Search

This letter presents an improved circuit topology to minimize the number of external control voltages that are required to set the state of an N-bit microwave digital attenuator. An alternative method to connect the control signal is proposed. Typically, the control signal is connected to the gate terminal of the field effect transistor while the source terminal is DC grounded. Here, the control signal is applied to the source terminal of the field effect transistor while the gate is connected to a fixed reference voltage. In this way, only one control voltage is necessary to set the state of single attenuator cell vs two control voltages required in the typical case. The proposed method becomes particularly beneficial as the number of bits increases (ie, >4). The topology has been validated through design, realization, and testing of a 5-bit Monolithic Microwave Integrated Circuit (MMIC) attenuator operating over the full C-band (4-8 GHz).

High-repetition-rate nanosecond pulses are used widely in many fields, and pulses of different polarities have different effects. A new pulse-generator structure is proposed based on an improved Blumlein pulse-forming line (BPFL) and a transmission-line transformer (TLT). The proposed structure generates pulses with polarity that can be adjusted among positive, negative, and bipolar. A modular design is used for the generator. In each module, three groups of solid-state switches are used to control the BPFL. By adjusting the timing of the control signal, the BPFL can generate high-repetition-rate nanosecond primary pulses with adjustable polarity. These primary pulses are then transmitted to the load through the TLT with amplification and superposition. The pulse-forming process is analyzed theoretically for matched impedance. The strategy for controlling the switches is also illustrated. In addition, the feasibility of the proposed generator is verified by simulations and experiments. Finally, a four-stage prototype is developed that can produce pulses with amplitudes of 0–10 kV, a width of 30 ns, repetition rates up to 200 kHz and adjustable polarity.

Delayed feedback control method is used for one dimensional lattice model by incorporating the effect of passing. In order to check the stability of system under control theory Hurwitz criteria is used and H ∞ norm of transfer functions are obtained. The efficiency of control signal in minimizing the jamming transitions due to passing, is shown through Bode plot. The results show that the control parameter helps in reducing congestion and makes the flow stable even at higher rate of passing. Simulations are carried out and are found in good agreement with theoretical results.

An angular aperture of an acousto-optical filter upon a linear frequency-modulated (chirp) control signal has been experimentally studied for the first time. The results of studying the spectral and angular dependences of the spectral transmission function of a filter upon a frequency modulation have shown the possibility of an efficient increase of the output optical signal. The value of the optical signal was increased by 2000 times using the selected design of the acousto-optical filter. This makes it possible to obtain a gain in the measurement time or in the value of the detected optical signal. Such an increase of the output signal upon a chirp control signal is provided by the increase of the angular aperture and broadening of the spectral transmission bandwidth together with the required proportional increase of the control signal power.

This work augments an existing LPV feedback controller by a new LPV feedforward filter to improve the stability of a vehicle subject to driver-induced roll disturbances. In particular, the proposed LPV feedforward filter is designed by a Full-Information control approach and uses the saturation indicator concept to consider the restrictive state-dependent force constraints of semi-active dampers. Hence, in the event of saturation, the feedforward filter reduces its contribution to the control signal. The roll stability improvement due to the LPV feedforward filter is demonstrated by lane change experiments.

This paper proposes new adaptive controllers for uncertain nonlinear systems in the presence of input quantization. The control signal is quantized by a class of sector-bounded quantizers including the uniform quantizer, the logarithmic quantizer and the hysteresis quantizer. To clearly illustrate our approaches, we will start with a class of single-loop nonlinear systems and then extend the results to multi-loop interconnected nonlinear systems. By using backstepping technique, a new adaptive control algorithm is developed by constructing a new compensation method for the effects of the input quantization. A hyperbolic tangent function is introduced in the controller with a new transformation of the control signal. When considering multi-loop interconnected systems with interactions, a totally decentralized adaptive control scheme is developed with a new compensation method incorporated for the unknown nonlinear interactions and quantization error. Each local controller, designed simply based on the model of each subsystem by using the adaptive backstepping technique, only employs local information to generate control signals. Unlike some existing control schemes for systems with input quantization, the developed controllers do not require the global Lipschitz condition for the nonlinear functions and also the quantization parameters can be unknown. Besides showing global stability, tracking error performance is also established and can be adjusted by tuning certain design parameters. Simulation results illustrate the effectiveness of our proposed schemes.

This paper proposes an adaptive global terminal sliding mode control scheme for tracking control of uncertain nonlinear systems. Using the proposed global sliding surface, the reaching period is omitted and the robust performance of the whole system is improved. The discontinuous sign function is involved in the controller derivative and then, the control signal achieved after integration is continuous and attenuates the chattering problem. Two adaptation laws are employed to cope with the uncertainties and disturbances whose upper bounds are not required to be known, where the proposed technique is more flexible in the real implementations. This method guarantees robustness against uncertainties, disturbances and nonlinearities of the system. Moreover, the proposed scheme removes the chattering phenomenon using the adaptive-tuning parameters and hyperbolic tangent function in the reaching control law. Numerical simulations display the success and applicability of the proposed scheme in comparison with the results of the other method.

Robust backstepping control of non-linear systems with derivation orders (commensurate or non-commensurate) lying at interval (0, 2) is proposed in this study. The stability and robustness properties are proved using a linearisation procedure in contrast to the classic recursive Lyapunov approach to backstepping. Vector, adaptive and robustness extensions are then developed to solve general tracking and stabilisation control problems. The adaptive extension is proved with a non-Lyapunov approach based on inequalities on non-negative fractional integrals. The mixed-order nature enables to control integer order systems using fractional operators. Through simulations, it is shown that the performance of the controllers depends on their derivation orders. In particular, for transient behaviour and the root mean square value of the control signal, the fractional controllers proposed exhibit improved responses as compared with the integer ones.

The healthcare system needs to track and monitor patients’ status and information. One of the most important requirements is that the patient is able to access the service anywhere at any time. Systems are being developed using the Internet to monitor patients’ status, and in some areas, especially rural areas and motorways, the Internet may not be available, even though the mobile network is available. In some cases, the network might be overloaded, so the patient information cannot be delivered to the hospital or medical centre. We propose a new method that uses the spare extension of the random access channel (RACH), which is carried by physical random access channel (PRACH) to send the patient information to the medical centre. We present the mathematical model of the channel and compare the results with another system from 3GPP to evaluate the results. The results show that the proposed method needs less time to transmit the patient’s information.

In Thailand, red light running is considered as one of the most dangerous behaviors at intersection. Red light running (RLR) behavior is the failure to obey the traffic control signal. However, motorcycle riders and car drivers who are running through red lights could be influenced by human factors or road environment at intersection. RLR could be advertent or inadvertent behavior influenced by many factors. Little research study has been done to evaluate the contributing factors influencing the red-light violation behavior. This study aims to determine the factors influencing the red light running behavior including human characteristics, physical condition of intersection, traffic signal operation, and traffic condition. A total of 92 intersections were observed in Chiang Mai, Nakhon Ratchasima, and Chonburi, the major provinces in each region of Thailand. In addition, the socio-economic characteristics of red light runners were obtained from self-reported questionnaire survey. The Binary Logistic Regression and the Multiple Linear Regression models were used to determine the characteristics of red light runners and the factors influencing rates of red light running respectively. The results from this study can help to understand the characteristics of red light runners and factors affecting them to run red lights. For motorcycle riders and car drivers, age, gender, occupation, driving license, helmet/seatbelt use, and the probability to be penalized when running the red light significantly affect RLR behavior. In addition, the results indicated that vehicle travelling direction, time of day, existence of turning lane, number of lanes, lane width, intersection sight distance, type of traffic signal pole, type of traffic signal operation, length of yellow time interval, approaching speed, distance from intersection warning sign to stop line, and pavement roughness significantly affect RLR rates.

Semi-passive vibration control with the Synchronized Switching Damping on Inductor (SSDI) technique has attracted significant attention in recent years. However, the damping performance of the SSDI technique will be decreased by the lag in detection of switching time. In order to detect switching time without lag, the paper proposes a self-powered semi-passive vibration damping system based on self-sensing approach. In the proposed technique, the switching control signal is obtained by properly processing the voltage of one piezoelectric element which is also used for vibration damping at the same time. Compared with other self-powered SSDI techniques, the proposed approach can detect switching time without lag, while keeping simplicity of implementation with a small number of piezoelectric elements. The proposed technique is also experimentally implemented by a self-powered circuit in the paper. The theoretical analysis, the experimental validation and the drawback of the proposed technique are discussed in the paper.

Background: The computer apparatus for electro-acupuncture diagnostics and medicated testing "IMEDIS-EXPERT" made in Russia was used for the purposes of this work to detect SARS-CoV-2 (COVID-19) or to prove its absence, and to select homoeopathic preparations, nosodes, and their relevant doses. The methods of the system-nosological approach (SNA) were used for the therapy of patients, which included recording and appliance of relevant control signals (C.S.) of homoeopathic preparations, both native and informational (electronic) copies. Aims: 1. Develop an algorithm to select preparations from the group of nosodes and homoeopathy to prevent the development of SARS-CoV-2 (COVID-19); 2. Evaluate the possibility of preventing treatment and therapy of coronavirus infection employing an "electronic vaccine" produced employing coronavirus C.S. Methodology: The electronic preventing "immunization" was made for patients as the preventing treatment of COVID-19, which was an adaptation to coronavirus C.S. conducted in accordance with a special algorithm. The three-block scheme of SNA therapy was used for the therapy of ill patients, which was composed of three preparations, which were used sequentially: 1. Control signal of coronavirus targeted on a patient's CMH; 2. Cerebral response (C.R.) with a patient's cumulative impact of: C.S. of coronavirus and the sum of target organs (blood-forming system, lymphatic systems, lungs, bronchus, gastrointestinal system) and test-indicators of immune regulation targeted on the second CMH marker amplification; 3. Drainages in the form of homeopathic preparations were used (after the impact of two previous preparations), which were: Arsenicum, Arsenicum iod, Carbo vegetabilis, Spongia, Drosera, Naya, Rhus Toxicodendron, and Ferrum met. The preparations were selected to compensate the third impact of CMH. Results: At present, 175 people have asked for help due to COVID-19, an electronic preventing vaccine ("immunization") made for 112 people on the SNA algorithm. According to the diagnostic testing results made for 63 ill patients and who asked for treatment: 47 people tested coronavirus infection, 16 people tested ARVI, and 12 people tested pneumonia caused by a virus. The coincidence of VRT tests (vegetative resonance tests) and PCR was found ranged from 68 to 75%. 4 people got ill by coronavirus among those who got preventing immunization (112 people) by "the electronic sensibilization method" (that was proved by VRT and PCR tests). The illness had the light form among 2 of them, and two people had moderate severity of illness without hospital admission. Conclusion: An algorithm is developed, which allows to select C.S. of therapeutic nosodes and homoeopathic preparations to prevent the development of SARS-CoV-2. The efficiency of applying the electronic immunization method according to the algorithms of SNA using coronavirus C.S. is 95%.

Electrowetting technique is an actuation method for manipulating position and velocity of fluids in the microchannels. By combining electrowetting technique and a freestanding mode triboelectric nanogenerator (TENG), we have designed a self-powered microfluidic transport system. In this system, a mini vehicle is fabricated by using four droplets to carry a pallet (6 mm × 8 mm), and it can transport some tiny object on the track electrodes under the drive of TENG. The motion of TENG can provide both driving power and control signal for the mini vehicle. The maximum load for this mini vehicle is 500 mg, and its highest controllable velocity can reach 1 m/s. Freestanding TENG has shown excellent capability to manipulate microfluid. Under the drive of TENG, the minimum volume of the droplet can reach 70-80 nL, while the tiny droplet can freely move on both horizontal and vertical planes. Finally, another strategy for delivering nanoparticles to the designated position has also been demonstrated. This proposed self-powered transport technique may have great applications in the field of microsolid/liquid manipulators, drug delivery systems, microrobotics, and human-machine interactions.

A comparative study of two adaptive current-mode controllers for a high-order hybrid-type dc-dc boost converter is presented. The implementation of the traditional current-mode controller for this converter requires the knowledge of the nominal value of the load resistance to compute the control signal. As such, it is unable to handle systems with uncertain loads well. To address this, an adaptive law is used to estimate the load conductance in order to generate the reference current input. In this adaptive law, the derivative of the estimator is optimised as well as bounded. Moreover, the converter has two inductor currents which can be used for feedback purposes. Considering this, two adaptive current-mode controllers using the input and output inductor currents of the converter are separately designed to find the most appropriate inductor current for the implementation of the proposed controller. Finally, some simulation and experimental results comparing the performance of the adaptive controller using the output inductor current with that of the traditional current-mode controller are also presented. Published version

Sliding mode control comprises of improving the control law for the best attainment of results by rejecting the perturbation and for achieving the system desired performance within a specified band of operation. The sliding mode control observes the dynamical behavior of plant which consequences the comparison of actual and reference signal which in turns into control signal and becomes actuating signal after it gets process from actuator to achieve the optimal performance irrespective of system parameter changes. Control of uncertain systems is vital due to extensive range of their applications because these systems are multi-input multi-output consisting of high nonlinearities. Subsequently, it is problematic to design accurate mathematical models for uncertain systems. So strong mathematical trappings is used in advanced control strategies to design an intelligent controller which can meet the expectations of dealing plant to have a adequate enactment. Most outstanding nonlinear robust control practices for controlling uncertain systems is none other than is sliding mode control. The paper contracts through the claim of diverse sliding mode schemes for the uncertain systems and offers a elaborated comparison among the various methodologies on the basis of their approach to deal with the control issues. A comparative analysis is depicted to illustrate the usefulness of sliding mode control techniques in the various fields. A categorized list of numerous publications on this topic is arranged for rapid reference.

Electroencephalogram signals and the states of subjects are nonstationary. To track changing states effectively, an adaptive calibration framework is proposed for the brain-computer interface (BCI) with the motion-onset visual evoked potential (mVEP) as the control signal. The core of this framework is to update the training set adaptively for classifier training. The updating procedure consists of two operations, that is, adding new samples to the training set and removing old samples from the training set. In the proposed framework, a support vector machine (SVM) and fuzzy C-mean clustering (fCM) are combined to select the reliable samples for the training set from the blocks close to the current blocks to be classified. Because of the complementary information provided by SVM and fCM, they can guarantee the reliability of information fed into classifier training. The removing procedure will aim to remove those old samples recorded a relatively long time before current new blocks. These two operations could yield a new training set, which could be used to calibrate the classifier to track the changing state of the subjects. Experimental results demonstrate that the adaptive calibration framework is effective and efficient and it could improve the performance of online BCI systems.

This paper addresses the problem of aperiodic sampled-data control of linear parameter varying (LPV) systems under input saturation. It is explicitly assumed that plant scheduling parameter can continuously vary between two sampling instants, while the control signal is computed using the measurement of this parameter only at the sampling instants. Assuming an affine parameter dependence, conditions based on the use of a parameter dependent (PD) looped-functional and a PD generalized sector approach, are proposed to compute a sampled-data LPV state feedback control law that ensures the regional asymptotic stability of the closed-loop system. LMI-based optimization procedures to maximize an estimate of the region of attraction of the origin or the allowable bound on the intersampling interval for a guaranteed region of stability are proposed.

In this paper, a third-order discontinuous integral controller is designed to jointly swing-up and robustly stabilize in finite-time the upright position of the Reaction Wheel Pendulum (RWP) system, despite some uncertainties and perturbations. To show this, a numerical estimation of the domain of attraction of the controller is used. The control algorithm produces a continuous control signal, thus reducing the usual chattering effect of the sliding-mode controllers. The theoretical results of the paper are verified by simulations and experiments in a laboratory setup.

The PI controller with an additional pole (PI + P) already has been proposed to decrease the noise effect on the control signal. In this paper, a fractional order pole is employed to increase the P...

This paper presents an output-feedback control strategy based on the variable gain super-twisting algorithm. The proposal achieves robust global/semi-global exact tracking results for plants with arbitrary relative degree. This is ensured in spite of parametric uncertainties and disturbances that may be state-dependent and time-varying. The construction of such controller is based on a (non)homogeneous higher order sliding-mode differentiator with dynamic gains. The gain adaptation schemes for the controller and differentiator are based on norm observers to overcome the lack of state measurement. The continuous nature of the obtained control signal alleviates the chattering phenomenon. The stability properties of the proposed controller are demonstrated by means of a Lyapunov function-based analysis. The theoretical results are verified through a simulation example, and experimentally tested on a seesaw module.

In this paper, we consider the control problem of linear systems with state time-delays when the control signal is affected by a possibly time-varying delay. The problem is solved by a chain of predictors under the assumption that a stabilizing control exists for the case of no input delay. This solution is then extended to the case of partial information when only delayed output is available. Both the input and the output delays may have arbitrary bounds. With respect to previous approaches to the same problem appeared recently in the literature the method proposed here has a simpler structure and in particular it does not need the computation of distributed terms. As a by-product we show that it is possible to derive an observer for a system with state and output delays from an observer for the same system without output delays.

Summary In this work, a new self-triggered model predictive control (STMPC) algorithm is proposed for continuous-time networked control systems. Compared with existing STMPC algorithms, the proposed STMPC is implemented based on linear interpolation (first-order hold) rather than the standard zero-order hold, which helps further reduce the difference between the self-triggered control signal and the original time-triggered counterpart and thus reduce the rate of triggering. Based on the first-order hold implementation, a self-triggering condition is derived and the corresponding theoretical properties of the closed-loop system are analyzed. Finally, the comparison between the proposed algorithm and the zero-order hold–based STMPC is carried out through both theoretical analysis and a simulation example to illustrate the effectiveness of the proposed method.

In this paper, a lattice hydrodynamic model is derived considering not only the effect of flow rate difference but also the delayed feedback control signal which including more comprehensive information. The control method is used to analyze the stability of the model. Furthermore, the critical condition for the linear steady traffic flow is deduced and the numerical simulation is carried out to investigate the advantage of the proposed model with and without the effect of flow rate difference and the control signal. The results are consistent with the theoretical analysis correspondingly.

Taking account of the effect of the driver's memory, an extended car-following model is proposed in this paper. A control signal including the velocity contrast of considered car and the following car is taken into account in this extended model. Numerical simulations are implemented to prove that the application of the model can suppress the traffic congestion successfully.

Precise movement of a rigid body with jerk as the control signal, and with friction compensation is considered. The optimal solution for the minimization of the electrical energy consumption is obtained. The optimal solution was tested numerically.

Iterative learning control (ILC) is a method for improving the performance of stable, repetitive systems. Standard ILC is constructed in the temporal domain, with performance improvements achieved through iterative updates to the control signal. Recent ILC research focuses on reformulating temporal ILC into the spatial domain, where 2D convolution accounts for spatial closeness. This work expands spatial ILC to include optimization of multiple performance metrics. Performance objectives are classified into primary, complementary, competing, and domain specific objectives. New robustness and convergence criteria are provided. Simulation results validate flexibility of the spatial framework on a high-fidelity additive manufacturing system model.

Taking account of the road consisting of curved part and straight part, an extended car-following model is proposed in this paper. A control signal including the velocity difference between the considered vehicle and the vehicle in front is taken into account. The control theory method is applied into analysis of the stability condition for the model. Numerical simulations are implemented to prove that the stability of the traffic flow strengthens effectively with an increase of the radius of curved road, and the control signal can suppress the traffic congestion. The results are in good agree with the theoretical analysis.

Embodiments of the present invention provide a tape transport control system with enhanced regulation of tape tension and velocity over the entire length of the tape. The tape transport control system comprises of circuitry adapted to output and circuitry adapted to receive one or more signals representing a tape velocity, at least one radius of either the first tape reel or the second tape reel, and a tape tension, and based on the received signals, generate at least one control signal to control at least one of the first reel motor or the second reel motor so as to reduce a tension disturbance at a minimum, one frequency corresponding to a time-varying reel-rotation frequency, based on controller parameters that depend on the tape velocity and on the at least one radius of either the first tape reel or the second tape reel.

A prediction-based approach is proposed for control systems with limited and time-varying computational resources. The limited and time-varying computational resources can make the control system run in an open-loop fashion which may severely degrade the system performance or even destabilize the system. This issue is dealt with by producing more than one forward control predictions when abundant computational resources are available, and then using these forward control predictions to close the system when the computational resources are insufficient to calculate real-time control signal. This achievement is made without additional requirement for the computational resources and can be regarded as a useful completion of the scheduling algorithms. With a controller designed using a modified model predictive control method, the effectiveness of the proposed approach is successfully illustrated by a numerical example.

In this paper we asked the question: if we artificially raise the variability of torque control signals to match that of EMG, do subjects make similar errors and have similar uncertainty about their movements? We answered this question using two experiments in which subjects used three different control signals: torque, torque+noise, and EMG. First, we measured error on a simple target-hitting task in which subjects received visual feedback only at the end of their movements. We found that even when the signal-to-noise ratio was equal across EMG and torque+noise control signals, EMG resulted in larger errors. Second, we quantified uncertainty by measuring the just-noticeable difference of a visual perturbation. We found that for equal errors, EMG resulted in higher movement uncertainty than both torque and torque+noise. The differences suggest that performance and confidence are influenced by more than just the noisiness of the control signal, and suggest that other factors, such as the user's ability to incorporate feedback and develop accurate internal models, also have significant impacts on the performance and confidence of a person's actions. We theorize that users have difficulty distinguishing between random and systematic errors for EMG control, and future work should examine in more detail the types of errors made with EMG control.

This paper studies the control of coexisting attractors in an impacting system via a recently developed control law based on linear augmentation. Special attention is given to two control issues in the framework of multistable engineering systems, namely, the switching between coexisting attractors without altering the system’s main parameters and the avoidance of grazing-induced chaotic responses. The effectiveness of the proposed control scheme is confirmed numerically for the case of a periodically excited, soft impact oscillator. Our analysis shows how path-following techniques for non-smooth systems can be used in order to determine the optimal control parameters in terms of energy expenditure due to the control signal and transient behavior of the control error, which can be applied to a broad range of engineering problems.

Background. Previous studies have demonstrated the presence of intact axons across a spinal cord lesion, even in those clinically diagnosed with complete spinal cord injury (SCI). These axons may allow volitional motor signals to be transmitted through the injury, even in the absence of visible muscle contraction. Objective. To demonstrate the presence of volitional electromyographic (EMG) activity below the lesion in motor complete SCI and to characterize this activity to determine its value for potential use as a neuroprosthetic command source. Methods. Twenty-four subjects with complete (AIS A or B), chronic, cervical SCI were tested for the presence of volitional below-injury EMG activity. Surface electrodes recorded from 8 to 12 locations of each lower limb, while participants were asked to attempt specific movements of the lower extremity in response to visual and audio cues. EMG trials were ranked through visual inspection, and were scored using an amplitude threshold algorithm to identify channels of interest with volitional motor unit activity. Results. Significant below-injury muscle activity was identified through visual inspection in 16 of 24 participants, and visual inspection rankings were well correlated to the algorithm scoring. Conclusions. The surface EMG protocol utilized here is relatively simple and noninvasive, ideal for a clinical screening tool. The majority of subjects tested were able to produce a volitional EMG signal below their injury level, and the algorithm developed allows automatic identification of signals of interest. The presence of this volitional activity in the lower extremity could provide an innovative new command signal source for implanted neuroprostheses or other assistive technology.

This paper proposes a simple anti-windup mechanism for a model reference adaptive control scheme subject to saturation constraints. The anti-windup compensator has, in essence, the same structure as positive μ modification for the same class of systems. It is shown how this structure can, under certain circumstances, display characteristics similar to anti-windup schemes proposed for linear control systems. In particular, it is shown that if the (unknown) ideal control signal eventually lies within the control constraints, then the response of the adaptive control system will converge to that of the reference system—provided certain conditions are satisfied. The paper illustrates the challenge of designing anti-windup compensators for model-reference adaptive control systems.

El control auto-disparado produce secuencias de muestreo no periódico que varían dependiendo de factores de diseño relacionados con la estabilidad y el rendimiento del sistema a ser controlado. Dentro de este marco, recientemente han sido desarrollados dos enfoques dirigidos a minimizar un costo cuadrático, considerando un rendimiento óptimo y persiguiendo el mismo objetivo de control; cada una de ellos sigue una regla de muestreo diferente. Un enfoque se basa en mantener el valor de control actual tanto tiempo como sea posible, mientras que un umbral de rendimiento óptimo no se traspase. El otro enfoque se basa en la generación de una señal de control a trozos que se aproxima a una señal de control óptima continua, sujeta a determinadas limitaciones. Este artículo presenta un estudio comparativo entre los dos enfoques, proporcionando una percepción útil para la realización de futuras investigaciones. Como métricas de interés, el rendimiento de control y la utilización de recursos fueron considerados, y para evaluarlos, se hizo uso del intervalo de muestreo promedio y del costo normalizado. Se demostró que el diferente espacio de búsqueda de cada enfoque plantea un desafío para diseñar un marco de comparación equitativo, y que ambos enfoques superan al muestreo periódico.

The initial iterative control signal is often adopted a zero or a certain value in the conventional iterative learning control (ILC) system, and an ILC process needs to renew again as long as the desired trajectory is changed. In this paper, the NURBS (Non-Uniform Rational B-Splines) model is used for describing all trajectory primitives and the desired trajectory. It is studied that the problem of the initial iterative control signal is extracted in ILC, which presents a method of extracting the initial iterative control signal based on the trajectory primitive optimal matching and combining algorithm. Firstly, the definition of the similarity index between the two different spacial trajectories is introduced. Secondly, an optimal matching and combining algorithm is designed under a certain similarity index, which is used to find two or more combined primitive sequences with space patterns similar to the desired trajectory. Thirdly, the initial iterative control signals of the desired trajectory are extracted by using the control information of the combined primitive sequences. Finally, the simulation is carried out to demonstrate the effectiveness of the present method.

This technical note studies the robust output tracking controller design for a class of uncertain discrete-time systems subject to actuator saturation. To achieve this capability, a new controller is proposed by robustifying the discrete-time composite nonlinear feedback (DCNF) control law. Since, the proposed controller may be saturated; a precise analysis is done to show its robust performance in spite of presence of actuator saturation and time-varying external disturbances. Additionally, a theorem is given and proved which guarantees the disturbance attenuation via the proposed control law for three different cases of the saturation function and it is shown that even if the control signal is saturated, the proposed controller achieves steady-state error of order $O(T)$ for state regulation. Finally, computer simulations are performed for a practical system and the applicability of the proposed controller is shown.

The new delayed-feedback control strategy is applied for lattice hydrodynamic model of traffic flow by considering the control signal of the variation rate of the optimal velocity. The linear stability condition is derived in the frequency-domain with control theory. Then, different feedback gains under the periodic boundary scenery and on-ramp scenery are simulated. The periodic boundary scenery provides an initial small disturbance situation on the circle road, while the on-ramp scenery reproduces the disturbance triggered by the on-ramp on the open road. Both the theoretical analysis and simulations show that this new control signal has a positive effect to suppress traffic jams.

A method for optimization of PID controller parameters and measurement filter time constant is presented. The method differs from the traditional approach in that the controller and filter parameters are simultaneously optimized, as opposed to standard, sequential, design. Control performance is maximized through minimization of the integrated absolute error (IAE) caused by a unit step load disturbance. Robustness is achieved through Hinf constraints on sensitivity and complementary sensitivity. At the same time, noise attenuation is enforced by limiting either the H2 or Hinf norm of the transfer function from measurement noise to control signal. The use of exact gradients makes the synthesis method faster and more numerically robust than previously proposed alternatives. (Less)

Тема выпускной квалификационной работы: «Разработка устройства формирования сложного радиолокационного сигнала Х-диапазона». Данная квалификационная работа посвящена проектированию устройства формирования частот излучения, входящего в состав приемозадающего блока. Сама разработка проводилась в несколько основных этапов: анализ технических требований к узлу, выбор конструкции устройства, разработка структуры для корректного функционирования устройства, подбор элементной базы. В результате было разработано устройство, осуществляющее преобразование частот входного сигнала к заданной частоте зондирующего сигнала. Проведены лабораторные измерения, иллюстрирующие характеристики выходного зондирующего и контрольного сигналов, удовлетворяющие техническим требованиям, предъявляемым к формирователю. Устройство предполагается эксплуатировать в составе бортовых радиолокационных станций, производимых предприятием АО «Заслон»., Theme of final qualification work: “Development of a device for the formation of a complex X-band radar signal”. This qualification work is devoted to the creation of device, which is part of the transmitter-receiving unit. The development has an applied character and relevance is due to the specifics of the development transmitter-receiving unit. The work was carried out in several main stages: analysis of the technical requirements for the unit, selection of the de-vice design, development of the structure for the correct functioning of the device, selection of the element base, PCB tracing and subsequent device tests. As a result, a device was developed that converts the frequencies of the input signal to a given frequency of the probing signal. Laboratory measurements have been made illustrating the characteristics of the output probing and control signals that satisfy the technical requirements for the shaper. The device is supposed to be used as part of airborne radar stations manufactured by the AO «Zaslon» company.

In this article, a method was proposed for strapdown inertial navigation systems initial alignment by drawing on the conventional alignment method for stable platform navigation systems. When a vessel is moored, the strapdown inertial navigation system contributes to the disturbing motion. Moreover, the conventional methods of accurate alignment fail to succeed within an acceptable period of time due to the slow convergence of the heading channel in the mooring conditions. In this work, the heading was adjusted using the velocity bias resulting from the component of the angular velocity of the Earth on the east channel on the strapdown inertial navigation systems analytic platform plane to accelerate convergence in the initial alignment of navigation system. To this end, an extended Kalman filter with control signal feedback was used. The heading error was calculated using the north channel residual velocity of the strapdown inertial navigation systems analytic platform plane and was entered into an extended Kalman filter. Simulation and turntable experimental tests were indicative of the ability of the proposed alignment method to increase heading converge speed in mooring conditions.