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12 pages, 3696 KiB

Open AccessArticle

Development of a Rotary Damper Integrated with Magnetorheological Bearings toward Extremely High Torque–Volume Ratio

by Shengfeng Zhu, Ning Gong, Jian Yang, Shiwu Zhang, Xinglong Gong, Weihua Li and Shuaishuai Sun

Machines 2023, 11(3), 368; https://doi.org/10.3390/machines11030368 - 09 Mar 2023

Cited by 1 | Viewed by 1654

Abstract

Magnetorheological (MR) technology has provided effective solutions to many engineering bottleneck problems due to its controllable nature. However, designing a rotary MR damper with a high torque–volume ratio is always challenging, especially for some specific application scenarios with constrained space, such as robot [...] Read more.

Magnetorheological (MR) technology has provided effective solutions to many engineering bottleneck problems due to its controllable nature. However, designing a rotary MR damper with a high torque–volume ratio is always challenging, especially for some specific application scenarios with constrained space, such as robot joints. To solve this problem, a rotary damper based on MR bearings was designed and evaluated in this study. In this rotary damper, two MR bearings are utilized to provide controllable damping torques and serve as rotors, which greatly saves space while providing high torque. This feature grants the characteristics of compact design and high torque–volume ratio. Quasistatic testing shows that the damping torque of this rotary damper can reach 2.92 Nm when the applied current is 1.2 A. It achieves a high torque–volume ratio of 190 kN/m², which is nearly four times higher than that of existing rotary MR dampers. The experimental results show that the proposed MR damper is effective in satisfying the high torque requirement in a limited space. Full article

(This article belongs to the Special Issue Low-Frequency Vibration Control with Advanced Technologies)

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21 pages, 14290 KiB

Open AccessEditor’s ChoiceArticle

Semi-Active Vibration Control of Seat Suspension Equipped with a Variable Equivalent Inertance-Variable Damping Device

by Guangrui Luan, Pengfei Liu, Donghong Ning, Guijie Liu and Haiping Du

Machines 2023, 11(2), 284; https://doi.org/10.3390/machines11020284 - 14 Feb 2023

Cited by 6 | Viewed by 1597

Abstract

The seat suspension has a significant influence on riding comfort in many practical applications, such as heavy duty vehicles, military vehicles, and high-speed crafts. This paper proposes a seat suspension equipped with a variable equivalent inertance-variable damping (VEI–VD) device and a novel semi-active [...] Read more.

The seat suspension has a significant influence on riding comfort in many practical applications, such as heavy duty vehicles, military vehicles, and high-speed crafts. This paper proposes a seat suspension equipped with a variable equivalent inertance-variable damping (VEI–VD) device and a novel semi-active vibration control strategy. The VEI–VD device can control its equivalent inertance and damping by controlling two external resistors in its electric circuit. Especially, the VEI part of the device can store and release vibration energy via the inside flywheel, which enables the seat suspension to have a four-quadrant controllable capability in the available force–velocity diagram, similar to an active system. First, the dynamic model of the VEI–VD device is built, and a prototype is developed and tested to identify the model parameters and verify its characteristics. Then, a semi-active vibration control method is proposed for the VEI–VD seat suspension. The control method uses a sliding mode controller to acquire the desired control force for reducing vibration; then, according to the desired force and system states, the VEI–VD device is tuned by a force-tracking scheme to generate a real force. In the numerical validation, the vibration transmissibility of VEI–VD seat suspension around its natural frequency is tested with different states. The effectiveness of force-tracking control strategies for different types of suspensions is verified. In the random excitation test, the root means square acceleration of the VEI–VD seat is reduced by 30.72% compared with a passive seat. The VEI–VD seat suspension shows great potential in applications. Full article

(This article belongs to the Special Issue Low-Frequency Vibration Control with Advanced Technologies)

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15 pages, 6973 KiB

Open AccessEditor’s ChoiceArticle

Shock Absorption for Legged Locomotion through Magnetorheological Leg-Stiffness Control

by Matthew Daniel Christie, Shuaishuai Sun, Lei Deng, Haiping Du, Shiwu Zhang and Weihua Li

Machines 2023, 11(2), 236; https://doi.org/10.3390/machines11020236 - 06 Feb 2023

Cited by 3 | Viewed by 1238

Abstract

The objective of this study was to evaluate the performance of a magnetorheological-fluid-based variable stiffness actuator leg under high impact forces through optimal tuning and control of stiffness and damping properties. To achieve this, drop testing experiments were conducted with the leg at [...] Read more.

The objective of this study was to evaluate the performance of a magnetorheological-fluid-based variable stiffness actuator leg under high impact forces through optimal tuning and control of stiffness and damping properties. To achieve this, drop testing experiments were conducted with the leg at various drop heights and payload masses. The results showed that while lower stiffness and higher damping can lead to lower impact forces and greater energy dissipation, respectively, optimal control can also protect the leg from deflecting beyond its functional range. Comparison with a rigid leg with higher damping showed a 57.5% reduction in impact force, while a more compliant leg with lower damping results in a 61.4% reduction. These findings demonstrate the importance of considering both stiffness and damping in the design of legged robots for high impact force resistance. This simultaneously highlights the efficacy of the proposed magnetorheological-fluid-based leg design for this purpose. Full article

(This article belongs to the Special Issue Low-Frequency Vibration Control with Advanced Technologies)

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21 pages, 6033 KiB

Open AccessArticle

Takagi–Sugeno Fuzzy Model-Based Control for Semi-Active Cab Suspension Equipped with an Electromagnetic Damper and an Air Spring

by Bangji Zhang, Minyao Liu, Kunjun Wang, Bohuan Tan, Yuanwang Deng, An Qin and Jingang Liu

Machines 2023, 11(2), 226; https://doi.org/10.3390/machines11020226 - 03 Feb 2023

Cited by 3 | Viewed by 1285

Abstract

Variable damping shock absorbers have received extensive attention for their efficient vibration reduction performance, and air springs have also been widely used in high-end commercial vehicles due to their nonlinear stiffness characteristics. This paper presents a novel semi-active cab suspension integrated with an [...] Read more.

Variable damping shock absorbers have received extensive attention for their efficient vibration reduction performance, and air springs have also been widely used in high-end commercial vehicles due to their nonlinear stiffness characteristics. This paper presents a novel semi-active cab suspension integrated with an air spring and a variable damping electromagnetic damper (A-EMD). The electromagnetic damper (EMD) prototype was designed, manufactured and tested. Then, due to the interference of nonlinear stiffness characteristics of the air spring with the controller in the subsequent design, the Takagi–Sugeno fuzzy method was adopted to segmentally linearize its nonlinearity, based on which an H∞ state feedback semi-active controller was designed to control the EMD to generate variable damping force. Furthermore, a Luenberger state observer was designed to provide immeasurable state parameters for the controller. Numerical simulations were carried out to validate the effectiveness of the proposed approaches, and the results show that the proposed control strategy can significantly improve the ride comfort of the A-EMD system. The vibration dose value (VDV) acceleration under the bump road and the frequency-weighted acceleration root mean square (FWA-RMS) under the random road decreased by 36.05% and 19.77%, respectively, compared with the passive suspension system. Full article

(This article belongs to the Special Issue Low-Frequency Vibration Control with Advanced Technologies)

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14 pages, 11876 KiB

Open AccessArticle

Damping Characteristics of Cantilever Beam with Obstacle Grid Particle Dampers

by Junlong Zhang, Yin Hu, Jie Jiang and Hao Zan

Machines 2022, 10(11), 989; https://doi.org/10.3390/machines10110989 - 29 Oct 2022

Cited by 2 | Viewed by 1469

Abstract

In order to understand the damping effect and energy dissipation mechanism of the obstacle grid particle dampers, we conduct experimental and simulated studies. In this paper, the obstacle grid particle dampers are applied to the cantilever beam structure. The effect of filling ratio, [...] Read more.

In order to understand the damping effect and energy dissipation mechanism of the obstacle grid particle dampers, we conduct experimental and simulated studies. In this paper, the obstacle grid particle dampers are applied to the cantilever beam structure. The effect of filling ratio, particle size, particle material and excitation amplitude of the obstacle grid particle damper on the vibration characteristics of the cantilever beam is studied experimentally and compared with the conventional particle damper for damping effect. A simulation model of the particle damper was developed and experimentally validated using the discrete element method. The experimental results show that the vibration acceleration response of the obstacle grid particle damper decreases by 10.4 dB compared with the conventional particle damper at 90% filling ratio. The obstacle grid particle damper increases the area of energy transfer between the external vibration energy and the particles. It makes the particles, which originally have almost no contribution to the energy dissipation, produce violent motion and participate in the energy dissipation process, thus effectively improving the damping performance of the particle dampers. Full article

(This article belongs to the Special Issue Low-Frequency Vibration Control with Advanced Technologies)

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16 pages, 7287 KiB

Open AccessArticle

A Two-DOF Active-Passive Hybrid Vibration Isolator Based on Multi-Line Spectrum Adaptive Control

by Qingchao Yang, Zhaozhao Ma and Ruiping Zhou

Machines 2022, 10(10), 825; https://doi.org/10.3390/machines10100825 - 20 Sep 2022

Cited by 1 | Viewed by 1766

Abstract

In order to effectively control the low-frequency vibration of ship machinery, based on the improved multi-line spectrum adaptive control algorithm, a two-degree-of-freedom (two-DOF) active-passive hybrid vibration isolator composed of an electromagnetic actuator, rubber spring, and the hydraulic device is proposed. The dynamic model [...] Read more.

In order to effectively control the low-frequency vibration of ship machinery, based on the improved multi-line spectrum adaptive control algorithm, a two-degree-of-freedom (two-DOF) active-passive hybrid vibration isolator composed of an electromagnetic actuator, rubber spring, and the hydraulic device is proposed. The dynamic model of the two-DOF vibration isolation system is established and the main control force demand of the vibration isolation system at different damping forces is analyzed. By introducing the improved wavelet packet decomposition algorithm with the Hartley block least mean square algorithm to the filter-x least mean square (FxLMS) algorithm, an improved wavelet packet Hartley block filter-x least mean square (IWPHB-FxLMS) algorithm is established. The experimental results show that the IWPHB-FxLMS algorithm has better control performance. Compared with the traditional FxLMS algorithm, the IWPHB-FxLMS control algorithm improves the convergence speed by 91.7% and the line spectrum power spectrum attenuation by 58.1%. The active-passive hybrid vibration isolator is based on multi-line spectrum adaptive control and can achieve good control effects under the excitation of multi-frequency line spectrum and constant frequency line spectrum. Full article

(This article belongs to the Special Issue Low-Frequency Vibration Control with Advanced Technologies)

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19 pages, 6641 KiB

Open AccessArticle

Vehicle Engine Noise Cancellation Based on a Multi-Channel Fractional-Order Active Noise Control Algorithm

by Tao Li, Minqi Wang, Yuyao He, Ning Wang, Jun Yang, Rongjun Ding and Kaihui Zhao

Machines 2022, 10(8), 670; https://doi.org/10.3390/machines10080670 - 09 Aug 2022

Cited by 7 | Viewed by 2280

Abstract

For the problem of low-frequency noise suppression in a large area of the vehicle space, this paper proposes a novel multi-channel fractional-order active noise control algorithm and tests its ability for vehicle engine noise cancellation. The algorithm uses fractional-order calculus to replace the [...] Read more.

For the problem of low-frequency noise suppression in a large area of the vehicle space, this paper proposes a novel multi-channel fractional-order active noise control algorithm and tests its ability for vehicle engine noise cancellation. The algorithm uses fractional-order calculus to replace the integer-order gradient descent to update the weighting coefficients of the filter, thereby avoiding imbalance or over-tuning phenomena during adaptive active noise cancellation and improving the control accuracy of the algorithm. A computer simulation was conducted in the noise cancellation scene of the vehicle, which showed that the algorithm is capable of suppressing single- and mixed-frequency noises, reducing the average sound pressure by approximately 20 dB. The experimental results demonstrated that the algorithm can effectively reduce the peak sound pressure of low-frequency noise for a certain type of vehicle engine by approximately 10 dB, whereas the total sound pressure level is reduced by approximately 4.7 dB. Full article

(This article belongs to the Special Issue Low-Frequency Vibration Control with Advanced Technologies)

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Review

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41 pages, 15400 KiB

Open AccessReview

Recent Advances in Quasi-Zero Stiffness Vibration Isolation Systems: An Overview and Future Possibilities

by Zhaozhao Ma, Ruiping Zhou and Qingchao Yang

Machines 2022, 10(9), 813; https://doi.org/10.3390/machines10090813 - 16 Sep 2022

Cited by 23 | Viewed by 5910

Abstract

In recent decades, quasi-zero stiffness (QZS) vibration isolation systems with nonlinear characteristics have aroused widespread attention and strong research interest due to their enormous potential in low-frequency vibration isolation. This work comprehensively reviews recent research on QZS vibration isolators with a focus on [...] Read more.

In recent decades, quasi-zero stiffness (QZS) vibration isolation systems with nonlinear characteristics have aroused widespread attention and strong research interest due to their enormous potential in low-frequency vibration isolation. This work comprehensively reviews recent research on QZS vibration isolators with a focus on the principle, structural design, and vibration isolation performance of various types of QZS vibration isolators. The negative-stiffness mechanism falls into two categories by different realization methods: passive and active/semi-active negative-stiffness mechanisms. Representative design, performance analysis, and practical application are elaborated for each category. The results show that passive vibration isolation systems have excellent low-frequency vibration isolation performance under specific payload and design parameters, whereas active/semi-active vibration isolation systems can better adapt to different environmental conditions. Finally, the development trends and challenges of QZS vibration isolators are summarized, and the solved and unsolved problems are highlighted. This review aims to give a comprehensive understanding of the QZS vibration isolation mechanism. It also provides guidance on designing new QZS vibration isolators for improving their vibration isolation performance and engineering applicability. Full article

(This article belongs to the Special Issue Low-Frequency Vibration Control with Advanced Technologies)

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