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External validation and sub-cohort analysis of stochastic forecasting models in NICU cohorts

BIOMEDICAL SIGNAL PROCESSING AND control 2013年第4期8卷 409-419页

作者： Dickson, Jennifer L. Floyd, Richard P. Le Compte, Aaron J. Fisk, Liam M. Chase, J. Geoffrey Lynn, Adrienne Shaw, Geoffrey M. Univ Canterbury Dept Mech Engn Christchurch 1 New Zealand Christchurch Womens Hosp Neonatal Dept Christchurch New Zealand Christchurch Hosp Dept Intens Care Christchurch New Zealand

Hyperglycaemia is a prevalent complication in the neonatal intensive care unit (NICU) and is associated with worsened outcomes. It occurs as a result of prematurity, under-developed endogenous glucose regulatory systems, and clinical stress. The stochastic targeting (STAR) framework provides patient-specific, model-based glycaemic control with a clinically proven level of confidence on the outcome of treatment interventions, thus directly managing the risk of hypo- and hyper-glycaemia. However, stochastic models that are over conservative can limit control performance. Retrospective clinical data from 61 episodes (25 retrospective to STAR, and 36 from a prospective-STAR blood glucose control study) of insulin therapy in very-low birth weight (VLBW) and extremely-low birth weight (ELBW) neonates are used to create a new stochastic model of model-based insulin sensitivity (S-I [L/mU/min]). Sub-cohort models based on gestational age (GA) and birth weight (BW) are also created. Performance is assessed by the percentage of patients who have 90% of actual intra-patient variability in S-I captured by the 90% confidence bands of the cohort based (inter-patient) stochastic variability model created. This assessment measures per-patient accuracy for any given cohort model. Per-patient coverage trends were very similar between prospective and retrospective cohorts, providing a measure of external validation of cohort similarity. Per-patient coverage was improved through the use of BW and GA dependent stochastic models, which ensures that the stochastic models more accurately capture both inter- and intra-patient variability. Stochastic models based on insulin sensitivities during insulin treatment periods are tighter, and give better and safer glycaemic control. Overall it seems that inter-patient variation is more significant than intra-patient variation as a limiting factor in this stochastic forecasting model, and a small number of patients are essentially different in beha

关键词： Insulin sensitivity control algorithms Physiological models Simulation Intensive care

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Development of a New Contact Angle control Algorithm for Level-Set Method

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JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME 2019年第6期141卷 061301-061301页

作者： Li, Mengnan Zeng, Kaiyue Wonnell, Louis Bolotnov, Igor A. North Carolina State Univ Dept Nucl Engn Raleigh NC 27695 USA Kansas State Univ Dept Mech & Nucl Engn Manhattan KS 66506 USA

A contact angle control algorithm is developed and implemented in the multiphase interface tracking flow solver-PHASTA. The subgrid force model is introduced to control the evolving contact angle. The contact angle force is applied when the current contact angle deviates from the desired value (or range of values) and decreases to zero when it reaches the desired value. The single bubble departure simulation and the capillary flat plates simulation are performed for verification purpose. The numerical results are compared with the analytical solution with good agreement. The mesh resolution sensitivity analysis and parametric study are conducted for both simulations. Coupled with the other existing capabilities in PHASTA like evaporation and condensation algorithm, the contact angle control algorithm will allow us to investigate the boiling phenomenon in various conditions with lower cost (by utilizing localized mesh refinement for bubble growth region) compared to uniformly refined structured meshes and in engineering geometries.

关键词： Simulation Resolution (Optics) Bubbles control algorithms Surface tension Simulation results Water Flat plates Errors Flow (Dynamics)

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Simulink Generated control Algorithm for Nine-phase PMS Motor

Simulink Generated Control Algorithm for Nine-phase PMS Moto...

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作者： Kozovský, Matúš Brno University of Technology

This paper deals with the nine-phase motor control algorithm development, mainly with its implementation in target hardware using MATLAB Simulink. This environment allows control algorithm design using model based approach and the subsequent automatic conversion of control algorithms into C code using Simulink Embedded coder which is then used in the inverter software. Field oriented control algorithm has been designed and tuned for this motor. control algorithm has been tuned according to the measured motor parameters in simulations and then fine tuned on a real motor. The inverter control unit is based on AURIX Tricore microcontroller TC275. The code generation in Simulink has many settings. This paper analyses computational time depending on these settings. Potential problems with floating point math functions are outlined. Automatic code generation proves to be quick and easy tool for replacement of control algorithms or for fast control algorithm adaptation to different hardware.

关键词： control algorithms Simulink code generation multi-phase motor permanent magnet synchronous motor.

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Legged robots - an overview

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TRANSACTIONS OF THE INSTITUTE OF MEASUREMENT AND control 2007年第2期29卷 185-202页

作者： Liu, Jing Tan, Min Zhao, Xiaoguang Chinese Acad Sci Inst Automat Key Lab Complex Syst & Intelligence Sci Beijing 100080 Peoples R China

Legged robots, as one kind of mobile robots, can be used for tasks too dangerous or difficult for human to perform, eg, planetary exploration, disaster salvation and anti-terrorism action. Consequently, the issues of legged robots, including mechanical structure, stability analysis and control algorithms, have become an important research direction in the field of robotics in recent years. This paper surveys the current status with respect to legged robots, and describes the existent research approaches in terms of mechanical structure, stability analysis and control algorithms of legged robots. To conclude, this paper proposes the problems to be solved and discusses the future development of legged robots.

关键词： control algorithms legged robots mechanical structure stability analysis

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Manipulation System for Measuring Heat Flux in Radioactive Melt

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JOURNAL OF NUCLEAR ENGINEERING AND RADIATION SCIENCE 2021年第2期7卷 021801页

作者： Knedlik, Michal Rot, David Hrbek, Jan Univ West Bohemia Fac Elect Engn Dept Elect Power Engn Univ 8 Plzen 30614 Czech Republic Res Ctr Rez Dept Nucl Fuel Cycle Hlavni 130 Husinec Rez 25068 Czech Republic

This article is focused on introducing of the manipulation system, which is used to insert equipment or measuring probes into the chamber of a cold crucible during experimental induction skull melting. The measuring probe could be, e.g., calorimeter for measuring heat flux from a melt, which is created in the cold crucible by electromagnetic induction. The first part describes the technical parameters of the manipulator and the possibilities of manipulator controlling. The manipulation system is controlled by the algorithm implemented in the programmable logic controller CompactRIO or by mechanical controller called manual pulse generator, which is independent of the programmable logic controller. Different control methods increase the safety of the system. The next part contents basic information about the control algorithm based on LabVIEW software and the user interface of the touch screen. The article also deals with testing the manipulator, which was used in an experiment simulating corium behavior under conditions of the severe accident of a nuclear power plant. The last part describes simulations of electromagnetic field and temperature field in the chamber of the cold crucible, which were confirmed with real measuring. The goal of the simulations was to determine the effect on the manipulation system and calculation of Joule's losses in the calorimeter before immersion into the melt. The most significant heat transfer to the calorimeter was the radiation from a melt, which was also calculated.

关键词： Simulation control algorithms Electromagnetic induction Temperature Generators Computer software Accidents User interfaces Heat flux Programmable controllers Manipulators Computer simulation Testing Heat transfer Melting Electromagnetic fields Radiation (Physics) Probes Safety Nuclear power stations

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Energy Method for controlling a Traction Electric Drive

SAE INTERNATIONAL JOURNAL OF ELECTRIFIED VEHICLES

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SAE INTERNATIONAL JOURNAL OF ELECTRIFIED VEHICLES 2021年第2期10卷 195-205页

作者： Smolin, Victor Goun, Valentina South Ural State Univ Power Engn Fac Chelyabinsk Russia SuSu Chelyabinsk Russia

The aim of this study was to develop algorithms for controlling an automobile electric drive based on the equations for the instantaneous balance of the active and reactive power of induction (IM) and synchronous machines (SM). We considered the information properties of the first harmonics of the three-phase voltage between the inverter and electrical machines. Our examination showed that processing the primary data of current and voltage sensors according to the algorithms of the generalized energy flow allows us to obtain complete information on the parameters of the three-phase circuit in the form of generalized state variables. We further investigated the metrological support of a traction electric drive, which makes it possible to complete a wide range of control, diagnostics, protection, and backup tasks. We present energy models of IMs and SMs obtained by summing the instantaneous power of the individual phases into a single energy stream. We show that taking the impact of the magnetic field energy (magnetization energy) and the kinetic energy of the load into account allows us to analyze the dynamics of electrical machines as second- and third-order nonlinear control objects. The article contains a general solution of the algorithms for controlling the basic variables of electrical machines: the amplitude of a three-phase voltage and the electromagnetic moment. The analytical equations of the algorithms are presented as the sum of two terms: the first accounts for the dynamics of the mechanical load and the second for the dynamics of the electromagnetic system of electrical machines. This article provides a brief review of our publications containing the results of adapting the general solution in accordance with the criteria of energy efficiency, quasi-independent excitation and minimizing the electrical heating of the IM rotor, and adaptive control of the SM. We detail an innovative strategy for controlling a traction electric drive based on the use of th

关键词： Traction electric drive Induction machine Synchronous machine Energy models Information support control algorithms control system

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A COMPARISON OF 2 DESIGN METHODS FOR PID controlLERS

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ISA TRANSACTIONS 1994年第2期33卷 147-151页

作者： HANG, CC HO, WK CAO, LS Department of Electrical Engineering National University of Singapore 10 Kent Ridge Crescent Singapore 0511 Singapore

Analytical formulae for designing PID controllers to give specified gain and phase margins have been proposed recently in the literature. This approach is attractive as the gain margin and phase margin serve as important measures of not only performance but also robustness. Another popular approach with similar emphasis is the internal model control method. In this paper, a comparison study of these two approaches for designing a PI and a PID controller is made. The comparison shows the differences and the similarities of the two approaches. Recommendations on when and which method to apply are also given.

关键词： ADAPTIVE control control algorithms AUTOTUNING PID controlLERS GAIN AND PHASE MARGINS INTERNAL MODEL control

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COMPARISON OF CONTINUOUS AND DISCRETE ADAPTIVE IDENTIFICATION algorithms

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JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND control-TRANSACTIONS OF THE ASME 1977年第4期99卷 313-315页

作者： COLBURN, BK BOLAND, JS Department of Electrical Engineering Texas A & M University College Station Texas Department of Electrical Engineering Auburn University Auburn Ala.

Discretization of a popular continuous-time control algorithm is effected and an equivalent discrete-time identification law developed and compared to a published discrete identification algorithm developed from Lyapunov Theory. Results are compared as regards asymptotic stability as insured using Lyapunov theory. Some analysis and design guidelines are proposed as regards implementation and practical utility.

关键词： Stability Design control algorithms algorithms

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Developments in Direct-Field Acoustic Testing

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SOUND AND VIBRATION 2014年第11期48卷 6-10页

作者： Larkin, Paul Maryland Sound Int Baltimore MD 21207 USA

Direct-field acoustic testing (DFAT (R)) has been developing to include new control schemes, hardware geometry and setup parameters in an effort to improve sound pressure uniformity. In addition, research is being conducted into the modeling and control of standing waves created by either room geometry or wave interference patterns in the DFAT sound field. control schemes that use additional microphones or accelerometers in conjunction with nonsymmetry in the geometry of the setup to reduce the magnitude of standing waves is discussed. It will also be shown how control microphone placement and the type of control scheme can also heavily influence the creation of standing waves.

关键词： Military aircraft Costs control theory controllers control algorithms Random vibration

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3-DIMENSIONAL HYDRAULIC FRACTURE SIMULATION USING FIXED GRID FINITE-ELEMENT algorithms

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JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME 1994年第1期116卷 2-9页

作者： LEE, TS ADVANI, SH PAK, CK Department of Mechanical Engineering Sogang University Shinsu-Dong Mapo-Gu Seoul Korea College of Engineering and Applied Science Lehigh University Bethlehem PA 18015 Department of Mechanical Engineering and Mechanics Lehigh University Bethlehem PA 18015

A three-dimensional hydraulic fracture simulator (HYFFIX) is reformulated using finite element methodology and a newly adapted fixed grid. The numerical procedures for the coupled equations governing the fracture width, fluid pressure, and evolution of equilibrium planar crack in layered media are summarized. Fixed grid mesh control algorithms for the efficient tracking of the moving crack/fracture fluid front are detailed. The introduction of these novel algorithms in the simulator makes it numerically efficient and stable, in comparison to previously reported models which utilize migrating mesh techniques. Due to the enhanced numerical efficiency and compactness of the refined code, the model can also be readily implemented on a workstation or microcomputer.

关键词： Simulation Fluids control algorithms Fracture (Materials) Equilibrium (Physics) Fluid pressure algorithms Finite element analysis

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