Search

In this paper, a theorem is obtained that gives sufficient input-to-state stability conditions for linear systems with control delay and additive disturbances. Stabilizing feedback is considered available in the absence of delay and disturbances. The mathematical tools are the Lyapunov–Krasovskii functional, the Jensen inequality and the double Hadamard inequality. The critical delay is highlighted. [ABSTRACT FROM AUTHOR]

The traffic control of signalized intersection has become even more important as the rate of motorization is rapidly growing nowadays. Many methods are known in the world for calculating fixed-time signaling plans. The effective operation of fixed-time signalized intersection is achieved through plans calculated on the basis of peak-hour data so that the plans respond to both free traffic conditions and congested ones. One of the most frequently used methods is the wellknown Webster's formula. The classic Webster formula has its own flaws regarding the overestimation of the cycle time in cases where the degree of saturation rate corresponds to congestion conditions. In this paper a new regression model is proposed applying linear programming optimization namely Simplex method. To emphasize the usability of optimized model over the Webster formula the comparisons of the deterministic queue length and Webster uniform delay is done. New model gives satisfactory numerical results toward the estimation of cycles lengths compared to classical Webster's formula. [ABSTRACT FROM AUTHOR]

The application of multisampling technology in voltage-source inverters (VSIs) systems can significantly reduce the control delay and break the bandwidth limitations of traditional synchronous sampling schemes. However, when sampling the capacitor voltage, the high-frequency ripple is introduced into the control loop, leading to the local vertical crossing (VC) phenomenon. Previous studies have demonstrated that a moving average filter (MAF) or improved repetitive filter (IRF) can effectively remove the high-frequency ripple. However, they introduce additional phase lag, which undermines the advantages of multisampling technology in terms of phase boost. The approach of spectrum analysis can be used to study the impact of voltage ripple. The results indicate that after modulation, the output signal contains low-frequency harmonics, and the superposition of the ripple makes the modulation process more susceptible to saturation. Therefore, a 20k ripple notch filter (RNF) is proposed to attenuate the ripple signal while introducing a more minor phase lag. Additionally, a 90° phase shift filter is proposed to suppress the aliasing signals generated in the system. Finally, the effectiveness of the proposed methods is verified through the experimental test of a 10kW single-phase VSI system.

In the current literature, it is clearly seen that most of the traffic chaos is generally observed at intersections of the urban roads in cities. On the other hand, many current traffic studies and research prove that fixed-time signalized intersections cannot have a good ability to control and manage current traffic flow at signalized intersection legs. For this aim, intelligent intersections were developed and started to be used in many cities all over the world in the last decade. These new intelligent intersection systems suggest dynamic signal times for all intersection legs by using real-time measured traffic data. These systems generally use cameras or loop detectors, which are located in the proper places on a signalized intersection leg and record vehicle movements. Within the scope of this study, a performance comparison was made for before and after the camera-based intelligent intersection applications at three isolated pilot signalized intersections within the scope of the "Smart City Traffic Safety" project, which is one of the largest Intelligent Transportation System projects in Turkey. After the system was activated, it was observed that the drivers had impatient behaviors in the beginning and had difficulty getting used to these new systems. After the signal cycle was regulated with the learning of artificial intelligence, it was seen that the drivers had more patience and more observant behaviors. It was also obtained from the analysis results that these new intelligent systems resulted in an average 16% decrease in control delays and a 20% decrease in vehicle speeds.

Aiming at the characteristics of high order and strong coupling of current source inverter (CSI) ultra high speed motor drive system, an improved decoupling control strategy based on stator current feedback active damping is proposed. Firstly, by constructing the equivalent model of CSI super high speed motor second‑order system considering control delay in Z domain, a hierarchical decoupling drive system consisting of complex vector decoupling current outer loop and feedforward decoupling voltage inner loop is designed. Secondly, the stability of the three closed loop control system in the full speed domain is analyzed based on the reconstructed model, and the correlation between the instability of the decoupling strategy and the resonance problem of the second order system under high‑speed conditions is discussed. Therefore, the stator current feedback active damping is introduced into the current loop regulator in this paper to solve the high order system resonance problem and realize the high performance and stable operation of the ultra high speed motor in the full speed domain. Finally, a CSI drive platform of 550 000 (r·min-1 )/110 W ultra high speed permanent magnet synchronous motor is built, and relevant simulations and experiments are carried out to verify the effectiveness and superiority of the proposed improvement strategy. [ABSTRACT FROM AUTHOR]

In the current literature, it is clearly seen that most of the traffic chaos is generally observed at intersections of the urban roads in cities. On the other hand, many current traffic studies and research prove that fixed-time signalized intersections cannot have a good ability to control and manage current traffic flow at signalized intersection legs. For this aim, intelligent intersections were developed and started to be used in many cities all over the world in the last decade. These new intelligent intersection systems suggest dynamic signal times for all intersection legs by using real-time measured traffic data. These systems generally use cameras or loop detectors, which are located in the proper places on a signalized intersection leg and record vehicle movements. Within the scope of this study, a performance comparison was made for before and after the camera-based intelligent intersection applications at three isolated pilot signalized intersections within the scope of the "Smart City Traffic Safety" project, which is one of the largest Intelligent Transportation System projects in Turkey. After the system was activated, it was observed that the drivers had impatient behaviors in the beginning and had difficulty getting used to these new systems. After the signal cycle was regulated with the learning of artificial intelligence, it was seen that the drivers had more patience and more observant behaviors. It was also obtained from the analysis results that these new intelligent systems resulted in an average 16% decrease in control delays and a 20% decrease in vehicle speeds. [ABSTRACT FROM AUTHOR]

Due to the long delay of their control chains， voltage source converters （VSCs） in the high frequency band tend to show negative damping， which may give rise to high-frequency resonance when VSCs are connected to power systems. Flexible low-frequency alternating current transmission （LFAC） system adopts the modular multilevel matrix converter （M3C） as the core equipment and its high-frequency resonance risk needs to be evaluated. Based on practical engineering， this paper establishes the high-frequency impedance model of M3C. It evaluates the high-frequency resonance risk of the LFAC system under multiple operating modes through impedance analysis method. The operating conditions with high resonance risk are obtained， and the generation mechanism of the resonance is analyzed. Furthermore， a high-frequency resonance suppression strategy of installing an extra low-pass filter in the voltage feedforward control of M3C is proposed for practical engineering. Finally， the accuracy of the analysis results and the effectiveness of the proposed high-frequency resonance suppression strategy are verified by electromagnetic transient simulation.

In this paper, the consensus tracking problem for the linear and nonlinear partial difference multi-agent systems with switching communication topology and control delay is investigated. Based on relative local measurements of neighboring followers, while considering spatio-temporal discretization and initial state deviation, a discrete distributed consensus protocol with initial value learning is designed for each agent via D-type iterative learning approach. Through rigorous mathematical theoretical analysis, the necessary and sufficient conditions are obtained. Under the switching of the communication topology, these conditions ensure that the consensus tracking control of the MASs can be solved. After applying the designed protocol, in the sense of the L 2 norm and along the positive direction of the iteration axis, the consensus tracking error between any two agents can converge to zero. Finally, some simulation examples are used to demonstrate the validity of the protocol and theoretical results. • A novel partial difference MASs dynamic model is established to describe the discrete spatio-temporal evolution behavior. • A new distributed iterative learning approach with initial value learning for partial difference MASs is given. • The proposed control approach can solve the problem of switching topology and control delay simultaneously. [ABSTRACT FROM AUTHOR]

In this paper, a theorem is obtained that gives sufficient input-to-state stability conditions for linear systems with control delay and additive disturbances. Stabilizing feedback is considered available in the absence of delay and disturbances. The mathematical tools are the Lyapunov–Krasovskii functional, the Jensen inequality and the double Hadamard inequality. The critical delay is highlighted.

The traffic capacity of a roundabout depends very much on the existing traffic volumes on each approach, each direction of travel having an impact on the other movements in the intersection, especially on those with which it conflicts.

For reducing the control delays introduced by the digital control of dc/ac converters, multisampling technology applying high sampling frequency of exact multiples of the switching frequency becomes attractive. In this way, higher control bandwidth and stability margin are achievable. However, multiupdate (>2) of the modulation signal within one switching cycle is not usually allowed on the digital signal processors. Besides, multiupdate within one switching cycle leads to an abnormal phenomenon referred to as vertical crossing when the modulation signal intersects the carrier signal vertically. The vertical crossing further causes the deadband effect of the pulsewidth-modulation signal and distortion of the output waveform. The abovementioned phenomenon greatly restricts the application of multisampling technology. In order to break the aforementioned barriers, a novel multicarrier-based multisampling method by dividing the triangular carrier signal into N equal sawtooth segments is proposed in this article. Moreover, the problem of vertical crossings and the resulting deadband effect in the multiupdate mode is solved. Simulation and experimental results on a single-phase dc–ac inverter are provided to validate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Under low-switching-frequency condition, there is harmonic coupling in grid-connected inverter. The harmonic state-space (HSS) modeling method is an effective means to analyze the output harmonic characteristics of inverter. When the switching frequency is low, the sampling/holding and control delay make the update of pulsewidth modulation pulses more untimely, which will have a non-negligible impact on system output. However, the current relevant research fails to take these factors into account in the HSS model. In addition, the existing work fails to thoroughly study the calculation and analysis methods of HSS model, and the relevant work is insufficient. Based on this, this article studies the closed-loop HSS model and its calculation and analysis methods of three-level grid-connected inverter considering the digitization impact. First, according to the different calculation and analysis methods of the HSS model of the grid-connected inverter, the methods considering the digitization impact are proposed, respectively. Second, according to the proposed method, the harmonic characteristics of low-switching-frequency grid-connected inverter are analyzed, and the necessity of considering the digitization impact is explained. Finally, the effectiveness and accuracy of the proposed HSS-model calculation and analysis methods considering the digitization impact are verified by simulation and experiment. [ABSTRACT FROM AUTHOR]

Copyright of Zhejiang Electric Power is the property of Zhejiang Electric Power Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Considering the slow response and unstable velocity of agricultural machinery caused by soil resistance, actuator delay, environmental change, velocity fluctuation, and other internal and external factors under real working conditions, a kind of agricultural machinery following a control system that considers variable load and control delay was proposed. Taking distance-keeping, velocity-following, and acceleration-following as parameters, the controller model was deduced, and the influence of different values of model parameters on the driving stability of agricultural machinery was analyzed in detail. In addition, this paper describes a kind of agricultural machinery following a strategy that can realize the graded adjustment of vehicle distance with the dynamic increase in vehicle weight. Then, the following strategy, under the influence of velocity and quality, was simulated and verified using MATLAB/Simulink (MATLAB2016a, mathworks: Natick, Massachusetts, USA). When the crop harvester was at 1.5 m/s and the amplitude of velocity fluctuation was 0.3 m and 1.3 m, respectively, the grain truck could adjust its velocity to keep up with the crop harvester to complete the operation task. Simulation verification was carried out for the proposed graded adjustment of vehicle distance of agricultural machinery following strategy. The unit mass of the crops was set at 360 kg, and the vehicle distance changed at 18s to adapt to the graded adjustment of the vehicle distance following strategy. Finally, a real-vehicle validation test was carried out, and the results show that the grain truck velocity can keep up with the change of crop harvester velocity on the basis of maintaining the desired vehicle distance, the grain truck velocity can keep up with the change of crop harvester velocity on the road condition, which verifies the effectiveness and feasibility of the proposed method. [ABSTRACT FROM AUTHOR]

Control delay is the key performance indicator of a signalized intersection that defines the level of service. Several models have been developed in previous research work for estimating control delays, but many of them were based on homogeneous traffic conditions. In the present study, an Open Street Map (OSM) tracker mobile application was used to measure control delays from the field. A non-linear model was developed in the present study for estimating control delays in mixed traffic conditions using a MATLAB fitting tool. The field delay is compared with the developed non-linear model delay along with the Indian Highway Capacity manual (INDO HCM) and Highway Capacity Manual (HCM) models. The control delay estimated using the model developed in the present study shows a close relation with the field delay obtained using an OSM tracker when compared to that obtained using the INDO HCM and HCM models. Therefore, the OSM tracker mobile application can be used as a field control delay measuring technique.

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

For current-controlled grid-connected inverters with LCL filter, the essence of grid voltage full feedback is to improve the output impedance of grid-connected inverters to infinity, which can eliminate the influences of grid voltage distortion and the non-negligible grid impedance. However, existing full feedforward strategies are complex and control delay cannot be compensated precisely, which leads to the instability of system when the full feedforward of the voltage at the point of common coupling under the weak grid is adopted. This article first proposes a simplified full feedforward strategy based on grid-side inductor volt-age differential feedback active damping (GIVD-AD). Second, repetitive prediction (RP) is used to compensate for the control delay. Then, a virtual impedance branch is added and an adaptive algorithm for modifying virtual impedance based on the difference between predicted grid voltages by Newton interpolation prediction (NIP) and RP is proposed. With the proposed method, grid-connected inverters can work stably when grid impedance changes suddenly and exhibit strong rejection ability against grid-voltage harmonics. Finally, simulative and experimental results from a 3-kW single-phase grid-connected inverter are provided to prove the effectiveness of the proposed strategy. [ABSTRACT FROM AUTHOR]

Signal coordination plays an important role in urban traffic control systems. Studying the influence of some factors such as the link length on the potential benefits of signal coordination can result in more efficient traffic control. Researchers have observed a highly fluctuating or damped sine-wave type relationship between the link length and the delay in two-way coordinated control, but a clear explanation of this relationship is still lacking. This paper presents a thorough analysis of the mechanism by which link length affects the delay in two-way coordination. The impact of the link length involves two aspects. We first derived formulas for the delay using shockwave queuing profiles that included the impact of the offsets in the two directions. We then conducted numerical experiments employing Robertson’s platoon dispersion model to incorporate the impact of platoon dispersion. By comparing the results from the derived formulas and the numerical experiments, we concluded that the periodicity is due to the mutual relation between the offsets in the two directions, whereas the attenuation is due to platoon dispersion. The findings should provide valuable insights for developing a more reasonable correlation degree model for the coordination of adjacent intersections. In addition, we found that platoon dispersion has a negligible influence on the critical link lengths at which the delay cannot be reduced by signal coordination. This means that whether or not platoon dispersion is considered, it will not affect the choice between the simultaneous and the alternative progressions to minimize the delay under a given link length, which is very meaningful in practical work.

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract In this research work, we investigate the controllability of linear fractional differential control systems with state and control delay. By using an explicit solution formula, a rank criterion for controllability is established. For the controllability criteria, we establish necessary and sufficient conditions of a fractional differential systems with state and control delay. In the end, a numerical example is constructed to support the results.

Considering the slow response and unstable velocity of agricultural machinery caused by soil resistance, actuator delay, environmental change, velocity fluctuation, and other internal and external factors under real working conditions, a kind of agricultural machinery following a control system that considers variable load and control delay was proposed. Taking distance-keeping, velocity-following, and acceleration-following as parameters, the controller model was deduced, and the influence of different values of model parameters on the driving stability of agricultural machinery was analyzed in detail. In addition, this paper describes a kind of agricultural machinery following a strategy that can realize the graded adjustment of vehicle distance with the dynamic increase in vehicle weight. Then, the following strategy, under the influence of velocity and quality, was simulated and verified using MATLAB/Simulink (MATLAB2016a, mathworks: Natick, Massachusetts, USA). When the crop harvester was at 1.5 m/s and the amplitude of velocity fluctuation was 0.3 m and 1.3 m, respectively, the grain truck could adjust its velocity to keep up with the crop harvester to complete the operation task. Simulation verification was carried out for the proposed graded adjustment of vehicle distance of agricultural machinery following strategy. The unit mass of the crops was set at 360 kg, and the vehicle distance changed at 18s to adapt to the graded adjustment of the vehicle distance following strategy. Finally, a real-vehicle validation test was carried out, and the results show that the grain truck velocity can keep up with the change of crop harvester velocity on the basis of maintaining the desired vehicle distance, the grain truck velocity can keep up with the change of crop harvester velocity on the road condition, which verifies the effectiveness and feasibility of the proposed method.

Copyright of Electric Machines & Control / Dianji Yu Kongzhi Xuebao is the property of Electric Machines & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In view of problems of strong interaction effect between STATCOM and power grid under weak power, the power voltage feed-forward control strategy is not effective in resisting power grid voltage distortion due to the delay, a current tracking control strategy for mine chain STATCOM considering control delay was proposed. The control strategy is based on the traditional proportional resonance control strategy, and compensation link is added in power grid voltage feed-forward link. The compensation link is equal to reciprocal of product of sample delay and control delay transfer function. The approximation expression of compensation link available to meet the requirements is derived through McLaughlin expansion. The compensation strategy added compensation link can eliminate control delay and avoid influence of grid voltage distortion, so that the STATCOM can still work normally when power grid voltage harmonics are large. The simulation results show that the control strategy has strong ability to resist power grid voltage disturbance and good control effect of current tracking.

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the LCL-filtered grid-tied inverter, the classical low-cost control strategy which is composed of the single converter-side current control and the unit grid voltage feedforward compensation, is commonly employed to inject the sinusoidal current into the utility. However, the inverter output admittance features the non-passive behaviour, which indicates that the harmonic currents may be amplified under the disturbances of the grid voltage and the grid impedance. Therefore, two dedicated current loops based on only the converter-side current feedback are proposed, which consist of the low-pass filter-based current regulation and the high-pass filter-based active damping (HFAD). The mixed asymmetrical regular sampling method is further used to reduce the control delay of the HFAD. Moreover, the low-pass filter-based feedforward is developed to make a compromise between the disturbance rejection and the stability. Fair comparisons with other typical control strategies are made through analysing the virtual resistor in parallel with the filter capacitor, which reveals that the positive virtual resistance at the frequency lower than half of the switching frequency is maintained. With the elaborated control parameters, the exhaustive experimental results finally verify the effectiveness of the proposed method in passivating the inverter output admittance. [ABSTRACT FROM AUTHOR]

In this paper we present two adaptive state control algorithms for the class of linear multi-input multi-output plants under external disturbances and the presence of control delay. Reference signal and external disturbance are considered as multi-harmonic signals with unknown frequencies, amplitudes, and initial phases. The algorithms are developed using the direct adaptive control method based on the internal model principle and do not require identification of disturbance parameters and/or the reference signal. [ABSTRACT FROM AUTHOR]

To suppress airfoil flutter, a lot of control methods have been proposed, such as classical control methods and optimal control methods. However, these methods did not consider the influence of actuator faults and control delay. This paper proposes a new finite-time H ∞ adaptive fault-tolerant flutter controller by radial basis function neural network technology and adaptive fault-tolerant control method, taking into account actuator faults, control delay, modeling uncertainties, and external disturbances. The theoretic section of this paper is about airfoil flutter dynamic modeling and adaptive fault-tolerant controller design. Lyapunov function and linear matrix inequality are employed to prove the stability of the proposed control method of this paper. The numeral simulation section further proves the effectiveness and robustness of the proposed control algorithm of this paper. [ABSTRACT FROM AUTHOR]

In this research work, we investigate the controllability of linear fractional differential control systems with state and control delay. By using an explicit solution formula, a rank criterion for controllability is established. For the controllability criteria, we establish necessary and sufficient conditions of a fractional differential systems with state and control delay. In the end, a numerical example is constructed to support the results. [ABSTRACT FROM AUTHOR]

There are several possible bus stop locations and configurations. A bus stop can be located before or after the intersection as curb-side stop, bus bay or bus bulb. Determining the proper configuration and location of bus stop represents an important planning decision. While previous research efforts in literature have suggested some advantages and disadvantages regarding bus stop locations and configurations, little effort has been made towards understanding the joint impact of bus stop location and configuration on the transit and other vehicle traffic performance on the intersection. So, this paper analyses the joint impact of bus stop location and configuration on the operational characteristics of traffic flow in terms of average bus trip time and control delay. These operational performance measures for various intersection layouts, volume distributions, movement splits, average bus dwell times and bus departure frequencies have been obtained using calibrated microsimulation traffic software.

In this paper, we propose a solution to the problem of designing a combined output control system for a nonlinear nonaffine plant with a delay in the control loop under a priori parametric uncertainty and external interference. Simulation results confirm the performance of the control system, and the resulting controller provides tracking of the plant to the reference signal. [ABSTRACT FROM AUTHOR]

Traffic streams in most of the urban areas of developing countries are highly heterogeneous with poor lane discipline. Traffic simulation and optimization packages based on microscopic traffic flow models are popular for modeling traffic flow and optimizing traffic controls all around the globe. However, applying microsimulation packages to model undisciplined and heterogeneous traffic streams may not yield perfect results. But, macroscopic models can be easily calibrated for such heterogeneous and undisciplined traffic streams. This research applies the calibrated Cell Transmission Model (CTM)-based optimization tool to determine optimal signal plans and to evaluate the potential of reduction in control delay at signalized intersections. Most of the traffic signals in Karachi are pre-timed with a constant signal plan throughout the day, despite significant changes in traffic dynamics within a day. This study evaluates the performance of existing signal timing plans at two different locations in Karachi. The selected locations include a segment of urban arterial with three consecutive signals in close proximity. The second location was a standalone signalized intersection. Twelve-hour traffic and delay data on typical working days were collected through video recording technique. The data collected from the field were simulated using CTM-based signal optimization software, DISCO. The optimization results show an improvement of 45% in the existing delay at the selected segment of Khayaban-e-Ittehad. The delay at KDA intersection can be reduced by 29% by optimizing signal plans. The study shows that optimum signal timings based on accurate data can reduce delays and improve traffic network performance. [ABSTRACT FROM AUTHOR]

Highlights • The system stability with grid current feedback active damping is analyzed. • The stability criterions of control parameters are established. • A systematic controller design method is proposed. Abstract An LCL filter is commonly used in grid-connected inverter to attenuate the switching harmonics; nevertheless, the stability problems will arise in the grid current control if the resonance of LCL filter is not properly damped. High pass filter-based grid current feedback active damping is an effective solution to solve the aforesaid problem. However, for systems with digital control, the system may exhibit non-minimum phase system characteristics due to the control delay effect, which will affect the system stability. Moreover, the frequency responses of current controller parameters and active damping parameters are coupled. Therefore, to ensure the system stability and good dynamic performance, the current controller parameters and active damping parameters should be designed together, considering the control delay effect. For this issue, a systematic controller design method is proposed for the digitally controlled LCL -type grid-connected inverter with grid-current-feedback active damping. With the proposed method, the satisfactory regions of the control parameters for satisfying the system specifications can be obtained, from which the proper control parameters can be easily and quickly picked out, without the trial and error. Finally, the proposed design method is verified by the experiment. [ABSTRACT FROM AUTHOR]

This paper presents a comfort-enhanced vibration control design approach for vehicle active suspensions with control delay. By introducing some novel relaxed inequalities, a less conservative bounded real lemma is derived such that the suspension system is asymptotically stable and has an enhanced vibration attenuation performance in the presence of road disturbance and control delay. In the control design, an augmented Lyapunov–Krasovskii functional is proposed to enlarge the degree of freedom of design. A suitable controller can be obtained via a sufficient condition with linear matrix inequality constraints. Compared with the previous methods based on frequently used inequalities and the traditional Lyapunov–Krasovskii functional, the proposed controller can provide better comfort performance for different control delays. Finally, the advantages of the proposed method are demonstrated using numerical examples. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, a disturbance attenuation controller is presented for networked vehicle active suspension with measurement noise and random control delay. By defining the appearing probabilities of control delay as the membership function, the Takagi–Sugeno (T–S) fuzzy model of networked vehicle active suspension is established with the consideration of the persistent irregular road disturbance, the random actuator delay, and the measurement noise. By designing a transformation vector, the disturbance attenuation control problem is reformulated as an equivalence two-point-boundary-value problem under the constrains of a delay-free system with respect to an equivalence performance index. After that, an optimal disturbance attenuation controller is proposed by solving a Riccati equation and a Stein equation, in which a Kalman filter is employed to estimate the road disturbance state with Gaussian white noise. Finally, by employing a simple vehicle active suspension, simulation results show that the designed controller can attenuate the vibration and compensate the control delay for the networked T–S fuzzy vehicle active suspension, in which the values of the sprung mass acceleration, the suspension deflection and the tyre deflection can be reduced effectively. [ABSTRACT FROM AUTHOR]

Teleoperation of unmanned aerial vehicles is hampered by communication delay, which causes feedback from command inputs to take considerable time to be displayed to the operator. For an international internet connection, round trip latencies can reach 500 ms. The satellite connections used for military unmanned aerial vehicles can have latencies in the order of seconds. This delay presents a substantial control problem, which has been solved in the past by control abstraction (instead of "roll left" the aircraft might be instructed "go to these coordinates"). Manual control remains difficult. This study borrows the client-side prediction concept from multiplayer video games to attempt to address the control delay to allow manual control. An estimate of the change in the vehicle state due to the commands that are yet to affect the feedback is computed and then the feedback that the pilot receives is modified to reflect this predicted change. Because of this change, the pilot can see immediately the effect of the control inputs. This study has explored the concept and built a prototype system functional in real time for flight testing with qualitative results presented. [ABSTRACT FROM AUTHOR]

This paper deals with the adaptive learning based recoil suppression control problem of deepwater drilling riser systems subject to parametric perturbations, platform heave motion, and friction resistance force of drilling fluid discharge. First, a stochastic configuration network based approximator is presented to predict the friction resistance force of drilling fluid discharge. Then, model reference adaptive learning recoil controllers are developed for the drilling riser system, and the existence condition and supporting algorithm are provided. Simulation results show that: (i) the designed stochastic configuration network approximator is efficient to predict the friction resistance of drilling fluid discharge on the riser; (ii) the presented model reference adaptive learning recoil controllers are effective to restrain the recoil response of the riser; (iii) compared with the existing recoil controllers, which are all based on the exact dynamic recoil control models, the model reference adaptive learning recoil controllers proposed in this paper are no longer constrained by the accuracy of recoil model; (iv) the model reference adaptive learning recoil controllers are more robust than the existing ones to the unmodeled dynamics, systematic uncertainty, and parametric perturbations, and have better transient performance of system thereby guaranteeing the safety of the drilling riser systems effectively. • A learning-based friction force predictor of drilling fluid discharge is designed. • Model reference adaptive learning recoil controllers are proposed for riser systems. • Adaptive recoil controllers are robust to unmodeled system dynamics and disturbances. [ABSTRACT FROM AUTHOR]

In analysis of priority junctions, control delays to minor street automobiles are often approximated utilizing the present mathematical models. Nevertheless, the applicability of such a technique depends on the basis and the source of the data with which the model was calibrated. This research was accomplished to establish control delays using Multi-Linear Regression (MLR) for left- and right-turning maneuver from minor road at priority junctions in suburban areas. The data were gathered at two priority junctions utilizing video recording method. In both movements, control delays to minor street automobiles increase as the volumeof main street traffic increases. The comparisons among observed control delays and the values estimated utilizing the Malaysia Highway Capacity Manual pointed out that; in general, the observed delays were not in a good agreement with the values computed by theoretical model especially within right turn from minor road. Additionally, the outcomes of this study revealed that the observed delays were in a well agreement with values predicted using the MLR’s models for left and right turns. Such a finding signifies that new model is directly applicable to the evaluation of control delays at priority junctions in Malaysia.