Energy-harvesting Shock Absorber Research Articles

Dynamic characteristics and transmission efficiency of energy-harvesting shock absorber with low speed and heavy duty capacity

Traditional hydraulic shock absorbers commonly encounter challenges such as cavitation, oil leakage, and the management of energy dissipation. The proposed regenerative shock absorber, which utilizes a ball screw mechanism, offers advantages such as high efficiency and heavy load capacity. This paper focuses on the design, modeling, and testing of a mechatronic shock absorber. Virtual prototype simulation techniques are employed to investigate the dynamic behaviors of the shock absorber. The paper presents a systematic efficiency model of a shock absorber, which is based on the ball screw and gearbox mechanisms. The study comprehensively analyzes the effects of rotation speed, axial load, and structure parameters on transmission efficiency. The results demonstrate that a peak power of 38 W can be achieved with a damping force of only 340 N, and the recovery efficiency can reach up to 28%. The experimental test results validate the effectiveness and reliability of the proposed dynamic and efficiency models. The originality of this study lies in the development of a novel energy-harvesting shock absorber with a ball screw mechanism in series with a gearbox, which shows excellent energy recovery potential and transmission efficiency under low speed and high duty conditions.

Design and analysis of a piezoelectric energy harvesting shock absorber for light truck applications

Vehicle suspension vibration is a prevalent form of oscillation, with approximately 22.5 % of automobile energy dissipated through suspension-induced vibration. This phenomenon suggests that recovering the energy dissipated by the suspension system holds significant potential. This paper introduces a novel piezoelectric energy harvesting shock absorber (EHSA) based on non-contact magnetic force for light truck applications. The vibration of the vehicle suspension system is transformed into the rotation of a ball screw, enabling the one-way high-speed output of the rotor through a one-way bearing and planetary gear mechanism. Based on the non-contact magnetic force, the piezoelectric patches generate frequent oscillations, and a novel energy harvesting circuit is designed that efficiently converts the output of multiple piezoelectric units into usable electricity. The damping and energy harvesting characteristics of the EHSA with different external and internal variables are explored. Under sinusoidal excitation of 40 mm amplitude and 0.4 Hz frequency, the EHSA achieves a maximum output power of 7.51 W, with an average output power of 1.89 W. Furthermore, under random action, the EHSA can successfully illuminate 824 LED lights, enabling the temperature and humidity sensor to function normally. These findings indicate that the proposed EHSA can effectively harness vehicle suspension vibration to power onboard self-powered appliances while offering a new design idea for integrating vibration energy harvesters into vehicles.

Design and development of a novel Four-Links rotational hybrid Energy-Harvesting suspension system compatible with conventional suspension technologies

This study introduces a novel rotational Energy Harvesting Shock Absorber (EHSA), specifically designed for use alongside existing vehicle suspension systems. Addressing issues faced by standalone EHSAs, this design incorporates a four-bar mechanism coupled to a rotary energy recovery system. The proposed EHSA system, dubbed the FL-EHSA (Four Links Energy Harvesting Shock Absorber), is based on link connections and is highly versatile. It has the potential to significantly improve vehicle efficiency by harnessing energy usually wasted by traditional shock absorbers. Using a geometric definition process influenced by various factors such as vehicle suspension type and commercial availability of components, the FL-EHSA system was modeled, and bench-tested to validate the system’s energy recovery potential and performance. The movement of the mechanism was analyzed to achieve the target damping value matching the value of a conventional suspension and to maximize efficiency through DOE analysis and to avoid mechanical locking (singular positions). It explains the effect of backlash in mechanical components through simulation and highlights the importance of using dedicated gearboxes for energy recovery. In addition, this work highlights the untapped potential of four-bar mechanisms in automotive energy recovery applications. Moreover, the proposed design is easily integrated into any vehicle, making it a promising solution for EHSA systems.

An energy harvesting shock absorber for powering on-board electrical equipment in freight trains

To realize smart detection and safe operation of freight trains, a continuous and stable energy source is required for electrical equipment on the train. It is a feasible scheme to harvest the vibration energy of train suspension to supply power for on-board electrical equipment. This paper presents an energy-harvesting shock absorber (EHSA) based on the slider-crank mechanism and ratchet-pawl mechanism, which provide a vibration reduction effect and renewable electricity. To determine the damping performance and the power generation performance of EHSA, a dynamic model is established based on MATLAB. According to the tests on the mechanical testing and sensing (MTS) bench, the maximum power generation mechanical efficiency of the EHSA is 67.75%, and the maximum output power of the EHSA is 1.65W. In addition, the charging tests on the MTS bench show that the proposed device is applicable to power on-board electrical equipment on freight trains.

Enhanced Energy Recovery in Magnetic Energy-Harvesting Shock Absorbers Using Soft Magnetic Materials

Enhanced Energy Recovery in Magnetic Energy-Harvesting Shock Absorbers Using Soft Magnetic Materials

An Innovative Energy Harvesting Shock Absorber System for Motorbikes

This article presents an innovative energy recovery shock absorber system for motorcycles. The shock absorber is named synchronous pulley - energy harvesting shock absorber (SP-EHSA). The SP-EHSA is the first system specifically designed to maximize the energy recovery of motorcycles without compromising their dynamic behavior. Throughout the article, the theoretical design, computer modeling, optimization, design, and testing of the system are presented. The article results in a validated computer model of the SP-EHSA shock absorber. The validation is done by manufacturing and testing a physical prototype on a test bench. A study of the energy recovery potential for different road profiles at speeds between 20 and 100 km/h was carried out, obtaining in a typical type B road at 60 km/h an estimated 19.68 W average power. Finally, the effect of energy management (i.e., battery's state of charge) on the dynamic behavior of the vehicle is analyzed.

Quantitative Power Flow Characterization of Energy Harvesting Shock Absorbers by Considering Motion Bifurcation

Vibration energy harvesting technology can capture ambient energy forms. Using an energy harvesting shock absorber (EHSA) is one of the methods to achieve this function. The EHSA with mechanical motion rectifier (MMR) has motion bifurcation, which can improve energy harvesting performance and reduce the impact between gears. However, the motion bifurcation makes it difficult to quantitatively predict the vibrational energy dissipation and energy harvesting of the MMR−EHSA. Evaluating the performance of an MMR−EHSA during the design phase becomes highly complex. In this paper, a novel nonlinear dynamics model of MMR−EHSAs is established to solve motion bifurcation and quantitative power flow. Furthermore, the proposed MMR−EHSA prototype is fabricated, and dynamics testing is initiated to verify the theoretical model under harmonic vibration. The testing results show that the theoretical model can predict the working characterization of MMR−EHSAs. The resistance of optimal harvesting energy and maximum damping power is revealed by the quantitative power flow model under harmonic vibration. In addition, the working performance under random vibration is discussed. The proposed nonlinear dynamics model has advantages when solving random vibration input and has potential for practical application.

Simultaneous Suspension Control and Energy Harvesting Through Novel Design and Control of a New Nonlinear Energy Harvesting Shock Absorber

Simultaneous vibration control and energy harvesting of vehicle suspensions have attracted significant research attention over the past decades. However, existing energy harvesting shock absorbers (EHSAs) are mainly designed based on the principle of linear resonance, thereby compromising suspension performance for high-efficiency energy harvesting and being only responsive to narrow bandwidth vibrations. In this paper, we propose a new EHSA design -- inerter pendulum vibration absorber (IPVA) -- that integrates an electromagnetic rotary EHSA with a nonlinear pendulum vibration absorber. We show that this design simultaneously improves ride comfort and energy harvesting efficiency by exploiting the nonlinear effects of pendulum inertia. To further improve the performance, we develop a novel stochastic linearization model predictive control (SL-MPC) approach in which we employ stochastic linearization to approximate the nonlinear dynamics of EHSA that has superior accuracy compared to standard linearization. In particular, we develop a new stochastic linearization method with guaranteed stabilizability, which is a prerequisite for control designs. This leads to an MPC problem that is much more computationally efficient than the nonlinear MPC counterpart with no major performance degradation. Extensive simulations are performed to show the superiority of the proposed new nonlinear EHSA and to demonstrate the efficacy of the proposed SL-MPC.

Modeling, bench test and ride analysis of a novel energy-harvesting hydraulically interconnected suspension system

A novel energy-harvesting hydraulically interconnected suspension (EH-HIS) is proposed, modeled, built and tested in this paper to enhance riding comfort and road handling performances for vehicles while converting the vibration energy traditionally wasted into usable electricity. A sub-module prototype has been developed to validate the analytical model and tested to study the damping characteristics and energy harvesting capability of the EH-HIS. The studies are performed to compare the dynamic responses and energy harvesting performance of the full-vehicle equipped with the traditional suspension, hydraulically interconnected suspension (HIS), hydro-electromagnetic energy-harvesting shock absorber (HESA) and the proposed EH-HIS, respectively. Bench test results show that the damping coefficient of the EH-HIS ranges from 3608 to 9913 Ns/m. The average harvested power of the sub-module reaches 82 W at the excitation of 2 Hz frequency and 20 mm amplitude, while the full-size SUV equipped with the EH-HIS can obtain 215 W and 525 W average power on D-class road with a driving velocity of 60 km/h and 80 km/h, respectively. Moreover, the vehicle equipped with EH-HIS has better riding comfort on rough terrains and satisfying handling stability compared with other suspension systems. The analysis also indicates that EH-HIS exhibit 60% and 11% improvements in the anti-rolling and anti-pitching performances over the traditional suspension during emergency steering and braking maneuvers.

Design of novel energy-harvesting regenerative shock absorber using barrel cam follower mechanism to power the auxiliaries of a driverless electric bus

This paper presents a novel energy-harvesting shock absorber using a barrel cam follower mechanism to harvests energy from the vehicle suspension system. The proposed system comprises an input module, transmission module, generator module, and power storage module. The input module converts the low-frequency irregular vibration caused by the road roughness into bi-directional rotary motion with a barrel cam and follower mechanism. The transmission module changes the bi-directional rotary motion into unidirectional rotary motion. The power produced by the generator is stored in a supercapacitor for power supply to auxiliaries when the vehicle is stationary. The simulation and experimental investigation techniques were performed using MATLAB and Mechanical Testing and Sensing system, respectively. Furthermore, the unpredictable variations in the experimental condition were evaluated by uncertainty analysis. The experimental and simulation results were compared under similar loading conditions and found a maximum relative error of 5.5% at 2.5 mm and 1 Hz. Finally, the highest output power of 3.85 W was harvested at 7.5 mm sinusoidal amplitude and 2 Hz input frequency with a maximum efficiency of 51.4%. The harvested energy can power the sensors of driverless electric buses to reduce battery consumption.

Characterization and implementation of a double-sided arm-toothed indirect-drive rotary electromagnetic energy-harvesting shock absorber in a full semi-trailer truck suspension platform

Heavy goods vehicles (HGVs), which usually travel on rough and dirt roads, have great potential for harvesting the dissipated energy during the damping routines. Thus, this study explores the benefits of energy-harvesting shock absorbers when integrated into HGVs due to their vibration's densities. The double-side arm-toothed indirect-drive rotary electromagnetic energy-harvester is consequently proposed. The contribution lies in that, (a) it could be the first time applying a double-side arm-toothed indirect-drive rotary electromagnetic energy-harvesting shock absorber in an articulated truck semi-trailer model; (b) complete characterization of the arm-toothed indirect-drive regenerative damper via parametrical conflict and sensitivity analyses; (c) quantitative assessment of the total harvestable power and voltage of the proposed 12 double-sided arm-toothed regenerative truck shock absorbers; and (d) Taguchi method simulation to perform a sensitivity ranking analysis of the truck influential parameters considering the harvested power, the truck ride quality and road holding criteria. The results indicate that the truck harvested an average power of 0.33, 1.33, 5.24, 21.3 W under road Classes of B, C, D, and E at 120 km/h. Regardless of the frequency range, the truck suspension can still maintain a comfortable driver ride index while simultaneously harvest power via the 12 integrated double-sided arm-toothed regenerative dampers.

Can a Semi-Active Energy Harvesting Shock Absorber Mimic a Given Vehicle Passive Suspension?

Energy harvesting shock absorbers (EHSA) have made great progress in recent years, although there are still no commercial solutions for this technology. This paper addresses the question of whether, and under what conditions, an EHSA can completely replace a conventional one. In this way, any conventional suspension could be replicated at will, while recovering part of the wasted energy. This paper focuses on mimicking the original passive damper behavior by continuously varying the electrical parameters of the regenerative damper. For this study, a typical ball-screw EHSA is chosen, and its equivalent suspension parameters are tried to be matched to the initial damper. The methodology proposes several electrical control circuits that optimize the dynamic behavior of the regenerative damper from the continuous variation of a load resistance. The results show that, given a target damper curve, the regenerative damper can adequately replicate it when there is a minimum velocity in the damper. However, when the damper velocity is close to zero, the only way to compensate for inertia is through the introduction of external energy to the system.

Global Optimization of the Hydraulic-Electromagnetic Energy-Harvesting Shock Absorber for Road Vehicles With Human-Knowledge-Integrated Particle Swarm Optimization Scheme

This article proposes a human-knowledge-integrated particle swarm optimization (Hi-PSO) scheme to globally optimize the design of the hydraulic-electromagnetic energy-harvesting shock absorber (HESA) for road vehicles. A newly developed k-fold swarm learning framework is the key to the Hi-PSO scheme, which runs k groups (folds) of individual local optimization (using a selected learning cycle), and validation (using the other k-1 testing cycles) with the concept of digital twin introduced into the design of the HESA. It aims to achieve the optimum energy recovery efficiency globally in both learning cycles and testing cycles. Within the learning framework, a nearest-neighborhood particle swarm learning algorithm is developed to incorporate human knowledge (e.g., ISO standards) for local optimization so that the computational load can be reduced through downsizing of the learning spaces. Experiments have been conducted to evaluate the energy recovery and damping performance under both local conditions (duty cycles used for learning) and global conditions (six duty cycles covering the main equivalent amplitudes and frequencies of the suspension's operation). Compared with the conventional PSO algorithm, Hi-PSO is shown to be more robust by achieving a 5.17% higher mean value in 10 trials while achieving the same maximum energy efficiency. The global optimum result is obtained under 20 mm/1.5 Hz condition and achieves an average energy efficiency of 59.07%.

Methodology for Comprehensive Comparison of Energy Harvesting Shock Absorber Systems

In recent years, there has been a lot of work related to Energy Harvesting Shock Absorbers (EHSA). These devices harvest energy from the movement of the vehicle’s shock absorbers caused by road roughness, braking, acceleration and turning. There are different technologies that can be used in these systems, but it is not clear which would be the best option if you want to replace a conventional shock absorber with an EHSA. This article presents a methodology to compare the performance of different EHSA technologies that can replace a shock absorber with a given damping coefficient. The methodology allows to include different analysis options, including different types of driving cycles, computer vehicle models, input signals and road types. The article tests the methodology in selecting the optimal EHSA technology for a particular shock absorber and vehicle, optimizing at the same time energy recovery. In addition, a study of parameters in each type of technology is included to analyze its influence on the final objective. In the example analyzed, the EHSA technology with a rack and pinion system turned out to be the best. The proposed methodology can be extrapolated to other case studies and design objectives.

Modeling and Analysis of a Hydraulic Energy-Harvesting Shock Absorber

This paper proposes a hydraulic energy-harvesting shock absorber prototype, which realizes energy harvesting of the vibration energy dissipated by the automobile suspension system. The structural design of the proposed shock absorber ensures that the unidirectional flow of oil drives the hydraulic motor to generate electricity while obtaining an asymmetrical extension/compression damping force. A mathematical model of the energy-harvesting shock absorber is established, and the simulation results indicate that the damping force can be controlled by varying the load resistance of the feed module, thus adjusting the required damping force ratio of the compression and recovery strokes. By adjusting the external load, the target indicator performance of the shock absorber is achieved while obtaining the required energy recovery power. A series of experiments are conducted on the prototype to verify the validity of the damping characteristics and the energy recovery efficiency as well as to analyze the effect of external load and excitation speed on these characteristics.

Energy Harvesting Shock Absorber with Linear Generator and Mechanical Motion Amplification

Energy Harvesting Shock Absorber with Linear Generator and Mechanical Motion Amplification

Design and Potential Power Recovery of Two Types of Energy Harvesting Shock Absorbers

Numerous authors have studied Energy Harvesting Shock Absorbers (EHSA) over the last decade, proposing different designs with diverse geometries, parameters, and components. This article analyzes the energy recovery potential of two types of rotational EHSA, those that use ball-screw and those based on cable transmission. This paper presents the design, manufacturing and mathematical modeling of both options as well as the estimation of the potential power recovery with both technologies. Two types of vehicles are used as references, each one with the characteristic curves of their shock absorbers. Results are presented for different vehicle speeds and road types. Finally, some qualitative characteristics of both EHSAs are detailed to be taken into consideration for their possible use in vehicle suspension.

A novel design of a damping failure free energy-harvesting shock absorber system

Abstract An energy-harvesting shock absorber can adjust the damping coefficient in real time to meet the vibration reduction, and it can also harvest energy from the vibration of a suspension. This paper proposed a novel design for an energy-harvesting shock absorber system. The study focusses mainly on the realization of energy harvest and damping control. A closed loop damping control strategy is proposed, with which, the shock absorber is not only able to supply a controllable electromagnetic damping force but can also harvest energy from the vibration. The system construction and working principle is introduced, and the experiment platforms are established. A series of simulations and experiments were conducted to demonstrate the effectiveness of the proposed shock absorber system. The results show that an average energy recovery efficiency of 40.72%–70.55% can be obtained when tested under sinusoidal excitation and random road excitation. The proposed system is characterized by a high response speed of 4 Hz, and it can meet the operating requirements under random road excitation. The results also indicate that the damping coefficient can be adjusted with a high precision of 93.56%, and thus, both the damping failure and damping fluctuation are effectively eliminated.

The influence of friction parameters in a ball-screw energy-harvesting shock absorber

Energy-harvesting shock absorbers (EHSAs) have been introduced in the last decade as a viable technology for improving the performance and durability of electric and/or hybrid vehicles. However, in order to gauge the potential that can be obtained from this technology in different environments, the computational models that are used should behave as close to reality as possible. One of the limiting factors in EHSAs, in terms of recoverable energy, is frictional losses between its moving parts. Depending on the friction losses, the dynamics and efficiency of the system will vary. This paper presents a method of identifying the friction parameters in a ball-screw energy-harvesting shock absorber (BS-EHSA) system for subsequent computational simulation. In addition, it shows qualitative and quantitative results of how these friction parameters could affect the comfort and adhesion of the vehicle, as well as the generated power and energy efficiency of the BS-EHSA.

An Innovative Energy Harvesting Shock Absorber System Using Cable Transmission

This paper presents an innovative design of an energy harvesting shock absorber using cable transmission called cable dynamics energy harvesting shock absorber (CD-EHSA). It includes the design, modeling, bench experiments, and road tests results. Experimental tests are carried out with the CD-EHSA system in an MTS 835 machine, in order to analyze its behavior and validate the computational model of the CD-EHSA with the tests carried out on the actual component. Likewise, the paper presents the results of recovered electric power by the system during road tests at a speed between 20 and 30 km/h. With four CD-EHSA installed in a Renault Twizy, an average power of 105 W and power peaks of 400–500 W when passing through speed bumps are obtained. The designed system mechanical can reach an efficiency of around 60%.