Abstract

Although pneumatic actuators are widely used in industry, they have two major weaknesses-nonlinearities associated with compressibility of air and low energy efficiency. The former limits its applicability whenever accurate positioning is required, and the latter has a negative impact on users through increased energy costs. This paper addresses these issues with the aim of developing a widely applicable servo control strategy, which combines improved tracking accuracy and energy efficiency. A detailed actuator system model is linearized through nonlinear input-output feedback linearization, and the energy optimal velocity profile is derived. Simulation and experimental studies indicate that energy efficiency improvements of 3-7 are possible, while tracking accuracy can be ensured. The method is suitable for real-time implementation and is cost effective; it requires the implementation of an improved velocity profile, while hardware components do not need to be altered. © 2012 American Society of Mechanical Engineers.