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The sliding door’s movement is 3-dimensional unlike the conventional door. So the electric power and signal are exchanged via the long ‘Power Cable’. It has a quite complex structure in order to be suitable to connect the vehicle’s body and the sliding door even during it’s moving. As the result, it is more expensive than conventional door’s one and the quality could not be guaranteed easily. In this paper, I have developed new technology which could transfer electric power by ‘wireless transfer’ in order to resolve the problem from using ‘Power cable’. I would propose the proper structure to transfer the electric power at any position of the sliding door without any physical connection. To transfer the electric power which drives the window regulator and the actuators in door, I have applied the ‘inductive coupling’ system.

The large luxury sedan seat has a 22-way Movement. It offers a wide range of adjustments to enhance passenger comfort performance while it has many constraints on movement in constrained indoor space. In addition, the power seat is operated by a motor, which makes it difficult for the user to determine the amount of adjustment, unlike determining the amount of adjustment by the power and feel of a person, such as manual seat adjustment. IMS, one-touch mode, is also constrained by parameters such as indoor space package, user's lifestyle, etc. during function playback. This paper aims to design the seat control logic to achieve the best seat comfort while satisfying each constraint. The results of this study are as follows. Increase robustness of power seat control logic. Provide optimal adjustments and comfort at each location. Offer differentiated custom control and seating modes for each seat. Improve customer satisfaction and quality by upgrading software.

Due to improvements in vehicle powertrain performance, friction material fade performance is becoming an important topic. For this reason, needs for studies to improve thermal characteristics of the brake system is increasing. Methods for improving the fade characteristics have several ways to improve the thermal characteristic of friction materials and increase disc capacity. However, increasing disc capacity(size) have some risk of weight and cost rise, and friction factor improvements in friction material tend to cause other problems, such as increasing squeal wire brush noise and increasing metal pick up on disc surface. Therefore, a slot disc study is needed to overcome the problems discussed previously. Currently, there is few research history for slot disc related to fade and metal pickup improvements.

The sliding surface of the brake friction material is not uniform but composed of random contact plateaus with a broad pressure distribution, which are known to closely related to the triggering mechanism of friction induced noise and vibrations. The non-uniform contact plateaus are attributed to the various ingredients in the friction material with a broad range of physical properties and morphology and the size and stiffness of the plateau play crucial roles in determining the friction instability. The incorporation of friction surface inhomogeneity is, therefore, crucial and has to be counted to improve the accuracy of the numerical calculation to simulate brake noise. In this study, the heterogeneous nature of the friction material surface was employed in the simulation to improve the correlation between numerical simulations and experimental results.

This paper presents the design of an additional structure based on acoustic metamaterial (AMM) for the reduction of vibro-acoustic transfer function of a car body panel. As vehicles are lighter and those engine forces are bigger recently, it has become more difficult to reduce the vibration and noise transfer through body panels by using just conventional NVH countermeasures. In this research, a new approach based on AMM is tried to reduce the vibration and noise transfer of a firewall panel. First, a unit cell structure based on the locally resonant metamaterial is devised and the unit cell’s design variables are studied to increase the wave attenuation in the stop band of a dispersion curve, where the Floquet-Bloch theorem is used to estimate the dispersion curve of a two-dimensional periodic structure. Also, the vibration transfer and the vibro-acoustic transfer are predicted in a FE model of meta-plate which is composed of a periodic system of the devised unit cell.

The squeak noise generated during the moving of the door glass has a influence on the performance of vehicles felt by the consumer. In order to improve the noise, it is necessary to understand the principle of a friction vibration. In this paper, it is confirmed that the principle on the waist belt is most closely related to stick-slip and sprag-slip among various vibration characteristics. Stick-slip is expressed by energy accumulation and divergence due to difference in static and dynamic friction coefficient. Sprag-slip define instability of geometric structure due to angle of lips on the belt. In this paper, the physical model and the energy equation are established for the above two phenomena. Stick-slip can be solved by decreasing the difference of the static and dynamic friction coefficient. Sprag-slip is caused by the ratio of compressive and shear stiffness of the lips. The belt uses flocking to ensure durability, not coating.

Voice Recognition (VR) systems have become an integral part of the infotainment systems in the current automotive industry. However, its recognition rate is impacted by external factors such as vehicle cabin noise, road noise, and internal factors which are a function of the voice engine in the system itself. This paper analyzes the VR performance under the effect of two external factors, vehicle cabin noise and the speakers’ speech patterns based on gender. It also compares performance of mid-level sedans from different manufacturers.

Polylactide (PLA), which is one of the most important biocompatible polyesters that are derived from annually renewable biomass such as corn and sugar beets, has attracted much attention for automotive parts application. The manufacturing method of PLA is the ring-opening polymerization of the dimeric cyclic ester of lactic acid, lactide. For the PLA composites including stereocomplexed with L- and D-PLA, we developed the unit processes such as fermentation, separation, lactide conversion, and polymerization. We investigated D-lactic acid fermentation with a view to obtaining the strains capable of producing D-lactic acid, and through catalyst screening test for polycondensation and depolymerization reactions, we got a new method which shortens the whole reaction time of lactide synthesis step. Poly(d-lactide) is obtained from the ring-opening polymerization of d-lactide. Also we investigated several catalysts and polymerization conditions.

Squeak and rattle (S&R) problems in body structure and trim parts have become serious issues for automakers because of their influence on the initial quality perception of consumers. In this study, various CAE and experimental methods developed by Hyundai Motors for squeak and rattle analysis of door systems are reported. Friction-induced vibration and noise generation mechanisms of a door system are studied by an intelligent combination of experimental and numerical methods. It is shown that the effect of degradation of plastics used in door trims can be estimated by a numerical model using the properties obtained experimentally. Effects of changes in material properties such as Young's modulus and loss factor due to the material degradation as well as statistical variations are predicted for several door system configurations. As a new concept, the rattle and squeak index is proposed, which can be used to guide the design.

It is common knowledge that body structure is an important factor of road noise performance. Thus, a high stiffness of body system is required, and determining their optimized stiffness and structure is necessary. Therefore, a method for improving body stiffness and validating the relationship between stiffness and road noise through CAE and experimental trials was tested. Furthermore, a guideline for optimizing body structure for road noise performance was suggested.

Recently, the demand for improving the merchantability of hood open system has been increasing. A novel concept hood open system was proposed by Hyundai Motor Company (HMC) in 2012, which was based on a two-step open latch mechanism. The new hood opening mechanism satisfies Safety laws and improves merchantability.

This paper outlines an improved methodology to perform calculations to verify the compliance of automotive door latch systems to minimum legal requirements as well as to perform additional due diligence calculations necessary to comprehend special cases such as roll over crashes and locally high inertial loadings. This methodology builds on the calculation method recommended by SAE J839 and provides a robust and clear approach for application of this method to cable release systems, which were not prevalent at the time J839 was originally drafted. This method is useful in and of itself but its utility is further increased by the application of the method to a Computer Aided Design (CAD) template (in this case for Catia V5), that allows some automation of the calculation process for a given latch type. This will result in a savings of time, fewer errors and allows for an iterative concurrent analysis during the design process.

It is necessary for vehicle horns not only to satisfy regulations on the sound level but also to fulfill various demands related with sound quality. For example, a disk type horn which is attached on most of small size vehicles has been required to improve its sharp feeling sound. However, the improvement of horn sound has been deterred mainly due to the deficiency of the understanding on how design factors are related with emotional judgments on horn sound. In addition, a proper CAE tool is not available in the process of horn design since it is difficult to describe multi-physical phenomena engaged with horns. The purpose of this study is to improve the sound quality of a disk type horn. In order to achieve this goal, firstly, acoustic characteristics of horns were obtained through a series of experiments. In addition, various sound quality metrics were examined in order to derive design factors affecting sound quality enhancement.

We developed the hard IP (Instrument Panel) that is integrally over molded with a soft layer (TPO, Thermo Plastic Olefin) for the soft feeling and cost reduction. And also we produced the cost-effective PAB(Passenger-side Airbag) door system that had an in-mold tearseam and avoided competitors' patents simultaneously. The development procedure of this technology is; ① Material for overmolding ② Design optimization ③ Solving tool challenges. The reduction of process through integrally molding with soft material helped to accomplish a soft feeling on the IP and cost reduction at the same time. The deployment, head impact and heat aging tests were conducted and 5 patents were applied such as the optimization of the mold structure and injection condition.

Invisible Passenger-side Airbag (IPAB) door system must be designed with a weakened area such that the airbag will break through the Instrument Panel (IP) in the intended manner, with no flying debris at any temperature. At the same time, there must be no cracking or sharp edges at the head impact test (ECE 21.01). Needless to say, Head impact test must keep pace with the deployment test. In this paper, we suggested soft airbag door system that is integrally molded with a hard instrument panel by using Two-shot molding. First of all, we set up the design parameters of IPAB door for the optimal deployment and head impact performance by CAE analysis. And then we optimized the open-close time at each gate of the mold so that the soft and hard material could be integrally molded with the intended boundary. We could make the boundary of two materials more constant by controlling the open-close time of each gate with resin temperature sensor.

Due to technological evolutions and social demands, motor vehicles are requested to be enhanced in terms of occupant safety and comfort. As a result, many countries are reinforcing crash regulations and new car assessment programs. Automotive seats are essential parts for providing passenger safety and comfort and have become most important. Many automotive companies concentrate on optimization of the seat structure. This paper presents an overview of the recent evolution of the seat structures and gives a development procedure covering seat frame design, optimization and validation. Through the study, a competitive frame design is drawn as a case result and a design guideline and a standard development procedure is established

An increasing number of cars which are being used to foster leisure and a convenient life for consumers are being outfitted with roof racks and/or cross bars. This trend of installing roof racks is partly for the function of carrying objects on the roof of the vehicle and partly as a way to affect the style and exterior look of the vehicle. Therefore, the application of roof racks and cross bars is becoming increasingly important in the automotive industry. Because of the expanding application of roof racks on vehicles, the challenge of reducing wind noise caused by exposed cross bars becomes the main issue in this field. For solving this problem, the cross bar shape is designed and evaluated in the development stage, and if there is a problem, it is re-designed and re-evaluated many times. This repetitive corrective action is called “trial and error”.

Hard panel types of invisible passenger-side airbag (IPAB) door system must be designed with a weakened area such that the airbag will deploy through the Instrument Panel (IP) in the intended manner, with no flying debris at any required operating temperature. At the same time, there must be no cracking or sharp edges in the head impact test (ECE 21.01). If the advanced-airbag with the big difference between high and low deployment pressure ranges are applied to hard panel types of IPAB door system, it becomes more difficult to optimize the tearseam strength for satisfying deployment and head impact performance simultaneously. We introduced the ‘Operating Window’ idea from quality engineering to design the hard panel types of IPAB door applied to the advanced-airbag for optimal deployment and head impact performance. To accurately predict impact performance, it is important to characterize the strain rate.

Ground systems in automobiles become more important as more electric devices are installed and the amount of currents flowing increases. The performance of the devices depends on the ground voltage, which is generated between ground points by I-R voltage drops. Therefore, low ground voltages are required for the reduction of the unnecessary power dissipation as well as the reliable performance of the devices. In this paper, we propose an automotive ground system model to analyze ground structure and reveal the main cause of ground voltages. The equivalent resistor network model is presented to describe the relationship between ground points. Then, we validate the model by comparing the simulation results with the measurements in a real car. The presented analysis can provide guidance on designing a reliable ground system such as how to reduce the ground voltages for the proper operation of devices.

Recently weight reduction is increasingly needed in automotive industry to improve fuel efficiency and to meet a CO2 emission requirement. In this paper, we prepared composite body panels for the lightweight vehicle based on a small passenger car. Fender, roof, door, side outer panel, and tailgate are made from hand layup using a glass/carbon hybrid reinforcement. Hood is made from low pressure sheet molding compound (SMC) to investigate feasibility of mass production. Both hand layup and low pressure SMC materials are newly developed and their physical properties are examined. CAE simulation was done for strength analysis and optimization of thickness for the body panels.