The McKibben artificial muscle is a pneumatic actuator whose properties include a very high force to weight ratio. This characteristic makes it very attractive for a wide range of applications such as mobile robots and prosthetic appliances for the disabled. Typical applications often require a significant number of repeated contractions and extensions or cycles of the actuator. This repeated a...

Soft actuators driven by pneumatic pressure are promising actuators for mechanical systems in medical, biological, agriculture, welfare fields and so on, because they can ensure high safety for fragile objects from their low mechanical impedance. In this study, a new rubber pneumatic actuator made from silicone rubber was developed. Composed of one chamber and one air-supply tube, it can genera...

For robotic systems that use on/off (solenoid) pneumatic actuators, a sliding mode control law for precise position control and low switching (open-close) activity of the valves is presented in this paper. Given a pneumatic actuator with two chambers and four solenoid valves, there are sixteen possible input combinations defined directly from the state of the four on/off valves present in the s...

This paper presents an energetically derived control methodology to specify and regulate the oscillatory motion of a pneumatic hopping robot. An ideal lossless pneumatic actuation system with an inertia is shown to represent an oscillator with a stiffness, and hence frequency, related to the equilibrium pressures in the actuator. Following from an analysis of the conservative energy storage ele...

The ready availability of low cost microprocessors and mechantronic components allow industrial users to consider adopting servo-controlled pneumatic actuators with an acceptable cost. This leads to a demand for a software tool in pneumatic actuator system CAS/CAD. Therefore, the paper introduces a software tool developed by the research group in Liverpool for pneumatic actuator system computer...

Abstract The paper conducts energy efficiency analysis of servo pneumatic actuator systems and presents a method of energy efficient optimal control. The system is linearised through input/output state feedback and then energy efficient optimal control theory is applied to the linearised system. An optimal control strategy is developed with respect to the transformed states of the linear system...

In the coming advanced age society, an innovative technology to assist the activities of daily living of elderly and disabled people and the heavy work in nursing is desired. To develop such a technology, an actuator safe and friendly for human is required. It should be small, lightweight and has to provide a proper softness. We call such an actuator soft actuator. A pneumatic rubber artificial...

This study deals with group robots forming a mechanical structure. In this paper, we address the concrete motion mechanisms of the robots. Each robot has a cubic shape with pneumatic actuators. It rotates with a corner of the robot as an axis. To realize the movement, we propose two kinds of mechanical devices. One is a stabilization mechanism that the pneumatic actuator stably forms an arched ...

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 ...