Search results for " Feedforward"

showing 3 items of 3 documents

Exploring directionality in spontaneous heart period and systolic pressure variability interactions in humans: implications in the evaluation of baro…

2004

Although in physiological conditions RR interval and systolic arterial pressure (SAP) are likely to interact in a closed loop, the traditional cross-spectral analysis cannot distinguish feedback (FB) from feedforward (FF) influences. In this study, a causal approach was applied for calculating the coherence from SAP to RR ( Ks-r) and from RR to SAP ( Kr-s) and the gain and phase of the baroreflex transfer function. The method was applied, compared with the noncausal one, to RR and SAP series taken from 15 healthy young subjects in the supine position and after passive head-up tilt. For the low frequency (0.04–0.15 Hz) spectral component, the enhanced FF coupling ( Kr-s = 0.59 ± 0.21, signi…

AdultMalemedicine.medical_specialtySympathetic Nervous SystemPhysiologyPeriod (gene)PostureRR intervalBlood PressureBaroreflexHeart RateTilt-Table TestCoherence and transfer functionFeedback and feedforward mechanismPhysiology (medical)Internal medicineHumansMedicineDirectionalityNonbaroreflex interactionFeedback Physiologicalbusiness.industryModels CardiovascularCardiovascular regulationHeartVagus NerveBaroreflexBlood pressureCirculatory systemCardiologySystolic arterial pressureFemaleCross-spectral analysiCardiology and Cardiovascular MedicinebusinessClosed loopAmerican Journal of Physiology-Heart and Circulatory Physiology
researchProduct

Enhanced Current Loop PI Controllers with Adaptive Feed-Forward Neural Network via Estimation of Grid Impedance: Application to Three-Phase Grid-Tied…

2022

This paper describes a single-stage grid-connected three-phase photovoltaic inverter feeding power to the grid. Using the Recursive Least Squares (RLS) Estimator, an online grid impedance technique is proposed in the stationary reference frame. The method iteratively estimates the grid resistance and inductance values and is effective in detecting inverter islanding according to IEEE standard 929-2000. An Adaptive Feedforward Neural (AFN) Controller has also been developed using the inverse of the system to improve the performance of the inner-loop Proportional-Integral controllers under dynamical conditions and provide better DC link voltage stability. The neural network weights are comput…

Photovoltaic System Adaptive Feedforward Grid Connected Inverter Grid Impedance Neural Network and Recursive Least Squares Estimation.
researchProduct

Development of 3D Anti-Swing Control for Hydraulic Knuckle Boom Crane

2021

In this paper, 3D anti-swing control for a hydraulic loader crane is presented. The difference between hydraulic and electric cranes are discussed to show the challenges associated with hydraulic actuation. The hanging load dynamics and relevant kinematics of the crane are derived to model the system and create the 3D anti-swing controller. The anti-swing controller generates a set of tool point velocities which are added to the electro-hydraulic motion controller via feedforward. A dynamic simulation model of the crane is made, and the control system is evaluated in simulations with a path controller in actuator space. Simulation results show significant reduction in the load swing angles …

Engineeringbusiness.industryComputerApplications_COMPUTERSINOTHERSYSTEMSQA75.5-76.95SwingBoomAutomotive engineeringComputer Science ApplicationsKnucklemedicine.anatomical_structureloader crane; anti-swing; hydraulics; kinematics; feedforward; pressure feedbackControl and Systems EngineeringModeling and SimulationElectronic computers. Computer sciencemedicineHardware_INTEGRATEDCIRCUITSbusinessSoftwareModeling, Identification and Control
researchProduct