Control Signal Transmission Research Articles

Noise effect on the signal transmission in an underdamped fractional coupled system

The signal transmission phenomenon in an underdamped fractional system composed of two harmonically coupled particles, but only the first particle, which is driven by a periodic force, is studied. We obtain the analytical expressions for the steady-state response of the two coupled particles by applying the stochastic averaging method and define the signal transmission factor to characterize signal transmission efficiency. We analyze the impact of noise on signal transmission efficiency and provide the discriminant criterion for the emergence of the signal transmission enhancement phenomenon. We also analyze the resonance behavior of the signal transmission factor and provide the discriminant criterion for the emergence of different types of resonance behavior based on system parameters. We draw the phase diagrams for varying resonance behavior versus different parameters and study the influences of the parameters on resonance behavior. It is found that the coupling strength and fractional-order exert important influences on the signal transmission efficiency and resonance behavior, and the fractional coupled system exhibits complicated dynamic behaviors than the integer coupled system. Lastly, numerical simulations for the signal transmission factor $$\eta $$ , and the output signal-to-noise ratio (SNR) transmission gain $$\text {SNR}_{\eta }$$ are performed. We can control signal transmission efficiency and resonance behavior within a certain range by understanding the effects of system parameters on the underdamped fractional coupled system, and it has potential applications in modern science.

Digital Watermarks with Adaptive Information Ring Width in the Issue of Hidden Transmission of a Control Signal in the Multi-Target Robotic System

Purpose of research. The article is devoted to the issue of ensuring the safe transmission of control signals between the elements of a multi-agent robotic system. The purpose of the work is to provide hidden data transmission with the possibility of unambiguous extraction of control signals.Methods. To solve the task set, an algorithm based on the methods of digital watermarks and digital steganography was proposed. The method of forming a digital watermark in the form of a ring with symmetry allows not only ensuring maximum imperceptibility of embedding (insignificant distortion of the container during concealment), but also to protect the transmitted signal from such complex distortions as image rotation. The steganographic concealment method allows regulating the intensity of embedding using the force factor; it is computationally simple and straightforward. The proposed approach to identifying and understanding the transmitted signal differs from modern methods of cryptography and steganalysis in that it does not require 100% correct signal extraction. After several modifications, the method allows minimizing the time spent on formation (adaptive width of the ring with signal bits) and embedding of a digital watermark (minimization of the processed area of the container for embedding).Results. The proposed approach makes it possible to transmit control signals in a hidden way within the framework of the transmission of digital objects; the conducted experiments have shown that the control signal is unambiguously understood even with such distortions as a decrease or increase in contrast or brightness, image rotation, and compression.Conclusion. Application of the proposed technique for transmitting control signals in a multi-agent robotic system will male it possible to receive the necessary information timely and safe, with a minimum probability of loss.

Delay-Tolerant Predictive Power Compensation Control for Photovoltaic Voltage Regulation

Voltage regulation is imperative for the successful operation of electricity distribution networks, especially with a high penetration level of photovoltaic (PV) systems. Power compensation control (PCC) that uses both reactive power compensation and active power curtailment has shown promising results in alleviating voltage rise problems. It crucially relies on real-time communications among distributed PV systems. However, the transmission of state measurements and control signals in PCC is hampered by inevitable communication delays. Therefore, it is important to not only estimate the maximum tolerable communication delay (MTCD) but also develop an alternative technique for PCC under abnormal communication delay (ACD) conditions. This article presents a delay-tolerant predictive PCC for voltage regulation in distribution feeders. After estimating the MTCD based on voltage and power mutation, it uses normal PCC for effective operation when communication delay is within MTCD, or switches to predictive PCC under ACD conditions. An accurate prediction is achieved using a double neural network with online adjustment of weights and samples. Simulations on a sample distribution network demonstrate the effectiveness of our presented approach.

Hidden Markov model-based smith predictor for the mitigation of the impact of communication delays in wide-area power systems

The use of an open communication network in a wide-area power system (WAPS) introduces random delays into the transmission of frequency measurements and control signals, which can deteriorate the load frequency control (LFC) performance. Current studies are focusing on developing a suitable delay margin controller to maintain the stability of the WAPS. This paper introduces a new Smith predictor (SP) with tools to accurately predict the input time delays and consequently mitigate the LFC performance loss caused by unreliable communication. The time delays are predicted via the discrete hidden Markov model (DHMM) and the exponentially weighted moving average (EWMA) model. The predicted delays are then input to the SP. The DHMM adopts two different scalar quantization methods, i.e., the uniform technique and the K-means clustering technique. It then maps the time delays on to a discrete observational space. To validate the findings for practical applications, we conduct a case study on a test platform, namely a single-area WAPS with Ethernet, which is implemented via the Truetime simulator. The results indicate that the SP is more effective in eliminating load disturbances and enhancing the robustness against time delays than existing delay-margin-based controllers. The K-means DHMM-based SP achieved better LFC performance than the one with the EWMA. The stability of the LFC system with time-varying delay is discussed using a Lyapunov–Krasovskii-based delay-dependent criterion and the small gain theorem.

Formula omitted] control of uncertain linear systems with a triggering threshold dependent approach

This paper investigates the H∞ control of uncertain linear systems under the event-triggered control framework. The uncertainty is a mismatched type without known upper bounds. To reduce the redundant transmission of control signals, three triggering strategies are developed, namely, the absolute threshold triggering manner is built firstly to deal with the small control input variation. By revisiting the first one, the large control input is monitored by the second triggering scheme. Lastly, a trade-off between the above two triggering measures is made to cover all possible inputs without sacrificing system performance largely. Based on the proposed triggering strategies, different adaptive controllers containing the triggering threshold bound are constructed to eliminate the unknown uncertainty and ensure uniformly bounded with the required H∞ performance level, which is verified by simulation studies.

Displaying images on a plane of rotation via mutual inductance coupling wireless controls

This work presents an innovative display technique, which renders the image displaying capability to the plane of rotation by installing a rectilinear LED array. Basing on the persistence of vision of human eyes, the rotating scan of LEDs generates the stable display of images under the timing control. Because of the cyclic motions during the rotating scan, the timely display control signals have to be received wirelessly. Further considering the desire for long-time usages, the electricity supply is also required to be achieved through wireless energy harvest. As per these requirements, we present an implementation scenario based on the mutual inductance coupling of coaxial coils. During the rotation, the noncontact coils maintain the relative positions unchanged, thus preserve the reliable transmission of control signals and power supply in a stable electromagnetic environment. Also benefited from the mutual inductance coupling design, the construction of wireless communications is achieved by using a primitive micro-controller circuit. The hardware simplicity enables the setting up of ad hoc screens via a convenient refit of rotatable objects (e.g., vehicle wheels and propellers), and realizes fashionable and customizable consumer electronics with the additional information broadcasting function.

A 400MHz Single‐Chip CMOS Transceiver for Long Range High Definition Video Transmission in UAV Application

A fully-integrated 400MHz transceiver for high definition video transmission in Unmanned aerial vehicle (UAV) is presented. The transceiver integrates a Receiver (RX), a Transmitter (TX), a tunable multi-mode complex filter, two sigma-delta fractional-N PLL frequency synthesizers and some baseband calibration circuits, which is applicable for both Time division duplex (TDD) and Frequency division duplex (FDD) systems. In order to meet different data rate and sensitivity requirements for control signal and video signal transmission, the transceiver supports BPSK/QPSK/QAM modulation. The receiver sensitivity is -75dBm and the transmitter provides emission power up to 12dBm. Besides, the Error vector magnitude (EVM) of -35dB is measured under 64QAM modulation with 54Mbps data rate. Fabricated in a standard 130nm CMOS process and operated at 1.2V supply for most circuits excluding PA, 3.3V supply for PA, the receiver and the transmitter consume 68.2mW and 164.3mW, including the frequency synthesizer, respectively. The total chip area with pads is 6.25mm2.

Towards Safety Improvement of Measurement and Control Signals Transmission in Marine Environment.

This paper is dedicated to some aspects of maritime on-board safety improvement. The contribution of this article is a proposal to extend wireless communication on the ship, supported by examples of solutions that have not previously been used on board. Analyzed aspects concern the measurement and control signal transmission in hostile marine environment. A problem to solve is formulated, how to reduce a negative impact of this environment on effectiveness and reliability of maritime on board communication. The proposed ways for solving a problem under consideration cover recommendations concerning some aspects of ship construction and implementation of wireless sensor network. The main topic faced by the paper is concentrated on case study-based ZigBee as well as WiFi networks implementation in the area of the acquisition of data from sensors and measuring transducers connected to the terminal network. The exemplary implementation of ZigBee network, elaborated in Gdynia Maritime University is related, firstly, to the configuration of a simple wireless measurement and control channel, and secondly, to wireless communication channel supported by autonomously working microprocessor measurement and control system. WiFi networks were also tested in the same area of application. Finally, some concluding remarks are formulated.

Event-triggered non-fragile finite-time guaranteed cost control for uncertain switched nonlinear networked systems

In this paper, the finite-time event-triggered and guaranteed non-fragile cost control problem is discussed for a class of uncertain switched nonlinear networked control systems (SNNCS) which involves parameter uncertainties and time-varying transmission delays. The main aim of this work is to synthesize finite-time event-triggered and guaranteed cost non-fragile controller for ensuring the finite-time boundedness of the resulting SNNCS with optimal dissipative performance index. By proposing an appropriate Lyapunov–Krasovskii functional and using the average dwell time technique, a set of new delay-dependent finite-time boundedness conditions is established in terms of linear matrix inequalities to obtain the desired result. The proposed approach unifies the H∞,L2−L∞, passivity and (Q,S,R) - dissipativity performance concept in a single framework. Further, the associated optimization problem is formulated to minimize the guaranteed cost performance bound. To save communication resources, an event-based rule is also introduced and implemented for the control signal transmission. Finally, two numerical examples with simulations are provided to demonstrate the efficiency of the developed control design technique.

A Delay-Tolerable Master–Slave Current-Sharing Control Scheme for Parallel-Operated Interfacing Inverters With Low-Bandwidth Communication

Parallel-operated inverters with common dc and ac bus can be used as an interface for dc systems connecting to an ac network. High cost and complicated wiring of communication are the main drawbacks of communication-based current-sharing methods for the parallel systems. Many new communication tools, e.g., power line communication (PLC), Bluetooth, and Zigbee modules, are cheap and require no extra wire connection, but have low communication bandwidth and low data rate, which result in a large communication delay and zero-order-hold period that could cause stability issues if used to transmit control signals. This article presents a method to mitigate the instability issue caused by communication effects, in parallel grid-tied inverter system with master-slave current-sharing control. First, the master-slave current-sharing control scheme is introduced. Then, the influence of communication delay and zero-order-hold on the system is analyzed. And design criterion to reduce the influence of low-bandwidth communication (LBCom) is studied and determined. New approaches, by designing a current reference low-pass filter and a voltage feedforward loop in slave modules, are introduced. The performance of the proposed control structure and design criteria are experimentally verified. With the proposed method, LBCom tools can be applied to systems with master-slave control architecture while keeping the robustness and transient performance, with improved modularity and operation flexibility.

An Improvement of Remote Control Panel for Numerous Electrical Devices in Smart Homes Using RF and Wifi

This study aims to improve a remote control panel for numerous electrical devices in smart homes using radio frequency (RF) and wifi. In this study, RF315MHz transceiver module and Arduino Ethernet Shield wifi module are combined by a programmed algorithm to transmit control signals from a central processor to the electrical devices in the smart house. The RF315 MHz transceiver with hard coding is modified to be a soft coding module in which each control channel can switch on/off 256 electrical devices. Then, a remote control panel is developed to control numerous electrical devices based on the requirements of the number of control buttons and the technology in the smart house. Moreover, this proposed method allow to control the electrical devices in the house by various panels. An experimental model with two separate transmission channels using two soft-coded RF315MHz modules has been done to verify the applicability of the proposed method.

Regulation of the glutamate release by pH and GABA at the axon terminal of rod photoreceptors

AbstractPurposeRegulation of synaptic transmission at the rod synaptic terminal, between rods and rod bipolar cells (RBC) and horizontal cells (HC) is not well understood. The RBC depolarize as a consequence of the decrease in the calcium regulated glutamate release by the rod axon terminal. This effect is mediated by mGluR6 receptors coupled to Gi‐TRPM1 expressed in the RBC. We propose to investigate, in living animals, the modulatory effect by GABAergic HC on this synaptic transmission by means of electroretinogram (ERG) recordings.MethodsBinocular ERG were obtained from C57BL6/J adult mice in response to low intensity full field light stimuli (0.01 cd·s·m−2) (rod response). The right eye of each animal was injected with 1 μl of phosphate buffer solution (PBS) containing either GABA (100 mm), Glutamate (100 mm), Bicuculline (10 mm), DNQX (30 mm), APB (25 mm), Hepes (100 mm) or a combination of these drugs. The left eye of each animal was injected with 1 μl of PBS. Burian‐Allen corneal electrodes were used and responses from both eyes were compared.ResultsThe intraocular injection of APB produces the abolition of the rod response, which is explained by continued activation of mGluR6 receptors by APB. Stimulation by GABA and/or glutamate of membrane receptors expressed in HC produces a significant increase in the rod response (p < 0.05), while their antagonists (Bicuculline and DNQX) produce a significant response decrease (p < 0.05). These effects can only be explained by changes in the pH of the synaptic cleft, since the acidification of the synaptic space produces the blockage of the calcium channels expressed in the axon terminal of the rods. The acidification mechanism is justified since the intraocular injection of Hepes produces the same effect as the inhibition of HC.ConclusionRegulation of the pH in the triad of rod terminal synaptic cleft by GABA receptors seems to be an effective mechanism to control signal transmission from the photoreceptors to RBC.

Stochastic LQ control under asymptotic tracking for discrete systems over multiple lossy channels

This study addresses the asymptotic tracking problem subjected to linear quadratic (LQ) constraints for linear discrete-time systems, where packet dropout occurs in actuating channels. To solve this objective control problem, the controller-coding co-design approach is adopted, i.e. the controller, encoder and decoder are designed for taking full advantage of the network resource collaboratively, thereby achieving better transmission of control signals. A stabilisability condition in the mean square sense that reveals the fundamental limitation among the H 2 norm of the plant, data arrival rates and coding matrices is first derived. Then, a solvability condition is conducted to handle the additional stochastic LQ control objective by a modified discrete-time algebraic Riccati equation, and an iterative algorithm is also given for designing the corresponding state feedback gain and coding matrices. Relied on such design, the asymptotic tracking constraint is further fulfilled through solving a Sylvester equation, and the feedforward gain related to tracking is parameterised. Finally, a simulation with the implementation of the design method on two cooperative robots is included to show the effectiveness of the current results.

Serial communication protocol for FPGA-based systems

The article presents results of development of communication protocol for UART-like FPGA-systems. Developed communication protocol supports asynchronous oversampled signal transmission, with 4b/6b encoding for DC-balance maintaining. Algorithm of CPLD-based receiver of signals forming by this protocol is described. This development is relevant for the task of continuous transmission of several control signals over a fiber-optic line, when the use of ready-made UART devices is unjustified. The presented protocol and algorithm are easily implemented on the FPGA and can be used in devices where it is important to minimize the number of elements used. Also, the protocol contains encoding that allows the transmission of low-frequency signals along a line with DC-coupling.

Prescribed performance control of strict‐feedback systems under actuation saturation and output constraint via event‐triggered approach

SummaryIn this work, we study the performance‐guaranteed event‐triggered control for a class of uncertain nonlinear systems in strict‐feedback form subject to input saturation and output constraint. The prescribed performance (ie, convergence rate, tracking error accuracy) and output constraint are firstly taken into account for nonlinear systems with event‐triggered input. By blending a speed transformation into the barrier Lyapunov function and introducing an intermediate variable to the system, two different event‐triggered control schemes are proposed for systems with and without saturation, respectively. Each scheme has two rules to determine triggering time sequences, one for control signal updating and the other for control signal transmission with the latter being a subsequence of the first. Meanwhile, it is proved that the tracking error converges to a preset compact set around zero at the prescribed decay rate and the output is maintained within a given bound at all times. Simulation verification also confirms the effectiveness of the proposed approach.

A Unified Event-Triggered Control Approach for Uncertain Pure-Feedback Systems With or Without State Constraints.

Existing schemes for systems with state constraints require the bounds of the constraints for controller design and may result in conservativeness or even become invalid when they are applied to systems without such constraints. In this paper, we study the problem of event-triggered control for a class of uncertain nonlinear systems by considering the cases with or without state constraints in a unified manner. By introducing a new universal-constrained function and using certain transformation techniques, the original-constrained system is converted into an equivalent totally unconstrained one. Then, an event-triggered adaptive neural-network (NN) controller is designed to stabilize the unconstrained system and compensate for the control sampling errors caused by event-triggered transmission of control signals. Unlike some existing control schemes developed for systems with state constraints, which need to check whether each virtual control meets certain feasibility conditions at every design step, our proposed unified method enables such feasibility conditions to be relaxed. In addition, a suitable event-triggering rule is designed to determine when to transmit control signals. It is theoretically shown that the designed controller can achieve the desired tracking ability and reduce the communication burden from the controller to the actuator at the same time. Simulation verification also confirms the effectiveness of the proposed approach.

Numerical evaluation of sine-Gordon chain energy control via subdomains state feedback under quantizationand time sampling

The paper is devoted to the numerical performance evaluation of the speed-gradient algorithms, recently developed in (Orlov et al., 2018; Orlov et al., 2019) for controlling the energy of the sine-Gordon spatially distributed systems with several in-domain actuators. The influence of the level quantization of the state feedback control signal (possibly coupled to the time sampling) on the steady-state energy error and the closed loop system stability is investigated in the simulation study. The following types of quantization are taken into account: sampling-in-time control signal quantization, the level quantization for control, continuous in time; control signal quantization on level jointly with time sampling; control signal transmission over the binary communication channel with time-invariant first order coder; control signal transmission over the binary communication channel with first order coder and time-based zooming; control signal transmission over the binary communication channel with adaptive first order coder. A resulting impact on the closed-loop performance in question is concluded for each type of the quantization involved.

IPT system for tail‐free household appliances in the smart home system

Inductive power transfer (IPT) is a new power supply technology for household appliances to eliminate the effects of sparks and wires. Besides, the smart home is a popular intelligent system to connect the facilities in the home. To combine the advantages of IPT technology and smart home system perfectly, the transmission of the control signal is as important as the transmission of power for IPT system. This work proposes a method that makes the power and control signal transmission synchronously from the supply side to receiving end to achieve the wireless power supply and the intelligent control for household appliances such as televisions, air conditioners, air purifiers etc. In the proposed method, the fundamental and harmonic components of the inverter output voltage are used as the power carrier and the signal carrier, respectively. One is to supply power to household appliances and the other is to transmit a control signal to them. On the basis of this method, the features of harmonics such as low energy and high frequency are well used, which enable both stable power transmission and high-speed signal transmission. The effectiveness of the proposed method is verified by an experimental platform of kW level.

Remote Control of Space Robots Change-Adaptive in its External Environment

In the paper a method of remote bilateral control of space robots operating in a non-deterministic environment with a large delay in control signals transmission is presented. The method provides adaptation of space robot behavior to possible changes in its external environment. Compared to the known approaches this method reduces influence of external environment variation on the control process.

Fatigue Analysis and Optimization of a Conductive Slip Ring with Finite Angle of Rotation

In this paper, according to the working environment characteristics and technical requirements of the conductive slip ring of a two-dimensional space tracking and aiming system, the power and control signal transmission between two relative rotating mechanisms is realized by using flexible circuit board, and a precise conductive slip ring with limited rotation angle is designed and optimized. The fatigue life performance of the conductive slip ring is verified and analyzed by testing and testing.