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This paper proposes a Magneto Rheological linear clutch for use in human safe robotic applications. The force transmitted to the links of the robot must be precisely controlled for any manipulator if it has to be operated safely alongside humans. The traditional approaches to this problem is using various compliant actuating schemes like Series Elastic Actuators, Joint Torque Control etc. Research...
In process industries, compressor plants provide process fluids with certain flows and pressures. The plant behavior may change over the entire life cycle due to component-specific time-variable factors. Control valves applied in compressor plants are affected by time-variable factors. Their modeling with consideration of specific time-variable factors is described in this paper. Control valves ensure...
Magnetorheological (MR) fluid is a widely used smart material due to its outstanding properties. This paper presents the design, development, modeling, and prototype testing of a self-energizing and self-powered MR brake-by-wire system, whose aforementioned capabilities are enabled by brake energy harvesting. The system is composed mainly of a typical T-shaped drum-type MR brake and a wedge mechanism...
Miniaturized actuators are a key element for the manipulation and automation at small scales. Here, we propose a new miniaturized actuator, which consists of an array of micro gas bubbles immersed in a fluid. Under ultrasonic excitation, the oscillation of micro gas bubbles results in acoustic streaming and provides a propulsive force that drives the actuator. The actuator was fabricated by lithography...
In this paper, a novel miniature multi-mode haptic pen is developed to interact with image on mobile terminal. The haptic pen can provide two types of vibrotactile feedback by linear resonant actuator (LRAs) and piezo-ceramic actuator. It can provide passive force feedback by a miniature magnetorheological (MR) fluids damper which is designed independently. In order to obtain the features of an image,...
Modeling of an electrically driven fluid flow system for multi-domain simulation is reported. The electrically driven actuator force is considered by an actuator component model, based on a spring-mass-damper system with force balance formulation. The fluid flow model is developed on the basis of a Kirchhoffian network which is derived from the mass transport equation. The actuator and the fluid models...
A new modeling framework of an electrically driven fluid flow system for mixed-domain circuit simulation is reported. Coupling between electrical and fluidic domains is implemented by developing an organic actuator compact model. The actuator model is based on force balance spring-mass-damper system equation. Fluid compact model is derived from mass transport equation. The actuator and the fluid models...
Compliant-motion control implementation on a humanoid robot with electrohydraulic joints is presented. Characterization results are shown, leading to a dynamic model used in feedback. A Natural Admittance Controller is designed, and its performance is demonstrated in demanding manipulation tasks, including dual-arm palmar manipulation of an egg and dual-arm valve turning.
Microfluidic devices depend on the miniaturization of some components such as sensors, actuators and reactors to enable its applications and expand the possibilities. In this context, we fabricated an actuator capable of pumping fluids through microchannels and ensure the portability of the microfluidic device. The actuator uses the magnetic field generated by a coil to move a neodymium magnet over...
This paper presents a new miniature haptic button based on MR fluids which conveys realistic and exiting haptic button profiles in small handheld devices. A novel mechanism is presented to maximize the resistive force and create various kinesthetic sensations even in the small size. After construction of a prototype, the performance of the proposed haptic button was measured by varying input voltages...
In order to research the actuator principle of work, enhance its anti-vibration performance, the inertia channel semi-active suspension actuator is designed. The mechanical control model is established, the mathematical model is derived, seeks out the expression of dynamic stiffness? dynamic damping and force transmission rate. Carries on the dynamic characteristic simulation through the change inertia...
Hydraulic catapult is a high speed fluid power based launching system and the actuator is a 3-level telescopic cylinder. Limited by the traveling distance of the cylinder, There is no much room left for the cushion process, which leads to the impossible apply of the traditional hydraulic absorber. The structure of the cylinder also makes it impossible to design a cushion structure inside it. In this...
A highly maneuverable, compact vehicle for underwater precision inspection of complex structures is presented. The vehicle will have no appendages such as rudders, screws, and other external thrusters, which might get tangled and interfere with the underwater structure in a cluttered environment. A multi-axis, integrated thruster mechanism using Coanda-effect high-speed valves for switching the direction...
Magnetorheological (MR) fluid is a smart fluid, which theological behavior can be controlled by magnetic field. Rotary devices using MR fluids have the benefits of high torque, good controllability, and low power requirement. Recently, we developed a new MR actuator and applied it to assistive knee braces. It was demonstrated that the knee brace with this MR actuator can provide proper torque under...
Electro-conjugate fluid (ECF) is a kind of functional fluid, which produces a jet flow (ECF jet) when subjected to high DC voltage. It is known that a strong ECF jet is generated under nonuniform electric field, for example, the field with a pair of needle and ring electrode (a needle-ring electrode pair). This study introduces the ECF jet to develop a novel robot finger. First, we propose a concept...
A new piezoelectric/ electrorheological hybrid hydraulic ultra-precision step actuator that uses a hybrid mode of piezoelectric stack pump hydro-drive and electrorheological valve control to the precision hydraulic cylinder is presented. It achieves high frequency, ultra-precision hydraulic step drive. The working principle of the step actuator is analyzed and its experimental characteristics are...
This paper proposes a novel flexible sliding actuator driven by fluid power. The actuator called Λ-drive is basically composed of a flat tube and a slider. In the slider the tube is bent, then the buckling point occurs, which helps to cut off the fluid passage in order to provide the driving force to the slider when pressurizing one side of the tube. The proposed actuator is applicable to not only...
This work first provides an overview of haptic gloves found in the literature, with a focus on their applications and their requirements. This information is then used to justify the use of Magnetorheological Fluid (MRF), a smart fluid which reversibly changes viscosity proportionally to an applied magnetic field, to effect the force feedback in a haptic glove. This is followed by the development...
This paper presents a piezoelectric stack pump for precise actuator. The piezoelectric pump is characterized by long travel range, precise flow, large driving force, etc. The actuator is controlled by PC and Data Acquisition and Control System (DACS). Simulations and experiments showed that the piezoelectric pump has high efficiency and good performance. With a voltage of 100 V, the flow rate is linear...
We present a lumped-parameter dynamic model for a planar poly(dimethylsiloxane) (PDMS) micropump using in-contact, virtually zero-leakage check valves to provide critical insights into the dynamic characteristics of the planar micropump operation. The model features a single-plane microfluidic chamber sandwiched between two check valves, which allows for reliable operation and easy system integration...
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