Hydraulic actuators are characterized by their ability to impart large forces at high speeds and are used in many industrial motion systems. In applications where good dynamic performance is important it is common to contain the actuator in a servo loop comprising a feedback transducer and electronic controller. The majority of electronic servo-controllers used in these systems are analogue bas...

Positioning stages using piezoelectric stack actuators (PEA) possess very high theoretical bandwidth and resolution. However, their tracking performance deteriorates as nonlinear dynamics due to inherent hysteresis starts to dominate when the total length of travel increases. When tracking periodic trajectories, which is common in most industrial applications, the uncertain nonlinearity from hy...

Electrohydraulic servosystems exhibit highly nonlinear behavior to the effect that classical linear controllers, e.g., PD, usually achieve a limited performance. Load static and dynamic parameters variations are also contributing to the limitation of their position and force tracking performance. This paper presents a modelbased controller applied to a fully detailed model of an electrohydrauli...

Force-controlled series elastic actuators (SEA) are widely used in novel human-robot interaction (HRI) applications, such as assistive and rehabilitation robotics. These systems are characterized by the presence of the “human in the loop”, so that control response and stability depend on uncertain human dynamics, including reflexes and voluntary forces. This paper proposes a force control appro...

In this work, an active vibration control method using compliant-based actuators is proposed for controlling a wide range of vibration and its noise-associated applications. The compliant-based actuator combines a conventional actuator with elastic elements, such as passive springs, that can be demonstrated to have better accuracy and robustness for force control compared to conventional stiff ...

In this article, a novel control method is proposed for feedforward compensation of hysteresis non-linearity in various frequency ranges. By integrating a multirate hysteresis compensator controller with PID feedback control, a combined controller is developed and experimentally validated for a piezoelectric micro-positioning system. Piezoelectric materials show non-linear hysteresis behaviour ...

An asymmetric dielectric barrier discharge model is presented for real gas eight species air chemistry using a self-consistent multi-body system of plasma, dielectric and neutral gas modeled together to predict the electrodynamic momentum imparted to the working gas. The equations governing the motion of charged and neutral species are solved with Poisson equation on finite elements using a Gal...

Human muscles contrast sharply with traditional robot actuators in that they consist of several motor units, connected in series and parallel, which can be progressively recruited, or brought into the active state. Some roboticists have explored this idea in robotic actuators, striving for improvements such as the ability to withstand partial damage, inexpensive repeatability by discrete open l...

Force controlled series elastic actuators (SEA’s) are widely used components of novel physical human-robot interaction applications such as assistive and rehabilitation robotics. These systems are characterized by the presence of the “human in the loop” so that control response and stability depend on uncertain human dynamics. A common approach to guarantee stability is to use a passivity-based...

Hyst.eresis in smart actuators presents a challenge in control of these actuators. A fundamental idea to cope with hysteresis is inverse compensation. But due to the open loop nature of inverse compensation, its performance is susceptible to model uncertainties and to errors introduced by inverse schemes. In this paper we develop a robust control framework for smart actuators by combining inver...