Fast Control System Research Articles

Prototype design of a timing and fast control system in the CBM experiment

The Compressed Baryonic Matter (CBM) experiment is designed to handle interaction rates of up to 10 MHz and up to 1 TB/s of raw data generated. With triggerless streaming data acquisition in the experiment and beam intensity fluctuations, it is expected that occasional data bursts will surpass bandwidth capabilities of the Data Acquisition System (DAQ) system. In order to preserve integrity of event data, the bandwidth of DAQ must be throttled in an organised way with minimum information loss. The Timing and Fast Control (TFC) system provides a latency-optimised datapath for throttling commands and distributes a system clock together with a global timestamp. This paper describes a prototype design of the system with focus on synchronisation and its evaluation.

Path Following Control Design for a Gliding Missile

A path following control architecture that drives a gliding missile, that is a missile without thrust, toward a prespecified linear path in an inertial frame using only torque control is developed and flight results are presented. A fast time-scale inner-loop control system stabilizes the orientation dynamics with a custom control law. Two slow time-scale outer-loop designs are proposed that render the inertial path exponentially stable for the missile’s translational dynamics. Since a gliding missile has no thrust input, the outer-loop is unable to directly actuate its control. Instead, we present an orientation extraction scheme to convert the outer-loop’s control signal into a desired orientation for the inner-loop. The control algorithm is implemented on a proprietary missile and empirical flight data are presented to demonstrate its effectiveness.

A perturbation-based hybrid methodology for control drum worth prediction applied to the HOLOS-Quad microreactor concept

Fast and accurate control system reactivity worth estimates are desirable in many applications. Unfortunately, the full core Monte Carlo transport simulations often used to estimate the reactivity worth of control drums are often too costly to run in the time scale needed for many applications, such as model predictive control, reactor design optimization, uncertainty quantification and sensitivity analysis. Therefore, this paper presents a general methodology for control drum worth estimation that is based on a hybrid model consisting of physics-based and statistics-based components. It was found that in the application of the methodology to the HOLOS-Quad Reactor Concept, errors as low as 50 pcm were achieved. Model accuracy was also analyzed as a function of training set size and it was found that the most accurate model required about 70 transport model evaluations to train with further reactivity estimates being calculated on the order of milliseconds.

Research on super-capacitor fast power control system

In the context of carbon peak and carbon neutrality targets, high-proportion new energy power systems exhibit low inertia and weak damping characteristics. The frequency stability of the new power system has become a major problem for the safe and stable operation of the power grid. The traditional primary frequency modulation technology based on thermal power units or hydropower units has the defects of slow response speed and long frequency detection delay time. Therefore, we propose a multi-functional multiplexing super capacitor fast power control system, which has the functions of frequency stability control and voltage sag management. In the meantime, we proposed a fast frequency detection algorithm for cascaded signal delay, and the frequency detection delay is less than 10 ms. The system uses a high-speed communication ring network, and the communication delay is less than two milliseconds. Finally, we built a super capacitor energy storage system with a capacity of 50kW to verify that the super-capacitor has the ability to quickly and actively support the power system under frequency disturbances.

Smart actuator for IM speed control with F28335 DSP application

In the industrial application, the induction motors (IMs) and the digital signal processing (ZQ28335) combination are very important in the scientific field. Two thirds of consumption of electricity is due to motor driven equipment. The direct torque control (DTC) is the standard of the industry and it has fast response control system applications. The drawback of DTC is the flux and torque ripples in the measurements. The scalar control can be considered as a solution to this drawback but with poor response. Torque and speed of IM are controlling individually, the variable speed drive (VSDs) is used. This occurs with variation of the voltage and frequency of IM supply. To decrease the levels of flux and torque ripples, 3-level inverters represent an attractive technique. The compromise of a huge flux and torque at the beginning level and low values at steady state of operation is crucial to ensure better stability with feedback linearization of the nonlinear behavior. In this paper, VSD with DTC IM with multilevel inverter with the newest version of ZQ28335 digital signal processor (DSP) is proposed. Emulation and the results of experiment through DSP ZQ28335 make certain correct dynamic response to the operations of torque and flux.

Design, simulation, and experiment research on fast control system of steam turbine inlet valve

In this paper, a new fast control system of steam turbine inlet valve is designed, which is composed of the fast closing system and the fast opening system. For the first time, this paper proposes that the fast closing system is designed by means of the special structure of the slide valve in an oil servo motor on the basis of the transformation of the hydraulic control system of steam turbine inlet valve. For the first time, a differential oil discharge fast opening system is designed by use of two cartridge valves. The mathematical model of electro-hydraulic fast control system is presented. With the use of simulation software Advanced Modeling Environment for Simulation of engineering systems , the curves of parameters such as piston displacement, piston velocity, oil pressure of upper and nether cavities of oil servo motor, and flow flux of upper and nether cavities of oil servo motor are obtained. The fast closing time of the piston for whole journey from the simulation results is 0.36 s. The fast opening time of the piston for whole journey from the simulation results is 1.55 s. According to the designed structure of the fast control system, the fast control experiment system is built. The fast closing time of the piston for whole journey from the experiment results is 0.22 s. The fast opening time of the piston for the whole journey from the experiment results is 1.97 s. The simulation and experimental results show that the designed fast control system can realize the fast closing and fast opening of the inlet valve. The fast closing time of the fast control system is <0.5 s, and the fast opening time of the fast control system is <3 s, which meets the fast control time requirement of the steam turbine inlet valve. Compared with the existing fast control system products, the fast control system and the inlet valve servo regulation system share a set of oil sources. And the fast control system has the advantages of low cost, simple structure, easy implementation, etc.

A novel method for Lorentz force detuning compensation in multi-cell superconducting RF cavity and its validation at room temperature.

A tuner is an important element of a superconducting radio frequency (SCRF) cavity, which is used to tune the cavity at resonance frequency. The measurement and control of the pulsed detuning phenomenon is very challenging and can be measured in the superconducting state of the cavity at a high voltage gradient. This paper describes an innovative method and unique approach for the measurement of dynamic changes in resonance frequency of the SCRF cavity even at room temperature. For this purpose, a 1.3GHz nine-cell prototype dressed cavity with RRCAT's designed X-link tuning device is used. A test setup for measurements of dynamic changes in resonance frequency of the RF cavity has been designed and developed. The cavity response for piezo-excitation at various pulse widths has been determined. In order to simulate the Lorentz force detuning (LFD) effect, the source frequency has been modulated similar to the superconducting scenario in the SCRF cavity. To compensate the simulated detuning, a fast tuner is operated with half sinusoidal pulses at various combinations of pulse width and time advance to find out an optimum waveform. This optimized waveform will be used with a fast tuning control system to control LFD under actual operation conditions of the SCRF cavity.

Formulation and evaluation of inhalable microparticles of Rizatriptan Benzoate processed by spray freeze-drying

The aim of the current study was to prepare and evaluate inhalable microparticles of Rizatriptan benzoate in order to further benefit from its pulmonary delivery, the expected enhanced bioavailability and accelerated onset of action. The spray freeze drying (SFD) technique was used to produce microparticles consisting of a fixed amount of a sugar which was either mannitol or trehalose and an amino acid component including leucine, phenylalanine or serine. The powders were then characterized for particle size distribution, morphology, thermal properties and in vitro aerosolization performance. It was demonstrated that various formulations of inhalable Rizatriptan could be efficiently aerosolized and offered acceptable fine particle fraction (FPF) ranging up to 61.1%. In particular, a spray-freeze-dried powder composed of trehalose and phenylalanine showed the most superior inhalation performance (FPF = 61.1%), indicating better dispersion properties of those spherical porous microparticles with less adhesion and agglomeration. These results successfully demonstrated that Rizatriptan could be engineered into respirable microparticles to be proposed as a promising delivery system for fast and effective control of migraine attacks.

MINARO HD: control and evaluation of a handheld, highly dynamic surgical robot

PurposeCurrent surgical robotic systems are either large serial arms, resulting in higher risks due to their high inertia and no inherent limitations of the working space, or they are bone-mounted, adding substantial additional task steps to the surgical workflow. The robot presented in this paper has a handy and lightweight design and can be easily held by the surgeon. No rigid fixation to the bone or a cart is necessary. A high-speed tracking camera together with a fast control system ensures the accurate positioning of a burring tool.MethodsThe capabilities of the robotic system to dynamically compensate for unintended motion, either of the robot itself or the patient, was evaluated. Therefore, the step response was analyzed as well as the capability to follow a moving target.ResultsThe step response show that the robot can compensate for undesired motions up to 12 Hz in any direction. While following a moving target, a maximum positioning error of 0.5 mm can be obtained with a target motion of up to 18 mm/s.ConclusionThe requirements regarding dynamic motion compensation, accuracy, and machining speed of unicompartmental knee arthroplasties, for which the robot was optimized, are achieved with the presented robotic system. In particular, the step response results show that the robot is able to compensate for human tremor.

Research and Analysis of On-Line Optimization Algorithm of Nonlinear Model Predictive Control Based on Hydropower Installation Field

Because of the strong nonlinearity of the controlled system, it cannot be expressed in the form of state space, and the calculation of nonlinear programming is large, so it is difficult to get the analytical solution. At present, it is generally solved by numerical method. The GPC stability theory based on state space analysis and internal model control is difficult to be applied in this case. In this paper, a fast algorithm of online optimization of nonlinear model predictive control based on the field of hydropower installation is presented. A fast algorithm control system of online optimization of nonlinear model predictive control is established and simulated by MATLAB. The simulation results show that the dimension of nonlinear programming solution in rolling optimization is effectively reduced and the feasibility of MPC is improved. Compared with single machine and multi machine systems, the model predictive control method is proved to have strong ability of generator terminal voltage maintenance and electromechanical oscillation damping.

InAs/InP Quantum Dash Semiconductor Coherent Comb Lasers and their Applications in Optical Networks

We report on the design, growth, and fabrication of InAs/InP quantum dash (QD) gain materials and their use in lasers for optical network applications. A noise performance comparison between QD and quantum well (QW) Fabry–Perot (F-P) lasers has been made. By using the QD gain material we have successfully developed and assembled C-band coherent comb laser (CCL) modules with an electrical fast feedback loop control system to ensure a targeted mode frequency spacing. The frequency spacing was maintained within ±100 ppm and the operation wavelengths locked on the desired ITU grid within 0.01 nm over a period of several months. We also investigated a 25-GHz C-band QD CCL with an external cavity self-injection feedback locking (SIFL) system to reduce the optical linewidth of each individual channel to below 200 kHz in the wavelength range from 1537.55 nm to 1545.14 nm. The RF mode beating signal 3-dB bandwidth was also reduced from 9 kHz to approximately 500 Hz with this SIFL system. These QD CCLs with ultra-low relative intensity noise (RIN), ultra-narrow optical linewidth, and ultra-low timing jitter are excellent laser sources for multi-terabit optical networks. Using a 34.2 GHz QD CCL we demonstrate 10.8 Tbit/s (16QAM 48 × 28 GBaud PDM) coherent data transmission over 100 km of standard single mode fiber (SSMF) and 5.4 Tbit/s (PAM-4 48 × 28 GBaud PDM) aggregate data transmission capacity over 25 km of SSMF with error-free operation.

MARTe2 and MDSplus integration for a comprehensive fast control and data acquisition system

Abstract MARTe is a framework for real-time control that has been used in several fusion experiments. Recently, a new version named MARTe2 has been developed adhering to software quality standards. MDSplus is a data system widely adopted in the fusion community. MDSplus provides fast data acquisition and access to pulse files and is intended to provide a complete interface both for the configuration of the experiment and the experimental results. MDSplus and MARTe2 are already integrated via a set of components that are able to store a data stream originated in real-time in the pulse file and get experiment set-up information. A further integration is proposed here, that is, using the Device abstraction provided by MDSplus to specify the components involved in the data acquisition process and MDSplus expressions to specify data relationships, in order to describe also the real-time components and the associated data flow. Following this approach, the whole real-time configuration will be described exactly as the rest of the other non real-time data acquisition components and the corresponding MARTe2 configuration will be generated on the fly, integrating all the required consistency checks.

Design of new quick control power protection system of EAST

Aiming at the problems that may arise in the work of the AC-DC-AC converter of the new fast-control power system of the Experimental Advanced Superconducting Tokamak (EAST), a control and protection method for each link is proposed. Based on in-depth research on the protection mechanism of fast control power in the field of nuclear fusion, and combination with the needs of nuclear fusion devices, a surge current suppression circuit, a voltage protection circuit, an overcurrent protection circuit, an overt-emperature protection circuit, an energy leakage protection circuit, and a crowbar were designed. Compared with the traditional protection method, the scheme has a wide protection range, strong reliability and high security. The experimental results show that the power protection system can ensure safe and reliable exit of the power supply in the event of a sudden failure, and effectively protect the superconducting magnets and power components of the superconducting Tokamak experimental device from damage, verifying the correctness and effectiveness of the designed scheme.

Auxiliary lasers for Advanced Virgo Gravitational Wave detector using single pass Second Harmonic Generation in Periodically Poled Lithium Niobate crystal

The Advanced Virgo (AdV) detector is composed of different degrees of freedom (DOFs) i.e. Michelson interferometer, two Fabry-Perot arm cavities, signal recycling cavity, and power recycling cavity. These DOFs need to be locked to precise accuracy with robust, fast and reliable control systems. The control signals used to lock all the DOFs are mildly decoupled in frequency and the optical response of the DOFs are nonlinear, where the linear range of operation is just some percentage of the fringe for each DOF, thus posing difficulty in resonance lock at input laser wavelength for all the cavities. In particular, the control status of the arm cavities can alter the state of the detector’s operational configuration. Using Auxiliary Lasers to lock the arm cavities at different wavelength offers flexible and robust lock of the detector and more spatial margin on the control signals. Second harmonic generation offers the most direct way to have laser beam with different wavelength and phase locked to the AdV input laser beam. We generated upto 97 mW of SH beam in single configuration at 532 nm using fibered amplified laser source at 1064 nm in a 10 mm long Poled Lithium Niobate crystal.

Synchronized Phasor Measurements with GPS Time Stamping using 64 Point DFT in PMU

This paper describes about the time synchronization of different locations voltage or current signals for accurate comparison of signals on single phasor graph, all the measured phasors are synchronized with Global Positioning System (GPS) time stamping. Day to day power demand increases very rapidly, to meet the growing demand of electrical energy new energy resources are required and manage them efficiently. For efficient allocation of sources there should be a good monitoring and fast control system. For better monitoring and control of the system accurately it requires “Wide Area Monitoring” of power system. In the wide area monitoring system collection of data from the power system should be at a faster level. The collection of data from the power system at faster level is possible by using “Phasor Measurement Units(PMUs)”. PMU collects the data at faster rate rates like 50-60 samples for cycle, this information is send to local Phasor Data Concentrator (PDC). Local phasor data concentrator collects the data from different PMUs which are located in different areas. This PDC helps to take the necessary action on power system. For synchronization, pulse per second(PPS) is taken from GPS module. From this 1PPS, 3200 pulses is generated for high accuracy of 64 point DFT of 50Hz signal using microcontroller. System frequency is calculated by using time period between the two consecutive raising edges or falling edges of square wave. This is in synchronous with the input sinusoidal signal.

MEASUREMENT CONTROL OF READY-MADE GARMENTS WITH IMAGE ANALYSIS METHODS

In the ready-made clothing industry accurate garment measurement is one of the most important points for the right fitting of the apparel. Garments should be produced to the determined size by the customer or the enterprise. Although, the measurement control of the final product is made by trained operator, the factors such as gradually loose of attention, fatigue and stress could cause faults that could lead to lack of quality and waste of time. In this sense, developing and using objective, fast and economic measurement control systems in terms of both cost effectiveness and the reliability of the controls has become a must. The purpose of the study is to design a system and develop an algorithm to control the measurements of garments automatically. This study, which is determined that image analysis method can be used in measurement control of ready-made garments, will be a new measurement control method in the literature and an example for similar studies. By benefiting from the image analysis methods, measurement mistakes likely to result from the operator will be prevented and the results will be made more reliable.

Reformation of the Electron Internal Transport Barrier with the Appearance of a Magnetic Island

When realising future fusion reactors, their stationary burning must be maintained and the heat flux to the divertor must be reduced. This essentially requires a stationary internal transport barrier (ITB) plasma with a fast control system. However, the time scale for determining the position of the foot point of an ITB is not clearly understood even though its understanding is indispensable for fast profile control. In this study, the foot point of the electron ITB (eITB) was observed to be reformed at the vicinity of a magnetic island when the island started to form. In addition, the enhanced confinement region was observed to expand during the eITB formation according to the radial movement of the magnetic island toward the outer region. Compared to the time scales of the local heat transport, the faster time scales of the movement of the eITB foot point immediately after island formation (~0.5 ms) suggest the importance of the magnetic island for plasma profile control to maintain stationary burning.

Predictive control of a permanent magnet synchronous generator connected to an MMC converter in an oscillating water column based power plant

Modular Multilevel Converters (MMC) are traditionally used in high-power applications although their field of application has lately widened to lower powers. In medium and low-power applications such as electric drives, a fast control system is usually required and model-based predictive control approaches (MPC) are highly suitable to obtain superior performance. Unfortunately, although MPC is widely used with two-level three-phase power converters, typically in motor and generator control applications, it has been barely developed for MMC. Recent studies discuss MPC approaches for MMC but they are primarily focused on improving the internal operation of MMC. In contrast, this paper presents an MPC which is designed to control the torque and the magnetic field of a surface permanent magnet synchronous generator (SPMSG) by means of an MMC. The proposed approach features a new and fast method to find the location of the reference voltage vector among the large number of multilevel vectors present in typical MMCs. The performance of the new control system has been demonstrated for an oscillating water column (OWC) based power plant simulation. The control system stands out for its fast response, low THD currents and reasonably low computing time which enables its easy implementation in microcontrollers (MCU).

Grid-Forming Inverters: A Critical Asset for the Power Grid

Increasing inverter-based sources reduces the system’s inertia resulting in possible frequency stability issues. Understanding low-inertia systems and their stability properties is of crucial importance. This article introduces fundamental ways to integrate high levels of renewable energy (RE) and distributed energy resources (DERs) in the power system while creating a more flexible power system. Using RE and DER in the distribution system has many advantages such as reducing the physical and electrical distance between generation and loads, bringing sources closer to loads contributes to the enhancement of the voltage profile, reduction in distribution and transmission bottlenecks, improved reliability, lower losses, and enhances the potential use of waste heat. A basic issue for high penetration of DER is the technical complexity of controlling hundreds of thousands to millions of inverters. This is addressed through autonomous techniques using local measurements eliminating the need for fast control systems. The key issues addressed in this article include using inverter damping to stabilize frequency in systems with low or no inertia, autonomous operation, methods for relieving inverter overload, energy reserves, and their implementation in photovoltaics (PV) systems. This article provides important insight into the interactions between inverter bases sources and the high-power system. The distinction between grid-forming (GFM) inverter and grid-following (GFL) inverter is profound. GFM inverters provide damping to frequency swings in a mixed system, while GFL inverter can aggravate frequency problems with increased penetration. Rather than acting as a source of inertia, the GFM inverter acts as a source of damping to the system. On the other hand, the application of inverters in the power system has two major issues. One is the complexity of controlling hundreds of thousands to millions of inverters. This is addressed through autonomous techniques using local measurements. The other is the potential of high overcurrent in GFM inverters and techniques for explicitly protecting against overloading. To exploit the innate damping of GFM inverters, energy reserves are critical.

A tight cold-inducible switch built by coupling thermosensitive transcriptional and proteolytic regulatory parts.

Natural organisms have evolved intricate regulatory mechanisms that sense and respond to fluctuating environmental temperatures in a heat- or cold-inducible fashion. Unlike dominant heat-inducible switches, very few cold-inducible genetic switches are available in either natural or engineered systems. Moreover, the available cold-inducible switches still have many shortcomings, including high leaky gene expression, small dynamic range (<10-fold) or broad transition temperature (>10°C). To address these problems, a high-performance cold-inducible switch that can tightly control target gene expression is highly desired. Here, we introduce a tight and fast cold-inducible switch that couples two evolved thermosensitive variants, TFts and TEVts, as well as an additional Mycoplasma florum Lon protease (mf-Lon) to effectively turn-off target gene expression via transcriptional and proteolytic mechanisms. We validated the function of the switch in different culture media and various Escherichia coli strains and demonstrated its tightness by regulating two morphogenetic bacterial genes and expressing three heat-unstable recombinant proteins, respectively. Moreover, the additional protease module enabled the cold-inducible switch to actively remove the pre-existing proteins in slow-growing cells. This work establishes a high-performance cold-inducible system for tight and fast control of gene expression which has great potential for basic research, as well as industrial and biomedical applications.