thermal properties of Mg/Ti/Cu composites has been investigated. The addition of Cu was found to decrease the strength, hardness, and wear rate. On the other hand, the thermal conductivity increased. The strength, wear resistance and thermal stability of the prepared Mg- based hybrid composites are sufficient enough to replace some components of cast iron and aluminum in automotive special seat frames, door panels, brake disks of light-duty vehicles, etc. Thus, the prepared material is recommended for use in automotive and other industries. [ABSTRACT FROM AUTHOR]

Embedded wireless sensors are important components of mobile distributed computing networks, and one of the target applications areas is health care. The preservation of mobility for senior citizens is one of the key issues in maintaining an independent lifestyle. Thus health technologies inside a car can contribute both to safety issues (supervision of driver fitness) as well as healthcare issues by monitoring vitals signs imperceptibly. In this paper, three embedded measurement techniques for non-contact monitoring of vital signals have been investigated. Specifically, capacitive electrocardiogram (cECG) monitoring, mechanical movement analysis (ballistocardiogram, BCG) using piezo-foils and inductive impedance monitoring were examined regarding their potential for integration into car seats. All three sensing techniques omit the need for electroconductive contact to the human body, but require defined mechanical boundary conditions (stable distances or, in the case of BCG, frictional connection). The physical principles of operation, the specific boundary conditions regarding automotive integration and the results during wireless operation in a running car are presented. All three sensors were equipped with local intelligence by incorporating a microcontroller. To eliminate the need for additional cabling, a wireless Bluetooth communication module was added and used to transmit data to a measurement PC. Finally, preliminary results obtained during test drives on German city roads and highways are discussed. [ABSTRACT FROM AUTHOR]

Embryogenesis depends on a tightly regulated balance between mitosis, differentiation, and morphogenesis. Understanding how the embryo uses a relatively small number of proteins to transition between growth and morphogenesis is a central question of developmental biology, but the mechanisms controlling mitosis and differentiation are considered to be fundamentally distinct. Here we show the mitotic kinase Polo, which regulates all steps of mitosis in Drosophila, also directs cellular morphogenesis after cell cycle exit. In mitotic cells, the Aurora kinases activate Polo to control a cytoskeletal regulatory module that directs cytokinesis. We show that in the post-mitotic mesoderm, the control of Polo activity transitions from the Aurora kinases to the uncharacterized kinase Back Seat Driver (Bsd), where Bsd and Polo cooperate to regulate muscle morphogenesis. Polo and its effectors therefore direct mitosis and cellular morphogenesis, but the transition from growth to morphogenesis is determined by the spatiotemporal expression of upstream activating kinases. The mechanisms regulating mitosis and differentiation during development are thought to be distinct. Here they show that in Drosophila the mitotic kinase Polo regulates cellular morphogenesis after cell cycle exit. [ABSTRACT FROM AUTHOR]

The characteristic subcutaneous hemorrhage along the seat belt in motor vehicle accidents is called the seat belt sign (SBS). The risk of organ injuries is especially high when abdominal SBS is located above the anterior superior iliac spine (ASIS). The purpose of this study analyzed the physical and radiographic factors of healthy volunteers sit on car seat that affect initial position of abdominal seat belt, namely "lap belt", related to the seat belt injury. This study was examined prospectively relation between physical characteristics of one hundred healthy volunteers and lap belt position sitting the car seat. Physical findings were clarified age, sex, height, body mass index (BMI), and waist circumference. Radiographical findings were measured lumber lordosis (LL), sacral slope (SS), and initial lap belt position by marking with lead tape for the center and ASIS of the lap belt installed on the driver's car seat. In the lateral X-ray image, we measured the horizontal distance (X-value) and vertical distance (Z-value) from the ASIS to the central marker. The lap belt angle was determined to measure the angle between the horizontal line and the straight line connecting the upper edges of the markers. Statistical analysis of the relationships between physical characteristics and radiological findings was performed. X-value and Z-value were positively correlated with body weight, BMI, and waist circumference, while the lap belt angle was negatively correlated with body weight, BMI, and waist circumference. The relationship between physical characteristics and the initial position of seat belt was analyzed. Since the lap belt is positioned higher than the ASIS in occupants with a high BMI, it is likely to cause seat belt injury. This analysis can help to develop safer seat belts and to enlighten car occupants. [ABSTRACT FROM AUTHOR]

A novel polypropylene glycol (designated PPG) which contains an extremely smaller amount of by-products (monols) was developed to improve the riding comfort of an automotive seating foams, The current trend in the automotive seating industry is moving to low resilience molded foam due to the structure change from "full foam" to "foam and high tension spring combination," new automotive seating foams were desired to have low resilience with keeping the low transmissibility at 6 Hz. Riding comfort mainly consists of three factors such as static property, dynamic property and durability. Each issue was solved by means of increasing the polymer molecular weight and the crosslinking density in the polymer matrix. Furthermore, it was also cleared that the transmissibility at resonance frequency of the foam can lower by means of the adjustment of closed cell ratio in the foam. In this paper, we describe the foam properties (static property, dynamic property, durability) of TDI/MDI based molded foams and make clear the mechanism of the Riding comfort of automotive seating foams. [ABSTRACT FROM AUTHOR]

At present, the safety performance and lightweight of passenger car seat has become more and more important. The multi-objective lightweight optimization of the passenger car seat frame is carried out in this study. The novelty of this study is that we propose a detailed optimization design method and a design process in lightweight optimization for passenger car seat. In more detail, firstly, according to the ratio of energy absorption to mass method, the lightweight design components are selected. Secondly, different seat safety tests are conducted to optimize the corresponding components by considering both continuous thickness variables and discrete material variables. Thirdly, the strain index, the displacement of key points, the material cost, and the total mass of the components which need to be optimized (opti-components) are considered objectives. After that, the grey relational analysis (GRA) is adopted to optimize the material thickness scheme of the lightweight design components. Besides, the optimized coefficient of variation (OCV) method is applied to evaluate the corresponding weighting values of the objectives. Meanwhile, the availability of the grey relational analysis and optimized coefficient of variation (GRA&OCV) is assessed through comparing advantages among the method of GRA&OCV, the grey relational analysis and coefficient of variation (GRA&CV), the technique for order preference by similarity to ideal solution and coefficient of variation (TOPSIS&CV), as well as the technique for order preference by similarity to ideal solution and optimized coefficient of variation (TOPSIS&OCV) in the multi-objective lightweight optimization of passenger car seat frame. As a result, the total material cost and mass of the passenger car seat frame are reduced by 17.00% and by 2.08 kg (12.46%), respectively, with guaranteed vibrational and safety performance. Therefore, GRA&OCV can be effectively applied in multi-objective lightweight optimization of the passenger car seat frame. [ABSTRACT FROM AUTHOR]

Instead of a monolayer, multi-layered cushion can be promising to develop more comfortable automotive seat if the layer materials are properly selected. In this study, we have examined the seating comfort of different types of multilayer seat cushions. Polyurethane foams (PUFs) of three different hardness, memory foam, and technogel were used in different combination to prepare four types of multilayer seat cushions. The short-term seating comfort of the seat cushions has been investigated in terms of hardness, initial hardness factor (IHF), modulus irregularity factor (MIF), sag factor (SF), and hysteresis loss as derived from the indentation force deflection (IFD) curves. Long-term comfort has been compared to the respective stress relaxation behavior of the seat cushions. It has been observed that both the short and long-term conditions of comfort are not only influenced by the characteristics of the upper layer, but also by the bottom layer (i.e., supporting material). The present work will help the seat designer to consider the material characteristics for fabricating a good automotive seat on the basis of the desired features needed to provide traveling passengers with proper short- and long-term comfort. [ABSTRACT FROM AUTHOR]

Productivity is a key-factor for companies manufacturing parts and sets to the automotive industry. Automation plays an important role in this matter, allowing development of entire manufacturing cells without the direct need of workers. Even in countries where the labour cost is relatively low, it becomes necessary to improve the level of automation applied to manufacturing cells and reduce the dependence of the human labour unpredictability, also increasing the quality and reducing the costs. This case study was developed based on an industrial request in order to improve a semi-automatic cell devoted to seat suspension mat manufacturing. The original cell allows several automatic operations but it needs two workers for two specific operations not considered in the initial design. Thus, new concepts of wire feeding and manipulation were developed in order to allow a better material flow throughout the cell. The new cell was designed and built with success, allowing to obtain a full-automated system, which leads to a better productivity and reliability of the manufacturing process. [ABSTRACT FROM AUTHOR]

We face a real-world train-unit assignment problem for an operator running trains in a regional area. Given a set of timetabled train trips, each with a required number of passenger seats, and a set of train units, each with a given number of available seats, the problem calls for an assignment of the train units to the trips, possibly combining more than one train unit for a given trip, that fulfills the seat requests. With respect to analogous case studies previously faced in the literature, ours is characterized by the fairly large number of distinct train-unit types available (in addition to the fairly large number of trips to be covered). As a result, although there is a wide margin of improvement over the solution used by the practitioners (as our results show), even only finding a solution of the same value is challenging in practice. We present a successful heuristic approach, based on an ILP formulation in which the seat requirement constraints are stated in a “strong” form, derived from the description of the convex hull of the variant of the knapsack polytope arising when the sum of the variables is restricted not to exceed two. Computational results on real-world instances are reported, showing the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]