Multichannel Control Research Articles

Implementation of coherence-based-selection multi-channel wireless Active Noise Control in headphone

Active noise control (ANC) headphone is widely used to attenuate the noise around human' s ear. The microphone mounted on the conventional ANC headphones collected the mixed reference signals when more than one noise sources are often present in the surrounding. In this case, the uncorrelated noise sources involved in the mixed reference usually deteriorate the noise reduction performance of the ANC headphones. To solve this problem, wireless microphones are proposed to install close to each potential noise source in the environment. The microphones pick up the clean reference signals and transmit them to the ANC controller embedded in the headphones with time-advance wirelessly. Every reference signal selected by a coherence-based-selection algorithm is provided individual control filter in each ear. Each control filter updated by using a single clean reference offers better noise reduction performance for ANC headphones. Furthermore, numerical simulations and real-time experiment results in this paper demonstrate the improvement of the proposed method compared with conventional ANC headphones.

Multi-Channel Data Stream Transmission Method of Internet of Things in Power Systems (IOTIPS) Based on Big Data Analysis

To solve the problems of frequent network link jitter and high bit error rate is the development direction of power grid communication technology. Therefore, a multi-channel data stream transmission method of Internet of things in power systems based on big data analysis is proposed. The data stream matching method based on big data stability mechanism is constructed by using data stream matching method to match the data stream to be transmitted and improve the anti-noise performance of the transmission process; the multichannel model of data stream transmission is constructed, and the matched data stream is transmitted by the multi-channel model; the big data analysis technology is used to process the data stream transmission process and improve the transmission performance of the model; the adaptive multi-channel equalization control method of sampling decision is used to realize the equalization design of data stream transmission channel, optimize the model transmission process, and reduce the bit error rate of transmission. Experimental results show that this method has better channel equalization performance; the link jitter frequency of this method is low, and it has better transmission stability; the lowest bit error rate can reach 0%, and the reliability of data stream transmission is high.

Pre-test analysis to reproduce random pressure fields with multi-channel acoustic control

Pre-test analysis is proposed as a methodology to design control strategies for environmental acoustic tests. In the space industry these tests are used to assess the survivability of hardware, which is exposed to harsh dynamic loads in service. In this work an array of loudspeakers and microphones is used in a laboratory to reproduce the acoustic environment generated during the launch of a spacecraft. Active control is required to design the signals driving the loudspeakers. Pre-test analysis uses an internal model of the electro-acoustic plant responses to automatically design the control parameters required by multi-channel random control algorithms. The outcome of pre-test analysis is the automatic selection of the control microphones, and a set of realizable test references in the form of a spectral density matrix. The methodology proposed in this work to design the control strategies is validated experimentally on system level tests. Compared with other approaches, proper design of the control strategy for the environmental acoustic test significantly enhances the correlation between the measured and desired pressure responses.

Serialized gradient chromatography for the digital blending of colored fibers and spinning of gradient colored yarn

Gradient colored yarns are manufactured by controlling the blending ratios of three-primary-colored fibers in a slight distribution of gradients along the yarn length, thereby resulting in a continuous natural variation in mixed colors of the fibers throughout the whole yarn. The spinning of gradient colored yarns still remains a challenge, which requires the reliance on digital blending theory of colored fibers and the supporting of multi-channel computer numerical control (CNC) spinning technique. This paper constructed a three-primary-colored fiber gridded color mixing model and its mass mixing matrix and color mixing chromatography matrix by mass discretization and coupling pairing with a 10% gradient for the three-primary-colored fibers. With the aim of continuous natural gradient of mixed colors, the blending ratio gradient path of three-primary-colored fibers was planned based on the mass mixing matrix, and a method of regulating the gradient of color difference between adjacent color segments was proposed. In order to realize the natural gradient of color of the forming yarn, the spinning mechanism of gradient colored yarn was established based on three-channel CNC spinning mechanism and the time-series yarn simulation model, and the time-series spinning processing parameters of three-channel CNC spinning machine were devised. Four gradient colored yarns with different gradient paths were designed and prepared, the linear density, twist, unevenness, surface hairiness, and tensile strength of the spun yarns were measured, compared, and analyzed, and knitted fabrics with color gradient effect were fabricated by small circular knitting machine to obtain continuous and natural color transition with a dreamy and mysterious color effect.

Multi-channel drive system of phased array based on DDS chips

Ultrasonic phased array focusing transducer has the advantages of adjustable focusing and achieving transcranial focusing. A multi-channel high-precision phase control drive system is one of the key technologies that determine whether it can be used in clinical practice. This paper proposes a design scheme of a phased array drive system based on direct digital synthesizer (DDS) chips. The scheme not only realizes the high-precision phase-controlled output of sine wave and square wave but also in the technical implementation, one electronic channel can be increased with only one main controller general-purpose input/output (GPIO) consumed. This means that the expansion of the number of channels much easier, solving the problem of complicated control circuit caused by the array with dense elements and large aperture. Based on the proposed scheme, a 49-channel array drive system with a phase resolution of 12-bit was fabricated using a microcontroller unit (MCU) as the main control chip. The circuit board test and ultrasonic focusing experiment results show that the phase control error of the multi-channel signal generation board is less than 0.2 degree. And the results of acoustic field distribution obtained by experimental measurement are very similar to those obtained by theoretical simulation, which indicates that the frequency and phase of the output waveform of the array drive system are stable. The design method can provide a reference value for the design of the drive system of phased array transducer with different numbers of elements.

Analysis of the characteristics of bimetallic and semiconductor heat flux sensors for in-situ measurements of envelope element thermal resistance

Monitoring of the thermal resistance of building envelopes for assessing their energy efficiency is carried out through in-situ measurements of the heat flux. It is therefore necessary to take into account not only the heat transfer conditions of the studied object but also the characteristics of the measuring instruments, which may depend on these conditions. This paper presents the results of a study of the characteristics of heat flux sensors of two types —bimetallic and semiconductor — which are the most common in the control of building envelopes. The case studies were focused on the characteristics of the sensors, such as the conversion coefficient (inversely proportional to sensitivity to the heat flux), the temperature dependence of the conversion coefficient, the response time of the sensors, and the emissivity of the sensor surface. The conversion coefficient of a bimetallic sensor was determined under the conditions of conduction and radiation supply of heat energy, which revealed the dependence of the conversion coefficient on the heat transfer conditions of the sensor surface. The value of the emissivity of the semiconductor sensor surface is lower than that of bimetallic sensors, and the time constant of bi-metallic sensors is two times less than that of semiconductor sensors. Verification of the obtained results was carried out by studying the metrological characteristics of the multi-channel thermal resistance control system, which included bimetallic heat flux sensors as sensitive elements. Thus, we suppose that the results of our study could be used to improve the accuracy in measuring the thermal resistance of building envelopes by the correct selection of heat flow sensors, or by making corrections to the measurement results that take into account the influence of experimental conditions on the characteristics of the sensors.

STRUCTURAL ANALYSIS OF ON-BOARD MULTIMODE AUTO TRACKING SYSTEM

Two variants of two-channel structures of tracking systems has been introduced into consideration, which are sequentially used in two modes of operation of the on-board automatic tracking system. Taking into account the fact of quantization according to the level of signals for measuring the angles of mismatch of each of the channels, it is justified to use not one, but two different structures in the second auto-tracking mode. Using mathematical modeling, the expediency of increasing the number of two-channel structures from two to three, used in a single auto-tracking process according to the criterion of the provided dynamic accuracy, have been demonstrated. This paper presents a two-channel structures investigation for tracking systems operating in tracking mode of maneuverable targets, taking into account various systems of carrier operations. Considered multichannel complex control system (CCS) structure that include precise channel (PC) and coarse channel (CC). CC use the carrier and the flight control system (FCS) to make rude tracking. The PC function implemented by an optoelectronic device (OED) has placed in a traditional angular mechanical suspension, which act with high accuracy. Described three CCS operation modes classified by target mark fall inside or outside direction finder (DF) CC or PC field of view. At the capture mode can be used only information from the CC DF. At the complex control mode becomes possible to use information from both CC DF and PC DF. At the precision mode, it is advisable to use information only from the PC DF. Developed CCS functioning math model to check main points of this work. Math model makes possible to carry out simulation tests for each mode in a separate operation, as well as when they are integrated into a single complex automatic target tracking mode. Has been described efficiency factor as the total time of satisfactory accuracy relative to entire experiment time. On math model modes efficiency has compared to each other. As result precision mode have higher efficiency and capture mode lowest. As conclusion recommended use a precision mode to achieve higher accuracy at auto tracking tasks.

Flow-Field-Assisted Dielectrophoretic Microchips for High-Efficiency Sheathless Particle/Cell Separation with Dual Mode.

Prefocusing of cell mixtures through sheath flow is a common technique used for continuous and high-efficiency dielectrophoretic (DEP) cell separation. However, it usually limits the separation flow velocity and requires a complex multichannel fluid control system that hinders the integration of a DEP separator with other microfluidic functionalities for comprehensive biomedical applications. Here, we propose and develop a high-efficiency, sheathless particle/cell separation method without prefocusing based on flow-field-assisted DEP by combining the effects of AC electric field (E-field) and flow field (F-field). A hollow lemon-shaped electrode array is designed to generate a long-range E-field gradient in the microchannel, which can effectively induce lateral displacements of particles/cells in a continuous flow. A series of arc-shaped protrusion structures is designed along the microchannel to form a F-field, which can effectively guide the particles/cells toward the targeted E-field region without prefocusing. By tuning the E-field, two distinct modes can be realized and switched in one single device, including the sheathless separation (ShLS) and the adjustable particle mixing ratio (AMR) modes. In the ShLS mode, we have achieved the continuous separation of breast cancer cells from erythrocytes with a recovery rate of 95.5% and the separation of polystyrene particles from yeast cells with a purity of 97.1% at flow velocities over 2.59 mm/s in a 2 cm channel under optimized conditions. The AMR mode provides a strategy for controlling the mixing ratio of different particles/cells as a well-defined pretreatment method for biomedical research studies. The proposed microchip is easy to use and displays high versatility for biological and medical applications.

Mathematical model of free-flying space manipulation robot when approaching a non-cooperative spacecraft

The paper investigates the service satellite control system when approaching a non-cooperative spacecraft in the state of uncontrollable motion. The service satellite control system is considered as a two-level multichannel control system, and multicriteria optimization methods with cross-links are developed. The mathematical model of the control system for a free-flying space manipulation robot at the guidance and stabilization phase is proposed. The efficiency criteria are presented.

Optimal parametric design of delayless subband active noise control system based on genetic algorithm optimization

Active noise control systems are generally application-specific, and an appropriate algorithm with an optimal configuration is desirable in the first stage of active noise control system design and deployment. This study presents a design of the subband active noise control system with optimal parameters for a practical broadband active noise control. Although the delayless subband active noise control has gained wide attention for broadband noise cancellation, an optimal design remains a challenge because of the complex interplay between multiple factors such as spectral leakage, delay and weight stacking distortion subject to a number of configurable parameters, and weight stacking method. The configurable parameters can hardly be optimized independently because the active noise control performance depends on the combined configuration. A simple near black box active noise control algorithm optimization model is thus established by incorporating the genetic algorithm optimization into the parametric design of the delayless subband algorithm. The automated process does not require an understanding of the performance characteristics for different parameters. The significance of applying the automated genetic algorithm optimization to the complex multiparameter nonlinear active noise control design is revealed by numerical simulations, particularly for the multichannel low-frequency broadband active noise control system configured with the delayless subband algorithms. This provides a way for the optimal parametric design of subband active noise control before being used in a practical complex scenario.

Design and multichannel electromyography system-based neural network control of a low-cost myoelectric prosthesis hand

Abstract. This study introduces a new control method for electromyography (EMG) in a prosthetic hand application with a practical design of the whole system. The hand is controlled by a motor (which regulates a significant part of the hand movement) and a microcontroller board, which is responsible for receiving and analyzing signals acquired by a Myoware muscle device. The Myoware device accepts muscle signals and sends them to the controller. The controller interprets the received signals based on the designed artificial neural network. In this design, the muscle signals are read and saved in a MATLAB system file. After neural network program processing by MATLAB, they are then applied online to the prosthetic hand. The obtained signal, i.e., electromyogram, is programmed to control the motion of the prosthetic hand with similar behavior to a real human hand. The designed system is tested on seven individuals at Gaziantep University. Due to the sufficient signal of the Mayo armband compared to Myoware sensors, Mayo armband muscle is applied in the proposed system. The discussed results have been shown to be satisfactory in the final proposed system. This system was a feasible, useful, and cost-effective solution for the handless or amputated individuals. They have used the system in their day-to-day activities that allowed them to move freely, easily, and comfortably.

Involvement of the ERK MAPK Cascade in the Formation of Adhesions in the Abdominal Cavity

Background. ERK1 and ERK2 (extracellular signal-regulated kinase) are related protein serine / threonine kinases that are involved in the regulation of the cell cycle, cell migration and survival, differentiation, metabolism, and proliferation. Evaluation of this cascade is promising to determine the possibility of influencing pathological conditions through the regulation of ERK1/2. Aim of the study. To assess the involvement of the ERK MAPK cascade in the development of adhesions in the abdominal cavity. Methods . The experiments were carried out on male Wistar rats. The adhesion process in the abdominal cavity was simulated (n = 40). The research time is from 2 hours to 30 days. Tissue samples from 5 intact animals were examined as a control. Histological sections were prepared and stained histochemically for ERK1. The expression of ERK1 and ERK2 was assessed by PCR. Results . Using the PCR method, the involvement of both the ERK1 and ERK2 cascades in the process was established, and, judging by the change in gene expression, the latter is more actively involved in the process. Histochemical study confirmed the role of ERK cascades in the management of repair in serous membrane injury. Histochemically revealed an increase in ERK1 expression with two peaks of activity – at 1 and 30 days. Conclusion . Our data establish multichannel control of the reparative process in the area of damage to the serous membrane with the involvement of both the p38 and ERK MAPK cascades, which is important to consider when developing methods of influencing the wound healing process in the abdominal cavity.

Algorithm for Multi-Channel Robotic Device Control Based on Minimizing Bayesian Risk

Currently, mobile robotic devices are widely used in various fields of human activity, which imposes high requirements on the reliability of their operation. Improving the reliability and quality of control of mobile robotic devices is possible through the use of multi-channel control systems. Signals coming from different control channels are subject to various interference, which can lead to wrong decisions. In this regard, the problem of minimizing the risk of making an incorrect control decision is urgent. This paper gives a theoretical justification for the algorithm for choosing a control command for a multi-channel control system of a mobile robotic device. The algorithm is based on minimizing the Bayesian risk of choosing an erroneous command. To implement the algorithm, it is necessary to have statistical information about the quality of functioning of each control channel.

Design of multi-channel data acquisition system for real-time perception lidar

Lidar is the most effective means for real-time environmental awareness. Based on the demand of multi-channel perception lidar with large amount of data, real-time data transmission and miniaturization, a multi-channel parallel signal acquisition and processing system was designed based on FPGA and DSP. A self-developed three-dimensional lidar was designed, including mechanical scanning, linear array detection, data acquisition and control system. The system was implemented and verified in the three-dimensional point cloud imaging experiments. In this system, FPGA was responsible for multi-channel lidar data acquisition, control and transmission. DSP was used for data calculation and uploading the point cloud data to the upper computer through the network to realize the real-time display of point cloud. The experiments of lidar show that the proposed real-time data acquisition system could meet the requirements of point cloud calculation at 2 Mpts/s, with real time data acquisition and procession at 20 fps. The rapid calculation of lidar point cloud of the environment and obstacles is realized. It can be applied to automatic driving, navigation obstacle avoidance, perimeter security and etc.

MC-COCO4V2P: Multi-Channel Clustering-Based Congestion Control for Vehicle-to-Pedestrian Communication

Vehicle-to-Pedestrian communication can extend crash prevention capabilities of the current driver assistance systems in vehicles. This requires vehicles and pedestrians to exchange safety messages with each other. However, as the number of pedestrians increases, the numerous safety messages transmitted by pedestrians can quickly congest the network. This can severely affect Vehicle-to-Pedestrian and Vehicle-to-Vehicle communication. Hence, a mechanism for the mitigation of network congestion caused by pedestrian safety messages is required. This article proposes a Multi-channel Clustering-based Congestion Control (MC-COCO4V2P) algorithm, a proactive and infrastructure-independent clustering-based approach to mitigate the network congestion caused by pedestrians. Our approach clusters pedestrians based on their location and direction and uses separate channels for exchanging cluster and safety messages, thereby reducing the control information overhead. It also employs a transmit power control mechanism to make the clustering mechanism energy efficient. Our results show that the clustering of pedestrians can significantly improve network performance and reduce the power consumption of pedestrians' devices.

Synthesis of a Control Algorithm for Nonlinear Plant Using Correction of Controlled Plant Dynamics and Compensation of Perturbations

This paper introduces a new approach to control of nonlinear non-stationary multichannel plant with lumped parameters and additive perturbations. Controlled plant is represented as a set of equations in matrix-vector form, with number of output variables equal to the number of controlled variables. The problem is stated as follows: to control plant output provided that output variables and state variables are observable. Plant equations are converted into a state dependent coefficient (SDC) form, then method of correction of plant dynamics and compensation of perturbations is used. A variant of conversion to the SDC form based on E. A. Barabashin’s method is suggested. Reverse models of the plant are defined with respect to reference and deviation channels. Algebraic equations are presented, which, when solved, yield reverse models. Definitions of etalon filters are introduced, allowing a physical implementation of a controller when used in conjunction with reverse models. Conditions to which matrices of etalon filters must conform are considered. It was found by examples that part of coefficients of etalon filters can be chosen arbitrarily. Using the method of correction of controlled plant dynamics and perturbations, utilizing reverse models and etalon filters, a physically implementable controller algorithm was constructed. Then it was transformed to physically implementable form using equivalent transformations. Components of the final algorithm are obtained by the means of algebraic transformations of functional matrices of the plant and etalon filter. Equations for closed control system are presented. It follows from these equations that system is asymptotically stable and that transient processes correspond with their respective etalon filters. Even though compensation method was used, a multichannel closed-loop control system was obtained. An advantage of suggested method is that it allows a simple procedure for the control algorithm synthesis using evident physical initial data. The efficacy of obtained algorithms was verified using several examples. Computer simulation showed that control systems are robust and comply with specified requirements. Directions for further research were suggested.

Preliminary Analysis of the Therapeutic Mechanism of Feiluoning in Convalescent Patients With COVID-19

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), is often accompanied by injury to pulmonary function and pulmonary fibrosis. Feiluoning (FLN) is a new Chinese medicine prescription which is available for the treatment of severe and critical convalescence of COVID-19 patients. FLN also has a positive effect on pulmonary function injury and pulmonary fibrosis. We explored the potential mechanism of FLN’s effect on the convalescent treatment of COVID-19. According to the pharmacodynamic activity parameters, we screened the active chemical constituents of FLN by comparing the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform. The Uniprot database was used to querying the corresponding target genes, and Cytoscape 3.6.1 was used to construct a herb-compound-target network. Protein interaction analysis, target gene function enrichment analysis, and signal pathway analysis were performed using the STRING, DAVID, and Kyoto Encyclopedia of Genes and Genomes pathway databases. Molecular docking was used to predict the binding capacity of the core compound with COVID-19 hydrolase 3 Cl and angiotensin-converting enzyme 2 (ACE2). The herb-compound-target network was successfully constructed and key targets identified, including prostaglandin G/H synthase 2, estrogen receptor 1, heat shock protein HSP 90, and androgen receptor. The major affected metabolic pathways were pathways in cancer, pancreatic cancer, nonsmall cell lung cancer, and toll-like receptor signaling. The core compounds of FLN, including quercetin, luteolin, kaempferol, and stigmasterol, could strongly bind to COVID-19 3 Cl hydrolase, and other compounds, including 7-O-methylisomucronulatol and medicocarpin, could strongly bind to ACE2. Thus, it is predicted that FLN has the characteristics of a multicomponent, multitarget, and multichannel overall control compound. FLN’s mechanism of action in the treatment of COVID-19 may be associated with the regulation of inflammation and immune-related signaling pathways, and the influence of COVID-19 3 Cl hydrolase binding ability.

Energy and Resource Efficiency in Apatite-Nepheline Ore Waste Processing Using the Digital Twin Approach

The paper presents a structure of the digital environment as an integral part of the “digital twin” technology, and stipulates the research to be carried out towards an energy and recourse efficiency technology assessment of phosphorus production from apatite-nepheline ore waste. The problem with their processing is acute in the regions of the Russian Arctic shelf, where a large number of mining and processing plants are concentrated; therefore, the study and creation of energy-efficient systems for ore waste disposal is an urgent scientific problem. The subject of the study is the infoware for monitoring phosphorus production. The applied study methods are based on systems theory and system analysis, technical cybernetics, machine learning technologies as well as numerical experiments. The usage of “digital twin” elements to increase the energy and resource efficiency of phosphorus production is determined by the desire to minimize the costs of production modernization by introducing advanced algorithms and computer architectures. The algorithmic part of the proposed tools for energy and resource efficiency optimization is based on the deep neural network apparatus and a previously developed mathematical description of the thermophysical, thermodynamic, chemical, and hydrodynamic processes occurring in the phosphorus production system. The ensemble application of deep neural networks allows for multichannel control over the phosphorus technology process and the implementation of continuous additional training for the networks during the technological system operation, creating a high-precision digital copy, which is used to determine control actions and optimize energy and resource consumption. Algorithmic and software elements are developed for the digital environment, and the results of simulation experiments are presented. The main contribution of the conducted research consists of the proposed structure for technological information processing to optimize the phosphorus production system according to the criteria of energy and resource efficiency, as well as the developed software that implements the optimization parameters of this system.

Implementation of a single-channel active noise control system with multiple reference sensors

When multiple sources contribute competitively to the noise level, multi-channel control architecture is needed, leading to more cost and time for control computation. We, hence, are concerned with a single-channel control method with a single-reference signal obtained from a linear combination of the multiple source signals. First, we selected 3 source signal sensors for the reference signals and the error sensor, selected a proper actuator and designed the controllers: 3 cases of single-channel feedforward controllers with a single-reference signal respectively from the source signals, a multi-channel feedforward controller with the reference signals from the source signals, and the proposed controller with the reference signal from weighted sum of the source signals. The weighting factors and the filter coefficients of the controller were determined by the FxLMS algorithm. An experiment was then performed to confirm the effectiveness of the proposed method comparing the control performance with other methods for a tower air conditioner. The overall sound pressure level (SPL) detected by the error sensor is compared to evaluate their performance. The reduction in the overall SPL was obtained by 4.74 dB, 1.96 dB and 6.62 dB, respectively, when using each of the 3 reference signals. Also, the overall SPL was reduced by 7.12 dB when using the multi-reference controller and by 7.66 dB when using the proposed controller. Conclusively, under the multiple source contribution, a single-channel feed forward controller with the reference signal from a weighted sum of the source signals works well with lower cost than multi-channel feedforward controller.

Continuous chromatography with multi-zone and multi-column dynamic tandem techniques for the isolation and enrichment of class compounds from natural products of Panax notoginseng.

Efficient and economical separation and enrichment of high-content class compounds from complex natural plants are of great importance. This study describes a novel continuous chromatography system (CCS) with multi-zone and multi-column dynamic tandem techniques for the efficient and economical separation and enrichment of high-content class compounds from natural products. The CCS was split into eight zones (each zone covered 2 or 3 columns connected dynamically in a series) via a multi-channel logic control valve to continuously and automatically separate and enrich class compounds from complex natural plants. CCS separation conditions were optimized by static and dynamic adsorption and desorption experiments. With the CCS system, 120.82 kg of Panax notoginseng saponins (PNS) was isolated from 1.0 t of P. notoginseng. Importantly, the total contents of five main saponins (R1, Rg1, Re, Rb1, and Rd) in PNS exceeded 90%, and the recovery rate exceeded 85%. In addition, this separation system enhanced the separation efficiency and decreased the mobile phase used. Thus, CCS with multi-zone and multi-column dynamic tandem techniques is an efficient and economical method for the large-scale preparation of high-content total saponins from P. notoginseng and will have wide application prospects, especially in the large-scale preparation of high-content class compounds from natural plants.