6,712 research outputs found
Robust tuning of robot control systems
The computed torque control problem is examined for a robot arm with flexible, geared, joint drive systems which are typical in many industrial robots. The standard computed torque algorithm is not directly applicable to this class of manipulators because of the dynamics introduced by the joint drive system. The proposed approach to computed torque control combines a computed torque algorithm with torque controller at each joint. Three such control schemes are proposed. The first scheme uses the joint torque control system currently implemented on the robot arm and a novel form of the computed torque algorithm. The other two use the standard computed torque algorithm and a novel model following torque control system based on model following techniques. Standard tasks and performance indices are used to evaluate the performance of the controllers. Both numerical simulations and experiments are used in evaluation. The study shows that all three proposed systems lead to improved tracking performance over a conventional PD controller
Guidance, Flight Mechanics and Trajectory Optimization. Volume 5 - State Determination And/or Estimation
Guidance, flight mechanics, and trajectory optimizatio
Control of flexible joint robotic manipulator using tuning functions design
The goal of this thesis is to design the controller for a single arm manipulator having a flexible joint for the tracking problem in two different cases. A controller is designed for a deterministic case wherein the plant parameters are assumed to be known while another is designed for an adaptive case where all the plant parameters are assumed to be unknown. In general the tracking problem is; given a smooth reference trajectory, the end effector has to track the reference while maintaining the stability. It is assumed that only the output of the manipulator, which is the link angle, is available for measurement. Also without loss of generality, the fast dynamics, that is the dynamics of the driver side of the system are neglected for the sake of simplicity; In the first case, the design procedure adopted is called observer backstepping. Since the states of the system are unavailable for measurement, an observer is designed that estimates the system states. These estimates are fed to the controller which in turn produces the control input to the system; The second case employs a design procedure called tuning functions design. In this case, since the plant parameters are unknown, the observer designed in case one cannot be used for determining the state estimates. For this purpose, parameter update laws and filters are designed for estimation of plant parameters. The filters employed are k-filters. The k-filters and the parameter update laws are given as input to the controller, which generates the control input to the system; For both cases, the mathematical models are simulated using Matlab/Simulink, and the results are verified
A new retuning approach for DoA reference tracking improvement
In this paper, a retuning strategy for a controller is proposed in order to improve the reference BIS tracking in patients, by means of simultaneous administration of propofol and of remifentanil, in the presence of model uncertainties. This strategy proves to be useful as is shown by simulations. (c) IFAC
JUNO Conceptual Design Report
The Jiangmen Underground Neutrino Observatory (JUNO) is proposed to determine
the neutrino mass hierarchy using an underground liquid scintillator detector.
It is located 53 km away from both Yangjiang and Taishan Nuclear Power Plants
in Guangdong, China. The experimental hall, spanning more than 50 meters, is
under a granite mountain of over 700 m overburden. Within six years of running,
the detection of reactor antineutrinos can resolve the neutrino mass hierarchy
at a confidence level of 3-4, and determine neutrino oscillation
parameters , , and to
an accuracy of better than 1%. The JUNO detector can be also used to study
terrestrial and extra-terrestrial neutrinos and new physics beyond the Standard
Model. The central detector contains 20,000 tons liquid scintillator with an
acrylic sphere of 35 m in diameter. 17,000 508-mm diameter PMTs with high
quantum efficiency provide 75% optical coverage. The current choice of
the liquid scintillator is: linear alkyl benzene (LAB) as the solvent, plus PPO
as the scintillation fluor and a wavelength-shifter (Bis-MSB). The number of
detected photoelectrons per MeV is larger than 1,100 and the energy resolution
is expected to be 3% at 1 MeV. The calibration system is designed to deploy
multiple sources to cover the entire energy range of reactor antineutrinos, and
to achieve a full-volume position coverage inside the detector. The veto system
is used for muon detection, muon induced background study and reduction. It
consists of a Water Cherenkov detector and a Top Tracker system. The readout
system, the detector control system and the offline system insure efficient and
stable data acquisition and processing.Comment: 328 pages, 211 figure
Modeling of GERDA Phase II data
The GERmanium Detector Array (Gerda) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double-beta (0\u3bd\u3b2\u3b2) decay of 76Ge. The technological challenge of Gerda is to operate in a \u201cbackground-free\u201d regime in the region of interest (ROI) after analysis cuts for the full 100 kg\ub7yr target exposure of the experiment. A careful modeling and decomposition of the full-range energy spectrum is essential to predict the shape and composition of events in the ROI around Q\u3b2\u3b2 for the 0\u3bd\u3b2\u3b2 search, to extract a precise measurement of the half-life of the double-beta decay mode with neutrinos (2\u3bd\u3b2\u3b2) and in order to identify the location of residual impurities. The latter will permit future experiments to build strategies in order to further lower the background and achieve even better sensitivities. In this article the background decomposition prior to analysis cuts is presented for Gerda Phase II. The background model fit yields a flat spectrum in the ROI with a background index (BI) of 16.04 120.85+0.78\ub710 123 cts/(keV\ub7kg\ub7yr) for the enriched BEGe data set and 14.68 120.52+0.47\ub710 123 cts/(keV\ub7kg\ub7yr) for the enriched coaxial data set. These values are similar to the one of Phase I despite a much larger number of detectors and hence radioactive hardware components
Recommended from our members
TAO Conceptual Design Report: A Precision Measurement of the Reactor Antineutrino Spectrum with Sub-percent Energy Resolution
The Taishan Antineutrino Observatory (TAO, also known as JUNO-TAO) is a
satellite experiment of the Jiangmen Underground Neutrino Observatory (JUNO). A
ton-level liquid scintillator detector will be placed at about 30 m from a core
of the Taishan Nuclear Power Plant. The reactor antineutrino spectrum will be
measured with sub-percent energy resolution, to provide a reference spectrum
for future reactor neutrino experiments, and to provide a benchmark measurement
to test nuclear databases. A spherical acrylic vessel containing 2.8 ton
gadolinium-doped liquid scintillator will be viewed by 10 m^2 Silicon
Photomultipliers (SiPMs) of >50% photon detection efficiency with almost full
coverage. The photoelectron yield is about 4500 per MeV, an order higher than
any existing large-scale liquid scintillator detectors. The detector operates
at -50 degree C to lower the dark noise of SiPMs to an acceptable level. The
detector will measure about 2000 reactor antineutrinos per day, and is designed
to be well shielded from cosmogenic backgrounds and ambient radioactivities to
have about 10% background-to-signal ratio. The experiment is expected to start
operation in 2022
Total Mass TCI driven by Parametric Estimation
This paper presents the Total Mass Target Controlled Infusion algorithm. The system comprises an On Line tuned Algorithm for Recovery Detection (OLARD) after an initial bolus administration and a Bayesian identification method for parametric estimation based on sparse measurements of the accessible signal. To design the drug dosage profile, two algorithms are here proposed. During the transient phase, an Input Variance Control (IVC) algorithm is used. It is based on the concept of TCI and aims to steer the drug effect to a predefined target value within an a priori fixed interval of time. After the steady state phase is reached the drug dose regimen is controlled by a Total Mass Control (TMC) algorithm. The mass control law for compartmental systems is robust even in the presence of parameter uncertainties. The whole system feasibility has been evaluated for the case of Neuromuscular Blockade (NMB) level and was tested both in simulation and in real cases
- …