Active Control Strategy Research Articles

Active Compliance Smart Control Strategy of Hybrid Mechanism for Bonnet Polishing.

Compliance control strategies have been utilised for the ultraprecision polishing process for many years. Most researchers execute active compliance control strategies by employing impedance control law on a robot development platform. However, these methods are limited by the load capacity, positioning accuracy, and repeatability of polishing mechanisms. Moreover, a sophisticated actuator mounted at the end of the end-effector of robots is difficult to maintain in the polishing scenario. In contrast, a hybrid mechanism for polishing that possesses the advantages of serial and parallel mechanisms can mitigate the above problems, especially when an active compliance control strategy is employed. In this research, a high-frequency-impedance robust force control strategy is proposed. It outputs a position adjustment value directly according to a contact pressure adjustment value. An open architecture control system with customised software is developed to respond to external interrupts during the polishing procedure, implementing the active compliance control strategy on a hybrid mechanism. Through this method, the hybrid mechanism can adapt to the external environment with a given contact pressure automatically instead of relying on estimating the environment stiffness. Experimental results show that the proposed strategy adapts the unknown freeform surface without overshooting and improves the surface quality. The average surface roughness value decreases from 0.057 um to 0.027 um.

A hybrid active fault-tolerant control scheme for wind energy conversion system based on permanent magnet synchronous generator

A hybrid active fault-tolerant control scheme for wind energy conversion system based on permanent magnet synchronous generator

A New Active Motion Control Strategy for Built-in Wave Energy Converter of Ocean Data Buoys

A New Active Motion Control Strategy for Built-in Wave Energy Converter of Ocean Data Buoys

Grid-Forming Inverter Primary Control Using Robust-Residual-Observer-Based Digital-Twin Model

Grid-forming (GFM) inverters with inductor-capacitor (LC) filters are used to interface distributed generation with the grid. However, the GFM inverter systems are prone to incipient multiplicative faults due to the inherent parameter drift phenomenon of the LC filter. Motivated by this scenario, this paper presents a primary active fault-tolerant control (PAFTC) strategy based on the robust-residual-observer-based-digital-twin model (RRODTM) to achieve the fault-tolerant control for the incipient multiplicative faults. The RRODTM is composed of a robust residual observer and a residual-driven compensation controller. Specially, the residual-driven compensation controller is designed by the data-driven method based on the multiplicative uncertainty caused by the incipient multiplicative faults. At the same time, this paper constructs a data-driven-event-trigger mechanism based on stability margin to achieve the plug-and-play (PnP) function of the residual-driven compensation controller. Based on these, the PAFTC strategy improves the control performance online according to the degree of the incipient multiplicative fault. Comprehensive experiments show that compared to well-known control schemes in the literature, the PAFTC strategy improves the power distribution accuracy and transient response speed as well as enhances the robustness of the system.

Research on active suspension-based anti-rollover control strategy for side-unloading dump trucks during lifting operations

Research on active suspension-based anti-rollover control strategy for side-unloading dump trucks during lifting operations

Active Disturbance Rejection and Voltage Stabilization Control Strategy for Energy Storage Converter in Microgrid Based on Observation State Correction

Active Disturbance Rejection and Voltage Stabilization Control Strategy for Energy Storage Converter in Microgrid Based on Observation State Correction

Enhancing Vehicle Lateral Stability: A DDPG-Based Active Anti-Roll Bar Control Strategy

Enhancing Vehicle Lateral Stability: A DDPG-Based Active Anti-Roll Bar Control Strategy

Active Disturbance Rejection Control Strategy for a Novel Wide-rotor Bearingless Switched Reluctance Motor

Active Disturbance Rejection Control Strategy for a Novel Wide-rotor Bearingless Switched Reluctance Motor

Inverter PQ Control With Trajectory Tracking Capability for Microgrids Based on Physics-Informed Reinforcement Learning

The increasing penetration of inverter-based resources (IBRs) calls for an advanced active and reactive power (PQ) control strategy in microgrids. To enhance the controllability and flexibility of the IBRs, this paper proposed an adaptive PQ control method with trajectory tracking capability, combining model-based analysis, physics-informed reinforcement learning (RL), and power hardware-in-the-loop (HIL) experiments. First, model-based analysis proves that there exists an adaptive proportional-integral controller with time-varying gains that can ensure any exponential PQ output trajectory of IBRs. These gains consist of a constant factor and an exponentially decaying factor, which are then obtained using a model-free deep reinforcement learning approach known as the twin delayed deeper deterministic policy gradient. With the model-based derivation, the learning space of the RL agent is narrowed down from a function space to a real space, which reduces the training complexity significantly. Finally, the proposed method is verified through numerical simulation in MATLAB-Simulink and power HIL experiments in the CURENT center.With the physics-informed learning method, exponential response time constants can be freely assigned to IBRs, and they can follow any predefined trajectory without complicated gain tuning.

A Dual Receiver Inherent Hybrid CC-CV Topology With Half Active Rectifier Control Scheme for Semi-Dynamic WRIPT Electric Vehicle Charging System

A Dual Receiver Inherent Hybrid CC-CV Topology With Half Active Rectifier Control Scheme for Semi-Dynamic WRIPT Electric Vehicle Charging System

Projektovanje kretanja besposadnog guseničnog vozila po zadatoj putanji na osnovu ADRC regulatora i FIL simulacija

Introduction/purpose: The trajectory tracking control problem in an unmanned tracked vehicle (UTV) represents a challenging task, due to unknown and unmeasurable slippage dynamics which inevitably exists during movement. Therefore, the application of standard industrial control schemes is often limited. Methods: In this paper, an active disturbance rejection control (ADRC) scheme is proposed for the longitudinal (vehicle longitudinal velocity control) and lateral (vehicle course angle control) control channels of the UTV to collectively handle all the plant modeling uncertainties and acting slippage disturbances. Results: A step-by-step procedure for applying the ADRC algorithm for the specific case of UTV trajectory tracking is presented. It includes systematic design, discretization as well as performance analysis and validation utilizing FPGA-in-the-loop (FIL) simulations. Conclusions: The proposed FIL-based validation method reduces the gap between pure simulation design (which may be too idealized) and implementation on the real vehicle (which may be time-consuming). The obtained experimental results show the advantages of the proposed control structure over standard industrial PI/PID controllers in different working conditions.

Time-delayed control of a nonlinear self-excited structure driven by simultaneous primary and 1:1 internal resonance: analytical and numerical investigation

<p>Main objective of this research to eliminate the resonant vibrations and stabilize the unstable motion of a self-excited structure through the implementation of an innovative active control strategy. The control strategy coupling the self-excited structure with a second-order filter, which feedback gain $ \lambda $ and control gain $ \beta $, as well as a first-order filter, which feedback gain $ \delta $ and control gain $ \gamma $. The coupling of the second-order filter to establish an energy bridge between the structure and the filter to pump out the structure's vibration energy to the filter. In contrast, the primary purpose of coupling the first-order filter to stabilize the closed loop by adjusting the damping of the system using the control keys $ \delta $ and $ \gamma $. Accordingly, the mathematical model of the proposed control system formulated, incorporating the closed-loop time delay $ \tau $. An analytical solution for the system model obtained, and a nonlinear algebraic system for the steady-state dynamics of the controlled structure extracted. The system's bifurcation characteristics analyzed in the form of stability charts and response curves. Additionally, the system's full response simulated numerically. Findings the high performance of the introduced controller in eliminating the structure's resonant vibrations and stabilizing non-resonant unstable motion. In addition, analytical and numerical investigations revealed that the frequency band within which the second-order filter can absorb the structure's resonant oscillation relies on the algebraic product of $ \beta $ and $ \lambda $. Furthermore, it was found that the equivalent damping of the system depends on the algebraic product of $ \gamma $ and $ \delta $, which can be employed to stabilize the negatively damped self-excited systems. Finally, it reported that although the loop delay can potentially degrade vibration control performance, the time-delay stability margin is nonlinearly proportional to the product of $ \gamma $ and $ \delta $. This finding that increasing the value of $ \gamma \times \delta $ can compensate for the adverse effects of loop delay on both system stability and vibration suppression efficiency.</p>

Battery Degradation Oriented Active Control Strategy by Using a Reinforcement Learning Algorithm in Hybrid Energy Storage System

Battery Degradation Oriented Active Control Strategy by Using a Reinforcement Learning Algorithm in Hybrid Energy Storage System

Research on intelligent active disturbance rejection control algorithm for shock train leading edge of dual-mode scramjet

To prevent scramjet inlet unstart, stringent control over the shock train's leading edge in the isolator is necessary. Therefore, this study proposes a fuel flow active control scheme combining an adaptive particle swarm optimization algorithm (APSO) and active disturbance rejection control (ADRC) to enhance the traditional control (such as proportional-integral-derivative, PID) system's stability and anti-interference capabilities in complex and uncertain environments. Within this context, a simple, semi-empirical mathematical model of a dual-mode scramjet is constructed. An ADRC controller is designed to counteract the nonlinearity and disturbance of the dual-mode scramjet. ADRC, not requiring an accurate mathematical model, utilizes its extended state observer to estimate all uncertain factors affecting the controlled object based on the relationship between the shock train's leading edge and the controller's output, treating them as unknown disturbances for compensation, thereby exhibiting strong anti-interference capabilities. In order to optimize the performance, the APSO is introduced to fine-tune the ADRC controller parameters. The APSO reduces the rise time of ADRC from 22.28 to 11.39 ms, and the adjustment time from 40.05 to 13.64 ms. The APSO effectively tunes the parameters of the ADRC controller, which ensures rapidity comparable to the PID and all-coefficient adaptive control (ACAC) in managing the shock train's leading edge. At the same time, ADRC has stronger anti-interference ability and adaptive ability than ACAC and PID. This research preliminarily verifies the feasibility and advancement of the ADRC for shock train leading-edge control in scramjet isolators.

Generalized Predictive Control of the Active and Reactive Stator Powers of the DFIG for Wind Energy Generation

This paper proposes a Generalized Predictive Control (GPC) strategy for Wind Power Generation (WPG) based on a doubly fed induction generator (DFIG). The objective is to study and apply a robust active and reactive power control strategy based on GPC of the DFIG, this is likely to optimize the energy production and improve the quality of the energy produced. In order to maximize the amount of WPG taken even when the turbine is uncertain or the wind speed varies abruptly, the design is built utilizing the Maximum Power Point Tracking (MPPT) theory. Through numerical modeling with the aid of the Matlab/Simulink software, the predictive control (GPC) of the active and reactive stator powers of the DFIG was validated. A comparison between the GPC of the GADA and the indirect method based on a typical PI controller is developed in order to illustrate the viability of the suggested method. According to the simulation results of this comparison, the suggested method is viable and has promising results.

Active vibration hybrid control strategy based on multi-DOFs piezoelectric platform

With the increasing requirements for vibration isolation in multiple degrees of freedom (multi-DOFs), active control strategy is becoming more meaningful. However, the vibration isolation performance is limited by the time delay of feedback control, and cannot meet higher requirements. Therefore, this paper proposes a multi-DOFs active vibration hybrid control (AVHC) strategy based on a piezoelectric platform. The AVHC integrates the adaptive feedforward control based on the modified recursive least squares (MRLS) algorithm, and the feedback control based on the integral force feedback (IFF) algorithm. To achieve advanced response, the ground-based vibration signal is offset by the MRLS algorithm. To further reduce the coupling of multi-DOFs, the feedback and feedforward coordinates are fused through the matrix transformation, and the signals are linearly superimposed by the AVHC. The experimental results show that the AVHC can further reduce the resonance peaks of the three translational directions ( X/ Y/ Z) compared with the feedback (FB) control. The resonance peaks are reduced from 14.6 dB (FB) to 3.11 dB (AVHC), from 14.56 dB (FB) to 5.14 dB (AVHC), and from 12.44 dB (FB) to 3.78 dB (AVHC) in X/ Y/ Z directions, respectively. The attenuation rates are improved by 73.36%, 66.19%, and 63.10% in X/ Y/ Z directions, respectively.

Active distance control in multi-capsule endoscopy via closed loop electromagnetic force between capsules.

Capsule endoscopy offers a non-invasive and patient-friendly method for imaging the gastrointestinal tract, boasting superior tissue accessibility compared to traditional endoscopy and colonoscopy. While advances have led to capsules capable of drug delivery, tactile sensing, and biopsy, size constraints often limit a single capsule from having multifunctionality. In response, we introduce multi-capsule endoscopy, where individually ingested capsules, each with unique functionalities, work collaboratively. However, synchronized navigation of these capsules is essential for this approach. In this paper, we present an active distance control strategy using a closed-loop system. This entails equipping one capsule with a sphere permanent magnet and the other with a solenoid. We utilized a Simulink model, incorporating (i) the peristalsis motion on the primary capsule, (ii) a PID controller, (iii) force dynamics between capsules through magnetic dipole approximation, and (iv) position tracking of the secondary capsule. For practical implementation, Hall effect sensors determined theinter-capsule distance, and a PID controller adjusted the solenoid's current to maintain the desired capsule spacing. Our proof-of-concept experiments, conducted on phantoms and ex vivo bovine tissues, pulled the leading capsule mimicking a typical human peristalsis speed of 1cm/min. Results showcased an inter-capsule distance of 1.94mm ± 0.097mm for radii of curvature at 500mm, 250mm, and 100mm, aiming for a 2-mm capsule spacing. For ex vivo bovine tissue, the achieved distance was 0.97 ± 0.28mm against a target inter-capsule distance of 1mm. Through the successful demonstration of precise inter-capsule control, this study paves the way for the potential of multi-capsule endoscopy in future research.

Robust control of a single-ended primary inductor converter using adrc technique

Control of a single-ended primary inductor converter (SEPIC) is a challenging task as it is a fourth-order non-linear system. In this paper, an active disturbance rejection control (ADRC) scheme is proposed for the SEPIC converter with a high switching frequency. Selection of the observers and controller bandwidth is done according to the maximum sensitivity requirement to achieve robust performance towards varying input voltage and load. The effectiveness of the suggested ADRC is shown by calculating power and efficiencies for different loading conditions.

Transient Tip Clearance Prediction Model Considering Transient Radial Temperature Distribution of Discs in a Gas Turbine Engine

Abstract The tip clearance of turbomachinery components, such as compressor and turbine, significantly impacts the gas turbine engine performance, including the thrust and fuel consumption. Therefore, an appropriate prediction of the turbomachinery tip clearance is indispensable in improving the accuracy of engine performance evaluations. The traditional 1D transient tip clearance prediction model does not consider the radial temperature distribution of the disk (also called disc). However, as the engine performance keeps improving, the radial temperature gradient of the disk also increases. In order to maintain the prediction accuracy within an acceptable range, a generic transient tip clearance prediction model is developed in this paper. Based on the special treatment of the axial and radial convective heat transfer boundary regions of the disk, a 2D transient heat transfer model is established, and the radial temperature of the disk is predicted. At the same time, the interaction effect of the thermal expansion between the two different layers of the shroud is studied to improve the prediction accuracy further. In addition, the centrifugal deformation of the blade and disk with variable-thickness characteristics is considered in the new transient model. Compared with the traditional 1D transient prediction model, the model developed in this paper further improves the predicting accuracy of the transient tip clearance, which is verified by the high-fidelity fluid–solid–thermal coupling method. The prediction model provides a useful tool for evaluating the transient tip clearance. It may also benefit the future design strategy of active clearance control.

Design Methodology of Wind Turbine Rotor Models Based on Aerodynamic Thrust and Torque Equivalence

Limited by scaling effects, the physical model tests of FOWTs (floating offshore wind turbines) cannot simulate the aerodynamic loads on rotors correctly. To solve this problem, the real-time hybrid model tests in wind tunnels were developed and provided a feasible solution for the aerodynamic simulation. To perform the wind tunnel tests, the design of aerodynamic equivalent rotor models is most critical. In this study, an innovative methodology of aerodynamic equivalent design for the wind turbine rotors is developed based on GA (genetic algorithm). The NREL (National Renewable Energy Laboratory) 5 MW and DTU (Technical University of Denmark) 10 MW rotors are employed for the case studies to validate the proposed methodology. According to the results, the model-scale aerodynamic thrust performance can be accurately matched with the prototype in the entire region between cut-in and cut-out wind speeds, which allows the rotor model to provide correct thrust at different wind speeds. The variance of the aerodynamic torque with the wind speeds for the developed model is also in good agreement with the prototype, which could be beneficial for the design of the model-scale active pitch control strategy. Moreover, the applicability of the fitness functions of GA is discussed.