This study quantitatively analyzed Buzz, Squeak, and Rattle (BSR) noises occurring during automotive operation and identified their root causes. Abnormal noises were initially detected during a first test drive and were classified into BSR types based on data from a Noise Observer system. Case analysis revealed that in the 2020 G model, a squeak noise was caused by friction between solid components due to durability degradation and damage to the suspension bushing. In contrast, the 2022 G model exhibited a rattle noise resulting from insufficient structural gaps. As modern vehicles continue to pursue higher performance, safety, and cabin quietness, the reduction in component gaps has increased the likelihood of BSR occurrences. This study demonstrates the effectiveness of diagnosing the root causes of BSR and confirms its practical value in reducing maintenance time and minimizing misdiagnoses.
This study investigates the effects of various Throttle Position Sensor (TPS) signal anomalies and throttle body defects on automotive acceleration and safety by experimentally reproducing and analyzing eight distinct fault scenarios. The results demonstrate that the Electronic Control Unit (ECU) consistently detects signal anomalies and activates fail-safe modes, limiting throttle response and engine output to maintain automotive control. In all fault conditions, sudden unintended acceleration was effectively prevented, and braking performance remained unaffected. These findings underscore the robustness of the throttle control system against electrical and mechanical defects and offer valuable insights for the design of safer drive-by-wire systems.
This study investigates the impact of both direct and indirect moisture ingress into an automotive engine control unit(ECU) on vehicle behavior and operational safety. Two experimental conditions were examined: exposure to an environment with 100% relative humidity(indirect ingress) and direct injection of 1.0~2.0 cc of water onto the ECU(direct ingress). The results showed no abnormal behavior under indirect moisture conditions. However, direct moisture ingress caused engine malfunctions, warning light activations, and irregular vehicle behavior. Notably, the vehicle's safety logic functioned as intended, resulting in engine shutdown without leading to unintended acceleration. These findings provide quantitative data valuable for future reliability assessments of ECUs and investigations into sudden unintended acceleration phenomena.
NVH(Noise, Vibration, and Harshness) characteristics are critical indicators for evaluating automotive quality and diagnosing mechanical issues through abnormal vibrations during driving. Among various components, tires are the only part of the automotive in direct contact with the road, making them a major source of noise and vibration. Tire-related anomalies not only affect ride comfort but can also pose serious safety hazards. This study presents a diagnostic approach that utilizes NVH analysis, wheel balance inspection, and RFV(Radial Force Variation) measurement to identify and repair tire faults. Through case analysis, it was confirmed that abnormal vibrations caused by internal moisture accumulation and structural deformation of tires could be accurately diagnosed and addressed. The proposed method enables early detection of tire-related issues, providing a preventive maintenance strategy and contributing to enhanced automotive safety and reliability.
Recently, there has been growing anxiety about automotive due to accidents suspected to be caused by sudden unintended acceleration. A study was conducted on the effect of automotive defects on Sudden Unintended Acceleration. Experimental results were derived and analyzed by simulating the situation of sudden unintended acceleration while driving a automotive. It was experimentally confirmed that the defect in the TPS sensor had no direct effect on the rapid increase in RPM. It has been confirmed that the vehicle brakes normally when the brakes are applied even if there is a TPS sensor defect. In the future, it is necessary to investigate the correlation between automotive defects and sudden unintended acceleration through various experiments.
Recently, automotive are used not only as a means of transportation, but also as a private and leisure spaces. In order to secure competitiveness in the automobile market, we must improve durability and noise/vibration technologies. The driver wants to keep quiet even if the car is used for a long time. The types of noise and vibration generated by the automotive can be divided into NVH and BSR. NVH should be reduced because it is caused by mechanical defects and aging. In this study, it was possible to accurately analyze the cause of noise and vibration, also it could identify the location, and repair that. In the future, research of an abnormal and vibrations such as NVH and BSR in automotive is needed to clearly identify.
Automotive technology has developed rapidly and is becoming the intensive of cutting edge technology. For this reason, Automotive are used not only as a means of transportation, but also as a private and leisure spaces. The driver wants to keep quiet even if the car is used for a long time. NVH should be reduced because it is caused by mechanical defects and aging. In this study, it was presented that a seven-step procedure for failure diagnosis and repair to reduce noise/vibration. NVH was diagnosed by comparing the result of the rotator order tracking analysis with the problem frequency. It was possible to accurately analyze the cause of noise and vibration, also it coud identify the location, and repair that.
Recently, the number of elderly driver accidents has been steadily increasing. EDR(Event Data Recorder) helps a lot in understanding traffic accidents. In particular, as anxiety about SUA(Sudden Unintended Acceleration) increases, EDR data is playing an important role in accident analysis. In this study, EDR data of an accident vehicle suspected of SUA was analyzed to identify traffic accident circumstances and detailed accidents. Experimental results were derived and analyzed by simulating the situation of SUA while driving a car. As a result, it was found that normal braking is performed when the brake pedal is operated even in dangerous situations such as mechanical defects and driver malfunctions. Rather than finding the cause of an accident after a traffic accident, countermeasures are needed to prevent mechanical defects and driving malfunctions before a traffic accident.
When cooking, especially during processes such as grilling or frying, harmful gases are generated. Among them, fine dust is a major factor causing lung cancer, and to eliminate it, range hoods are commonly used. Particularly, when using portable cooking device like gas stoves, it is even more challenging to remove fine dust. In this study, a cooking device was developed to combine steam and cooled air in the air-curtain area to recover fine dust generated during the cooking process, allowing it to be collected as food. The device was evaluated according to criteria defined independently and validated through experiments. As a result, all criteria were satisfied within the specified range.
This study has assessed mechanical bonding strength of lead-free solder joint. Assessment methods was performing long-term reliability test about thermal shock, thermal life and high temperature & high humidity. Based on the results of analyzing mean values that was obtained from repetion of 5 times according to each conditions, reduction of mechanical bonding strength of each tests was confirmed. When it comes to HB chip, the order of high deviation rate was shown thermal shock, high temperature & humidity and thermal life. And the higher deviation rate of R0 is high temperature & humidity, thermal life and thermal shock. The order of high deviation rate of C1 chip is high temperature & humidity, thermal shock and thermal life. Related to this result of experiment, the most stable error range of mechanical bonding strength is established. From now on optimized quantity of solder and shape of solder-joint is needed by establishing a test method which can make error range of mechanical bonding strength minimize.
This study was analyzed the characteristics of temperature distribution in DPF(Diesel Particulate Filter) equipped with partitioned electric heaters. Analysis parameters was used by variation to the length of pipe from exhaust manifold to inlet of filter. The temperature of the exhaust gas flowing into the DPF is related closely to the regeneration of filter. Due to space constraints, the DPF have inlet of bent pipe. The inlet of bent pipe induce the heterogeneous distribution of flow. The heterogeneous trapping of smoke is induced according to the heterogeneous distribution of flow. And the heterogeneous distribution of temperature in DPF is induced. In this study, without the use of assistive devices for even distribution of flow into DPF, the characteristics of temperature distribution in DPF were investigated according to the variation of the length of inlet pipe.