Papers by Keyword: Actuator

Abstract: The emphasis of this paper is to research dynamic characteristic of giant magnetostrictive actuator (GMA). First, a prototype of GMA driving by a Φ5×40mm GMM rod (Terfenol-D) is made and the experimental test-bench is set, the optimal pre-pressure of GMA is 129N, and GMA can made 39.5μm strain with 218N output force under 5A current. Then, the energy of electrical, magnetic and mechanical of GMA is studied, equivalent circuit of energy conversion is summarized. At last, dynamic characteristic of GMA is measured, and hysteresis of strain under high frequency is tested. The results show that the resonant frequency of GMA is 1200Hz, and the magnetostriction coupling coefficient up to 0.572. The output strain of GMA increase with the frequency increasing before resonant frequency, and GMA has max output strain (49μm) under 1A current at 1200Hz.

Abstract: Gripper is mechanism that mounted on the end of the robot arm and used to hold an object and move it to a certain position. Generally, classical gripper is equipped with the driving motor (electric, pneumatic, fluid power) to move the gripper mechanism. In this research, the function of driving motor replaced with gripper motor actuators made of Shape Memory Alloys (SMA) of Nickel Titanium (NiTi) wire type SM495. Problem studied is response of grip force of gripper to varied electrics power input that given to the actuator of gripper made of NiTi SM495 wire. This is a real experimental research using parameters electrical power input which is obtained by varying the applied electric voltage 3, 6, 9, 12 Volt and constant electric current 5 A. Linear springs with various springs constants of 0.14 N/mm; 0.49 N/mm; 0.981 N/mm; 1.308 N /mm were used for measuring grip force of gripper. The obtained data then analyzed using statistics (analysis of variance). The results showed that the electrical power which given to the NiTi based actuator significantly influenced the grip force of gripper. Keywords: actuators, electric power, grip force, gripper, Nickel Titanium, Shape Memory Alloys, SM495 wire

Abstract: The general operation of a piezoelectric ultrasonic actuator is to convert the cyclic motion of the piezoelectric plate to a linear motion at the rotor or slider. The conventional piezoelectric ultrasonic actuator has two symmetric exciter electrodes on the front surface and each electrode covers one half of the front surface. The rear surface has only one electrode that severs as a common drain. In this paper, the design and simulation of the novel single-mode piezoelectric actuator with asymmetric electrodes were presented. The accomplishment of this study is to find the optimal dimensions of the piezoelectric plate and the asymmetric electrodes, and the stator tip on the piezoelectric ultrasonic actuator would have the larger vibrating amplitude. From the simulation experiment results, the optimal dimensions of the piezoelectric plate are 20×10×1 mm with 12 mm exciter electrode length, and the vibrating amplitude is from 0.73μm increasing to 0.91μm.

Abstract: The article is focused on the actuator with one pneumatic artificial muscle and spring which counteracts the tensile force of the artificial muscle. Such a solution requires only one inlet and one outlet electromechanical pneumatic valve. It is suitable for the synthesis of so-called low cost bioservosystems. The paper presents mathematical description and static characteristics of individual parts of the actuator and also characteristics of the all mechanism.

Abstract: The article contains information about the function and basic properties of the actuator based on pneumatic artificial muscles. The article presents the measurement results of the response of the actuator arm displacement depending on the input pulse. This dependence enables artificial muscles to be better adjusted to the needs of a practical operation, especially in terms of lagging. The article also included calculations of velocity and acceleration of individual time intervals. For the possibility of simulation application, a mathematical model of the approximation curve of the response development is presented.

Abstract: The static character of piezoelectric composite actuator with four tubes is studied. Taking into account the non-uniform electric field distribution in piezoelectric tube, the bending deflection, axial strain, output axial force and bending moment are discussed. The results calculated by proposed method are compared to that calculated by traditional thin wall theory and the proposed method is more accurate and reasonable. A prototype actuator was fabricated and tested to validate the theory results. The theoretic result and tested results agree well with each other. This research provides theoretical guidance and basis for the design of piezoelectric tubular composites actuators.

Abstract: Accurate identification of model parameters is to improve the giant magnetostrictive precision displacement control key, For single algorithm is difficult to achieve for giant magnetostrictive hysteresis nonlinear model parameters accurately identify problems, in this paper, the genetic algorithm and simulated annealing algorithm fusion, First, quick search ability of genetic algorithm are used to get a better community, recycle kick ability of simulated annealing algorithm to to adjust and optimize the whole group, Presented an improved genetic simulated annealing algorithm, And its application to the giant magnetostrictive actuator displacement hysteresis nonlinear model parameter identification. The algorithm combines the advantages of genetic algorithm and simulated annealing algorithm, both the faster convergence speed, and improves the precision and quality of the optimal solution.

Abstract: The paper shows how closed-loop control procedure, using the algorithm Proportional Integrative derivative (PID) was applied to improve the photo and video cameras stability correction in real time. The stability system contains an Attitude Heading reference System (AHRS) sensor that is connected to a microcontroller that will make the operations for measuring angles of rotation (roll, pitch and yaw) acquired from a camera displaced on a suspended cable. Closed loop PID algorithm applied to stabilize the system was implemented as programming subroutines dedicated to Atmega162 microcontroller, at which they were recorded and processed in real time as input signals sensor information measured by the AHRS system. Programming based on a closed loop process control through actuators ordered 3 servo-motors for real-time correction of camera rotation angles. In this way it could be provided the positioning cameras error compensation, the errors being caused by different perturbing external factors. The adopted solution has achieved a cost reduction necessary to stabilize the cameras placed in mobile systems. The solution ensures also to increase the stabilization efficiency reported to the case of human operator intervention.

Abstract: In this paper it is presented a ductile system for micropositioning in a two-dimensional coordinate system. Accuracy positioning results from usage of asymmetric flexure hinges. It also it is presented the modeling of the asymmetric flexure hinges, finite element analysis, and experimental work. For the micropositioning system are determined both theoretical and experimental displacements and stress. The system consists of three actuators which are individually controlled.

Abstract: In conventional Electrical Discharge Machining (EDM), the speed and accuracy are limited by probability and efficiency of the electrical discharges. To improve the machining speed and accuracy, we developed a high-speed, high-precision, 3-DOF controlled local actuator. For the actuator, a voice coil motor type of magnetic bearing having a positioning stroke of a few millimeters is used to control the motion of an electrode in the thrust direction in order to speedily maintain a suitable distance from the workpiece. Moreover, two piezoelectric devices having high response speed and high precision are used to achieve the vibration of the electrode in the radial directions to immediately remove the debris between the electrode and the workpiece. The positioning performance of the actuator was evaluated through experiments, and the experimental results show that the actuator possesses a positioning resolution of the order of micrometer, a bandwidth greater than 120Hz and a positioning stroke of 2mm.