This paper presents a rigorous analysis and design method for PWM-based control of pneumatic systems. An equivalent analytical model incorporating the effects of a finite PWM switching period is formulated. This equivalent model was motivated by a lack of control design and analysis techniques needed to treat the inherently non-analytical switching models associated with PWM-based systems. The ...

Abstract—The utilization of pneumatic muscles in the actuation of industrial systems is still in its early stages, hence studies on the constructive solutions which include an assessment of their functional performance with a focus on one of the most important characteristics-energy efficiency are required. A quality indicator that adequately reflects the energy efficiency of an actuator is the...

AbstructThis article models a pneumatic system consisting of double-acting or single acting cylinder and a servovalve with the goal of providing an insight into pneumatic design and control requirements for Berkeley Exoskeleton (ht<v://wwu..me. berkeZev.edu/heZ/). The modeling approach uses the thermodynamic principles of energy and mass conservation. We demonstrate that pneumatic systems suffe...

Considering rather severe parametric uncertainties and nonlinear uncertainties exist in the dynamic model of pneumatic muscles driven parallel manipulator, a discontinuous projection-based adaptive robust control strategy (ARC) is adopted to effectively handle the effect of various parameter variations of the system and hard-to-model nonlinearities such as the friction forces of the pneumatic m...

Pneumatic artificial muscles exhibit highly non-linear static characteristics especially due to inherent properties of their materials and compressibility of air. Therefore, it is difficult to control them without adequate modeling and simulation. The paper deals with the numerical approximation of the static characteristics of McKibben pneumatic artificial muscle. The muscle force dependence o...

In this paper, we model, analyze, and control an experimental set-up of a servo pneumatic cylinder. The dynamic behaviour of pneumatic actuator systems is dominant by nonlinear functions. First, a mathematical model for the pneumatic system is derived. Secondly, we investigate the mathematical properties of this model and show boundedness and positiveness of certain variables. Thirdly, we prove...

A problem with pneumatic positioning systems is the low energetic efficiency. This paper presents a structure of a compressed air saving for pneumatic positioning systems with capacity to move high loads. This structure use the loading to save compressed air and thus to increase the energetic efficiency of these systems. This configuration adds a fast switching on/off valve in a feedback betwee...

pneumatic rectosigmoid rapture is usually occurred following the inappropriate fun by direct entering a high volume of the air through the pneumatic device to the anus. such an event was reported for the first time in 1904 by stone. diagnosis and treatment of such injuries are often delayed because of some social limitations and preventing the patient form explaining the event. colon sigmoid ru...

The purpose of this study was to determine the effectiveness of pneumatic reduction of intussusception using equipment readily available in the hospital. Twenty-two children aged between four months and four years had pneumatic reduction of intussusception. The device used was assembled using (i) a hand-held pump attached to a pressure gauge, and (ii) a 3-way Foley's balloon catheter. There was...

Results: Their ages ranged from 18 months to 14 years (mean: 8.5 ± 3.5 years). The overall success rate for the holmium:YAG laser lithotripsy (100%) was higher than that of pneumatic lithotripsy (81.8%), but the difference was insignificant (P = 0.087). The complication rate was higher in pneumatic lithotripsy than in holmium:YAG laser lithotripsy (36.4% versus 4%, P = 0.023). Treatment time an...