Search results for " feedback"
showing 10 items of 291 documents
Input-Output Feedback Linearization Control with On-line MRAS Based Inductor Resistance Estimation of Linear Induction Motors Including the Dynamic E…
2016
This paper proposes the theoretical framework and the consequent application of the input–output feedback linearization (FL) control technique to linear induction motors (LIMs). LIM, additionally to rotating induction motor, presents other strong nonlinearities caused by the dynamic end effects, leading to a space-vector dynamic model with time-varying inductance and resistance terms and a braking force term. This paper, starting from a recently developed dynamic model of the LIM taking into consideration its end effects, defines a FL technique suited for LIMs, since it inherently considers its dynamic end effects. Additionally, it proposes a technique for the on-line estimation of the indu…
Improved Active Disturbance Rejection Control for Trajectory Tracking Control of Lower Limb Robotic Rehabilitation Exoskeleton.
2020
Neurological disorders such as cerebral paralysis, spinal cord injuries[acronym](SCI), and strokes, result in the impairment of motor control and induce functional difficulties to human beings like walking, standing, etc. Physical injuries due to accidents and muscular weaknesses caused by aging [english]affectsaffect people and can cause them to lose their ability to perform daily routine functions. In order to help people recover or improve their dysfunctional activities and quality of life after accidents or strokes, assistive devices like exoskeletons and orthoses are developed. Control strategies for control of exoskeletons are developed with the desired intention of improving the qual…
Hybrid Position/Force Control for Hydraulic Actuators
2020
In this paper a novel hybrid position/force control with autonomous switching between both control modes is introduced for hydraulic actuators. A hybrid position/force control structure with feed-forwarding, full-state feedback, including integral control error, pre-compensator of the deadzone, and low-pass filtering of the control value is designed. Controller gains are obtained via local linearization and pole placement accomplished separately for the position and force control. A hysteresis-based autonomous switching is integrated into the closed control loop, while multiple Lyapunov function based approach is applied for stability analysis of the entire hybrid control system. Experiment…
A screen for constituents of motor control and decision making in Drosophila reveals visual distance-estimation neurons
2016
AbstractClimbing over chasms larger than step size is vital to fruit flies, since foraging and mating are achieved while walking. Flies avoid futile climbing attempts by processing parallax-motion vision to estimate gap width. To identify neuronal substrates of climbing control, we screened a large collection of fly lines with temporarily inactivated neuronal populations in a novel high-throughput assay described here. The observed climbing phenotypes were classified; lines in each group are reported. Selected lines were further analysed by high-resolution video cinematography. One striking class of flies attempts to climb chasms of unsurmountable width; expression analysis guided us to C2 …
Ranolazine-Mediated Attenuation of Mechanoelectric Feedback in Atrial Myocyte Monolayers.
2020
[EN] Background Mechanical stretch increases Na(+)inflow into myocytes, related to mechanisms including stretch-activated channels or Na+/H(+)exchanger activation, involving Ca(2+)increase that leads to changes in electrophysiological properties favoring arrhythmia induction. Ranolazine is an antianginal drug with confirmed beneficial effects against cardiac arrhythmias associated with the augmentation ofI(NaL)current and Ca(2+)overload. Objective This study investigates the effects of mechanical stretch on activation patterns in atrial cell monolayers and its pharmacological response to ranolazine. Methods Confluent HL-1 cells were cultured in silicone membrane plates and were stretched to…
Hybrid State Feedback Position-Force Control of Hydraulic Cylinder
2019
A hybrid position-force control is proposed using a unified state feedback controller in combination with feedforward dead-zone compensation. Dead-zone compensator was constructed as inverse of the identified static map while the state feedback gains were obtained using a numerical optimization routine. An accurate state-space model affine in states and control, derived in a previous work, was used for closed-loop simulations and control tuning. A trigger event for automatic switching between position and force control was defined and integrated into overall control architecture alongside with a feedforward low-pass filter reducing high frequency components in the control signal. Experiment…
Rate of concurrent augmented auditory feedback in postural control learning in adolescents
2020
Introduction: The main objective of this study was to determine the rate of auditory concurrent feedback that best enhanced the learning of a continuous postural task in adolescents. Material and methods: A sample of thirty adolescents (13 to 14-years old) was used, who were assigned to three groups: i) control group (CG); ii) 100% auditory feedback group and iii) 67% auditory feedback group. The subjects performed a pre-test, practice, post-test and a retention (24 hours after the practice). In the postural control task subjects were instructed to remain on a seesaw (unstable in anteroposterior position) and keeping it as level as possible. Results: The results demonstrated that concurrent…
Musical Sonification of Arm Movements in Stroke Rehabilitation Yields Limited Benefits.
2019
Neurologic music therapy in rehabilitation of stroke patients has been shown to be a promising supplement to the often strenuous conventional rehabilitation strategies. The aim of this study was threefold: (i) replicate results from a previous study with a sample from one clinic (henceforth called Site 1; N = 12) using an already established recording system, and (ii) conceptually replicate previous findings with a less costly hand-tracking system in Site 2 (N = 30), and (iii) compare both sub-studies' outcomes to estimate the efficiency of neurologic music therapy. Stroke patients in both sites were randomly assigned to treatment or control groups and received daily training of guided sequ…
Influence of computer feedback on attentional biases to emotional faces in children
2016
We examined which type of corrective feedback in a computerized task produces an optimal balance between performance and emotional reactions in children. To that end, we conducted an emotional dot-probe task. We employed three types of corrective feedback (negative, positive, or mixed) along with a control, non-feedback condition. We tested the effect of feedback on: (i) task performance; (ii) immediate emotional reactions in terms of attentional preferences toward emotional faces (happy, sad, and angry); and (iii) self-reported affective experience after the task. Results showed that children committed more errors in the non-feedback group than in the mixed and negative feedback groups. Fu…
‘Monitoring’ in translation
2019
Abstract We assume that visual feedback from the written trace during translation plays an important role in monitoring the emerging translation. In this study, 44 participants translated with and without visual feedback from the target text (TT). Numerous measures were used to explore the differences between the texts that were created in the two conditions and the characteristics of the task performance in the two conditions. The impact of ST-TT semantic and syntactic relationships showed that there were differences on two of three behavioural measures across conditions. In the comparison of features of the translation process, findings show that ST reading times were longer without visua…