Experimental Characterization and Control of Miniaturized Pneumatic Artificial Muscle

2014 ◽  
Vol 8 (4) ◽  
Author(s):  
Shanthanu Chakravarthy ◽  
K. Aditya ◽  
Ashitava Ghosal

Robotic surgical tools used in minimally invasive surgeries (MIS) require miniaturized and reliable actuators for precise positioning and control of the end-effector. Miniature pneumatic artificial muscles (MPAMs) are a good choice due to their inert nature, high force to weight ratio, and fast actuation. In this paper, we present the development of miniaturized braided pneumatic muscles with an outer diameter of ∼1.2 mm, a high contraction ratio of about 18%, and capable of providing a pull force in excess of 4 N at a supply pressure of 0.8 MPa. We present the details of the developed experimental setup, experimental data on contraction and force as a function of applied pressure, and characterization of the MPAM. We also present a simple kinematics and experimental data based model of the braided pneumatic muscle and show that the model predicts contraction in length to within 20% of the measured value. Finally, a robust controller for the MPAMs is developed and validated with experiments and it is shown that the MPAMs have a time constant of ∼10 ms thereby making them suitable for actuating endoscopic and robotic surgical tools.

2009 ◽  
Vol 12 (4) ◽  
pp. 18-29
Author(s):  
Thanh Diep Cong Tu

In recent years, CPM - Continuous Passive Motion has been proved to be one of the most effective therapeutic methods for patients who have problems with motion such as spinal cord injury, ankle and knee injury, parkinson and so on. Many commercial CPM devices are found in market but all of them use motors as the main actuators. The lack of human compliance of electric actuators, which are commonly used in these machines, makes them potentially harmful to patients. An interesting alternative, to electric actuators for medical purposes, particularly promising for rehabilitation, is a pneumatic artificial muscle (PAM) actuator because of its high power/weight ratio and compliance properties. However, the highly nonlinear and hysteresis of PAM make it the challenging for design and control. In this study, a PID compensation using neural network control is studied to improve the control performance of the novel model of Knee CPM device.


2018 ◽  
Vol 18 (08) ◽  
pp. 1840031
Author(s):  
JUN ZHONG

Pneumatic muscle actuators (PMAs) have great potential in robotics and industrial applications. However, high non-linearities hamper the further applications in accurate performances. Pressure built-up process is highly non-linear due to non-linear elasticity of rubber tube of the PMA and air driving mode, and brings great challenges in approximation. This paper analyzes the experimental responses of charging and discharging process, respectively, and employs second-order linear system to model the charging and discharging dynamics inside PMA. Experiments are performed to validate the effectiveness of the established models and comparison between simulated curves and experimental data indicates that the built-up models can capture the dynamics of pressure changing processes inside PMA.


2007 ◽  
Vol 345-346 ◽  
pp. 1249-1252 ◽  
Author(s):  
Kyoung Rae Cha ◽  
Gwang Ho Kim ◽  
Ju Hwan Kim ◽  
Sang Hwa Jeong

In recent years, as the robot technology is developed, the researches on the artificial muscle actuator that enables robot to move dexterously like biological organ become active. Actuators are one of the key technologies underpinning robotics. Particularly breakthroughs of power-to-weight ratio or energy-density in actuator technology have significant impacts upon the design and the control of robotic systems. The widely used materials for artificial muscle are the shape memory alloy and electro-active polymer. These actuators have the higher energy density than the electromechanical actuators such as the electric motor. However, there are some drawbacks because these actuators have the hysteretic dynamic characteristics. In this paper, the segment control for reducing the hysteresis of SMA is proposed and the simulation of an anthropomorphic robotic hand is performed using ADAMS. A new approach to design and control of SMA actuators is presented. SMA wire is divided into many segments and their thermal states are controlled individually in a binary manner(ON/OFF). The basic experiment for evaluating the dynamic characteristics of SMA wire actuator is performed.


2012 ◽  
Vol 268-270 ◽  
pp. 1457-1463
Author(s):  
Li Chao Wang ◽  
Xiao Dong Wang

Artificial muscle is a new style of actuator with novel working principle, which owns the advantages of compact structure, high power-to-weight ratio, compliance and easy application. Pneumatic artificial muscle (PAM) is usually used in robotics, medical auxiliaries and other small force output occasions nowadays. However, it suffers problems of small power, hysteresis and poor repeatability. A kind of artificial muscle working at high pressure was researched. Different muscle styles are compared and MicKibben structure is selected while fluid media is determined. Furthermore, factors of geometry and material properties, which limit the ultimate pressure, are analyzed. Formulas and simulations verify the influence of limitation and help to calculate key parameters of 18MPa artificial muscle. Data show that it is possible in theory to design high pressure artificial muscle by overall consideration of initial diameter, initial contraction angle and material properties, initial length only influent the stroke.


2009 ◽  
Vol 74 ◽  
pp. 149-152
Author(s):  
X.M. Zhang ◽  
M. Yu ◽  
Silas Nesson ◽  
H. Bae ◽  
A. Christian ◽  
...  

This paper reports the development of a miniature pressure sensor on the optical fiber tip for in vitro measurements of rodent intradiscal pressure. The sensor element is biocompatible and can be fabricated by simple, batch-fabrication methods in a non-cleanroom environment with good device-to-device uniformity. The fabricated sensor element has an outer diameter of only 366 μm, which is small enough to be inserted into the rodent discs without disrupting the structure or altering the intradiscal pressures. In the calibration, the sensor element exhibits a linear response to the applied pressure over the range of 0 - 70 kPa, with a sensitivity of 0.0206 μm/kPa and a resolution of 0.17 kPa.


1986 ◽  
Vol 71 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Stanley Braude ◽  
David Royston

1. The effect in the rat of salbutamol infusion (1 μg min−1 kg−1) on acid-induced lung injury has been determined. Severity of lung injury was assessed by two techniques: the pulmonary clearance of 99mTc-diethylenetriaminepenta-acetate (99mTc-DTPA) and the lung wet/dry weight ratio, giving indices of alveolar epithelial permeability and transendothelial water filtration respectively. 2. Mean half-time of clearance of 99mTc-DTPA was increased significantly in rats who had intratracheal acid-induced injury and control (saline) intravenous infusion (19.4 ± 2.6 min) compared with non-acid-treated rats (98.1 ± 7.2) (P < 0.0001). However, those animals who had intratracheal acid injury and subsequent salbutamol intravenous infusion had significantly faster clearance (11.5 ± 1.9) than the acid and control infusion group (P < 0.05). 3. Gravimetric lung water in the acid-only rats (expressed as wet/dry weight ratio) was increased significantly (6.4 ± 0.3) compared with the non-acid-treated controls (5.4 ± 0.2) (P < 0.01). Acid-treated rats who had salbutamol infused had dramatically increased lung water (10.0 ± 0.6) (P < 0.001 vs acid and control infusion). 4. Intravenous salbutamol infusion itself produced no significant difference in the results for both techniques, compared with the non-acid-treated time-course controls. 5. Infused salbutamol accentuates acid-induced lung injury in the rat. Possible factors responsible for these findings include β2-adrenergic agonist mediated inhibition of hypoxic pulmonary vasoconstriction (HPV) and a predominant β1-adrenergic agonist inotropic effect of salbutamol with resultant rise in pulmonary artery pressure.


Author(s):  
Salim Meziani ◽  
Lynda Djimli

The first objective of this paper investigates the influence of the previous strain history on ratcheting of the 304 L stainless steel on ambient temperature. The identification is done using the Chaboche constitutive model. New tests were performed where different strain-controlled histories have been applied prior to ratcheting tests. It is demonstrated that under the same conditions, one can observe ratcheting, plastic shakedown or elasticity according to the prior strain-controlled history. The second objective points out the correlation between the experimental data base devoted to the identification of the material parameters and the quality of the predictions in cyclic plasticity. The results suggest that the choice of the tests should be closely linked to the capabilities of the model. In particular, the presence of non proportional strain-controlled tests in the data base may be not a good choice if the model itself is not able to represent explicitly such a character.


2001 ◽  
Author(s):  
Thomas DeMurry ◽  
Yanying Wang

Abstract The primary objectives of this study are (1) to validate the hardware design and control methodologies for preserving the thermo-mechanical integrity of a launch clutch emulating a torque converter and (2) to develop a simple, control oriented clutch-temperature model that may act as a virtual thermocouple in the processor of an automobile for real-time clutch-temperature predictions. In a dynamometer test cell, a Ford CD4E transaxle is instrumented with a thermocouple-based telemetry system to investigate clutch thermal characteristics during engagements, neutral idle, single and repeated launching, torsional isolation, and hill holding. A nonlinear, SIMULINK™-based model for estimating temperature is developed. The results from the simulations are in good agreement with the experimental data.


Author(s):  
H. T. Banks ◽  
C. A. Smith

Abstract In this presentation we will report on joint efforts with D.J. Inman and his colleagues at MSL, SUNY at Buffalo, to develop viable models for the analysis and control of elastic structures exhibiting coupled torsional and flexural vibrations. A model for coupled torsion and bending is developed which incorporates Kelvin Voigt damping and warping. Approximation techniques are introduced and preliminary numerical results are discussed. Experimental data is presented and used to test our computational results.


2001 ◽  
Author(s):  
Hidesada Kanda

Abstract For plane Poiseuille flow, results of previous investigations were studied, focusing on experimental data on the critical Reynolds number, the entrance length, and the transition length. Consequently, concerning the natural transition, it was confirmed from the experimental data that (i) the transition occurs in the entrance region, (ii) the critical Reynolds number increases as the contraction ratio in the inlet section increases, and (iii) the minimum critical Reynolds number is obtained when the contraction ratio is the smallest or one, and there is no-shaped entrance or straight parallel plates. Its value exists in the neighborhood of 1300, based on the channel height and the average velocity. Although, for Hagen-Poiseuille flow, the minimum critical Reynolds number is approximately 2000, based on the pipe diameter and the average velocity, there seems to be no significant difference in the transition from laminar to turbulent flow between Hagen-Poiseuille flow and plane Poiseuille flow.


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