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Добірка наукової літератури з теми "NVH reduction control"

Автор: Grafiati

Опубліковано: 14 березня 2023

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Статті в журналах з теми "NVH reduction control"

Guo, Han, Jianwu Zhang, and Haisheng Yu. "Robust optimisation of dynamic and NVH characteristics for compound power-split hybrid transmission." Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 233, no. 4 (June 25, 2019): 817–26. http://dx.doi.org/10.1177/1464419319856774.

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In this paper, vibro-acoustic characteristics of a power-split hybrid transmission including a compound planetary gear set are investigated by numerical procedure and refined system dynamics modelling. For validation of the numerical predictions, bench tests are performed for dynamic and acoustic responses of the hybrid transmission, contribution rates of acoustic radiation power induced due to the planetary gears, support bearings, transmission shafts and the gearbox housing are estimated. In improving the noise, vibration and harshness (NVH) performance of the transmission during hybrid vehicle acceleration, traction torques of the motors against the planetary gear parametric resonance are formulated and an optimal control strategy is proposed. By real road NVH test results acquired on board of the midsize hybrid car, it is demonstrated that a significant reduction of the planetary gear whine noise is achieved. As a result, numerical approaches applied to establish relationships between torques of the two traction motors and parametric excitations of the compound planetary gear train are experimentally validated.

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Jiang, Tao, Jiang Liu, Cheng Peng, and Shuliang Wang. "Laboratory Test of a Vehicle Active Noise-Control System Based on an Adaptive Step Size Algorithm." Applied Sciences 13, no. 1 (December 24, 2022): 225. http://dx.doi.org/10.3390/app13010225.

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NVH (noise, vibration, and harshness) is a key factor affecting vehicle comfort. Compared with traditional sound absorption and isolation methods, active noise control (ANC) offers a significant advantage in solving the problem of low- and medium-frequency noise from road surfaces. However, the classic filtered-x least mean squares (FxLMS) algorithm is ineffective in terms of adapting to different road noises to ensure a stable noise reduction effect when facing the complex and changeable noise environment of moving vehicles. Therefore, an adaptive step size algorithm (ASSFxLMS) is proposed in this paper, which can adjust the step size according to the size of the reference signal to ensure the stability of the adaptive process. In order to improve the performance of the algorithm, a particle swarm optimization algorithm is also used to automatically adjust the parameters, so that the step size of the adaptive algorithm always maintains a relatively ideal size. The simulated pulse noise of standard SαS distribution was used as the reference signal for the simulation. The simulation results show that compared with other algorithms, the proposed algorithm under different degrees of pulse noise conditions, noise reduction stability, and noise reduction amplitude are improved. In order to further verify the feasibility of the algorithm in vehicle road noise reduction, this paper also conducted a hardware-in-the-loop noise reduction experiment in the laboratory, employing the road noise data collected by the real vehicle. Under different interior noise conditions, the proposed active noise-control system has a maximum noise reduction effect of 12 dB for low-frequency noise below 100 Hz.

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Shin, Hyunki, Donghyuk Jung, Manbae Han, Seungwoo Hong, and Donghee Han. "Minimization of Torque Deviation of Cylinder Deactivation Engine through 48V Mild-Hybrid Starter-Generator Control." Sensors 21, no. 4 (February 18, 2021): 1432. http://dx.doi.org/10.3390/s21041432.

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Cylinder deactivation (CDA) is an effective technique to improve fuel economy in spark ignition (SI) engines. This technique enhances volumetric efficiency and reduces throttling loss. However, practical implementation is restricted due to torque fluctuations between individual cylinders that cause noise, vibration, and harshness (NVH) issues. To ease torque deviation of the CDA, we propose an in-cylinder pressure based 48V mild-hybrid starter-generator (MHSG) control strategy. The target engine realizes CDA with a specialized engine configuration of separated intake manifolds to independently control the airflow into the cylinders. To handle the complexity of the combined CDA and mild-hybrid system, GT-POWER simulation environment was integrated with a SI turbulent combustion model and 48V MHSG model with actual part specifications. The combustion model is essential for in-cylinder pressure-based control; thus, it is calibrated with actual engine experimental data. The modeling results demonstrate the precise accuracy of the engine cylinder pressures and of quantities such as MAF, MAP, BMEP, and IMEP. The proposed control algorithm also showed remarkable control performance, achieved by instantaneous torque calculation and dynamic compensation, with a 99% maximum reduction rate of engine torque deviation under target CDA operations.

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Mayer, Dirk, Thilo Bein, Hendrik Buff, Benedict Götz, Oliver Schwarzhaupt, and Dominik Spancken. "Enhanced lightweight design by composites – Results of the EU project ENLIGHT." Journal of Reinforced Plastics and Composites 37, no. 19 (March 22, 2018): 1217–24. http://dx.doi.org/10.1177/0731684418762321.

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Over recent decades, cars have become larger and heavier with every new generation. The main drivers of such a weight increase have been the improved safety and comfort requirements. Decades of R&D investments to tackle this tendency have resulted in a substantial increase in the weight-specific performance of components and assemblies in terms of cost, strength and stiffness. However, the need for weight reduction in future electric vehicles, without unduly compromising performance and safety, is even stronger since additional weight translates into either reduced driving range or in larger, heavier and more expensive batteries. Within this context, the European Green Vehicle project ENLIGHT developed highly innovative lightweight material technologies for application in structural vehicle parts of future volume produced electric vehicles. Among others, ENLIGHT developed thermoplastic matrix composite and associated manufacturing technologies to a stage that they were applicable at least in medium volume production. The material development was complemented by investigating the required manufacturing and assembly technologies as well. In this paper, a summary of the major results obtained during the four-year project year is presented. A special focus is given to a semi-active composite control arm with significant reduced weight but enhanced NVH properties.

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LØVDAL, IRENE STRANDEN, MARIA BEFRING HOVDA, PER EINAR GRANUM, and JAN THOMAS ROSNES. "Promoting Bacillus cereus Spore Germination for Subsequent Inactivation by Mild Heat Treatment." Journal of Food Protection 74, no. 12 (December 1, 2011): 2079–89. http://dx.doi.org/10.4315/0362-028x.jfp-11-292.

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Sublethal heat treatment may activate dormant spores and thereby potentiate the conversion of spores to vegetative cells. As the germinated spore is known to possess lower heat resistance than its dormant counterpart, it has been postulated that double heat treatment, i.e., spore heat activation followed by germination and then by heat inactivation, can be used to control spores in foods. Production of refrigerated processed foods of extended durability often includes more than one heat treatment of the food components. This work simulates conventional heat treatment procedures and evaluates double heat treatment as a method to improve spore control in model food matrixes of meat broth and cream sauce. Bacillus cereus NVH 1230-88 spores were supplemented in food model matrixes and heat activated at 70°C and then heat inactivated at 80 or 90°C. The samples were held at 29 to 30°C for 1 h between primary and secondary heat treatments, to allow spore germination. Nutrients naturally present in the food matrixes, e.g., amino acids and inosine, could act as germinants that induce germination. The levels of germinants could be too low to produce effective germination within 1 h. Following primary heat treatment, some samples were therefore supplemented with a combination of L-alanine and inosine, a germinant mixture known to be effective for B. cereus spores. In both matrixes, a combination of double heat treatment (heat activation, germination, and inactivation) and addition of germinants gave a reduction in spore counts equivalent to or greater than that obtained with a single heat treatment for 12 min at 90°C. Addition of germinants was essential to induce effective germination in cream sauce during 1 h at 29 to 30°C, and germinants were therefore a crucial supplement to obtain an effect of double heat treatment in this matrix. These data will be valuable when setting up temperature-time-germinant combinations for an optimized spore reduction in mild-heat–treated foods.

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Qiu, Yang, Dongwoo Hong, and Byeongil Kim. "Active Mitigation Strategy of Structure-Borne Vibration with Complex Frequency Spectra from Asymmetric Plate-like Mounting Systems in Next Generation Mobilities." Symmetry 15, no. 1 (January 7, 2023): 178. http://dx.doi.org/10.3390/sym15010178.

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The complicated spectrum produced by electric and hybrid car engines is particularly sensitive to the mid-frequency range. Furthermore, sensor placement in future mobility is crucial because when the positions and orientations of sensors are altered by excessive vehicle vibration, it results in the malfunctioning of autonomous driving systems. Smart structure-based active mounting approaches have been developed to reduce engine-induced vibration. These are made to continually adjust the mounts’ dynamic properties and enhance their performances in terms of noise, vibration, and harshness (NVH) under diverse operating circumstances. It can take the place of the engine support system’s current mount technique. The performance of the source part for reducing vibration when the structure is triggered by a sinusoidal and multi-frequency signal is the main subject of this study. The overall structure, which has two active mounts based on the source-paths-receiver structure, was modeled using a lumped parameter model. In the source section, sinusoidal, amplitude modulation (AM), and frequency modulation (FM) signals were used in order to assess the effectiveness of vibration reduction in the mid-frequency band. The normalized least mean-square (NLMS) technique was utilized to assess the effectiveness of an active mounting system, and a tracking signal was employed as a control signal. The algorithm was further expanded to the multi-NLMS algorithm to monitor the complex spectral signal. This demonstrates how an active mounting system can successfully reduce vibrations when the structure is activated by many mid-frequency complex signals.

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Courteille, E., and F. Mortier. "Idle shake vibration optimization of an engine mounting system through the practical application of transfer path analysis." Noise Control Engineering Journal 68, no. 6 (November 1, 2020): 459–69. http://dx.doi.org/10.3397/1/376838.

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This article presents a practical application of experimental transfer path analysis (TPA) for optimizing idle shake vibrations of a front-wheel-drive car with a transversely mounted four-cylinder diesel engine. Performance control of the vehicle engine mounting system must take into account the multiple dynamic interactions between the engine mounting system, subframe modes and the vehicle suspension. Experimental methods can be used in conjunction with simulations to design and optimize the engine mounting system. TPA is a powerful tool for the diagnosis of vibration and noise transmission via multiple solid paths. TPA allows a quick diagnosis of the engine mounting system performances on vehicle comfort. A strong synergy between numerical model and experimental data finally makes it possible to find better design alternatives, not necessarily obvious to the designer. This study is the guideline for an optimization of the engine mount noise vibration and harshness (NVH) performances by using a hybrid approach, combining an analytical approach and measurement data. First, a diagnosis of the transmission of structure-borne vibrations via the engine mounting system to the seat floor is done at constant idle speed. This method is used to rank individual engine mount contributions in the low-frequency vibration level inside the vehicle. Then, an original approach allows the optimization of the vibration level at idle speed by offsetting contributions of the engine mount paths by adding damping in the right engine mount. This approach has led to the design and validation of an original double inertia-track hydroelastic mount prototype which allows a 5-dB reduction on the seat floor vibration level. The future development of a new version is planned to confirm and optimized the obtained results. The length of the second inertia track will be increased to reach the targeted characteristics, and the adjustment system will be removed to respect the overall dimension constraints of the mount.

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Robinson, L., and K. Kimpinski. "P.004 Neurogenic orthostatic hypotension results in impaired information processing speed." Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques 45, s2 (June 2018): S17. http://dx.doi.org/10.1017/cjn.2018.106.

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Background: Neurogenic orthostatic hypotension (NOH) is characterized by a reduction in systolic blood pressure of ≥20 mmHg or diastolic blood pressure of ≥10 mmHg within three minutes of upright posture. NOH is prevalent in the elderly population who is at increased risk for cognitive decline, therefore it is imperative to investigate if there is a relationship between NOH and impaired cognition. Methods: Currently, 9 control subjects and 4 NOH patients have been recruited. Cognitive function is assessed using the symbol digit modalities test (SDMT) which assesses information processing speed and the Stroop test which measures response inhibition. SDMT and Stroop test are administered when the table is supine and during tilt. Results: NOH patients scored significantly worse on SDMT when lying (p=0.018) and standing (p=0.004) compared to the control group. Control subjects performed significantly better when standing for both SDMT (p=0.008) and Stroop (p=0.026), whereas NOH patients had similar scores when lying and standing for SDMT and Stroop. Conclusions: Preliminary results show that information processing speed is slower in NOH patients than controls in both the supine and standing positions. NOH patients have a more difficult time inhibiting unwanted responses compared to controls when standing, which is represented by a greater interference score in NOH patients.

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Rockswold, Sarah B., Gaylan L. Rockswold, David A. Zaun, and Jiannong Liu. "A prospective, randomized Phase II clinical trial to evaluate the effect of combined hyperbaric and normobaric hyperoxia on cerebral metabolism, intracranial pressure, oxygen toxicity, and clinical outcome in severe traumatic brain injury." Journal of Neurosurgery 118, no. 6 (June 2013): 1317–28. http://dx.doi.org/10.3171/2013.2.jns121468.

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Object Preclinical and clinical investigations indicate that the positive effect of hyperbaric oxygen (HBO2) for severe traumatic brain injury (TBI) occurs after rather than during treatment. The brain appears better able to use baseline O2 levels following HBO2 treatments. In this study, the authors evaluate the combination of HBO2 and normobaric hyperoxia (NBH) as a single treatment. Methods Forty-two patients who sustained severe TBI (mean Glasgow Coma Scale [GCS] score 5.7) were prospectively randomized within 24 hours of injury to either: 1) combined HBO2/NBH (60 minutes of HBO2 at 1.5 atmospheres absolute [ATA] followed by NBH, 3 hours of 100% fraction of inspired oxygen [FiO2] at 1.0 ATA) or 2) control, standard care. Treatments occurred once every 24 hours for 3 consecutive days. Intracranial pressure, surrogate markers for cerebral metabolism, and O2 toxicity were monitored. Clinical outcome was assessed at 6 months using the sliding dichotomized Glasgow Outcome Scale (GOS) score. Mixed-effects linear modeling was used to statistically test differences between the treatment and control groups. Functional outcome and mortality rates were compared using chi-square tests. Results There were no significant differences in demographic characteristics between the 2 groups. In comparison with values in the control group, brain tissue partial pressure of O2 (PO2) levels were significantly increased during and following combined HBO2/NBH treatments in both the noninjured and pericontusional brain (p < 0.0001). Microdialysate lactate/pyruvate ratios were significantly decreased in the noninjured brain in the combined HBO2/NBH group as compared with controls (p < 0.0078). The combined HBO2/NBH group's intracranial pressure values were significantly lower than those of the control group during treatment, and the improvement continued until the next treatment session (p < 0.0006). The combined HBO2/NBH group's levels of microdialysate glycerol were significantly lower than those of the control group in both noninjured and pericontusional brain (p < 0.001). The combined HBO2/NBH group's level of CSF F2-isoprostane was decreased at 6 hours after treatment as compared with that of controls, but the difference did not quite reach statistical significance (p = 0.0692). There was an absolute 26% reduction in mortality for the combined HBO2/NBH group (p = 0.048) and an absolute 36% improvement in favorable outcome using the sliding dichotomized GOS (p = 0.024) as compared with the control group. Conclusions In this Phase II clinical trial, in comparison with standard care (control treatment) combined HBO2/NBH treatments significantly improved markers of oxidative metabolism in relatively uninjured brain as well as pericontusional tissue, reduced intracranial hypertension, and demonstrated improvement in markers of cerebral toxicity. There was significant reduction in mortality and improved favorable outcome as measured by GOS. The combination of HBO2 and NBH therapy appears to have potential therapeutic efficacy as compared with the 2 treatments in isolation. Clinical trial registration no.: NCT00170352 (ClinicalTrials.gov).

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Chang, Chia-Cheng, Nobumasa Kuwana, Susumu Ito, and Tadashi Ikegami. "Response of cerebral blood flow and cerebrovascular reactivity to acetazolamide in patients with dementia and idiopathic normal-pressure hydrocephalus." Neurosurgical Focus 7, no. 4 (October 1999): E11. http://dx.doi.org/10.3171/foc.1999.7.4.12.

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The responses of cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to administration of acetazolamide were investigated in 16 patients with dementia and ventriculomegaly to clarify the cerebral hemodynamics in patients with idiopathic normal-pressure hydrocephalus (NPH). The mean CBF velocity in the whole brain was measured by the Patlak plot method by using technetium-99m hexamethylpropyleneamine oxime single-photon emission computerized tomography. The CVR values were obtained from the response to administration of 500 mg of acetazolamide and calculated as the percentage of change from the baseline mean CBF value. The mean CBF value was significantly reduced (p < 0.01) in six patients with (35.2 ± 5 ml/100 g/minute) and 10 patients without (33.5 ± 2.8 ml/100 g/minute) NPH compared with the age-matched normal controls (40.8 ± 3.2 ml/100 g/minute), showing no significant difference. The CVR was significantly impaired in patients with NPH (0.8 ± 1.7%; p < 0.001), whereas in patients without NPH preserved CVR (11.3 ± 3%) was demonstrated compared with the normal controls (14.7 ± 1.1%). In patients with NPH a significantly lower CVR (p < 0.001) was shown than in those without NPH. The CVR significantly increased (p < 0.001) after placement of a shunt in patients with NPH. Reductions in both CBF and CVR may be diagnostic indicators of NPH in patients with dementia in whom ventriculomegaly is present. In patients with dementia and idiopathic NPH both reduced CBF and extremely impaired CVR are shown. The results of the present study suggest that ischemia due to the process of NPH is responsible for the reduction of CBF and manifestation of symptoms in patients with idiopathic NPH.

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Книги з теми "NVH reduction control"

Outreach/risk reduction strategies for changing HIV-related risk behaviors among injection drug users: The National AIDS Demonstration Research (NADR) Project (NIH publication). For sale by the U.S. G.P.O., Supt. of Docs, 1994.

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Teixeira, Pedro, Monica Pinto, Lucilia Alves, and Ana Filipa Henriques. "Rehabilitation Nursing Care for the Person in the Context of Non-Invasive Ventilation." In Advances in Medical Diagnosis, Treatment, and Care, 10–30. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-3531-8.ch002.

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Non-invasive ventilation is, nowadays, a well received, successful therapeutic strategy for the treatment of different varieties of respiratory failure. Associated to respiratory rehabilitation and exercise training, NVI brings numerous advantages to the person, namely in the control of symptoms, in the quality of life, in the reduction of the perception of dyspnea, in the increase of the tolerance to the activity, and in the decrease in the use of health services. The intervention of the specialist nurse in rehabilitation nursing is essential in order to maximize health gains. However, the bibliography that supports these gains with the intervention of the EEER needs greater investment in the research area.

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Armstrong, F. Daniel, and Steven Pavlakis. "Neurocognitive Outcomes in Sickle Cell Disease." In Cognitive and Behavioral Abnormalities of Pediatric Diseases. Oxford University Press, 2010. http://dx.doi.org/10.1093/oso/9780195342680.003.0033.

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Sickle cell disease (SCD) is associated with a range of serious complications, including painful episodes, acute chest syndrome, stroke, splenic sequestration, overwhelming bacterial sepsis, and a host of other less frequent complications that impair quality of life and threaten long-term survival (National Institutes of Health [NIH] 2002). More than 98% of all children born in the United States are tested for SCD as part of state newborn screening programs, making it possible to identify infants who are at risk for these many complications of SCD (Centers for Disease Control and Prevention 2009). It is estimated that about 72,000–80,000 individuals of all ages are living with SCD in the United States, a large number of whom will experience cognitive complication at some point in their lives. Nearly 2 million carry sickle trait but do not have the clinical manifestations of the disease. Approximately 1 in 500 infants of African descent and one in 36,000 of Hispanic descent are born with SCD in the United States each year (National Heart, Lung, and Blood Institute (NHLBI), NIH 2009). While the cognitive complications of cerebrovascular infarction (stroke) have long been recognized, research over the last two decades has shown that cognitive functioning in both children and adults can be impaired for many reasons other than stroke. This chapter describes the underlying structural and biological mechanisms that lead to cognitive impairment, the cognitive outcomes associated with SCD, and emerging pharmacologic, behavioral, and educational intervention strategies to address the cognitive needs of this population. Sickle cell disease describes a group of hereditary hemoglobinopathies that have in common the presence of an abnormal hemoglobin variant known as sickle hemoglobin (HbS). The homozygous condition (HbSS) is also the most severe, and is known as sickle cell anemia. Although there are numerous other variations of sickle hemoglobinopathy, the most common include HbSβthal° and HbSC. Under oxidative stress, the sickle hemoglobin causes erythrocytes to collapse into rigid sickle-shaped molecules, with a significant reduction in oxygen-carrying capacity (NIH 2002).

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"Table 1: Average composition of faeces and urine after separation by a filter net (0.78x0.78) Faeces Urine Dry matter (%) 32.50 1.92 Crude ash of dry matter 25.70 63.10 N-Kj (%) 1.24 0.34 NH -N 34 0.35 (%) 1.64 0.05 K20 85 0.62 CaO 45 0.04 MgO 48 0.02 Cu ppm 197 2.50 pH 9.1 From Table 1 it is evident that the percentages of the minerals in the faeces are high. In the urine the percentages are much lower except potassium. By manuring grassland potassium is the limiting factor, while o.n arable land the quantity of nitrogen needs to be taken into account. In applying solid manure to cropland the Cu-content needs to be taken into account. Depending on the Cu-status of the soil, 0-6 kg Cu/ha is advised. By fertilizing with 10 t/ha of solid manure about 3 kg Cu/ha is administered Because only a small amount of copper is taken up by plant growth and lost through drainage, the application of solid manure needs to be spread out over a few years if Cu is not to accumulate in the soil. 5.2 Odour_emissions It can be concluded that separation and removal of urine and faeces from piggery result in a reduced formation of odour components (5). This might result in a decrease of the precieved odour as compared with a housing system with underslat slurry storage. In order to obtain a reliable figure for the actual odour reduction, measurements have been carried out. Samples of ventilation air from a pighouse with underslat slurry storage as well as a pighouse with filter nets were taken on a number of different occasions. All samples were collected in bags made from FEP-Teflon. Odour experiments were performed the following day using a dilution apparatus (olfactometer) and a group of observers (panel). Since the establishment of the odour intensity is a time consuming affair, it has become practice in Dutch agricultural odour research to concentrate on the establishment of the odour treshold (6). The odour treshold is defined as that dilution of odorous air which." In Odour Prevention and Control of Organic Sludge and Livestock Farming, 232. CRC Press, 1986. http://dx.doi.org/10.1201/9781482286311-92.

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Тези доповідей конференцій з теми "NVH reduction control"

Ying Gu, Yang Yue, Jianwei Jin, Wang Hailin, Fangwu Ma, Qiang Liu, and Fuquan Zhao. "Research of auto NVH material performance and noise reduction effect." In 2011 Second International Conference on Mechanic Automation and Control Engineering (MACE). IEEE, 2011. http://dx.doi.org/10.1109/mace.2011.5987951.

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Alwan, Jamil M., Chi-Chin Wu, Thomas H. Sheng, Chunhui (Kevin) Li, and Yi Liu. "Light Weight Steel Technology Used in a Vehicle Design: Safety CAE Analysis." In ASME 2001 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/imece2001/amd-25430.

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Abstract The automotive industry is facing new environmental requirements that call for more stringent rules to protect the environment and reduce material and resources usage. As such, the automotive industry is in more need to reduce fuel consumption and control emissions in order to meet the new environmental requirements. One of the methods that helps in acheiving lower fuel consumption targets is weight reduction. Making cars lighter sounds plausable, but is it acheivable without affecting vehicle Safety as well as other customer demands for more comfort and better vehicle performance (Criteria that are a must in today’s stringent safety requirements and competitive environment.). The body-in-white (BIW) accounts for about 25% of the total vehicle weight, and thus it provides a great opportunity for weight reduction. However, the challenge is not only to reduce the vehicle’s BIW weight, but also to maintain competitive vehicle functionality in Safety, NVH and Durability. The studied technologies include: Generic Body Architecture, Tailor Welded Blanks, Ultra High Strength Steel, Structural Foams, and Structural Adhesives. Each of these technologies was benchmarked in terms of weight savings, vs Safety, NVH, and Durability functionalities. The models that were used for the technology prove outs are based on generic modified Body Architecture CAE models. It was shown that the total weight savings acheived from architecture alone was 24 lb (out of 707 lb initial BIW weight, thus making the weight savings close to 3.4%). In addition, the combination of Tailor welded blanks and Ultra high strength steel has resulted in an 80 lb reduction in the BIW weight, which is close to 11.3%. Structural foams showed an effective increase in roof crush strength, and showed potential enhancement for frontal crash pulses as well as potential shortening of front ends. On the other hand, structural adhesives showed enormous NVH benefits in stiffness with as little as 1% energy absorption enhancement for crash. Thus producing the perfect method to compensate the reduced body stiffness due to sheet metal gage reduction and replacement with Ultra High strength steel. By such both safety and NVH functionalities are complemented without weight increase.

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Plattenburg, Joseph, Jason T. Dreyer, and Rajendra Singh. "Active and Passive Vibration Control Using Compact Damping Patches: Assessment of a Reduced Order Model for an Euler Beam." In ASME 2015 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/dscc2015-9636.

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Concurrent placement of compact active and passive damping patches for vibration reduction is a developing area of research. Analytical and computational models to evaluate alternate patch configurations and structural geometries are not widely available. To overcome this void, this paper presents a simplified discrete-system model for vibrations of a beam-like structure. A disturbance input is included in the model, along with a control input from an active patch. Localized structural damping resulting from a passive patch is modeled with an equivalent loss factor. Results from the simplified model are verified using a more detailed analytical formulation, which is based on the Ritz approximation. Verification studies include the effect of a passive damping patch on modal loss factors and broadband attenuation. Finally, a few case studies are proposed which show the efficacy of the reduced-order model for parametric design studies. These studies include determining the effect of localized damping on the control system parameters that are required for attenuation of localized and global motions. The effect of patch locations on system response is also studied. This work has potential applications in industry since compact damping patches are attractive NVH treatments that add minimal weight and complexity.

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Kim, Bo Min, Dae Sik Ko, and Jong Min Kim. "Vehicle’s New Anti-Roll System for Suspension Parasitic Stiffness Reduction and Non-Linear Roll Stiffness Characteristic." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63392.

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In general, vehicle uses torsional stiffness of a stabilizer bar to control the roll motion. But this stabilizer bar system has problems with degradation for ride comfort and vehicle’s NVH characteristic due to the suspension parasitic stiffness caused by deformation and wear of the stabilizer bar rubber bush. In addition, it is difficult to control the vehicle’s roll motion effectively in case of excessive vehicle roll behavior when it is designed to satisfy ride comfort simultaneously because of the stabilizer bar’s linear roll stiffness characteristic. In this paper, the new anti-roll system is suggested which consists of connecting link, push rod, laminated leaf spring, and rotational bearing. This new concept anti-roll system can minimize the suspension parasitic stiffness by using rotational bearing structure and give the vehicle non-linear roll stiffness by using the laminated leaf spring structure which are composed of main spring and auxiliary one. Reduction of suspension parasitic stiffness and realization of non-linear roll stiffness in this anti-roll system were verified with both vehicle dynamic simulation and vehicle test. Also, this study includes improvement of the system operating efficiency through material change and shape optimization of the leaf spring, and optimal configuration of the force transfer system.

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Yang, In Hyung, O. Cheol Kwon, Jung Youn Lee, and Jae-Eung Oh. "Sound Quality Evaluation for the Vehicle HVAC System After Active Noise Control." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-66584.

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The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver’s perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the HVAC sound among the vehicle interior noise has been reflected sensitively in the side of psychology. In previous study, we have developed to verify identification of source for the vehicle HVAC system through multiple-dimensional spectral analysis. Also we carried out objective assessments on the vehicle HVAC noises and subjective assessments have been already performed with 30 subjects. In this study, the linear regression models were obtained for the subjective evaluation and the sound quality metrics. The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Appropriation of regression model is necessary to R2 value and F-value. And testing for regression model is necessary to Independence, Homoscedesticity and Normality. To enhance sound quality, we applied active noise control (ANC) which is effective in the low-frequency bandwidth. Primary noise of the HVAC system is less than 500Hz. As a result of ANC application, sound quality is improved by more quiet, powerful, expensive, smooth.

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Campillo-Davoa, Nuria, Miguel Sanchez-Lozanoa, Ramon Peral-Ortsa, Bert Pluymersb, and Wim Desmetb. "New Features on Noise, Vibration and Harshness Posed by the Next Generation of Vehicles." In Applied Human Factors and Ergonomics Conference. AHFE International, 2021. http://dx.doi.org/10.54941/ahfe100695.

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Traffic noise is generally considered one of the most important sources of environmental pollution in urban and interurban areas. Each individual vehicle in the traffic flow contributes to the total emission by means of three different sub-sources: noise emitted by engine, exhaust and transmission; aerodynamic noise; and noise radiated during tire/road interaction. Those sub-sources play a different role depending on the characteristics of the traffic, i.e. for low speed traffic – less than 30km/h – mechanical noise coming from engine and drive chain is the prominent, whilst for high speed – above 30km/h – the main contribution is related to tire/road noise. The new generation of hybrid and electric vehicles (HEVs) will contribute to a reduction of noise pollution through reduced use or inexistence of the internal combustion engine. That feature, which is positive for environmental noise control, carries a negative connotation since low noise emissions of HEVs represent an actual danger to pedestrians. Also drivers of HEVs should adapt their driving style and behavior to the new features related to noise, vibration and harshness (NVH) inside the cabin. In order to solve that problem, warning sounds are being designed by HEVs manufacturers, but, it is not actually known how those new sounds will integrate into urban soundscapes. These and many other questions arise related to the increased presence of electric vehicles in city car fleets. The Research Group in Applied Mechanical Engineering of Miguel Hernandez University in Spain is currently coordinating the COST TU1105 Action “NVH analysis techniques for design and optimization of hybrid and electric vehicles”, together with the Noise and Vibration Research Group of KU Leuven in Belgium. The aim of the Action is to engage NVH experts from vehicle industry and renowned research groups in the accumulation, development and dissemination of novel analysis techniques to be developed for the next generation of vehicles and their drivers. In this article, new features posed by HEVs are discussed and latest developments on the topic are presented.

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Kwak, Jung-Myung, Yong-Hee Kim, Peter Zawadzky, and Simon Scherner. "Real-Time Torque Estimation of an Air Conditioner Compressor for the CO2 Emissions Reduction from an Engine Vehicle." In FISITA World Congress 2021. FISITA, 2021. http://dx.doi.org/10.46720/f2020-epv-071.

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Reducing the CO2 emissions from all new cars is essential to prevent a climate emergency. Even in the trend of accelerating the uptake of zero-emission models, the market forecasting of engine vehicles is still high in 2030. The technology to improve the CO2 emissions from conventional engine cars is getting more important. This paper introduces the new technology which is about the optimization of engine control to reduce the CO2 emissions of conventional engine cars. The engine has various accessories and the engine controller considers loads of various engine accessories to control the engine power. While running of air conditioner, the load of the air conditioner compressor has a huge portion of the total engine load. The torque of the A/C compressor is about 10 ~ 30% of the total engine torque at idle conditions. Inaccurate compressor torque estimation causes huge RPM fluctuation or even engine shut-down. And it results in NVH issues, poor drivability, poor fuel economy, and serious car accidents. Variable displacement A/C compressor has become the most popular compressor type for fuel economy. While driving, engine RPM is continuously changed by a driver. A/C compressor RPM is also changed by this dramatic engine RPM changes. These RPM changes cause mass flow changes of refrigerant which are results in the unstable cooling capacity of an evaporator. Thus variable displacement compressor continuously changes the stroke by itself to maintain the stable cooling capacity. The control valve of the compressor senses the changes of suction pressure of the refrigerant and controls the stroke mechanically by controlling the mass flow of pressurized refrigerant in the compressor. By this mechanical stroke control of the control valve, the compressor can react to the dramatic changes of engine RPM. But, due to this dynamic and mechanical stroke changes, the A/C controller can not estimate the accurate changing timing and values of A/C compressor torque. By real-time stroke sensing of A/C compressor and the new torque logic which uses stroke signal, the accurate torque value at transient engine RPM conditions can be estimated. This paper focuses on testing to validate the torque estimation accuracy and the effect of CO2 emissions reduction. This technology has been validated at the compressor test bench, A/C system test bench, and vehicle.

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Dolatabadi, N., S. Theodossiades, and S. J. Rothberg. "Power Loss Investigation in an Internal Combustion Engine Piston Equipped With a Nonlinear Energy Absorber." In ASME 2017 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/detc2017-67787.

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The piston impacts against the cylinder liner are the most significant sources of mechanical noise in internal combustion engines. Conventionally, the severity of impacts is reduced through the modification of physical and geometrical characteristics of components in the piston assembly. These methods effectively reduce power losses at certain engine operating conditions. Moreover, the conditions leading to the reduction in power losses inversely increase the engine noise due to piston impacts. An alternative control method that is robust to fluctuations in engine operating conditions is anticipated to improve the engine’s NVH performance whilst exacerbation in power loss remains within the limits of the conventional methods. The concept of Targeted Energy Transfer (TET) through the use of Nonlinear Energy Sinks (NES) has not been applied yet in automotive powertrains. Numerical studies have shown a potential in reducing the severity of impact dynamics by controlling piston’s secondary motion. The power loss of a piston equipped with a nonlinear energy sink is investigated in this study.

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Jocelyn D. Buchanan, David B. Parker, Marty B. Rhoades, Jacek Koziel, and William J. Rogers. "Assessment of Moisture Control and Additives for Odor Reduction from Open-Lot Feedyard Surfaces." In 2003, Las Vegas, NV July 27-30, 2003. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2003. http://dx.doi.org/10.13031/2013.13888.

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Manofsky Olesky, Laura, Jiri Vavra, Dennis Assanis, and Aristotelis Babajimopoulos. "Internal Residual vs. Elevated Intake Temperature: How the Method of Charge Preheating Affects the Phasing Limitations of HCCI Combustion." In ASME 2012 Internal Combustion Engine Division Spring Technical Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ices2012-81127.

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Homogeneous charge compression ignition (HCCI) has the potential to reduce both fuel consumption and NOx emissons compared to normal spark-ignited (SI) combustion. For a relatively low compression ratio engine, high unburned temperatures are needed to initiate HCCI combustion, which is achieved with large amounts of internal residual or by heating the intake charge. The amount of residual in the combustion chamber is controlled by a recompression valve strategy, which relies on negative valve overlap (NVO) to trap residual gases in the cylinder. A single-cylinder research engine with fully-flexible valve actuation is used to explore the limits of HCCI combustion phasing at a constant load of ∼3 bar IMEPg. This is done by performing two individual sweeps of a) internal residual fraction (via NVO) and b) intake air temperature to control combustion phasing. It is found that increasing both variables advances the phasing of HCCI combustion, which leads to increased NOx emissions and a higher ringing intensity. On the other hand, a reduction in these variables leads to greater emissions of CO and HC, as well as a decrease in combustion stability. A direct comparison of the two sweeps suggests that the points with elevated intake temperatures are more prone to ringing as combustion is advanced and less prone to instability and misfire as combustion is retarded. This behavior can be explained by compositional differences (air vs. EGR dilution) which lead to variations in burn rate and peak temperature. As a final study, two additional NVO sweeps are performed while holding intake temperature constant at 30°C and 90°C. Again, it is seen that at higher intake temperatures, combustion is more susceptible to ringing at advanced timings and more resistant to instability/misfire at retarded timings.

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