The scope of this letter is to show the applicability Twisted String Actuators (TSAs) for lightweight, wearable and assistive robotic applications. To aim, we have developed a novel surface electromyography (sEMG)-driven soft ExoSuit using TSAs perform both single dual-arm elbow proposed ExoSuit, with an overall weight 1650 g, uses pair mounted in back user, connected via tendons user's forearms actuate each arm independently supporting external loads. We confirm new light-weight...

For most nanopositioning systems, maximising positioning bandwidth to accurately track periodic and aperiodic reference signals is the primary performance goal. Closed-loop control schemes are employed overcome inherent limitations such as mechanical resonance, hysteresis creep. Most reported integer-order combine both damping tracking actions. In this work, fractional-order controllers from positive position feedback family namely: Fractional-Order Integral Resonant Control (FOIRC),...

This paper presents a climbing robot with wheeled locomotion which uses permanent magnets as adhesion mechanism. The designed is intended for the inspection of various types ferromagnetic structures, such ship hulls, wind turbine towers, bridges, and fuel tanks, in order to detect surface faults or cracks caused by, example aging atmospheric corrosion. proposed robotic system consists cordless teleoperated mobile platform can move on vertical walls. be equipped testing probes cameras that...

This paper presents a controller design to compensate the effects of time delay in flexure-based piezoelectric stack driven nanopositioner.The flexure nanopositioners is illustrated and identified by means experimentally obtaining frequency response system.Moreover, theoretical model which takes into account dependence between sampling introduced proposed.The proposed control methodology not only accommodates for but also ensures robust stability allows its application systems with larger...

In this article, we propose a new control approach for the twisted string actuation system; hybrid scheme consisting of two nested loops, considering motor angle and axial force at clamping point actuator as system outputs. We show that measuring base actuator, can effectively estimate compensate coupling torque between external load. Then, compensation allows formulating linear law to angular position and, same time, implement an loop regulate applied by actuator. Simulated experimental...

We report the mesomorphic behaviour, dielectric and ferroelectric properties, computational modelling of binary mixtures containing two bent-core liquid crystals: so-called NG75-COO (3,4́- Bis[4-(4-n-tetradecyloxybenzoyloxy)benzoyloxy]biphenyl), which forms smectic phases, IP31- AzB (3,4′ - Bis[4-(4-n-tetradecyloxyphenylazo)benzoyloxy]biphenyl), columnar phases. The phase diagram, assessed by polarised optical microscopy, shows that retain mesophase behaviour major component, whilst...

Vibrations are present in many mechanical structures and machines, often associated with their elastic parts. Characterizing these vibrations, i.e., obtaining frequencies, amplitudes phases, is of most interest applications ranging from the maintenance civil to motion control. This paper presents a method for online reliable identification defining parameters two unknown sinusoidal signals through use measured sum presence noise an offset. It based on algebraic derivative approach, defined...

The Butterworth filter is known to have maximally flat response. Incidentally, the same response desired in precise positioning systems. This paper presents a method for obtaining closed-loop pattern using common control schemes applications, i.e. Integral Resonant Control (IRC), Force Feedback (IFF), Positive Position (PPF), and Velocity (PVPF). Simulations show significant increase bandwidth over traditional design methods verify pole placement achieved. simulations also limitation of...

On-orbit satellite servicing is a technology that expected to transform the space sector in coming years. Space robotics promising approach refuel, repair, update, and transport satellites on orbit. However, safe reliable docking with client satellite, needed as part of most operations, still considered challenge. This paper presents an autonomous robot-based for this purpose. An impedance control strategy added controller conventional robotic manipulator allow compliant manipulation...

In this paper a two-input, two-output (TITO) fractional order mathematical model of laboratory prototype hydraulic canal is proposed. This made up two pools that have strong interaction between them. The inputs the TITO are pump flow and opening an intermediate gate, outputs water levels in pools. Based on experiments developed parameters models been identified. Then, considering model, first control loop closed to reproduce real-world conditions which level pool not dependent upstream thus...

A new control scheme composed of two independent stages utilised to achieve precise positioning single-link flexible manipulators is presented herein. Traditional techniques for the utilise only one actuator and types sensor measurement (e.g angular position motor acceleration or strain measurements) move manipulator in order damp residual vibrations produced displacement manipulator. However, proposed another additionally pair actuator-sensor improve speed precision controlled system. On...

Accurate trajectory tracking is a paramount objective when mobile robot must perform complicated tasks. In high-speed movements, time delays appear reaching the desired position and orientation, as well overshoots in changes of which prevent execution some One aspects that most influences performance control system actuators wheels. It usually implements PID controllers that, case low-cost robots, do not yield good owing to friction nonlinearity, hardware delay saturation. We propose...

This paper proposes a Fractional-order modification of the traditional Integral Resonant Controller named as FIRC. The fractional integral action utilised in proposed FIRC is simple, robust, and well-performing technique for vibration control smart structures with collocated sensor-actuator pairs such nanopositioning stages. scheme robust sense being insensitive to spillover dynamics maintaining closed-loop stability even presence model inaccuracies or time-delays system. experimental...

Cardiospheres (CSs) are self-assembling multicellular clusters from the cellular outgrowth cardiac explants cultured in nonadhesive substrates. They contain a core of primitive, proliferating cells, and an outer layer mesenchymal/stromal cells differentiating that express cardiomyocyte proteins connexin 43. Because CSs both primitive committed progenitors for three major cell types present heart, is, cardiomyocytes, endothelial smooth muscle because they derived percutaneous endomyocardial...

In this paper a fractional order model for an irrigation main canal is proposed. This system has two pools that present strong interaction between them. Then multivariable with inputs: the pump flow and opening of intermediate gate, outputs: water levels in pools, derived. The identification parameters based on experiments developed laboratory prototype hydraulic application direct methodology. accuracy proposed models compared standard integer-order canal. mathematical have been identified...

Parameter uncertainty is a key challenge in the real-time control of nanopositioners employed scanning probe microscopy. Changes sample to be scanned introduces changes system resonances, requiring instantaneous online tuning controller parameters ensure stable, optimal performance. This paper presents method based on frequency-domain algebraic derivative approach for accurate identification nanopositioner's parameters. The parameter estimates are produced within fraction one period resonant...

The Butterworth filter is known to have maximally flat response. Incidentally, the same response desired in precise positioning systems. This paper presents a method for obtaining closed-loop pattern using common control schemes applications, i.e. Integral Resonant Control (IRC), Positive Position Feedback (PPF), and Velocity (PVPF). Simulations show significant increase bandwidth over traditional design methods verify pole placement achieved. Experiments are performed two-axis serial...

This paper presents a controller for robotic manipulator spacecraft docking operations oriented to on-orbit servicing. The proposed combines visual and force/torque feedback in order complete the approach contact phases of docking. Visual servoing is used not only guiding end-effector during phase, but also maintain probe correctly aligned phase. During an impedance generates compliant behavior needed minimize peak forces that could result failed has been tested experimentally...

We deal with the online identification of payload mass carried by a single-link flexible arm that moves on vertical plane and therefore is affected gravity force. Specifically, we follow frequency domain design methodology to develop an algebraic identifier. This identifier capable achieving robust efficient estimates even in presence sensor noise. In order highlight its performance, proposed estimator experimentally tested compared other classical methods several situations resemble most...