Experimental Validation of a Hybrid Electrostrictive Hydraulic Actuator Analysis

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Anirban Chaudhuri ◽  
Norman M. Wereley
Keyword(s):  
Active Material ◽  
Length Change ◽  
Domain Model ◽  
Basic Operation ◽  
Fluid Inertia ◽  
Hydraulic Actuator ◽  
Factors Affecting ◽  
Actuation System ◽  
Viscous Losses ◽  
Hybrid Actuation

The basic operation of smart material-based hybrid electrohydraulic actuators involves high frequency bidirectional length change in an active material stack (or rod) that is converted to unidirectional motion of a hydraulic fluid by a set of valves. In this study, we present the design and measured performance of a compact hybrid actuation system driven by the single-crystal electrostrictive material PMN-32%PT. The active material was actuated at different frequencies with variations in the applied voltage, fluid bias pressure, and external load to study the effects on output velocity. The maximum actuator velocity was 330 mm/s and the corresponding flow rate was 42.5 cc/s; the blocked force of the actuator was 63 N. The results of the experiments are presented and compared with simulation data to validate a nonlinear time-domain model. Linearized equations were used to represent the active material while the inertia, viscous losses, and compressibility of the fluid were included using differential equations. Factors affecting system performance are identified and the inclusion of fluid inertia in the model is also justified.

Design and Testing of a PMN-PT Based Compact Hybrid Actuator

2008 ◽  
Author(s):  
A. Chaudhuri ◽  
N. M. Wereley
Keyword(s):  
Flow Rate ◽  
Smart Materials ◽  
Active Material ◽  
Maximum Flow ◽  
Length Change ◽  
Basic Operation ◽  
Test Results ◽  
Electrostrictive Material ◽  
Hybrid Actuation ◽  
Design And Testing

Substantial research has been conducted in the development of hybrid hydraulic actuators driven by various smart materials. The basic operation of these actuators involves high frequency bidirectional length change of an active material stack (rod) which is converted to unidirectional motion of a hydraulic fluid by a set of active or passive valves. In this paper, we present the design and experimental test results of a compact hybrid actuation driven by the electrostrictive material PMN. The active material was actuated at different frequencies, with variations in the applied voltage and fluid bias pressure to study their effects on performance. The tests were carried out under no-load conditions and also with external weights to find the maximum flow rate and blocked force respectively. The maximum actuator velocity was calculated to be 330 mm/s and the corresponding flow rate was 42.5 cc/s. The blocked force of the actuator was found to be 63 N and the maximum power output was 8 W. Dynamic tests were also conducted to find the PMN stack response without any fluid loads. Results of the experiments are presented and compared with simulation data.

Reliability Analysis of Hybrid Actuation Based on GSPN

2012 ◽  
Vol 430-432 ◽  
pp. 1914-1917
Author(s):  
Li Ming Yu ◽  
Shou Qiang Wei ◽  
Tian Tian Xing ◽  
Hong Liang Liu
Keyword(s):  
Petri Nets ◽  
System Reliability ◽  
Operating Mode ◽  
Stochastic Petri Nets ◽  
Hydraulic Actuator ◽  
Reliability Models ◽  
Operating Modes ◽  
Actuation System ◽  
Generalized Stochastic Petri Nets ◽  
Hybrid Actuation

Generalized stochastic Petri nets is adopted to develop the reliability models of two operating modes of the hybrid actuation system, which is composed of a SHA (Servo valve controlled Hydraulic Actuator), an EHA (Electro-Hydrostatic Actuator) and an EBHA (Electrical Back-up Hydrostatic Actuator).The dependability of hybrid actuation is got through the Markov chain which the Petri nets sate is isomorphic to and the Monte-Carlo simulation. Simulations are conducted to analyze influences of the operating mode and the fault coverage on system reliability of hybrid actuation system.

Comparison of Piezoelectric, Magnetostrictive and Electrostrictive Hybrid Hydraulic Actuators

Aerospace ◽  
2006 ◽  
Author(s):  
Shaju John ◽  
Jayant Sirohi ◽  
Gang Wang ◽  
Norman M. Wereley
Keyword(s):  
Output Power ◽  
Lead Zirconate Titanate ◽  
Maximum Output Power ◽  
Active Material ◽  
Maximum Output ◽  
Hydraulic Actuator ◽  
Active Materials ◽  
Cross Sectional ◽  
Actuation System ◽  
Free Strain

In recent years, active material driven actuators have been widely researched for potential applications in the fields of aerospace, automotive and civil engineering. While most of these active materials, such as piezoelectric, magnetostrictive and electrostrictive materials, have high force and bandwidth capabilities, they are limited in stroke. In combination with hydraulic systems, the field dependent motion of these materials can be amplified to produce high force, high stroke actuators. In a hybrid hydraulic pump, the motion of an active material is used to pressurize a hydraulic fluid. Since the properties of active materials vary greatly in terms of free strain and block force, there is a need to identify the optimum active material for a particular application. This study compares four active materials, Lead-Zirconate-Titanate (PZT), Lead-Magnesium-Niobate (PMN) and Terfenol-D, as the drivers of a hybrid hydraulic actuation system. The performance of each of these active materials was evaluated in the same hydraulic actuator through systematic testing of the actuator while maintaining the same length and volume for each active material. In each case, the active material had a length of around 54 mm and a cross-sectional area of 25 mm2. Commonly used metrics such as output power and electromechanical efficiency are used for comparison. Of the four materials tested in this study, PMN presented the largest free strain (2000με), while Terfenol presented the least (1000με). The highest no-load velocity was also exhibited by the PMN based actuator (270mm/s). The maximum output power obtained was 2.5W for both PMN and Terfenol-D based actuators while the highest electromechanical efficiency obtained was 7% for the PMN based actuator.

Research on Performances of Hybrid Actuation System with Dissimilar Redundancies

2012 ◽  
Vol 430-432 ◽  
pp. 1559-1563 ◽  
Author(s):  
Li Ming Yu ◽  
Zi Qing Ye
Keyword(s):  
Operating Mode ◽  
Development Trend ◽  
Hydraulic Actuator ◽  
Actuation System ◽  
Electric Aircraft ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
The Development Trend ◽  
More Electric Aircraft ◽  
Mode A

Hybrid actuation system (HAS) with dissimilar redundancies conforms to the development trend of future actuation systems in more electric aircraft (MEA). Hybrid Actuation system is composed of a traditional servo valve controlled hydraulic actuator (SHA) and an electro-hydraulic actuator (EHA). It has two operating models, active/passive mode (A/P) and active/active mode (A/A). In A/A model both actuators are actively controlled. Corresponding to A/A model, SHA is actively controlled and EHA is passively controlled in A/P model. The hybrid actuation system is built in the AMESim simulation environment, comparative analysis is performed when system operates in these two modes, such as signal response and force fighting. The simulation results provide a guideline to determine the specific operating mode of the system in different circumstances.

Hydraulic Actuator Tuning in the Control of a Rotating Flexible Beam Mechanism

1995 ◽  
Author(s):  
Michael J. Panza ◽  
Roger W. Mayne
Keyword(s):  
Hydraulic Resistance ◽  
System Model ◽  
Flexible Beam ◽  
Hydraulic Actuator ◽  
Control Effort ◽  
Actuation System ◽  
Wide Range ◽  
Position Feedback ◽  
Simulation Results ◽  
Beam Mechanism

Abstract The end point position and vibration control of a rotating flexible beam mechanism driven by a hydraulic cylinder actuator is considered. An integrated nonlinear system model comprised of beam dynamics, hydraulic actuator, control valves, and control scheme is presented. Control based on simple position feedback along with a hydraulic actuation system tuned to suppress beam vibration over a wide range of angular motion is investigated. For positioning to small to moderate mechanism angles, a linear system model with the actuator tuned for good open loop performance is developed. Actuator tuning is accomplished by varying the system hydraulic resistance according to a dimensionless parameter defining the interaction between the actuator and flexible beam. Simulation results for a closed loop system indicate that this simple tuned control provides comparable performance and requires less control effort than an untuned system with a more complex state feedback optimal controller. To compensate for geometric nonlinearities that cause instability when positioning to large mechanism angles, an active actuator tuning scheme based on continuous variation of hydraulic resistance is proposed. The active variable resistance controller is combined with simple position feedback and designed to provide a constant dimensionless actuator-flexible beam interaction parameter throughout the motion. Simulation results are presented to show the stabilizing effect of this control strategy.

Theoretical Modeling for Electroactive Polymer-Ceramic Hybrid Actuation Systems

Aerospace ◽  
2004 ◽  
Author(s):  
Tian-Bing Xu ◽  
Ji Su
Keyword(s):  
Performance Optimization ◽  
High Performance ◽  
Electroactive Polymer ◽  
Actuation System ◽  
Electromechanical Responses ◽  
Electromechanical Performance ◽  
New Type ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
Further Development

An electroactive polymer-ceramic hybrid actuation system (HYBAS) was recently developed. The HYBAS demonstrates significantly-enhanced electromechanical performance by utilizing advantages of cooperative contributions of the electromechanical responses of an electrostrictive copolymer and an electroactive single crystal. The hybrid actuation system provides not only a new type of device but also a concept to utilize different electroactive materials in a cooperative and efficient method for optimized electromechanical performance. In order to develop an effective procedure to optimize the performance of a hybrid actuation system (HYBAS), a theoretical model has been developed, based on the elastic and electromechanical properties of the materials utilized in the system and on the configuration of the device. The model also evaluates performance optimization as a function of geometric parameters, including the length of the HYBAS and the thickness ratios of the constituent components. The comparison between the model and the experimental results shows a good agreement and validates the model as an effective method for the further development of high performance actuating devices or systems for various applications.

scholarly journals Multi-Fault Diagnosis Approach Based on Updated Interacting Multiple Model for Aviation Hydraulic Actuator

Information ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 410
Author(s):  
Xiaozhe Sun ◽  
Xingjian Wang ◽  
Siru Lin
Keyword(s):  
Fault Diagnosis ◽  
Flight Control ◽  
Failure Modes ◽  
Physical Parameters ◽  
Interacting Multiple Model ◽  
Multiple Model ◽  
Hydraulic Actuator ◽  
Multiple Faults ◽  
Actuation System ◽  
Diagnosis Method

The aviation hydraulic actuator (HA) is a key component of the flight control system in an aircraft. It is necessary to consider the occurrence of multiple faults under harsh conditions during a flight. This study designs a multi-fault diagnosis method based on the updated interacting multiple model (UIMM). The correspondence between the failure modes and the key physical parameters of HA is found by analyzing the fault mode and mechanism. The key physical parameters of HA can be estimated by employing a series of extended Kalman filters (EKF) related to the different modes of HA. The models in UIMM are updated once the fault is determined. UIMM can reduce the number of fault models and avoid combinatorial explosion in the case of multiple faults. Simulation results indicate that the multi-fault diagnosis method based on UIMM is effective for multi-fault diagnosis of electro-hydraulic servo actuation system.

Investigation of a High Precision Hydrostatic Actuation System: How Nonlinearities Affect Its Performance

2007 ◽  
Author(s):  
Wei Li ◽  
Richard Burton ◽  
Saeid Habibi
Keyword(s):  
Large Scale ◽  
Linear Models ◽  
Hydraulic Actuator ◽  
Complete Understanding ◽  
Positional Accuracy ◽  
Scale Modeling ◽  
Actuation System ◽  
Order Change ◽  
Physical Limitations ◽  
Large Scale Modeling

A prototype Electro-Hydraulic Actuator (EHA) system has demonstrated a positional accuracy in the order of 100 nanometer. Linearized models of the EHA have been formulated and have shown reasonable correlation to the performance of the physical EHA. However, these models predict zero steady state error (an impossible situation given the physical limitations of seals, friction etc.). Further, the prototype EHA indicates that the cut-off frequency decreases as the amplitude of the input signal decreases. This is not predicted by the linear models. In this paper the Bond-graph large scale modeling technique was used as the basis to formulate the describing equations of the EHA. The model was made increasingly more complex by introducing observable nonlinearities into the model. It was found that the introduction of nonlinear friction did show results whose trends were consistent with those observed experimentally. Assumed nonlinearities in the bulk modulus could not be substantiated. In addition, some of the observed experimental trends could not be predicted (such as order change) and pose additional challenges to be solved before a complete understanding of the true physics of the EHA can be realized.

scholarly journals Design and operating mode analysis of hybrid actuation system based on EHA/SHA

2018 ◽  
Vol 2018 (13) ◽  
pp. 385-391
Author(s):  
Liu Zidong ◽  
Bai Zhiqiang ◽  
Xu Shuhan
Keyword(s):  
Operating Mode ◽  
Mode Analysis ◽  
Actuation System ◽  
Hybrid Actuation

A Magnetorheological Actuation System: Part I — Testing

2007 ◽  
Author(s):  
Shaju John ◽  
Jin-Hyeong Yoo ◽  
Norman M. Wereley
Keyword(s):  
Magnetic Field ◽  
Active Vibration Control ◽  
Active Material ◽  
Wheatstone Bridge ◽  
Mr Fluids ◽  
Actuation System ◽  
Hybrid Devices ◽  
Actuation Systems ◽  
Frequency Rectification ◽  
Moving Parts

There is a demand for compact hybrid actuation systems which combines actuation and valving systems in a compact package. Such self-contained actuation systems have potential applications in the field of rotorcraft (as active pitch links) and automotive engineering (as active vibration control devices). Hybrid hydraulic actuation systems, based on frequency rectification of the high frequency motion of an active material, can be used to exploit the high bandwidth of smart material to design devices with high force and stroke. Magnetorheological (MR) fluids are active fluids whose viscosity can be changed through the application of a magnetic field. By using MR fluids as the hydraulic fluid in such hybrid devices, a valving system with no moving parts can be implemented. Such a system will be attractive in rotorcraft applications with large centrifugal force loading. Thus, MR fluids can be used to control the motion of an output cylinder. The MR fluid based valves can be configured in the form of a Wheatstone bridge to produce bi-directional motion in an output cylinder by alternately applying a magnetic field in the two arms of the bridge. In this study, the actuation is performed using a compact Terfenol-D stack driven actuator. The frequency rectification of the stack motion is done using reed valves. This actuator and valve configuration form a compact hydraulic system with fluidic valves. The advantages of such systems are that part count is low, absence of moving parts and the possibility of continuous controllability of the output cylinder. By applying varying magnetic fields in the arms of the bridge (by applying different currents to the coils), the differential pressure acting on the output cylinder can be controlled. The description of the experimental setup, the tests performed and the experimental results are presented in this paper.

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