Front-end Control Research Articles

Power quality enhancement in micro grids by employing MPC-EKF

This paper proposesdesign of a novel multi-level Control system based on Model Predictive Control Algorithm with Extended Kalman Filter (MPC-EKF) to enhance the power quality. The system utilized here implements few controllers based on MPC-EKF front end control, Top down control system and Bottom up control system to monitor periodic signals for fast sampling .TheMPC control divides the said problem into steady-state and transient sub problems individually and improves the response of the individual states .EKF traces the harmonics in the system improves power quality. The top down control system is responsible to improve the separated transient response and the bottom up control system is responsible to track the steady state error. Thus the proposed method is provided with the capability to enhance the quality of power and reliable performance of the microgrid by tracing and removing the harmonics in the distribution system, thereby decreasing the computational time. Our proposed method can be implemented on the MATLAB/SIMULINK plat form to validate the results.

Electrolyzers Enhancing Flexibility in Electric Grids

This paper presents a real-time simulation with a hardware-in-the-loop (HIL)-based approach for verifying the performance of electrolyzer systems in providing grid support. Hydrogen refueling stations may use electrolyzer systems to generate hydrogen and are proposed to have the potential of becoming smarter loads that can proactively provide grid services. On the basis of experimental findings, electrolyzer systems with balance of plant are observed to have a high level of controllability and hence can add flexibility to the grid from the demand side. A generic front end controller (FEC) is proposed, which enables an optimal operation of the load on the basis of market and grid conditions. This controller has been simulated and tested in a real-time environment with electrolyzer hardware for a performance assessment. It can optimize the operation of electrolyzer systems on the basis of the information collected by a communication module. Real-time simulation tests are performed to verify the performance of the FEC-driven electrolyzers to provide grid support that enables flexibility, greater economic revenue, and grid support for hydrogen producers under dynamic conditions. The FEC proposed in this paper is tested with electrolyzers, however, it is proposed as a generic control topology that is applicable to any load.

The next generation Front-End Controller for the Phase-I Upgrade of the CMS Hadron Calorimeters

The next generation Front-End Controller (ngFEC) is the system responsible for slow and fast control within the Phase-I Upgrade of the CMS Hadron Calorimeters. It is based on the FC7, a μTCA compatible Advanced Mezzanine Card developed at CERN and built around the Xilinx Kintex®-7 FPGA. The ngFEC decodes the 40.0788 MHz LHC clock and the synchronization signals received from the backplane and distributes them to the front-end electronics through six GBT links. The latency of the fast control signals is fixed across power cycles. Even if the direct link to a front-end module is broken, a redundancy scheme ensures a successful communication using the link to the neighboring front-end module. Thanks to the ngFEC all front-end modules can be remotely programmed using the JTAG standard protocol. The CCM server software interfaces the ngFEC to the Detector Control System which constantly monitors voltages and temperatures on the front-end electronics. This document reviews the characteristics and the development status of the ngFEC.

Integration and testing of the DAQ system for the CMS Phase 1 pixel upgrade

The CMS pixel detector phase 1 upgrade in 2017 requires an upgraded data acquisition (DAQ) system to accept higher data rates. A new DAQ system has been developed based on a combination of custom and standard μTCA parts. Custom mezzanines on FC7 AMCs [1] provide a front-end driver for readout, and a front-end controller for configuration, clock and trigger. The DAQ system is undergoing a series of integration tests including readout of the pilot pixel detector already installed in CMS, checkout of the phase 1 detector during its assembly, and testing with the CMS central DAQ. This paper describes the DAQ system, integration tests and results, and an outline of the activities up to commissioning the final system at CMS in 2017.

A new data acquisition system for the CMS Phase 1 pixel detector

A new pixel detector will be installed in the CMS experiment during the extended technical stop of the LHC at the beginning of 2017. The new pixel detector, built from four layers in the barrel region and three layers on each end of the forward region, is equipped with upgraded front-end readout electronics, specifically designed to handle the high particle hit rates created in the LHC environment. The DAQ back-end was entirely redesigned to handle the increased number of readout channels, the higher data rates per channel and the new digital data format. Based entirely on the microTCA standard, new front-end controller (FEC) and front-end driver (FED) cards have been developed, prototyped and produced with custom optical link mezzanines mounted on the FC7 AMC and custom firmware. At the same time as the new detector is being assembled, the DAQ system is set up and its integration into the CMS central DAQ system tested by running the pilot blade detector already installed in CMS. This work describes the DAQ system, integration tests and gives an outline for the activities up to commissioning the final system at CMS in 2017.

Instrumental deformation monitoring system and its trial in open-pit diamond mine

The designed automated system for pitwall deformation monitoring consists of an independent data recorder, strain sensors, AD converters, and front-end and back-end controls. Data are accumulated on server in on-line mode via cellular modem. The self-contained tools are supplied from accumulators recharged by solar batteries, which expands operational life of the system. The system has been trailed in an open pit mine at Nyurbinskaya kimberlite pipe in deformation monitoring of faults in the eastern pitwall and estimation of its stability.

Deployment of the CMS Tracker AMC as backend for the CMS pixel detector

The silicon pixel detector of the CMS experiment at CERN will be replaced with an upgraded version at the beginning of 2017 with the new detector featuring an additional barrel- and end-cap layer resulting in an increased number of fully digital read-out links running at 400 Mbps. New versions of the PSI46 Read-Out Chip and Token Bit Manager have been developed to operate at higher rates and reduce data loss. Front-End Controller and Front-End Driver boards, based on the μTCA compatible CMS Tracker AMC, a variant of the FC7 card, are being developed using different mezzanines to host the optical links for the digital read-out and control system. An overview of the system architecture is presented, with details on the implementation, and first results obtained from test systems.

Dynamic cognitive control of irrelevant sound: Increased task engagement attenuates semantic auditory distraction.

Two experiments investigated reactive top-down cognitive control of the detrimental influence of spoken distractors semantically related to words presented visually for free recall. Experiment 1 demonstrated that an increase in focal-task engagement-promoted experimentally by reducing the perceptual discriminability of the visual target words-eliminated the disruption by such distractors of veridical recall and also attenuated the erroneous recall of the distractors. A recall instruction that eliminates the requirement for output monitoring was used in Experiment 2 to investigate whether increased task engagement shields against distraction through a change in output-monitoring processes (back-end control) or by affecting the processing of the distractors during their presentation (front-end control). Rates of erroneous distractor recall were much greater than in Experiment 1, but both erroneous distractor recall and the disruptive effect of distractors on veridical recall were still attenuated under reduced target-word discriminability. Taken together, the results show that task engagement is under dynamic strategic control and can be modulated to shield against auditory distraction by attenuating distractor processing at encoding, thereby preventing distractors from coming to mind at test. (PsycINFO Database Record

Functions and Theoretical Basis of Partial Discharge On-Line Monitoring System for High-Voltage Cables

A partial discharge (PD) on-line monitoring and positioning system for high-voltage cables based on double-ended testing technology is developed. The hardware of this system includes a high-frequency current sensor, site PD signal acquisition and PD monitoring server. In order to achieve real-time monitoring and remote diagnostics of the XLPE cable partial discharge status, the designed software system is divided into front-end control system and remote diagnostic system. And finally, the correctness and effectiveness of the system is verified by XLPE cable partial discharge testing.

Research of Carbon Monoxide Monitor System Based on Lonworks Industrial Control Network

The paper introduce NEURON3150 neuron chip with serial digital to analog - analog-to-digital converter TLC5615/TLC2543 interface method.Focused on the the Lonworks front-end intelligent monitoring and control network node software, hardware,and design and develop a system solutions for indoor hazardous gases CO data acquisition monitoring and alarm functions based on TMPN3150 neural network MCU. The paper brief introduce the Field Bus Lonworks to control network technology and reality of remote monitoring system on the basis of Integrated control network and information network,and analysis structural characteristics of distributed intelligent monitoring network system ,with certain promotional value.

Relaxing pre-selector filter selectivity requirements using cognitive RF front-end control

This paper proposes the use of a cognitive engine to control the local oscillator and sampling frequencies in a flexible receiver RF front-end. The analysis in this paper shows that this cognitive ...

Design of Carbon Monoxide Monitor System Based on Lonworks Technology

Focused on the Lon works front-end intelligent monitoring and control network node software, hardware, and design and develop a system solutions for indoor hazardous gases CO data acquisition monitoring and alarm functions. On this basis, Brief introduction to the Field Bus Lon works control network technology and reality of remote monitoring system on the basis of integrated control network and information network, and analysis structural characteristics of distributed intelligent monitoring network system, with certain promotional value.

Testing and feedback effects on front-end control over later retrieval.

In 2 experiments, we explored differences in cognitive control at retrieval on a final test to better understand the mechanisms underlying the powerful boost in recall of previously tested information. Memory retrieval can be enhanced by front-end control processes that regulate the scope of retrieval or by later processes that monitor retrieval to screen out incorrect candidates. In Experiment 1, prior testing with feedback improved front-end control over retrieval compared with restudy, but there was no difference in postretrieval monitoring processes. In Experiment 2, we disentangled the effects of successful retrieval and feedback on later recall by comparing testing with feedback to testing without feedback. Successful retrieval on the initial test improved front-end control processes that restricted access to the target during retrieval, regardless of whether feedback was provided. Compared with restudying, testing did not improve postretrieval monitoring. Results revealed unique contributions of testing and feedback to front-end control processes that optimize memory retrieval.

Introducing a new paradigm for accelerators and large experimental apparatus control systems

The integration of web technologies and web services has been, in the recent years, one of the major trends in upgrading and developing distributed control systems for accelerators and large experimental apparatuses. Usually, web technologies have been introduced to complement the control systems with smart add-ons and user friendly services or, for instance, to safely allow access to the control system to users from remote sites. Despite this still narrow spectrum of employment, some software technologies developed for high-performance web services, although originally intended and optimized for these particular applications, deserve some features suggesting a deeper integration in a control system and, eventually, their use to develop some of the control system's core components. In this paper, we present the conceptual design of a new control system for a particle accelerator and associated machine data acquisition system, based on a synergic combination of a nonrelational key/value database and network distributed object caching. The use of these technologies, to implement respectively continuous data archiving and data distribution between components, brought about the definition of a new control system concept offering a number of interesting features such as a high level of abstraction of services and components and their integration in a framework that can be seen as a comprehensive service provider that both graphical user interface applications and front-end controllers join for accessing and, to some extent, expanding its functionalities.

Source-constrained recall: Front-end and back-end control of retrieval quality.

Research on the strategic regulation of memory accuracy has focused primarily on monitoring and control processes used to edit out incorrect information after it is retrieved (back-end control). Recent studies, however, suggest that rememberers also enhance accuracy by preventing the retrieval of incorrect information in the first place (front-end control). The present study put forward and examined a mechanism called source-constrained recall (cf. Jacoby, Shimizu, Velanova, & Rhodes, 2005) by which rememberers process and use recall cues in qualitatively different ways, depending on the manner of original encoding. Results of 2 experiments in which information about source encoding depth was made available at test showed that when possible, participants constrained recall to the solicited targets by reinstating the original encoding operations on the recall cues. This reinstatement improved the quality of the information that came to mind, which, together with improved postretrieval monitoring, enhanced actual recall performance.

Measurement system for evaluation of the muon chambers for the LHCb experiment

Abstract In a detector with the complexity of the LHCb, where only for the muon system more than 1300 chambers, divided into 20 different types, will be used, resulting on more than 120 k channels to be readout, it is of crucial importance to study the many types of chambers to create a complete knowledge of the detector operation and to guarantee a high-quality performance during the experiment. To make it possible, a complete setup was built and a C++ based software was developed to carry out a set of measurements on the full-equipped chambers of the LHCb muon detector. The setup is made of front-end control electronics, high-voltage supply and acquisition circuitry while the software, running on a PC, remotely controls each element of the system and implements a number of automatized procedures to assess the main characteristics of the chambers. The main advantages of this system are its versatility and speed of measurement which are crucial to the experiment since there is the need to characterize every single chamber before final installation. Moreover, in this work it was proposed to measure the starting knee of the high-voltage operational plateau without the use of an external trigger by making use of the internal structure of the chambers. Two laboratories were prepared at CERN (European Laboratory for Particle Physics) to receive this system; one used to test chambers arrived from the CERN itself and the PNPI (Petersburg Nuclear Physics Institute) production sites, and one to test the chambers arrived from the INFN (National Institute of Nuclear Physics) production sites. In this document, the hardware and software setup will be presented together with the measurement-oriented implementations.

Experimental Verification of the Active Front-End Converters Dynamic Model and Control Designs

This paper presents a dynamic model of the active front-end (AFE) converter in the synchronous reference frame under balance input voltage condition. Transfer functions of the closed-loop control based on this dynamic model are verified experimentally in the frequency domain. Bode plots of these transfer functions are given to validate this synchronous frame-based dynamic model. Based on these results, this paper presents the control designs of the AFE converter to enhance the disturbance rejection capability and robustness. The control designs are then verified experimentally in the frequency domain. The frequency response of the AFE converter system is measured by an Agilent 35670A dynamic signal analyzer to validate the performance of the AFE converter system.

Optimal Geometric Control of Power Buffers

Modern power electronics are capable of regulating loads with bandwidths so high that they essentially enforce constant power on millisecond timescales and contribute to system-wide voltage instability problems. Active front-end control of such loads that implement a power buffer function has been shown to mitigate instability, but has relied on complicated hybrid control techniques. This paper proposes a geometric control surface that implements the power buffer function by coupling the input impedance to the stored energy and by altering the source and load dynamics. The surface is derived from optimal control theory where importance is placed on maintaining continuous input impedance and retaining as much local energy as possible. The optimal control is a tradeoff between the needs of the system and the needs of the load. This paper introduces a geometric control surface based on a change of variables that simply and effectively implements a power buffer function. The formulation and implementation of the optimal surface are presented, in addition to experimental validation of the new power buffer control law.

Diagnostic medical ultrasound systems having a method and circuitry for front-end gain control

A system and method of processing received signals in an ultrasound imaging system is disclosed. In the system, the received signals are amplified by means of a gain controlled amplifier, and the gain of the amplifier is varied, by varying the load capacitance, as a function of depth (time) to compensate for the attenuation of ultrasonic energy at different depths within a patient's body.

Methods and apparatus for using ultrasound with contrast agent

Methods and apparatus for producing zones with different contrast agent concentrations in a contrast agent infused target. An aspect of the method is subjecting the target to an ultrasound flash capable of producing first and second target zones, the first target zone having a higher concentration of contrast agent than the second target zone. Another aspect of the method is forming an ultrasound image of the target, wherein the first and second target zones in the ultrasound image have different ultrasonic responses. An embodiment of the apparatus of the present invention comprises a front-end controller (FEC) for use in a medical imaging system wherein the FEC controls a transducer to selectively radiate, in a single frame, a first beam position at a first energy and a second beam position at a second energy.