Mathematical Model of SMA Spring Actuator in a Miniature Flexible Tube Robot

Author(s):  
Nisha Bhatt ◽  
Sanjeev Soni ◽  
Ashish Singla
2011 ◽  
Vol 110-116 ◽  
pp. 2903-2910 ◽  
Author(s):  
K.V.S.S.D. Prasanth ◽  
M. Sreekumar

low pumps have been developed for classical applications in Engineering and medicine. They are vital instruments in areas such as Biology where the applications demand many such devices in miniaturized form to handle life saving fluids and drugs. The aim of this paper is to develop a new bio-mimic fluid pump, designed to achieve miniaturization in its size and volume. A new actuation technique is proposed which pumps the fluid based on the principle of flow due to pressure difference created by varying the cross-section of a flexible tube. The novelty and advantage being, no external pressurizing device is needed and the flow can be made bidirectional. This is in general not possible in normal or traditional pumps. Use of SMA wires as actuators helps in keeping the size and weight of the device as low as possible. The working principle of the device and the conceptual design are discussed. Mathematical model, relating the flow parameters required for controlling the device, and analytical results obtained from such relations are presented.


2011 ◽  
Vol 177 ◽  
pp. 65-75 ◽  
Author(s):  
Waldemar Rączka ◽  
Jarosław Konieczny ◽  
Marek Sibielak

The article discusses a prototype of a Shape Memory Alloy (SMA) spring intended for controlled vibration reduction systems. The spring has been subject to experiments and the article presents selected static and dynamic characteristics. The experiments were conducted at the Dynamics and Control of Structures Laboratory of the AGH University of Science and Technology. They permitted the formulation of a mathematical model for the SMA spring. The model takes into account the phenomena of energy accumulation and dissipation. The parameters of the spring model have been determined, based on the experimental data. The model takes into account the relationship of stiffness and damping to alloy temperature and the frequency of excitation. It has been demonstrated that the properties of the spring may be altered under controlled conditions. The spring model was then used in simulations. They served as the basis for the determination of the frequency response characteristics, which were then compared to the characteristics of a real spring. The mathematical model developed may be applied in the design of passive, semi-active, and active vibration reduction systems, as well as in the synthesis of adaptive smart vibration reduction systems.


2008 ◽  
Author(s):  
Ishii Akira ◽  
Yoshida Narihiko ◽  
Hayashi Takafumi ◽  
Umemura Sanae ◽  
Nakagawa Takeshi
Keyword(s):  

1974 ◽  
Vol 13 (03) ◽  
pp. 151-158 ◽  
Author(s):  
D. A. B. Lindbebo ◽  
Fr. R. Watson

Recent studies suggest the determinations of clinical laboratories must be made more precise than at present. This paper presents a means of examining benefits of improvement in precision. To do this we use a mathematical model of the effect upon the diagnostic process of imprecision in measurements and the influence upon these two of Importance of Diagnosis and Prevalence of Disease. The interaction of these effects is grossly non-linear. There is therefore no proper intuitive answer to questions involving these matters. The effects can always, however, be calculated.Including a great many assumptions the modeling suggests that improvements in precision of any determination ought probably to be made in hospital rather than screening laboratories, unless Importance of Diagnosis is extremely high.


Sign in / Sign up

Export Citation Format

Share Document