Real-time Control Module Research Articles

Real-Time Definite Sequence Modulation Based Spectral Broadening Scheme for High-Power Narrow-Linewidth Fiber Laser

High-power narrow-linewidth continuous fiber lasers have wide applications in the fields of power synthesis, nonlinear frequency conversion, and industrial processing. The output power of kW or even MW can be achieved by adopting spectral synthesis. However, in the power amplification process, the nonlinear effect represented by the stimulated Brillouin scattering (SBS) effect limits the further increase of the laser power. And the accompanying self-pulsing effect poses a threat to the safety of the laser system. A high-order phase modulation scheme using a definite time sequence has been proposed to realize the controllable spectral broadening of the seed source, so as to suppress the SBS effect and improve the output power in the amplification stage. In this paper, we demonstrate a real-time definite time sequence generation scheme by using an integrated field-programmable gate array (FPGA) and digital-to-analog converter (DAC). Combined with a single-stage phase modulator, the broadened bandwidth up to 30 GHz and controllable spectral shape can be achieved by adjusting the output waveform of the DAC directly. The generation principles and waveform control methods of real-time sequence are introduced in detail. Proven by a master oscillator power amplifier (MOPA) structure, the laser output power has increased by 30% under the extended bandwidth of 10 GHz compared to the cascaded white noise modulation case. This scheme provides a compact real-time control module for spectral broadening, which lays the foundation for implementing low-cost, compact, and standardized high-power narrow-linewidth fiber lasers.

A Real-Time Hardware Experiment Platform for Closed-Loop Electrophysiology.

Targeted stimulation of nervous system has become an increasingly important research tool as well as therapeutic modality, and the stimulation signal acquisition based on the expected signal needs a closed-loop system. Due to the difficulty of biological experiments, the real-time simulation of neural activity is of great significance for the mechanism analysis and the performance improvement of neuromodulation techniques. This paper proposes a real-time hardware experimental platform for closed-loop electrophysiology. The platform integrates a neural computing module and a real-time control module on TMS320F28377D digital signal processors (DSP), and it reserves a programmable interface for users to call the required modules and set module parameters simultaneously. The platform has high compatibility and can be used for closed-loop electrophysiological experiments with different models, different control algorithms and different clamps. We implement the thalamocortical relay neural computing model and iteration improves proportional-integral algorithm on the platform for experimental verification in this paper. The neuron firing waveforms of the DSP platform and the MATLAB R2020b simulation waveforms are consistent. Under the same physiological time, the simulation speed of DSP platform is 3 times faster than that of the Intel Core i5-8400 CPU computer, and the neural firing rate of DSP platform is due to the real-time. This platform can be used as a tool to explore the working mechanism of the nervous system. It may promote the development of neuroscience, especially the field of closed-loop neuroscience.

ASIP development of a real-time control module for a retrodirective antenna array

Electronically steerable antenna arrays become attractive due the possibility of simultaneously steering the main lobe in the desired direction and suppressing side lobes only by means of electronic control of excitation currents, hence avoiding mechanical components. However, this type of antenna requires intensive calculation for setting the excitation current of each array element in order to shape the radiation pattern for retransmission, thus demanding a dedicated hardware. This work reports the development of a digital control module for a retrodirective antenna array based on a customized dedicated microcontroller called PAMPIUM, which has been implemented on FPGA, aiming real-time response and low power consumption. A methodology for generation of optimized hardware in terms of area, power efficiency and performance is discussed. A design tool to provide the user with a practical and intuitive environment has been developed, which allows simulating and assessing statistics about execution and performance of the designed architecture. The developed digital control module is capable of updating the current coefficients of an eight-element antenna array in less than 1 s with a power consumption of 5.3 mW for beamsteering angles from 0° to 60°. The proposed methodology allows the demonstration of full efficiency of a retrodirective antenna array system.

Design and implementation of new control room system in Damavand tokamak

The aim of this paper is design and implementation of an up-to-date control room. The previous control room had a lot of constraints and it was not apposite to the sophisticated diagnostic systems as well as to the modern control and multivariable systems. Although it provided the best output for the considered experiments and implementing offline algorithms among all similar plants, it needed to be developed to provide more capability for complex algorithm mechanisms and this work introduces our efforts in this area. Accordingly, four leading systems were designed and implemented, including real-time control system, online Data Acquisition System (DAS), offline DAS, monitoring and data transmission system. In the control system, three real-time control modules were established based on Digital Signal Processor (DSP). Thanks to them, implementation of the classic and linear and nonlinear intelligent controllers was possible to control the plasma position and its elongation. Also, online DAS was constructed in two modules. Using them, voltages and currents of charge for the capacitor banks and pressure of different parts in vacuum vessel were measured and monitored. Likewise, by real-time processing of the online data, the safety protocol of plant performance was accomplished. In addition, the offline DAS was organized in 13 modules based on Field Programmable Gate Array (FPGA). This system can be used for gathering all diagnostic, control, and performance data in 156 channels. Data transmission system and storing mechanism in the server was provided by data transmitting network and MDSplus standard protocol. Moreover, monitoring software was designed so that it could display the required plots for physical analyses. Taking everything into account, this new platform can improve the quality and quantity of research activities in plasma physics for Damavand tokamak.

State‐of‐charge optimising control approach of battery energy storage system for wind farm

In recent years, configuring battery energy storage system (BESS) in wind farm has become the most popular method to smooth wind power fluctuation. The effectiveness of wind power fluctuation smoothing relies on the charging/discharging power control and state of charge (SOC) regulation of BESS. This study proposed a novel optimising SOC control approach for BESS in wind farm which could regulate wind power fluctuation in a suitable level and maintain SOC in an optimal range by utilising the wind power prediction information. A wind power prediction-based optimal SOC calculation module is designed to obtain an optimal range of SOC which makes BESS have enough capacity to smooth wind power fluctuation in a finite future period of time. It takes minimising over-charging and over-discharging time as optimisation objectives and biggest variations of wind farm outputting power within 1 and 10 min as restraint. A fuzzy self-adjusting of filter-based real-time control module is designed to smooth the wind power fluctuation in real time and regulate SOC to the optimal range. Finally, the effectiveness of the proposed approach was demonstrated through implementing it in wind power smoothing control simulation experiments.

A Wind Power and Load Prediction Based Frequency Control Approach for Wind-Diesel-Battery Hybrid Power System

A frequency control approach based on wind power and load power prediction information is proposed for wind-diesel-battery hybrid power system (WDBHPS). To maintain the frequency stability by wind power and diesel generation as much as possible, a fuzzy control theory based wind and diesel power control module is designed according to wind power and load prediction information. To compensate frequency fluctuation in real time and enhance system disturbance rejection ability, a battery energy storage system real-time control module is designed based on ADRC (active disturbance rejection control). The simulation experiment results demonstrate that the proposed approach has a better disturbance rejection ability and frequency control performance compared with the traditional droop control approach.

Modular Closed-Loop Control of Diabetes

Modularity plays a key role in many engineering systems, allowing for plug-and-play integration of components, enhancing flexibility and adaptability, and facilitating standardization. In the control of diabetes, i.e., the so-called "artificial pancreas," modularity allows for the step-wise introduction of (and regulatory approval for) algorithmic components, starting with subsystems for assured patient safety and followed by higher layer components that serve to modify the patient's basal rate in real time. In this paper, we introduce a three-layer modular architecture for the control of diabetes, consisting in a sensor/pump interface module (IM), a continuous safety module (CSM), and a real-time control module (RTCM), which separates the functions of insulin recommendation (postmeal insulin for mitigating hyperglycemia) and safety (prevention of hypoglycemia). In addition, we provide details of instances of all three layers of the architecture: the APS© serving as the IM, the safety supervision module (SSM) serving as the CSM, and the range correction module (RCM) serving as the RTCM. We evaluate the performance of the integrated system via in silico preclinical trials, demonstrating 1) the ability of the SSM to reduce the incidence of hypoglycemia under nonideal operating conditions and 2) the ability of the RCM to reduce glycemic variability.

Implementation of Real-time Wheel Order Recognition System Based on the Predictive Parameters for Speaker's Intention

In this paper new enhanced post-process predicting the speaker's intention was suggested to implement the real-time control module for ship's autopilot using speech recognition algorithm. The parameter was developed to predict the likeliest wheel order based on the previous order and expected to increase the recognition rate more than pre-recognition process depending on the universal speech recognition algorithms. The values of parameter were assessed by five certified deck officers being good at conning vessel. And the entire wheel order recognition process were programmed to TMS320C5416 DSP so that the system could recognize the speaker's orders and control the autopilot in real-time. We conducted some experiments to verify the usefulness of suggested module. As a result, we have confirmed that the post-recognition process module could make good enough accuracy in recognition capabilities to realize the autopilot being operated by the speech recognition system.

Multi-Axis EDM CNC System Based on RT-Linux

In order to manufacture geometrically complex or hard material parts, a new kind of multi-axis electro-discharge machining (EDM) computer numerical control (CNC) system, which is based on RT-Linux platform, was presented. Dual-kernel structure of System is adopted: Linux and RT-Linux are used to realize Time-sharing tasks and Real-time tasks separately. The system is divided macroscopically into two parts: Real-time part and Time-sharing part, microcosmically into three modules: Real-time Control Module, Drive Module and CNC User Module. Through the communications among them, three modules construct the whole system. Rimed Turbine Blisk was experimentalized to validate the performance of the system. The process and the results implied that the system is Real-time, stable and reliable.

Software environment for integrating critical real-time control systems

In the recent few years, integration of multiple real-time control modules has gained increased acceptance in the industry. Such integration can achieve lower overall hardware costs and reduced level of spares by sharing hardware resources among multiple applications. Single contemporary CPU can now harbor several applications which have been traditionally running on several older and slower computing platforms. However, the integrated approach faces new challenges such as the reusability of existing software and the prevention of fault propagation. The reuse of legacy application code, with minimal modifications, is strongly desirable since the cost of application re-development can be prohibitive. Resource sharing introduces dependencies among applications and thus requires additional design precautions to ensure that the effect of a failure in one application will not spread and impact other applications. This paper describes a two-layer software architecture, which enables the integration of multiple real-time applications while maintaining strong spatial and temporal partitioning among application modules. At the lower layer, a system executive creates multiple virtual machines. Each module accommodates an application with its choice of a real-time operating system. This architecture allows the reusability of existent software modules by enabling the integration of applications written for different real-time operating systems. The paper also addresses some issues related to the inter-application communication and to the handling of I/O devices.

Use of real time control modelling on the urban sewage system of Nancy

Since 1991, European Legislation on the urban treatment of wastewater requires local authorities to take into account the treatment of polluted water transported by the sewerage system and this during dry and wet weather conditions. In the seventies, the urban Community of Grand Nancy constructed storage tanks in its sewerage system in order to prevent flooding and wish today to use them to reduce and control the pollution discharges into the receiving water. This action is a part of a European LIFE project 1996-2000. The main aim of this project was to assess the effectiveness of reducing pollution of one particular retention basin, the 12,000 m3 Gentilly tank. This one has two operating modes: protection against floods during heavy rain and reduction of pollutant overflows during lighter rain. To assess its effect on the pollutant discharge, the HYDROWORKS DM software and its Real Time Control Module have been used, calibrated and validated. As this study is still in progress, this paper describes the studied site and the modelling results under different weather conditions and shows that the mathematical model can be used to simulate the operation of the catchment area and its associated sewerage system realistically.