Theoretical modeling of electroactive polymer-ceramic hybrid actuation systems

2005 ◽  
Vol 97 (3) ◽  
pp. 034908 ◽  
Author(s):  
Tian-Bing Xu ◽  
Ji Su
Keyword(s):  
Theoretical Modeling ◽  
Electroactive Polymer ◽  
Hybrid Actuation ◽  
Actuation Systems

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.

Bi-Directional Actuation of a Piston Using MR Valves and a Piezoelectric Pump

Aerospace ◽  
2005 ◽  
Author(s):  
Shaju John ◽  
Jin-Hyeong Yoo ◽  
Jayant Sirohi ◽  
Norman M. Wereley
Keyword(s):  
Mechanical Valve ◽  
Wheatstone Bridge ◽  
Piezoelectric Pump ◽  
Pump System ◽  
Mr Fluid ◽  
Bingham Plastic ◽  
Magnetic Circuits ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
Moving Parts

There is a demand for hybrid actuation systems which combine actuation and valving systems in a compact package. MR fluids can be used in valves to control the motion of an output cylinder. Such a valving system will have no moving parts and thus can be used in applications where there is high centrifugal loading. In the current setup, MR valves are configured in the form of a Wheatstone bridge where the two arms form the high and low pressure sides of the output cylinder. The actuation is performed using a compact piezoelectric stack driven actuator. The frequency rectification of the piezo stack motion is done using reed valves. This actuator and valve configuration form a compact hydraulic system with electro-mechanical valves. The advantages of such systems are that part count is low, fewer moving parts and the ability to control the motion of the output cylinder by controlling the fluid flow through the MR valves. By the application of different magnetic fields in the arms of the bridge (by applying different currents to the magnetic circuits), we can control the differential pressure seen by the output cylinder. This allows us to design different controllers for the system. The two systems in this configuration have been separately evaluated. The piezo pump system was first tested for its performance and efficiency with conventional hydraulic fluid and MR fluid. At this stage, the MR valve setup has not been added to isolate the actuating system from the valve system and the MR fluid acts merely as a transmission fluid. The Wheatstone bridge setup was then added and the efficiency of the MR valve was tested against a dummy mechanical valve. The modeling of the valve was done on the basis of standard rheological models like Bingham Plastic and bi-viscous models. Data for bi-directional actuation of the output cylinder is presented and assessed analytically.

A Hybrid Actuation System (HYBAS) and Aerospace Applications

2005 ◽  
Vol 888 ◽  
Author(s):  
Ji Su ◽  
Tian-Bing Xu ◽  
Shujun Zhang ◽  
Thomas R. Shrout ◽  
Qiming Zhang
Keyword(s):  
Single Crystal ◽  
High Performance ◽  
Theoretical Modeling ◽  
Synthetic Jet ◽  
Aerospace Applications ◽  
Actuation System ◽  
Electromechanical Responses ◽  
Control Technologies ◽  
Langley Research Center ◽  
Hybrid Actuation

ABSTRACTAn electroactive polymer-ceramic hybrid actuation system (HYBAS) has been developed at NASA Langley Research Center. The system demonstrates significantly-enhanced electromechanical performance by cooperatively utilizing advantages of a combination of electromechanical responses of an electroative polymer (EAP), and an electroactive ceramic single crystal, PZN-PT single crystal. The electroactive elements are driven by a single power source. Recently, a modification of HYBAS has been made to increase the capability of air driving for synthetic jet devices (SJ) used in aerodynamic control technologies. The dependence of the air driving capability of the modified HYBAS on the configuration of the actuating device has been investigated. For this particular application, the modified HYBAS demonstrated a 50% increase in the volume change in the synthetic jet air chamber, as compared with that of the HYBAS without the modification. The theoretical modeling of the performances of the HYBAS is in good agreement with experimental observation. The consistence between the theoretical modeling and experimental test make the design concept an effective route for the development of high performance actuating devices for many applications. The theoretical modeling, fabrication of the HYBAS and the initial experimental results will be presented and discussed.

scholarly journals A Review of Microrobot’s System: Towards System Integration for Autonomous Actuation In Vivo

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1249
Author(s):  
Zhongyi Li ◽  
Chunyang Li ◽  
Lixin Dong ◽  
Jing Zhao
Keyword(s):  
Medical Imaging ◽  
System Integration ◽  
Working Environment ◽  
Delivery Methods ◽  
Actuation System ◽  
Imaging Algorithms ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
And Control

Microrobots have received great attention due to their great potential in the biomedical field, and there has been extraordinary progress on them in many respects, making it possible to use them in vivo clinically. However, the most important question is how to get microrobots to a given position accurately. Therefore, autonomous actuation technology based on medical imaging has become the solution receiving the most attention considering its low precision and efficiency of manual control. This paper investigates key components of microrobot’s autonomous actuation systems, including actuation systems, medical imaging systems, and control systems, hoping to help realize system integration of them. The hardware integration has two situations according to sharing the transmitting equipment or not, with the consideration of interference, efficiency, microrobot’s material and structure. Furthermore, system integration of hybrid actuation and multimodal imaging can improve the navigation effect of the microrobot. The software integration needs to consider the characteristics and deficiencies of the existing actuation algorithms, imaging algorithms, and the complex 3D working environment in vivo. Additionally, considering the moving distance in the human body, the autonomous actuation system combined with rapid delivery methods can deliver microrobots to specify position rapidly and precisely.

A Magnetorheological Actuation System - Part II: Modeling

2007 ◽  
Author(s):  
Shaju John ◽  
Anirban Chaudhuri ◽  
Norman M. Wereley
Keyword(s):  
Active Vibration Control ◽  
Wheatstone Bridge ◽  
Bingham Plastic ◽  
Magnetic Circuits ◽  
Actuation System ◽  
System Part ◽  
Active Vibration ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
Moving Parts

There is a demand for hybrid actuation systems which combines actuation and valving systems in a compact package. Such self-contained actuation systems can be used in the field of rotorcraft as active pitch links and in the field of automotive engineering as active vibration control devices. MR fluids can be used in valves to control the motion of an output cylinder. Such a valving system will have no moving parts and thus can be used in applications where there is high centrifugal loading. In the current setup, MR valves are configured in the form of a Wheatstone bridge and bidirectional motion is produced in the output cylinder by alternate application of magnetic field in the arms of the wheatstone bridge. 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 low parts count, absence of moving parts and the ability to control the motion of the output cylinder by controlling the fluid flow through the MR valves. By the application of different magnetic fields to the arms of the bridge (by applying different currents to the magnetic circuits), we can control the differential pressure seen by the output cylinder. This add the capability of designing controllers for the system. This work concentrates on the modeling of the entire actuation system performance. The results of the modeling effort is then compared with experimental results. The system is modeled by ordinary differential equations governing the motion of the active stack, fluid in the different sections and the output cylinder shaft. The rheological properties of the MR fluid is modeled using both Bingham plastic and bi-viscous models.

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.

A novel iteration-based controller for hybrid machine systems for trajectory tracking at the end-effector level

Robotica ◽  
2010 ◽  
Vol 29 (2) ◽  
pp. 317-324 ◽  
Author(s):  
Z. H. Chen ◽  
Y. Wang ◽  
P. Ouyang ◽  
J. Huang ◽  
W. J. Zhang
Keyword(s):  
Trajectory Tracking ◽  
Degrees Of Freedom ◽  
Large Power ◽  
End Effector ◽  
Small Power ◽  
Hybrid Machine ◽  
Machine Systems ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
Control Accuracy

SUMMARYHybrid actuation systems consist of two types of motors: constant velocity (CV) motor and servo (SV) motor. The CV motor can produce a large power but with a poor task flexibility. On the other hand, the SV motor has an excellent task flexibility but with a small power capacity. Combination of these two types of motors into a coherent driver architecture for machine systems is extremely promising, because they complement each other. Existing studies on the hybrid actuation or machine system usually employ two servo motors, one of which substitutes the CV motor. This treatment compromises the control accuracy for the trajectory tracking at the end-effector. This paper presents a study on a new controller for the hybrid machine that considers one SV motor and one CV motor and for trajectory tracking at the end-effector level. A comparison of this new controller with the controller we developed previously is provided. A five-bar mechanism with two degrees of freedom is employed for the illustration purpose.

An electroactive polymer-ceramic hybrid actuation system for enhanced electromechanical performance

2004 ◽  
Vol 85 (6) ◽  
pp. 1045-1047 ◽  
Author(s):  
Ji Su ◽  
Tian-Bing Xu ◽  
Shujun Zhang ◽  
Thomas R. Shrout ◽  
Qiming Zhang
Keyword(s):  
Electroactive Polymer ◽  
Actuation System ◽  
Electromechanical Performance ◽  
Hybrid Actuation
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