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In this paper, a redundantly actuated chewing robot with two higher kinematic pairs (HKPs) is presented, which can be used in performance test and evaluation of denture material. The robot has six actuators, but only has four degrees of freedom, due to constraints of two HKPs which mimic two temporomandibular joints (TMJs) of human. Quasi-static force analysis in occlusion status is performed to calculate...
Considerable efforts have been devoted to the design of low-power digital electronics. However, after decades of improvements and maturation, CMOS technology could face an efficiency ceiling. This is due to the trade-off between leakage and conduction losses inherent to transistors. Consequently, the lowest dissipation per operation remains nowadays few decades higher than the theoretical Landauer''s...
In this paper, in order to replace a conventional electric linear actuator which is consist of rotary PM machine and ball screw, a novel double-sided five-phase modular linear permanent magnet synchronous machine (MLPMSM) is proposed and designed with the same volume. The basic structure of the machine is firstly described and the major dimensions of one module are then optimized to acquire the largest...
Needle-free jet injection allows delivery of liquid drugs through the skin in the form of a narrow fluid jet traveling at high speed, minimizing the risk of accidents. The use of a controllable actuator to drive this process has many advantages, but the voice coil actuators previously used are too large and heavy for practical use with common injection volumes (∼1 mL). We instead propose a compact...
In this paper, novel mechanical mechanism and control method using SEA are suggested for natural gait pattern and effective gait rehabilitation. Conventional body weight support system (BWS) focuses on static position lifting and has limitation for a subject to constrain natural gait pattern especially in the vertical and medial-lateral movement. To overcome such abnormal gait pattern during BWS rehabilitation,...
As a new actuator driven by Ampere force, Electro Magnetic Force driving Actuator (EMFA) is applicable to medium-high-voltage system with powerful output force, long stoke, simple structure and high reliability. In the paper, a new type of EMFA for 126kV VCB with single break is proposed on the basis of the mature manufacturing technology of 126kV vacuum interrupter. The model of EMFA is established...
This paper focused on a fast mechanical switch applied in 2kV hybrid DC contactor. An integrated design of vacuum switch based on Permanent Magnetic Actuator (PMA) is proposed. The stainless steel bellows is removed to avoid vacuum failure caused by air leakage and eliminate restriction of bellows' fatigue life compared to conventional vacuum switch. Both monostable structure and compact springs'...
We proposed a hybrid powered ankle exoskeleton. It can be able to supply positive mechanical power to the user during the swing phase of gait. The hybrid powered ankle exoskeleton was composed of a pair of compressed springs and a cable-driven actuator fasted to the shin. It was lightweight, and permitted the cable-driven actuator to provide the forces at the biological level to the ankle joint. Meanwhile...
The design employs direct drive torque motor to achieve a robot single joint with active compliance based on the impedance model. In order to maximize the torque density, transmission transparency and backdrivability, the joint employs a quasi-direct actuator that a single-stage planetary gear is mounted on the motor's rotor. When robot interacts with environments, it's inevitable to change the stiffness...
This paper presents an analysis of effect of external load on hemispherical resonator gyroscope (HRG) feedback control system with state constraint. Firstly, the analytical solution of dynamic equation under multi-electrode excitation is obtained based on dynamic equations of resonator in the second-order resonant state. Through analysis, two main reasons that external load influences feedback control...
This paper presents a system for dynamic measuring of leg length discrepancy (LLD). The system consists of two 3-RPS parallel manipulators with three degrees of freedom. Parallel manipulators have force sensors that determine the patient's center of gravity (COG) displacement. By changing the height of the moving platform of the parallel manipulator, COG returns in its expected position. The difference...
This paper focuses on the control system design for a wearable power assist device which provides force/torque support for people who are doing physically demanding tasks. The device is actuated by the McKibben artificial muscle. The McKibben actuator is know to exhibit high nonlinearity between the supply pressure and the contractile length, and it is basically difficult to design a high performance...
The paper presents a new type of electromagnetic actuator based on the attraction forces generated by a pair of electromagnets over a ferromagnetic disk, which uses a differential magnetic spring to generate the return forces. The paper also shows some functional characteristics of this device, obtained by numerical simulation with COMSOL Multiphysics. The proposed actuator has been experimentally...
Proportional-integral-derivative (PID) controller is popular algorithm in structure vibration control. In order to maintain minimum regulation error, the PID control require big proportional and derivative gains. The control performances are not satisfied because of the big uncertainties in the buildings. In this paper, the type-2 fuzzy system is applied to compensate the unknown uncertainties, and...
We describe a design for an “audio display”, a loudspeaker that employs the bending vibrations of a panel, such as flat-panel television screen or projection surface, to render localized sound sources anywhere on the surface of the panel. The method employs a two-dimensional Fourier series reconstruction of the desired panel spatial vibration profile, and an array of force actuators affixed to the...
The paper proposes an optimized geometry for a DC electromagnet combining the experimental design (DOE) and FEM. The optimization problem takes into account three geometrical parameters (coil shape ratio, support thickness ratio and support height ratio) and consists in maximization of the acting force related to the largest air-gap, preserving the global dimensions of the device (external radius,...
In this paper, the dynamic characteristics of two types of electromagnetic repulsive force actuators are compared using the simulation of finite element method. The two electromagnetic repulsive force actuators are equipped with a single-sided coil and a double-sided coil respectively. Initially, the construction and theory of each of the electromagnetic repulsive force actuators are discussed. Subsequently,...
The feasibility of zero-power control in flux-path control magnetic suspension is discussed. In the flux-path control magnetic suspension system, ferromagnetic control plates are inserted between a permanent magnet (magnetic source) and a floator and moved to vary the flux from the magnetic source to the floator. The zero-power control has been applied in active magnetic suspension with a DC electromagnet...
This paper describes the prediction and prevention of losing steps in helical teethed linear actuator (HTLA) for artificial muscle. When the rapid external force is applied to the HTLA, it becomes a state of losing steps. Therefore, it is important to predict and prevent this phenomenon. First, we clarified the phenomenon of losing steps in the HTLA by using numerical simulation with 3-D FEM. Next,...
A novel concept of modular bistable electromagnetic actuator in valve operation is numerically analysed, designed and experimentally tested. The actuator takes advantage of permanent magnets for assuring stable positions of the valve body and field coils for control of the valve operation. The paper presents the basic concept of the actuator together with its numerical investigation for the case of...
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