In this paper, the diagnosis of broken rotor bar (BRB) is investigated analytically and experimentally based on induction motors (IM) with variable speed drives (VSD). The analysis of the VSD process has understood that the sensorless control mode adjusts both supply voltage and current in order to maintain the operating speed within high accuracy. It means that any asymmetric problems with the...

he number of women of childbearing age who have congenital heart disease is increasing. 1 A similar proportion of these women can be expected to attempt pregnancy as women in general. 2 Although most of these women can be expected to tolerate pregnancy well, particularly if the pregnancy is carefully planned following appropriate clinical evaluation, not all pregnancies are planned, and some wi...

Passively compliant legs have been instrumental in the development of dynamically running legged robots. Having properly tuned leg springs is essential for stable, robust and energetically efficient running at high speeds. Recent simulation studies indicate that having variable stiffness legs, as animals do, can significantly improve the speed and stability of these robots in changing environme...

Humans employ varying stiffness in everyday life for almost all human motor skills, using both passive and active compliance. Robots have only recently acquired variable passive stiffness actuators and they are not yet mature. Active compliance controllers have existed for a longer time, but the problem of automatic determination of the necessary compliance to achieve a task has not been thorou...

Conventional constant speed turbo air centrifugal compressor systems (TACCSs) consist of an electric motor driven at the and inlet guide vane (IGV) for pressure control. TACCSs with inverter a variable drive (VSD) are more efficient than conventional TACCS because they have wide operating range can minimize power consumption. Therefore, this paper proposes quadratic V/f control VSD to reduce el...

The robots are interacting with humans in various aspects. Safety issues are increased in various robot applications. Many robot arms have been introduced for safety. The passive compliance methods have faster and high reliability than active methods. In this paper, a new safety mechanism based on passive compliance is proposed. The variable stiffness joint employed spring and roller is economi...

This study was designed to assess the efficacy of vacuum sealing drainage (VSD) on skull exposure wounds in rabbits and to investigate the underlying mechanism of the process. Full-thickness excisional circular wounds 2×2 cm with or without periosteum involvement were created in 88 New Zealand white rabbits (mean body weight: 3.0±0.65 kg). Animals were randomly divided into 4 groups: periosteum...

OBJECTIVE Both surgical and percutaneous device closure of ventricular septal defect (VSD) have drawbacks and limitations in infants. We report our experiences and midterm results of transthoracic device closure of VSDs (TDCVs) without cardiopulmonary bypass (CPB) in infants. METHODS Between September 2007 and September 2009, 32 patients, with a mean age of 7.2 ± 4.7 months, body weight of 6....

The work described in this paper is focused on the reduction of the impact force exerted by the ground on a falling humanoid robot. It proposes the use of a variable stiffness in the arms's motors to prevent damages. The proposed work is applicable when the falling prevention techniques fail or when falling is unavoidable. This work proposes the generation of variable stiffness in a motor throu...

BACKGROUND We present an alternative treatment employing a hybrid approach used in 3 patients with congenital heart disease. The goal was to provide optimal therapy by minimizing the potentially harmful effects of methods that accompany conventional surgical procedures. METHODS Two patients aged 4 and 6 months underwent beating-heart closure of a muscular ventricular septal defect (VSD) with ...