A pneumatic exoskeleton intended to decrease the muscle activity of the knee extensors during walking on a negative slope is presented. The device consists of an air spring that can be engaged and disengaged via a solenoid valve. When engaged, the air spring resists knee flexion. A preliminary evaluation of the device was conducted with a single healthy subject. During testing, the EMG activity...

BACKGROUND Intubation is frequently performed in intensive care unit patients. Overinflation of the endotracheal tube cuff is a risk factor for tracheal ischemia and subsequent complications. Despite manual control of the cuff pressure, overinflation of the endotracheal cuff is common in intensive care unit patients. We hypothesized that efficient continuous control of the endotracheal cuff pre...

the depth control systems used in iranian tractors are mechanical and they produce variable tillage depth in uneven field surface. in this research a rotary type electronic control valve was designed and constructed. by using this valve, electro-hydraulic tillage depth control system was developed and installed on the tractor. the control system was composed of: a depth sensor, a programmable l...

PDMS microfluidic devices whose whole inner surfaces are covered with PTFE (polytetrafluoroethylene) are described. The major problems of PDMS fluidic devices in practical use, are surface degradation with organic solvents and unexpected absorption of chemical materials. In order to overcome these problems, spin/dip-coated perfluoro amorphous polymer is used to form the passivation PTFE layer o...

Abstract Braking system performance is relevant for both railway safety and network optimization. Most trains employ air brake systems; systems of freight mostly cannot achieve a synchronous application forces, which usually customary passenger trains. The paper generalizes previous pneumatic model to describes the needed modifications. Among them, way pressure reduces in pipe generalized. More...

For a pneumatic teleoperation system with on/off solenoid valves, sliding-mode control laws for position and force, ensuring low switching (open/close) activity of the valves are developed. Since each pneumatic actuator has two pneumatic chambers with a total of four on/off valves, sixteen possible combinations (“operating modes”) for the valves’ on/off positions exist, but only seven of which ...

This paper describes one method to attain a robust positioning control of pneumatic driving system comprising a pneumatic cylinder and PCM digital control valves. A pneumatic driving system has become one of interests in the industrial fields, however, the control characteristics are inevitably affected by the friction force and parameter changes of plant due to air compressibility. The control...

This research investigates a pneumatic suspension system containing an air spring, air flow valve, and an accumulator, where the spring and damping functions are combined into one package. The spring and accumulator provide the spring characteristics, and the computer controlled adjustable valve provides the damping characteristics by automatically adjusting the air flow between the air spring ...