Energy regeneration from suspension dynamic modes and self-powered actuation

Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper concerns energy harvesting from vehicle suspension systems. The generated power associated with bounce, pitch and roll modes of vehicle dynamics is determined through analysis. The potential values of power generation from these three modes are calculated. Next, experiments are carried out using a vehicle with a four jack shaker rig to validate the analytical values of potential power harvest. For the considered vehicle, maximum theoretical power values of 1.1kW, 0.88kW and 0.97kW are associated with the bounce, pitch and roll modes, respectively, at 20 Hz excitation frequency and peak to peak displacement amplitude of 5 mm at each wheel, as applied by the shaker. The corresponding experimentally power values are 0.98kW, 0.74kW and 0.78kW. An experimental rig is also developed to study the behavior of regenerative actuators in generating electrical power from kinetic energy. This rig represents a quarter-vehicle suspension model where the viscous damper in the shock absorber system is replaced by a regenerative system. The rig is able to demonstrate the actual electrical power that can be harvested using a regenerative system. The concept of self-powered actuation using the harvested energy from suspension is discussed with regard to applications of self-powered vibration control. The effect of suspension energy regeneration on ride comfort and road handling is presented in conjunction with energy harvesting associated with random road excitations.Peer reviewedFinal Accepted Versio

Design of a vibration isolation system for a cycle ergometer to be used onboard the Space Shuttle

Low frequency vibrations generated during exercise using the cycle ergometer onboard the Space Shuttle are disrupting sensitive microgravity experiments. The design team is asked by NASA/USRA to generate alternatives for the design of a vibration isolation system for the cycle ergometer. It is the design team's objective to present alternative designs and a problem solution for a vibration isolation system for an exercise cycle ergometer to be used onboard the Space Shuttle. In the development of alternative designs, the design team emphasizes passive systems as opposed to active control systems. This decision is made because the team feels that passive systems are less complex than active control systems, external energy sources are not required, and mass is reduced due to the lack of machinery such as servomotors or compressors typical of active control systems. Eleven alternative designs are developed by the design team. From these alternatives, three active control systems are included to compare the benefits of active and passive systems. Also included in the alternatives is an isolation system designed by an independent engineer that was acquired late in the project. The eight alternatives using passive isolation systems are narrowed down by selection criteria to four considered to be the most promising by the design team. A feasibility analysis is performed on these four passive isolation systems. Based on the feasibility analysis, a final design solution is chosen and further developed. From the development of the design, the design team has concluded that passive systems are not effective at isolating vibrations for the low frequencies considered for this project. Recommendations are made for guidelines of passive isolation design and application of such systems

Active vibration control for a free piston stirling engine with linear alternator FPSE/LA

New regulations introduced by the European Network of Transmission System Operators for Electricity (ENTSO) have brought further requirements for grid connected generators into action in 2013. The β-type Stirling engine (FPSE/LA) used for micro combined heat and power systems (MCHP) is a synchronous machine that is designed and tuned to operate at 50Hz ± 0.5Hz. This type of technology has to comply with the new regulations that imposes a wider operating envelop (47Hz-53Hz). This engine suffers from continuous self-induced vibrations caused by the reciprocating motion of a permanent magnet attached to its piston inside a linear alternator. Currently, the damping of the vibrations in the FPSA/LA is achieved by employing a passive tuned mass damper (TMD) tuned to damp vibrations at 50Hz. While passive devices provide a simple and a reliable way to tackle many vibration problems, there exists distinct performance limitations associated with the use of only passive devices. As for this particular application, the main limitation of the TMD in its passive form is its narrow bandwidth of operation that cannot cope with the new bandwidth. Consequently, this could expose the engine to physical damage and failure. Therefore modifications to the existing TMD have to be introduced. This research involved the design and development of an active tuned mass damper (ATMD) and the suitable control strategies using an electromagnetic actuator, namely a linear voice coil motor (VCM). Starting with a validated vibration model of the engine based on two degrees of freedom system (2-DOF), two control techniques, Feedforward/Zero-Placement control with relative/absolute position and Linear Quadratic (LQ) optimal control, were investigated with numerical simulation in the frequency and time domains. For the purpose of testing and implementation, a test rig featuring an electromagnetic shaker, a VCM, and a TMD besides an embedded system was assembled. An electromechanical model of the test rig was also developed and simulated with the integration of the control strategies. A set of experimental tests were carried out and the concept of active vibration control was successfully illustrated. In addition to that, an in depth investigation of the effect of time delays on the control methodology was conducted. The study resulted in the identification of a time delay margin where below, stability is guaranteed. Furthermore, a set of comprehensive equations of the power and actuator force requirements to perform active damping with a VCM based on any general 2-DOF system are obtained for both the feedforward and the LQ control strategies

A state-of-the-art review on magnetorheological elastomer devices

© 2014 IOP Publishing Ltd. During the last few decades, magnetorheological (MR) elastomers have attracted a significant amount of attention for their enormous potential in engineering applications. Because they are a solid counterpart to MR fluids, MR elastomers exhibit a unique field-dependent material property when exposed to a magnetic field, and they overcome major issues faced in magnetorheological fluids, e.g. the deposition of iron particles, sealing problems and environmental contamination. Such advantages offer great potential for designing intelligent devices to be used in various engineering fields, especially in fields that involve vibration reduction and isolation. This paper presents a state of the art review on the recent progress of MR elastomer technology, with special emphasis on the research and development of MR elastomer devices and their applications. To keep the integrity of the knowledge, this review includes a brief introduction of MR elastomer materials and follows with a discussion of critical issues involved in designing magnetorheological elastomer devices, i.e. operation modes, coil placements and principle fundamentals. A comprehensive review has been presented on the research and development of MR elastomer devices, including vibration absorbers, vibration isolators, base isolators, sensing devices, and so on. A summary of the research on the modeling mechanical behavior for both the material and the devices is presented. Finally, the challenges and the potential facing magnetorheological elastomer technology are discussed, and suggestions have been made based on the authors' knowledge and experience

An application review of dielectric electroactive polymer actuators in acoustics and vibration control

Recent years have seen an increasing interest in the dielectric electroactive polymers (DEAPs) and their potential in actuator applications due to the large strain capabilities. This paper starts with an overview of some configurations of the DEAP actuators and follows with an in-depth literature and technical review of recent advances in the field with special considerations given to aspects pertaining to acoustics and vibration control. Significant research has shown that these smart actuators are promising replacement for many conventional actuators. The paper has been written with reference to a large number of published papers listed in the reference section

Electromechanical Simulation of Actively Controlled Rotordynamic Systems with Piezoelectric Actuators

Theories and tests for incorporating piezoelectric pushers as actuator devices for active vibration control are discussed. It started from a simple model with the assumption of ideal pusher characteristics and progressed to electromechanical models with nonideal pushers. Effects on system stability due to the nonideal characteristics of piezoelectric pushers and other elements in the control loop were investigated

Accelerated Controller Tuning for Wind Turbines Under Multiple Hazards

During their lifecycle, wind turbines can be subjected to multiple hazard loads, such as high-intensity wind, earthquake, wave, and mechanical unbalance. Excessive vibrations, due to these loads, can have detrimental effects on energy production, structural lifecycle, and the initial cost of wind turbines. Vibration control by various means, such as passive, active, and semi-active control systems provide crucial solutions to these issues. We developed a novel control theory that enables semi-active controller tuning under the complex structural behavior and inherent system nonlinearity. The proposed theory enables the evaluation of semi-active controllers’ performance of multi-degrees-of-freedom systems, without the need for time-consuming simulations. A wide range of controllers can be tested in a fraction of a second, and their parameters can be tuned to achieve system-level performance for different optimization objectives