A big problem in many technical applications is the complex hysteretic characteristic of sensors and actuators, which causes a non-linear and multi-valued mapping between the output variable and the input variable of the transducer. In the last few years at the LPA a general modeling and compensator design method was developed for such complex hysteretic nonlinearities which is based on the so-...

The deformable fluid actuators available on the market, i.e. pneumatic muscles and pneumatic springs, are designed to mainly exert compressive or tensile forces. This paper deals with a novel fluid deformable actuator, with three membranes, called BiFAc3, whose particular feature is the ability to exert both tensile and compressive forces. The structure of the actuator is based on three cylindr...

A piezoelectric (PZT) stack-based actuator was developed to provide a means of actuation with dynamic characteristics appropriate for small-scale manipulation. In particular, the design incorporates a highly nonlinear, large-ratio transmission that provides approximately two orders of magnitude motion amplijication from the PZT stack. In addition to motion amplijication, the nonlinear transmiss...

Piezoelectric stick-slip actuators have become the foundation of modern micromanipulation. Due to difficulty in closed-loop control with manipulators that use piezoelectric stick-slip actuators, methods for open-loop control with a human in the loop have been developed. The utility of such methods depends directly on the accuracy of the open-loop models of the manipulator. Prior research has sh...

Common robotic tracking tasks consist of motions along predefined paths. The design of time-optimal path-constrained trajectories for robotic applications is discussed in this paper. To increase industrial applicability, the proposed method accounts for robot kinematics together with actuator velocity, acceleration and jerk limits instead of accounting for the generally more complex dynamic equ...

This article presents a soft pneumatic bending actuator using a magnetically assisted bilayer composite composed of silicone polymer and ferromagnetic particles. Bilayer composites were fabricated by mixing ferromagnetic particles to a prepolymer state of silicone in a mold and asymmetrically distributed them by applying a strong non-uniform magnetic field to one side of the mold during the cur...

The aim of the paper is to design a robust actuator fault-tolerant control for a non-linear discrete-time system. Considered system is described by the Linear Parameter-Varying (LPV) model obtained with recurrent neural network. The proposed solution starts with a discretetime quasi-LPV system identification using artificial neural network. Subsequently, the robust controller is proposed, which...

This paper deals with the characterization and the modeling of the temperature effect on the piezoelectric tube actuator. Besides the sensitivity to the variation of the temperature, this actuator is characterized by the hysteresis and the creep non-linearities, the badly-damped vibration and the cross-couplings between its three axis. First, the characterization results of the sensitivity of t...

in this paper a novel direct adaptive fuzzy system is proposed to control flexible-joints robot including actuator dynamics. the design includes two interior loops: the inner loop controls the motor position using proposed approach while the outer loop controls the joint angle of the robot using a pid control law. one novelty of this paper is the use of a pso algorithm for optimizing the contro...

joint flexibility is a very important factor to consider in the controller design for robot manipulators if high performance is expected. most of the research works on control of flexible-joint robots in literature have ignored the actuator dynamics to avoid complexity in controller design. the problem of designing nonlinear controller for a class of single-link flexible-joint robot manipulator...