Equivalent Circuit Modeling of Vehicle Dynamics With Regenerative Shock Absorbers

Author(s):  
Peng Li ◽  
Lei Zuo

Regenerative shock absorbers have potential to recover a large amount of kinetic energy from vehicle vibration otherwise dissipated in traditional oil shock absorbers and at the same time to improve the ride comfort and road handling performances. Linear, rotational and mechanical motion rectifier (MMR) based electromagnetic designs have been proposed. They all have different energy conversion mechanisms, mass inertia effects, and even some nonlinear structures which make the damping behavior more complex; therefore their influence to the whole vehicle dynamics will need to be carefully assessed. This paper will present an integrated equivalent circuit model of the vehicle with electromagnetic regenerative shock absorbers, and then evaluate the vehicle dynamics performance and energy harvesting potential with different design parameters and under variable road conditions. The performance of different mechanisms of electromagnetic regenerative shock absorbers and constant shock absorber will be compared. Design guidelines for rotational electromagnetic regenerative shock absorbers will be developed based on analysis and simulation results.

Author(s):  
Lin Xu ◽  
Yilun Liu ◽  
Sijing Guo ◽  
Xuexun Guo ◽  
Lei Zuo

Many energy-harvesting shock absorbers have been proposed in recent years, the most popular design is the electromagnetic harvester including linear electromagnetic shock absorbers, rotational electromagnetic shock absorbers, the mechanical motion rectifier (MMR), and the hydraulic-electromagnetic energy-regenerative shock absorber (HESA). With different energy converting mechanisms, the complicated effects of the inertia and nonlinear damping behaviors will greatly influence the vehicle dynamic performance such as the ride comfort and road handling. In this paper, we will theoretically analyze the dynamics of the suspension system with the HESA and give a guide for the HESA design. Then a simulation model of the HESA is built in AMESim to make comparison studies on the different vehicle dynamics caused by the nonlinear damping behaviors of the HESA. The advantages of HESA in terms of ride comfort and road handling will be evaluated in comparison with the similar design without accumulators and the traditional oil shock absorbers.


Author(s):  
Sijing Guo ◽  
Lin Xu ◽  
Yilun Liu ◽  
Xuexun Guo ◽  
Lei Zuo

Energy-Harvesting Shock Absorber (EHSA), as a large-scale energy-harvesting mechanism for recovering suspension vibration energy, has been studied for years. A design of the regenerative shock absorber with Mechanical Motion Rectifier (MMR) has been proved to be more reliable and efficient. This paper reports a comprehensive study of the influence of MMR-based Energy-Harvesting Shock Absorber (MMR-EHSA) on vehicle dynamics performances. Models of MMR-EHSA and vehicle with MMR-EHSA with two degrees of freedom are created. Simulations are conducted on five typical vehicles, including passenger car, bus and three types of trucks. The ride characteristics of comfort, road handling and energy recovery are evaluated on these vehicles under various MMR rotational inertia and harvesting damping. The simulation results show that MMR-EHSA is able to improve both the ride comfort and road handling simultaneously under certain conditions over the traditional shock absorbers, which broadens our knowledge of MMR-EHSA’s applicable scenarios.


2021 ◽  
Author(s):  
Bonan Qin ◽  
Yuzhe Chen ◽  
Lei Zuo

Abstract This paper introduces a novel energy-harvesting hydraulically interconnected suspension (EH-HIS) to improve the riding comfort and road handling performance for off-road vehicles while harvesting the vibration energy traditionally dissipated into heat by the oil shock absorbers. To understand the system, we built a model of the off-road vehicle equipped with the EH-HIS and conducted the performance analysis. The system model is established based on the pressure drop principle and validated by commercial simulation software AMESim. The damping characteristic and energy harvesting performance have been investigated based on the mathematical suspension model. Further, a thorough analysis is implemented to compare the dynamic responses of the vehicle equipped with the traditional suspension and EH-HIS under different driving speeds and road classes. Results show that the EH-HIS system can provide tunable asymmetric damping from 3134 Ns/ to 7558 Ns/m, which covers most of the damping range of the off-road vehicles. The average regenerative power of the half EH-HIS system reaches 438 watts, and the corresponding hydraulic efficiency reaches 19%, at a vibration input of 2 Hz frequency and 30 mm amplitude. The ride analysis shows that the vehicle equipped with the EH-HIS system on the D class road has good handling stability and better ride comfort over the traditional suspension.


Frequenz ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Paikhomba Loktongbam ◽  
Chaitali Koley ◽  
Debasish Pal ◽  
Ayan Kumar Bandyopadhyay

AbstractThis paper presents a novel E armed dipole antenna for System On Chip (SOC) applications in the Sub-THz frequency band. The antenna is printed on a corrugated silicon substrate which suppresses surface waves and provides high efficiency and gain. The corrugated substrate also provides a better impedance matching. The antenna has a simulated gain of 5.4 dBi and 3 dB beam-width of 83.5 degree. The proposed antenna also has a very high radiation efficiency of 90%. Antenna resonates at 141.8 GHz and has an approximate −10 dB bandwidth of 1 GHz. To investigate the effects of different design parameters, some parametric analysis has been carried out and results have been shown. An equivalent circuit model has been reported. The equivalent circuit has been used to find the resonant frequency of the proposed dipole. The deviation of simulated and calculated resonant frequency is less than 0.5% which is well within the acceptable limits for antennas operating in mm-wave and sub-THz frequency band. This antenna is well suited for SOC, radar on-chip, high gain arrays, etc.


2012 ◽  
Vol 132 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Satoshi Maruyama ◽  
Muneki Nakada ◽  
Makoto Mita ◽  
Takuya Takahashi ◽  
Hiroyuki Fujita ◽  
...  

Author(s):  
Milan Paudel ◽  
Fook Fah Yap

E-scooters are a recent trend and are viewed as a sustainable solution to ease the first and last mile problem in modern transportation. However, an alarming rate of accidents, injuries, and fatalities have caused a significant setback for e-scooters. Many preventive measures and legislation have been put on the e-scooters, but the number of accidents and injuries has not reduced considerably. In this paper, the current design approach of e-scooters has been analyzed, and the most common range of design parameters have been identified. Thereafter, validated mathematical models have been used to quantify the performance of e-scooters and relate them with the safety aspects. Both standing and seated riders on e-scooters have been considered, and their influence on the dynamic performance has been analyzed and compared with the standard 26-in wheel reference safety bicycle. With more than 80% of the accidents and injuries occurring from falling or colliding with obstacles, this paper tries to correlate the dynamics of uncontrolled single-track vehicles with the safety performance of e-scooters. The self-stability, handling, and braking effect have been considered as major performance matrices. The analysis has shown that the current e-scooter designs are not as stable as the reference safety bicycle. Moreover, these e-scooters have been found unstable within the most common range of legislated riding velocity. The results corroborate with the general perception that the current designs of e-scooters are less stable, easy to lose control, twitchy, or wobbly to ride. Furthermore, the standing posture of the rider on the e-scooter has been found dangerous while braking to avoid any disturbances such as potholes or obstacles. Finally, the front steering design guidelines have been proposed to help modify the current design of e-scooters to improve the dynamic performance, hence the safety of the e-scooter riders and the surroundings.


Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1644
Author(s):  
Qian Zhang ◽  
Huijuan Liu ◽  
Tengfei Song ◽  
Zhenyang Zhang

A novel, improved equivalent circuit model of double-sided linear induction motors (DLIMs) is proposed, which takes the skin effect and the nonzero leakage reactance of the secondary, longitudinal, and transverse end effects into consideration. Firstly, the traditional equivalent circuit with longitudinal and transverse end effects are briefly reviewed. Additionally, the correction coefficients for longitudinal and transverse end effects derived by one-dimensional analysis models are given. Secondly, correction factors for skin effect, which reflects the inhomogeneous air gap magnetic field vertically, and the secondary leakage reactance are derived by the quasi-two-dimensional analysis model. Then, the proposed equivalent circuit is presented, and the excitation reactance and secondary resistance are modified by the correction coefficients derived from the three analytical models. Finally, a three-dimensional (3D) finite element model is used to verify the proposed equivalent circuit model under varying air gap width and frequency, and the results are also compared with that of the traditional equivalent circuit models. The calculated thrust characteristics by the proposed equivalent circuit and 3D finite element model are experimentally validated under a constant voltage–frequency drive.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Peng Zhao ◽  
Yihang Zhang ◽  
Rongrong Sun ◽  
Wen-Sheng Zhao ◽  
Yue Hu ◽  
...  

A compact frequency selective surface (FSS) for 5G applications has been designed based on 2.5-dimensional Jerusalem cross. The proposed element consists of two main parts: the successive segments of the metal traces placed alternately on the two surfaces of the substrate and the vertical vias connecting traces. Compared with previous published two-dimensional miniaturized elements, the transmission curves indicate a significant size reduction (1/26 wavelengths at the resonant frequency) and exhibit good angular and polarization stabilities. Furthermore, a general equivalent circuit model is established to provide direct physical insight into the operating principle of this FSS. A prototype of the proposed FSS has been fabricated and measured, and the results validate this design.


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