Bistable Valves for MR Fluid-Based Soft Robotic Actuation Systems

2021 ◽  
Vol 6 (4) ◽  
pp. 8285-8292
Author(s):  
Roman Balak ◽  
Yi Chen Mazumdar
Keyword(s):  
Mr Fluid ◽  
Actuation Systems

Bi-Directional Actuation of a Piston Using MR Valves and a Piezoelectric Pump

Aerospace ◽  
2005 ◽  
Author(s):  
Shaju John ◽  
Jin-Hyeong Yoo ◽  
Jayant Sirohi ◽  
Norman M. Wereley
Keyword(s):  
Mechanical Valve ◽  
Wheatstone Bridge ◽  
Piezoelectric Pump ◽  
Pump System ◽  
Mr Fluid ◽  
Bingham Plastic ◽  
Magnetic Circuits ◽  
Hybrid Actuation ◽  
Actuation Systems ◽  
Moving Parts

There is a demand for hybrid actuation systems which combine actuation and valving systems in a compact package. 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 where the two arms form the high and low pressure sides of the output cylinder. The actuation is performed using a compact piezoelectric stack driven actuator. The frequency rectification of the piezo stack motion is done using reed valves. This actuator and valve configuration form a compact hydraulic system with electro-mechanical valves. The advantages of such systems are that part count is low, fewer 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 in 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 allows us to design different controllers for the system. The two systems in this configuration have been separately evaluated. The piezo pump system was first tested for its performance and efficiency with conventional hydraulic fluid and MR fluid. At this stage, the MR valve setup has not been added to isolate the actuating system from the valve system and the MR fluid acts merely as a transmission fluid. The Wheatstone bridge setup was then added and the efficiency of the MR valve was tested against a dummy mechanical valve. The modeling of the valve was done on the basis of standard rheological models like Bingham Plastic and bi-viscous models. Data for bi-directional actuation of the output cylinder is presented and assessed analytically.

Guidance and Actuation Systems for an Adaptive-Suspension Vehicle

1984 ◽  
Author(s):  
M. R. Patterson ◽  
J. J. Reidy ◽  
R. C. Rudolph
Keyword(s):  
Adaptive Suspension ◽  
Actuation Systems

Investigation of ultrasonic properties of MR fluid under various sweep rates of magnetic field

2013 ◽  
Vol 49 (3-4) ◽  
pp. 430-433
Author(s):  
A. Isnikurniawan ◽  
Y. Fujita ◽  
S. Tanimoto ◽  
T. Sawada
Keyword(s):  
Magnetic Field ◽  
Mr Fluid ◽  
Ultrasonic Properties

scholarly journals Design and validation of an MPC controller for CMG-based testbed

2021 ◽  
Author(s):  
Matteo Facchino ◽  
Atsushi Totsuka ◽  
Elisa Capello ◽  
Satoshi Satoh ◽  
Giorgio Guglieri ◽  
...  
Keyword(s):  
Predictive Control ◽  
Attitude Control ◽  
High Speed ◽  
Control Method ◽  
Input Constraints ◽  
Virtual Reference ◽  
Control Moment ◽  
Pyramidal Configuration ◽  
Actuation Systems ◽  
Constraints Satisfaction

AbstractIn the last years, Control Moment Gyros (CMGs) are widely used for high-speed attitude control, since they are able to generate larger torque compared to “classical” actuation systems, such as Reaction Wheels . This paper describes the attitude control problem of a spacecraft, using a Model Predictive Control method. The features of the considered linear MPC are: (i) a virtual reference, to guarantee input constraints satisfaction, and (ii) an integrator state as a servo compensator, to reduce the steady-state error. Moreover, the real-time implementability is investigated using an experimental testbed with four CMGs in pyramidal configuration, where the capability of attitude control and the optimization solver for embedded systems are focused on. The effectiveness and the performance of the control system are shown in both simulations and experiments.

scholarly journals Conceptual Design of Electromechanical Actuation Systems for Large-Sized Directional Control Valves

Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 133
Author(s):  
Tobias Vonderbank ◽  
Katharina Schmitz
Keyword(s):  
Conceptual Design ◽  
Design Process ◽  
Operating Conditions ◽  
Function Structure ◽  
Advantages And Disadvantages ◽  
Conceptual Designs ◽  
Actuation Systems ◽  
Electromechanical Actuation ◽  
Function Structures ◽  
Valve Actuation

Increasing performance in modern hydraulics is achieved by a close investigation of possible enhancements of its components. Prior research has pointed out that electromechanical actuators can form suitable alternatives to hydraulically piloted control systems. Since the requirements at these actuation systems depend on the operating conditions of the system, each actuator can be optimized to the respective hydraulic system. Considering that many different conceptual designs are suitable, the phase of conceptual design plays a decisive role during the design process. Therefore, this paper focuses on the process of developing new conceptual designs for electromechanical valve actuation systems using the method of function structures. Aiming to identify special design features, which need to be considered during the design process of electromechanical actuation systems, an exemplary actuator was designed based on the derived function structure. To highlight the potential of function structures for the development of new electromechanical valve actuation systems, two principal concepts, which allow the reduction of the necessary forces, have been developed by extending the function structure. These concepts have been experimentally investigated to identify their advantages and disadvantages.

Design and experiment of a new structure of MR damper for improving and self-monitoring the sedimentation stability of MR fluid

2020 ◽  
Vol 29 (7) ◽  
pp. 075019
Author(s):  
Hui Huang ◽  
Chen Chen ◽  
Zhi-Chao Zhang ◽  
Ji-Nan Zheng ◽  
Yu-Zheng Li ◽  
...  
Keyword(s):  
Mr Damper ◽  
Sedimentation Stability ◽  
Mr Fluid ◽  
Self Monitoring

Magnetorheological Damping of Fragment Barrier Suspension Systems

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Kwon Joong Son ◽  
Eric P. Fahrenthold
Keyword(s):  
Ballistic Performance ◽  
Mr Fluid ◽  
Suspension Systems ◽  
Mr Fluids ◽  
Ballistic Protection ◽  
Protection Systems ◽  
Fluid Damping ◽  
Magnetorheological Damping ◽  
Impact Experiments ◽  
Very High

Magnetorheological (MR) fluids, well established as components of a variety of suspension systems, may offer opportunities to improve the performance of fabric ballistic protection systems, which typically do not incorporate significant energy dissipation mechanisms. A series of ballistic impact experiments has been conducted to investigate the potential of MR fluid damped fabric suspension systems to improve upon current fabric barrier designs. The results indicate that for the simple fabric suspension systems tested, MR fluid damping does not improve upon the very high weight specific ballistic performance of state of the art aramid fibers.

A Novel Design of Landing Gear Oleo Strut Damper Using MR Fluid for Aircraft and UAV’s

2012 ◽  
Vol 225 ◽  
pp. 275-280
Author(s):  
Chandra B. Asthana ◽  
Rama B. Bhat
Keyword(s):  
Shock Absorber ◽  
Fluid Viscosity ◽  
Simulation Approach ◽  
Body Frame ◽  
Mr Fluid ◽  
Orifice Area ◽  
Aerial Vehicle ◽  
Impact Kinetic Energy ◽  
The Impact ◽  
Novel Design

Most landing gears used in aircraft employ very efficient oleo-pneumatic dampers to absorb and dissipate the impact kinetic energy of the aircraft body frame. A single-acting shock absorber is most commonly used in the oleo strut that has a metering pin extending through the orifice, which can vary the orifice area upon compression and extension of the strut. This variation is adjusted by shaping the metering pin so that the strut load is fairly constant under dynamic loading. In this paper, it is proposed to further change the damping coefficient as a function of time in order to achieve a semi-active control of the aircraft vibrations during landing by using Magnetorheological (MR) fluid in the Oleo. With the metering pin designed for a nominal flight condition, further variation in the fluid viscosity would help achieve the optimal performance in off-nominal flight conditions. A simulation approach is employed to show the effect of different profiles for viscosity variation in the MR fluid. The utility of such a damper can be very well exploited to include different criteria such as the landing distance after touchdown. This type of system can be used also in Unmanned Aerial Vehicle (UAV) application where the focus of design may be to accomplish the task without the consideration of passenger comfort.

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