THE CONCOMITANT-EFFECT OF ELECTRORHEOLOGICAL FLUID IN A CONTROL FLOW FIELD

2005 ◽  
Vol 19 (07n09) ◽  
pp. 1263-1269 ◽  
Author(s):  
Shi-sha ZHU ◽  
Toyohisa FUJITA ◽  
Qi-xin WANG ◽  
Kejun LIU ◽  
Gjergj DODBIBA
Keyword(s):  
Flow Field ◽  
Power Transmission ◽  
Electrorheological Fluid ◽  
Control Flow ◽  
Fluid Power ◽  
Control Technology ◽  
Capture Effect ◽  
Shearing Flow ◽  
Er Fluid ◽  
Research Show

The description of ER response in a flow field is a key issue in researching control technology of ER fluid. In this paper, an experimental work on controlling flow field in fluid power transmission has been carried out. The results of research show that the control flow field differs from the rotary shearing flow field in an experimental instrument. Besides the ER effect there is a concomitant-effect of ER response called "capture effect" in the field, which is unbeneficial to the control on fluid power transmission.

CFD simulation of air effect on flow field characteristics of hydro-viscous clutch with constant speed difference

2018 ◽  
Vol 19 (2) ◽  
pp. 208
Author(s):  
Xudong Zheng ◽  
Fangwei Xie ◽  
Diancheng Wu ◽  
Xinjian Guo ◽  
Bing Zhang ◽  
...  
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Power Transmission ◽  
Volume Fraction ◽  
Phase Distribution ◽  
Constant Speed ◽  
Distribution Law ◽  
Two Phase ◽  
Oil Film ◽  
Speed Difference

The purpose of this paper is to study the air effects on transmission characteristics of hydro-viscous clutch and reveal the distribution law of the flow field of the oil film. The computational-fluid-dynamics (CFD) simulation model of oil film with radial oil grooves between friction pairs is taken as the study object. Considering the air effects, the pressure field, two-phase distribution, transmission torque and temperature field of the oil film are analyzed comparatively by using the CFD technology. The results show that the presence of air changes the pressure and temperature distributions of the oil film. With increase of the absolute rotational speed, the air volume fraction increases and the radius value of the air-liquid boundary decreases under condition of constant speed difference, which makes the coverage rate of the oil film on the surface of the friction disks reduce and the transmission torque of the oil film decrease. These simulation results are attributed to the study of hydro-viscous-drive and its applications. This paper also can provide a theoretical basis for the mechanism of power transmission through oil film in the presence of air effects.

Coordination of Movements of Two-Handed 12-DOF Robot Manipulators at Their Joint Manipulation

2021 ◽  
pp. 11-18
Author(s):  
L.A. Karginov ◽  
E.I. Vorobyov ◽  
A.K. Kovalchuk
Keyword(s):  
Inverse Problem ◽  
Initial Data ◽  
Degrees Of Freedom ◽  
Control Flow ◽  
Flow Chart ◽  
Hierarchical Approach ◽  
Kinematic Scheme ◽  
Kinematic Constraints ◽  
Generalized Coordinates ◽  
Research Show

The study focuses on a two-handed robot with twelve degrees of freedom, six for each arm, and gives an example of calculating generalized coordinates for the two-armed robot limbs at their joint manipulation. The initial data for obtaining generalized coordinates are represented by the location of the work object, which is a cube. When solving the problem, the last arm links reach the faces of the work object with a given orientation. To obtain generalized coordinates, we used a hierarchical approach, which is based on an algorithm for solving the inverse problem of kinematics, and developed a control flow chart. The values ??of generalized robot coordinates were obtained for each location of the object of work, taking into account the kinematic constraints in the joints of the robot actuator. Findings of research show that it is possible to obtain generalized coordinates for the coordinated movement of the robot actuators with tree-like kinematic scheme.

Dynamic Modeling of Robotic Fish Caudal Fin With Electrorheological Fluid-Enabled Tunable Stiffness

2015 ◽  
Author(s):  
Sanaz Bazaz Behbahani ◽  
Xiaobo Tan
Keyword(s):  
Equations Of Motion ◽  
Electrorheological Fluid ◽  
Robotic Fish ◽  
Dynamic Equations ◽  
The Finite Element Method ◽  
Modeling Framework ◽  
Caudal Fin ◽  
Body Theory ◽  
Tunable Stiffness ◽  
Er Fluid

In this study, we investigate the modeling framework for a robotic fish actuated by a flexible caudal fin, which is filled with electrorheological (ER) fluid and thus enables tunable stiffness. This feature can be used in optimizing the robotic fish speed or maneuverability in different operating regimes. The robotic fish is assumed to be anchored and the flexible tail undergoes undulation activated by a servomotor at the base. Lighthill’s large-amplitude elongated-body theory is used to calculate the hydrodynamic force on the caudal fin, and Hamilton’s principle is used to derive the dynamic equations of motion of the caudal fin. The dynamic equations are then discritized using the finite element method, to obtain an approximate numerical solution. In particular, simulation is conducted to understand the influence of the applied electric field on the stiffness and thrust performance of the caudal fin.

Sign in / Sign up

Export Citation Format

Share Document