4 results on '"Kim, Byeongil"'
Search Results
2. Location optimization standard of passive–active vibration isolation element for plate structures in next generation mobilities.
- Author
-
Qiu, Yang, Hong, Dongwoo, and Kim, Byeongil
- Subjects
VIBRATION isolation ,INTERNAL combustion engines ,PIEZOELECTRIC actuators ,ACTIVE noise & vibration control ,REAL-time control ,STRUCTURAL dynamics ,ELECTRIC vehicles ,FOOTBRIDGES - Abstract
The automotive industry has transitioned from internal combustion engine (ICE) vehicles to electric vehicles (EVs) in recent years. Also essential to the development of the next generation are the enhancement of engine performance and production of lightweight vehicle bodies. Through this method, it is possible to increase vehicle output. However, as the vehicle's excitation strength increases, structural noise and vibrations caused by the engine increase. Intelligent structure-based active mounting systems are widely used in the automotive industry to reduce vibration and noise. It can continuously control the dynamic characteristics of the mount system, enabling real-time control of active mounting systems. When determining the position of the active mounting system, it must be installed in the most efficient position possible. Therefore, the purpose of this study is to determine the optimal placement criteria for an active mounting system consisting of a piezoelectric actuator and a rubber grommet. The lumped parameter model is used to model the plate structure with two hybrid mounting systems based on the source–path–receiver structure. In addition, the forces of two active mounts are calculated using static and dynamic approaches. When the calculated force on the hybrid mount system is relatively low, the location with the greatest vibration reduction can be determined, and this location can be regarded as the optimal location for the active mounting system. In addition, a feasibility test is conducted to validate the proposed criteria and validate the static and dynamic results. The findings indicate that the optimal location for the active engine mounting system can be determined. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Development of Multi-Staged Adaptive Filtering Algorithm for Periodic Structure-Based Active Vibration Control System.
- Author
-
Yang, Qiu, Lee, Kyeongnak, and Kim, Byeongil
- Subjects
ACTIVE noise & vibration control ,ADAPTIVE filters ,AUTOCORRELATION (Statistics) ,HYBRID electric vehicles ,AUTOMOBILE power trains ,LEAST squares ,EXPONENTIAL functions ,FREQUENCY spectra - Abstract
A digital adaptive filtering system is applied to various fields such as current disturbance, noise cancellation, and active vibration and noise control. The least mean squares (LMS) algorithm is widely adopted, owing to its simplicity and low computational burden. A limitation of the LMS algorithm with fixed step size is the trade-off between convergence speed and stability. Several studies have tried to overcome this limitation by varying the step size according to filter input and error; however, the related algorithms with variable step size have not been suitable for signals with complex frequency spectra. As the error decreases, the quality of the output signal deteriorates due to the increase in the higher-order components, depending on the characteristics of the algorithm. Therefore, a novel adaptive filtering algorithm was proposed to overcome these drawbacks. It increased the stability of the system by decreasing the step size using an exponential function. In addition, the error was reduced through normalization using the power of the input signal in the initial state, and the misadjustments in the system were adjusted properly by introducing an energy autocorrelation function of instantaneous error. Furthermore, a novel multi-staged adaptive LMS (MSA-LMS) algorithm was introduced and applied to active periodic structures. The proposed algorithm was validated by simulation and observed to be superior to the conventional LMS algorithms. The results of this study can be applied to active control systems for the reduction of vibration and noise signals with complex spectra in next-generation powertrains, such as hybrid and electric vehicles. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
4. Design and Analysis of Model Based Nonlinear and Multi-Spectral Controllers with Focus on Motion Control of Continuous Smart Structures
- Author
-
Kim, Byeongil
- Subjects
- Engineering, model based control, smart structures, nonlinear control, multi-spectral control, motion control, hysteresis, active vibration control
- Abstract
Smart structures are currently utilized in many applications from precision positioning control of large space structures to active vibration control of machine components. Despite their relative easiness in controlling, positioning accuracy and longevity can be compromised by the hysteresis. In addition, current active control algorithms are limited predominantly to the control of a single or multiple sinusoidal waves and these are incapable of addressing more complicated multi-spectral signals such as modulated signatures. This dissertation introduces model-based and nonlinear control techniques aimed at the reduction of hysteretic effect and for their application to active motion control.A nonlinear energy-based hysteresis model is developed for a piezoelectric stack actuator and model predictive sliding mode control is applied to force the system state to reach a sliding surface in an optimal manner and to accurately track the reference signal. This method is employed on pre-stressed curved unimorph actuators (modeled by a second order differential equation) with an additional time delay term to describe the hysteretic effect. Simulations and experiments are conducted to validate this approach, and the results highlight significantly improved hysteresis reduction in the displacement control mode. Also, it has been verified that the performance of the novel control methods is not much affected by the accuracy of actuator model.Next, enhanced adaptive filtering algorithms are developed with application to active vibration control. A feedback loop with the model predictive sliding mode control is introduced in the adaptive filtering system. The goal of this study is to manage multi-spectral signals while achieving smooth and effective convergence, self-adaptability, and stability. The performance for new adaptive filtering algorithms is validated numerically and experimentally for different signals and other prevailing characteristics. The proposed algorithms are also compared with traditional algorithms for both narrowband and broadband control of signals with complex frequency spectra. The novel technique deals with primary peaks, sidebands, and broadband level simultaneously without a full knowledge of the unwanted signals.
- Published
- 2010
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.