2 Abstract Pneumatic actuators have several advantages such as light weight, safety, low cost and high compliance. However, many pneumatic actuators have complicated systems that include a compressor, air tubes, and pneumatic valves with electrical wires. This research proposes a new control method for a multiplex pneumatic transmission constructed with special resonant valves and air tubes wit...

It is a general assumption that pneumatic muscle-type actuators will play an important role in the development of an assistive rehabilitation robotics system. In the last decade, the development of a pneumatic muscle actuated lower-limb leg orthosis has been rather slow compared to other types of actuated leg orthoses that use AC motors, DC motors, pneumatic cylinders, linear actuators, series ...

Pressure control of a pneumatic actuator using fast switching On/Off valves continues to remain a major challenge for researchers. This article proposes a novel pulse width modulation–sliding mode controller that improves pressure tracking of pneumatic actuators. First, a comprehensive mathematical model of the pneumatic system was developed that consists of several submodels. The model compris...

This paper proposes a variation on a sliding mode control approach that provides significant energy savings for the control of pneumatic servo systems. The control methodology is formulated by first decoupling the standard four-way spool valve used for pneumatic servo control into two three-way valves, then using the resulting two control degrees of freedom to simultaneously satisfy both the sl...

This paper presents a comparative study among friction behavior of several double-acting pneumatic actuators available to industrial use. A brief review covering the manner that pneumatic actuator manufacturers and current literature approach friction force and its usual models also is presented. After depicting friction test methodology and test apparatus, the comparison work is carried out th...

Air brake system has been widely used in heavy trucks and intercity buses for its great superiority over other brake system. The practical performance of air brake system may be greatly different from if we analyze it with static theory. Thus, it is necessary to build an integrate air brake system model to simulate the process of brake accurately. However, the dynamic mathematic model of air br...

In this study, a non-contact type intraocular pressure (IOP) measuring system using reflected pneumatic pressure is proposed to overcome the disadvantages of existing measurement systems. A ring-type nozzle, a key component in the proposed system, is designed via computational fluid analysis. It predicts the reflected pneumatic pressure based on the nozzle exit angle and inner and outer diamete...

Train pneumatic brakes are part of a train safety system, and are thus critical components. This paper illustrates how modeling can be applied to efficiently design such system, from requirement definition to HIL testing. The valves modeling is discussed along with the system level model. Moreover, in order to study the wheel-slide protection device, a model of the wheel-rail interface has been...

This paper presents a control methodology that enables nonlinear model based control of pulse width modulated (PWM) pneumatic servo actuators. An averaging approach is developed to describe the equivalent continuous-time dynamics of a PWM controlled nonlinear system, which renders the system, originally discontinuous and possibly non-affine in the input, into an equivalent system that is both c...

This work describes a method for the simulation of multiple pneumatic actuators in a context of multi body mechanical systems. The model of the single actuator is based on elliptical approximation of non-linear pneumatic devices; friction and sticking phenomena are considered as well. Pneumatic devices introduce forces and new state variables into the complete multibody system: we developed a s...