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.

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.

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

Enhanced Electromechanical Responses of IPCNC Actuators

2010 ◽  
Author(s):  
Yang Liu ◽  
Sheng Liu ◽  
Hulya Cebeci ◽  
Roberto G. de Villoria ◽  
Jun-Hong Lin ◽  
...  
Keyword(s):  
High Performance ◽  
Volume Fraction ◽  
High Volume ◽  
Experimental Results ◽  
Composite Electrodes ◽  
Ionic Polymer ◽  
Electromechanical Responses ◽  
Electromechanical Performance ◽  
Vertically Aligned ◽  
Anisotropic Elastic

In this presentation, we will show several progresses in Ionic Polymer Conductor Network Composite Actuators (IPCNC) studies. First of all, we successfully fabricated ultra high volume fraction vertically aligned carbon nanotubes (VA-CNTs)/polymer composite electrodes which markedly improved the electromechanical performance of IPCNC actuators. The experimental results show that the continuous paths through inter-VA-CNT channels and low electrical conduction resistance due to the continuous CNTs lead to fast actuation speed (>10% strain/second). The experimental results also demonstrate that the VA-CNTs create anisotropic elastic property in the composite electrodes, which suppresses the vertical strain and markedly enhances the actuation strain (>8% strain under 4 volts). The data here show the promise of optimizing the electrode morphology in IPCNCs by the ultrahigh volume fraction VA-CNTs for ionic polymer actuators to achieve high performance.

A humanoid robot capable of carrying heavy objects

Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 667-681 ◽  
Author(s):  
Hyeung-Sik Choi ◽  
Wonhyun Na ◽  
Dongwan Kang
Keyword(s):  
Humanoid Robot ◽  
Ball Screw ◽  
Arm Processor ◽  
Actuation System ◽  
Distributed Controller ◽  
Closed Chain ◽  
New Type ◽  
Actuation Systems ◽  
Method Analysis ◽  
Chain Type

SUMMARYA new type of 28-DOF (degree of freedom) full-size humanoid robot, driven by a closed-chain type of joint actuation system, is developed in this paper. Each leg of the robot is composed of six joints, where three are at the hip, one is at the knee, and two are at the ankle. The robot has six joints for each arm, one balancing joint, and three joints for the head, with two cameras. The weight of the robot is 75 kg, and its height is 168 cm.The actuation systems of the pitching joint for the arms and legs of the robot are designed based on a closed-chain mechanism composed of four bar links driven by a ball screw, and each leg of the robot is designed to support 95 kg weight to include a 20 kg payload that can be carried by the robot arms having very light designs (with weight 8.5 kg), but each capable of carrying a 10 kg payload.An analysis of the closed-chain joint actuation systems of a light arm capable of handling heavy objects is performed, and the light arm is designed via finite-element method analysis performed using ANSYS. In addition, the kinematic analysis and the detailed structure of the arm and leg of the robot are performed.The main controller uses the ARM processor and a distributed controller for the leg joints is developed using the TMS320c2407 processor with the communications between the main and joint controllers being performed via the CAN system.Good performances of the proposed robot is demonstrated by presenting several experimental results; these include (1) experimentally handling a 13 kg payload, (2) through walking experiments of the robot supporting a 85 kg load, and (3) measurements of the arm and leg joint motors while performing walking experiments.

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.

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