Integral Gain Research Articles

Stage Motion Control: Nonlinear Integrators Revisited

Abstract Linear integrators are well known for their ability to counter static forces and improve low-frequency disturbance rejection properties in control systems. However, linear integrators introduce phase lag, which is a frequency-dependent time shift or delay. Since the early introduction of the Clegg integrator, nonlinear integrators have held the promise of providing phase advantages over linear integrators when evaluated from the perspective of a describing function. This could potentially reduce delay and therefore provide the means to surpass linear design limitations; for example, overshoot and settling times can be reduced or even avoided. In addition, loop gains can be increased, which improves the low-frequency disturbance rejection properties. For five nonlinear integrators—the Clegg integrator, a generalized first-order reset integrator called the constant-in-gain–lead-in-phase (CgLp) element, a hybrid integrator–gain system, a variable gain integrator, and a split-path integrator—this article provides a comparison and overview of recent developments in stage motion control. Benchmark examples are taken from the industrial practice of wafer scanners, which form the pivotal machines used in the manufacturing of computer chips.

Transportation for people with intellectual and developmental disabilities in Home- and Community-Based Services

BackgroundTransportation can help improve the health, quality of life, and community integration of people with intellectual and developmental disabilities (IDD). Yet, transportation is one of people with IDD's most common unmet needs. ObjectiveThe aim of this study was to examine if, and, how, states provide non-medical transportation to people with IDD in their Medicaid HCBS programs. MethodsUsing content analysis and descriptive statistics, this study analyzed fiscal year (FY) 2021 Medicaid HCBS 1915(c) waivers for people with IDD from across the nation to examine how they allocated transportation. ResultsIn FY 2021, all 44 states and the District of Columbia with HCBS waivers for people with IDD provided transportation services. Transportation was included either by providing a stand-alone service that exclusively provided transportation, or by being embedded within another service. Transportation was embedded within 896 different HCBS services for people with IDD, most commonly within residential habilitation services (26.70 %), supported employment services (19.44 %), and day habilitation (18.44 %). Thirty-three states (73.33 %) also provided 145 different stand-alone transportation services in their programs for people with IDD, to increase community integration and help people gain access to waiver services. A total of $781.78 million of spending was projected for stand-alone transportation services for 261,109 people with IDD (30.32 % of waiver recipients). ConclusionsHCBS waivers are an important resource for providing transportation for people with IDD. However, significant variation in how states do so may result in disparities or unmet needs.

The effects of FinTech adoption on bank loan spreads

PurposeThis paper aims to examine the impact of traditional banks’ financial technology (FinTech) adoption on corporate loan spreads and lending practices.Design/methodology/approachThis study examines the impact of FinTech adoption by banks on corporate loan spreads and lending practices. By analyzing data from bank 10-K filings, we develop a novel metric to assess FinTech adoption at the individual bank level. Our analysis reveals a significant positive correlation between increased FinTech adoption and higher corporate loan spreads, particularly for loans that are relatively informationally opaque. This causality is further validated through a quasi-natural experiment. Additionally, we identify trends toward loans with smaller sizes and longer maturities in banks with advanced FinTech integration.FindingsUsing a sample of corporate loans issued from 1993 to 2020, this paper documents a significant positive relationship between a bank’s increased FinTech adoption and higher loan spreads. This correlation is especially noticeable for loans that are informationally opaque. Moreover, the paper reveals trends toward smaller loan sizes and longer maturities with advanced FinTech integration in banks. Overall, these findings indicate FinTech enhances efficiency in processing hard information and holds the potential to enhance financial inclusion.Originality/valueThis paper contributes to two significant strands of finance literature. First, it highlights how banks with advanced FinTech integration gain advantages through enhanced processing of hard information. Furthermore, it underscores the role of FinTech in promoting financial inclusion, particularly for those borrowers facing informational opacity.

Design of hybrid optimized PI controller for power conditioning circuit of piezoelectric energy harvester

Abstract Piezoelectric Energy Harvesters (PEH) are vital in the present day to encourage advancing technology through producing sustainable energy and dealing with economic and ecological issues associated with batteries. The required stable energy production from the PEH is challenging due to its erratic behaviour with input. As such, a power conditioning circuit with an optimized controller is proposed in this paper. The Proportional Integral (PI) controller is utilized to control the boost converter of the PEH system. The conventional approach of selecting the controller parameters, such as Proportional gain (KP) and Integral gain (Ki), fails to produce optimal outcomes and is time-consuming. Metaheuristic optimization techniques such as Aquila Optimization (AO), African Vulture’s Optimization Algorithm (AVOA) and Hybrid Aquila Optimizer-based African Vulture’s Optimization Algorithm (HAOAVOA) are used to optimize the controller parameter. The different stages of PEH system (Rectifier, boost converter without controller, boost converter with un optimized controller and boost converter with optimized controller) are simulated and analysed using MATLAB-SIMULINK® software. An experimental study is executed to validate the performance of the PEH system with optimized controller. The experimentally obtained response is compared with simulation results. In which the HAOAVOA optimized PI controller gives the better response. Furthermore, the power conditioning circuit with a hybrid optimized controller produces an output of 12 V for the input of 6 V.

Design and multiobjective optimization of a two‐point contact ladder‐climbing robot using a genetic algorithm

AbstractThis paper presents the design and optimization of a climbing robot. The design of a ladder‐climbing robot is done with fundamental mathematical considerations. The designed robot is robust enough to manage all environmental calamities, and at the same time, it is optimized for lightweight to reduce the actuator's cost and ease of transportation. An analytical evaluation is carried out for both static and dynamic conditions to determine strength and motion characteristics. The multiobjective optimization of the design parameters of a ladder‐climbing robot is done to obtain optimized values of design parameters. The formulation of an optimization problem that considers the minimization of weight and natural frequency is performed. Using an evolutionary genetic algorithm (GA) for the multicriteria optimization problem is solved, and a Pareto front solution is obtained. The optimal values of the parameters are decided based on the knee selection technique. As both objective functions are contradictory, the optimum results significantly improve the robot's performance. Controlling the proportional–integral–derivative (PID) parameters is crucial as the robot climbs with a two‐point contact gait pattern. The controlling parameters impart stability to the robot. PID parameters like proportional, integral and derivative gain are tunned using the GA. Finally, the developed prototype is tested on the ladders of the tower, and satisfactory climbing motion is achieved.

Study on the stability and ultra-low frequency oscillation suppression method of pumped storage power plant with dual units sharing one pipeline

This paper aims to investigate the stability of the pumped storage power plant (PSPP) with dual units sharing one pipeline (DUSOP) and the method of suppressing the ultra-low frequency oscillation (ULFO) characteristics. Firstly, four nonlinear models of pumped storage regulation system (PSRS) with DUSOP are established under the design scenarios of no surge tank, upstream surge tank (UST), downstream surge tank, and upstream and downstream dual surge tanks. Then the stability of the PSRS under different surge tank arrangements (STAs) in the long diversion system design scenarios (LDSDS) is comparatively analyzed. Finally, based on the concept of stability margin, the influence mechanism of the operating points on the ULFO characteristics is investigated in the LDSDS with UST, and the influence of the governor parameters, hydrodynamic parameters, and mechanical parameters on the damping ratio and frequency of the system is also analyzed. The results show that among STAs, the design scheme of arranging the UST is more reasonable for PSPP with LDSDS from the comprehensive consideration of the economy of the project and the stability of the system. For PSPP with UST, on the line of equal stability margin, increasing the proportional gain, reducing the unit inertia time constant, reducing the water flow inertia time constant, and appropriately increasing the area of the surge tank can increase the frequency and reduce the amplitude, which is conducive to the suppression of ULFO. In the stability domain range, increasing the proportional gain increases the frequency and the system stability increases and then decreases. Increasing the integral gain decreases the frequency and then increases the system stability. At the same time, the frequency of the unit can be changed by adjusting the parameters of the system to avoid resonance between the frequency of the unit and the frequency of the power grid and to ensure the stability and safety of the unit operation.

Fuzzy Based Quick Acting DC Link Voltage Controller for Three Phases of D-Statcom Connected to the Microgrid

The microgrid systems are the combinations of solar photovoltaic, wind energy, fuel cell and battery systems, as well as conventional generators for backup. The micro grid system barriers that are encountered for their integration to the network. In power systems, voltage stability and power quality are major problems. Due to fluctuations in dc link voltage, changes in load may have an effect on the compensation. This work offers a fuzzy logic-based supervisory approach to enhance the performance of the dc link transient. The controllers employ proportional and integral gain changes with fuzzy logic PI controllers integrated with distribution static synchronous compensator (D-STATCOM). These changes occur in the transient response phase right after a load fluctuation. In order to verify the suggested controller, mathematical equations are given to compute the gains of the traditional controller using fuzzy-logic PI fast-acting dc-link voltage controllers for obtaining similar quick transient reaction. Fuzzy logic PI controller enhancements that employ greater sampling during the transient period and expert knowledge of system behavior enhance the controller's performance. Compared to a standard PI controller, a dc link error reduces the capacitor voltage during a load shift. Utilizing the suggested method and the outcomes of MATLAB simulations, it will be demonstrated that efficiency and the voltage's quick settling time.

A compensator design and stability margin monitor for digitally controlled DC-DC converters

ABSTRACT In this paper, an automatic direct digital design approach for compensators is presented to achieve a lookup table proportional – integral – derivative controller. Additionally, a correlation-based stability margin monitor with adaptive sliding window smoothing is proposed to increase the identifiable range for bandwidth detection. The proposed automatic compensator design approach meets the expected phase margin and crossover frequency and considers limit-cycle oscillation conditions throughout the design process. The digital controller with the direct digital design was implemented on a field programmable gate array to validate the approach and alternative design capabilities. Experimental results show that the direct digital design yields a higher crossover frequency than digital redesign. The best transient response performance can be obtained if a proper integral gain is designed. The digital controller with ASWS was fabricated using the TSMC 1P6M 0.18-μm standard CMOS process. Further experimental results show that the proposed ASWS provides a significantly more accurate identified frequency response by using narrow windows at low frequencies and expansive windows at high frequencies.

Control and recalibration of path integration in place cells using optic flow.

Hippocampal place cells are influenced by both self-motion (idiothetic) signals and external sensory landmarks as an animal navigates its environment. To continuously update a position signal on an internal 'cognitive map', the hippocampal system integrates self-motion signals over time, a process that relies on a finely calibrated path integration gain that relates movement in physical space to movement on the cognitive map. It is unclear whether idiothetic cues alone, such as optic flow, exert sufficient influence on the cognitive map to enable recalibration of path integration, or if polarizing position information provided by landmarks is essential for this recalibration. Here, we demonstrate both recalibration of path integration gain and systematic control of place fields by pure optic flow information in freely moving rats. These findings demonstrate that the brain continuously rebalances the influence of conflicting idiothetic cues to fine-tune the neural dynamics of path integration, and that this recalibration process does not require a top-down, unambiguous position signal from landmarks.

Adaptive neural event-triggered consensus control for unknown nonlinear second-order delayed multi-agent systems

In this paper, we discuss event-triggered consensus control for a heterogeneous second-order multi-agent systems with unknown nonlinear functions and state delays (SODMASs). Firstly, a broad adaptive dynamic event-triggered mechanism (ETM), which includes many existing ETM, is proposed. Based on this ETM and the approximation property of neural networks, an adaptive event-triggered protocol with weight estimation of neural network and time-varying integral gain compensation is designed to reduce communication frequency and to eliminate the uncertainty of nonlinear function and state delays. Then, the consensus problem for the heterogeneous SODMASs under the protocol is solved successfully by selecting a suitable Lyapunov–Krasovskii functional. In addition to these, it is also proved that all agents can exclude Zeno behavior under the proposed event-triggered protocol. Finally, a numerical example is given to verify the effectiveness of the proposed consensus protocol algorithm.

Regulation of mixed convective flow in a horizontal channel with multiple slots using P, PI, and PID controllers

AbstractThis study numerically investigates mixed convective cooling in a two‐dimensional horizontal channel containing periodically heated blocks by applying proportional (P), proportional‐integral (PI), and proportional‐integral‐derivative (PID) controllers. Three different controller configurations regulate the amount of cold air entering the chamber. The air's non‐dimensional temperature is continuously monitored at the set point to compare the controllers’ performance, and the percentage of overshoot and the steady‐state error are analysed. The investigated chamber comprises one inlet and two exit ports, a temperature sensor, and two heated blocks that are isotherm heat sources. The Galerkin finite element approach computationally solves the equations of continuity, momentum, and energy to analyse the thermo‐fluid phenomena occurring within the chamber. Parametric simulation is carried for different values of the proportional gain (Kp = 0.005, 0.010, 0.050 m s−1 K−1), the integral gain (Ki = 0.05, 0.10, 0.15 m s−2 K−1), the derivative gain (Kd = 10−5, 10−4, 10−3 m K−1) to achieve a consistent and expeditious response. Variations of Reynolds, Richardson, and mean Nusselt numbers with time are plotted to compare the system's performance. The investigation indicates that the PI controller produces a comparable level of performance with the PID controller, reducing the necessity to add a derivative controller.

Antenna Array Design Based on Low-Temperature Co-Fired Ceramics.

With the continuous development of wireless communication technology, the frequency band of 6G communication systems is moving towards higher frequencies such as millimeter waves and terahertz. In such high-frequency situations, wireless transmission requires antenna modules to be provided with characteristics of miniaturization, high integration, and high gain, which presents new challenges to the development of antenna technology. In this article, a 4 × 4 antenna array using multilayered low-temperature co-fired ceramic is proposed, operating in W-band, with a feeding network based on substrate-integrated waveguide, and an antenna element formed through the combination of a substrate-integrated cavity and surface parasitic patches, which guaranteed the array to possess the advantages of high integration and high gain. Combined with the substrate-integrated waveguide to a rectangular waveguide transition structure designed in the early stage, a physical array with a standard metal rectangular waveguide interface was fabricated and tested. The test results show that the gain of the antenna array is higher than 18 dBi from 88 to 98 GHz, with a maximum of 20.4 dBi.

A coherent integration method of an active sonar for maneuvering turning target detection.

The detection probability of underwater weak targets using active sonar is low, and inter-pulse coherent integration can improve the signal-to-noise ratio of echoes. When a target executes a maneuvering turn, complex range and Doppler frequency migrations occur during the coherent integration time that decrease the coherent integration gain. Most existing integration methods simplify the target motion to a finite-order polynomial model but fail to integrate a maneuvering turning target (MTT) due to model mismatch. Hence, this study proposes an underwater MTT integration method based on the modified Radon-Fourier transform. The proposed method constructs a theoretically accurate motion model for the MTT and a phase compensation function to compensate for the Doppler frequency migration. Furthermore, it yields a well-focused integration peak in the range-velocity and offset angle-turn rate dimensions and accurately estimates the target motion parameters. Moreover, the proposed method is suitable for targets with radial and oblique uniform motions. The effectiveness of the proposed method is demonstrated through simulations and a lake test. The proposed method demonstrates good integration performance, with an integration gain approximately 4-7 dB higher than that of traditional methods when using 30 integration pulses.

RESEARCH OF STRUCTURAL AND MECHANICAL PROPERTIES OF MEAT AS AN OBJECT OF PROCESSING IN MEAT COMMINUTOR

Reliable assessments of the state of modern energy show the relevance of scientific and technical developments aimed at solving its problems. In this regard, the use of resonance phenomena in electrical circuits with active-reactive elements acquires particular significance. Their various combinations open up exceptional opportunities for creating fundamentally new efficient energy sources. This article discusses a resonant active electrical power amplifier containing a sequence of several electrically connected active-reactive circuits, which, depending on the purpose, are excited in the voltage resonance or current resonance mode. An equivalent circuit is proposed for the proposed resonant amplifier of active electrical power, represented by two blocks, each of which consists of a sequence of inductively coupled active-reactive circuits excited at the same frequency. Calculations are presented showing the theoretical justification for the performance of the proposed scheme. The analysis of ongoing electromagnetic processes was carried out using well-known methods of the theory of electrical circuits without involving any hypotheses about the physics of resonance phenomena. It is shown that in the proposed amplifier circuit, the first block amplifies the reactive power of the harmonic signal with a high conversion coefficient, the second, with a slight gain, converts the reactive power of the harmonic signal into active power. The results of calculations are presented, illustrating the functional dependence of the integral gain on the main characteristics of the output resonant circuit. Numerical estimates of the main characteristics of the proposed circuit showed that with an appropriate choice of its parameters, high values of the output characteristics are possible, so the gain can reach a value of ~ 48. The significance of the results obtained for practice lies in their use for formulating recommendations for the creation of real efficient sources of electrical energy, the principle whose actions are based on the use of natural resonance phenomena.

A square split ring resonator-based metamaterial integrated high gain 4 × 4 MIMO antenna with circular polarization for wideband 5G millimeter-wave applications

A square split ring resonator-based metamaterial integrated high gain 4 × 4 MIMO antenna with circular polarization for wideband 5G millimeter-wave applications

Carbon-silicon based hybrid quantum dot short wave infrared photodetector

Recently infrared photodetectors based on low-dimensional semiconductors have developed rapidly. However, due to its poor light absorption and incompatibility with traditional silicon-based readout circuit processes, the sensitivity and integration of such photodetectors are limited. In this work, we proposes a 64 × 64 quantum dot short-wavelength infrared (SWIR) photodetector composed of carbon nanotube thin film transistor (CNT TFT) and silicon-based ROIC. CNT TFT's gate is constructed by PbS colloidal quantum dots (PbS CQDs) which improve the absorption rate of infrared light. The generated photovoltage is amplified and converted in situ by CNT TFT. Notably, under infrared radiation of 1300 nm, the noise equivalent current reach up to 1.25*10−13A/Hz1/2. At a drain-source bias (Vds)= -0.1 V. The device exhibits detectivity of 5.6*1013 Jones and a fast response of 0.57 ms. The silicon-based ROIC is implemented by CMOS 0.18um process, with a power supply voltage of 1.8 V. It mainly includes a programmable integrator, a sampling and holding circuit, and a 10bit/2.5 MHz successive approximation analog-to-digital converter (SAR ADC). The programmable integrator has four levels of integral gain to meet the application requirements of different infrared light intensities. The experiment results show that the imaging function of the overall photodetector is correct, laying the foundation for the development of carbon-silicon based heterojunction integrated photodetector in the future.

Observer‐based hybrid triggered control design for cluster synchronization of nonlinear complex dynamical networks

SummaryThe issues of cluster synchronization and state estimation for a class of nonlinear complex dynamical networks are concurrently focused in this study. In precise, led by the design of complex dynamical networks, a proportional integral‐based observer is implemented for achieving robustness, by the virtue of which the states of examined networks are estimated. Thereupon, a proportional integral observer‐based hybrid triggered control scheme is proposed, wherein, the switch‐over between time‐ and event‐ triggered scheme is governed through a Bernoulli distributed random variable. Further, with the application of mixed and passivity performance technique, the external disturbances for the addressed complex dynamical networks are reduced. Based on the Lyapunov stability theory, the requisite sufficient conditions in respect of linear matrix inequalities are provided which ensures the discussed complex dynamical network's synchronization phenomenon. In a further, the presented criteria are exploited for the attainment of required controller, proportional and integral gain matrices. In conclusion, the applicability of proposed results and efficacy of the undertaken strategy are evidently proven with the illustration of two numerical examples with Chua's circuit and Goodwin oscillator model.

Implementation of ARM STM32F4 microcontroller for speed control of BLDC motor based on bat algorithm

Brushless direct current (BLDC) motor speed performance is an essential component that must be considered in the electric vehicle drive system. This research aims to obtain the transfer function from the mathematical modeling of the BLDC motor and optimization of the BLDC motor so that a high transient response is received. The method used in this study is to identify system parameters and then model them using the structure of the autoregressive exogenous (ARX) polynomial model. Meanwhile, to get a high transient response performance, optimization is done with a hybrid intelligent controller. The experimental findings indicate that the optimization process utilizing the bat method yielded the most favorable transient response. The resulting values for the proportional gain (Kp), integral gain (Ki), and derivative gain (Kd) were determined to be 31.2685, 7.7375, and -1.1934, respectively. In the current investigation, the minimum frequency value is 6381934.619. Also determined are the transient response characteristics, which include a rise time of 0.289 seconds, a settling time of 10.9 seconds, an overshoot of 3.4%, and a peak time of 1.04 seconds. Furthermore, the closed-loop system demonstrates stable behavior in terms of stability.

A fuzzy adaptive complementary filter for attitude estimation based on norm judgment

Unmanned aerial vehicle (UAV) has great application prospect because of its capability of three-dimensional space operation. The reliability of attitude and heading reference system (AHRS) for UAV attitude estimation is crucial for the application of UAV. When a UAV is subjected to unknown electromagnetic interference and force interference in flight, its attitude detection system can suffer from reduced accuracy or even failure. In this paper, a fuzzy adaptive complementary filter (CF) for attitude estimation based on norm judgment is proposed to solve the problem that the sensor is easily disturbed by the complex flight environment and the fixed filter parameters are difficult to obtain the UAV attitude accurately under different flight states. Firstly, the correction model of the gyroscope, which includes four filter parameters, namely accelerometer weight, magnetometer weight, proportional gain P and integral gain I, is established. Secondly, the influence of the four parameters on the estimation accuracy is analyzed. Finally, the adaptive adjustment rules are designed to adjust the filter parameters online and thus achieve the accurate and reliable measurement of UAV attitude. The feasibility of the proposed algorithm is verified through static, dynamic and interference experiments with the specially designed AHRS test platform. And the results show that the attitude estimation algorithm designed in this paper can ensure the high accuracy of the system in both steady state and high-speed rotation, shield the pitch and roll angles from the acceleration of motion, and keep the yaw angle from the external magnetic field.

PID Optimization Tuning Using Lagrangian Mechanics

Creating a simulation of a system enables the tuning of control systems without the need for a physical system. In this paper, we employ Lagrangian Mechanics to derive a set of equations to simulate an inverted pendulum on a cart. The system consists of a freely-rotating rod attached to a cart, with the rod’s balance achieved through applying the correct forces to the cart. We manually tune the proportional, integral, and derivative gain coefficients of a Proportional Integral Derivative controller (PID) to balance a rod. To further improve PID performance, we can optimize an objective function to find better gain coefficients.