Output Control Research Articles

Synthesis of Output-Feedback Controllers for Mixed Traffic Systems in Presence of Disturbances and Uncertainties

In this paper, we study mixed traffic systems that move along a single-lane ring-road or open-road. The traffic flow forms a platoon, which includes a number of heterogeneous human-driven vehicles (HDVs) together with only one connected and automated vehicle (CAV) that receives information from a subset of neighbors. The dynamics of HDVs are assumed to follow a general continuous-time nonlinear car-following model, which is a function of their velocity, spacing, and the relative velocity. The acceleration of the single CAV is also directly controlled by a dynamical output-feedback controller. The ultimate goal of this work is to present a robust control strategy that can smoothen the traffic flow in the presence of undesired disturbances (e.g. abrupt deceleration) and parametric uncertainties. A prerequisite for synthesizing a dynamical output controller is the stabilizability and detectability of the underlying system. Accordingly, a theoretical analysis is presented first to prove the stabilizability and detectability of the mixed traffic flow system. Then, two <inline-formula> <tex-math notation="LaTeX">$H_\infty$</tex-math> </inline-formula> control strategies, with and without considering uncertainties in the system dynamics, are designed. The efficiency of the two control methods is subsequently illustrated through numerical simulations, and various experimental results are presented to demonstrate the effectiveness of the proposed controller to mitigate disturbance amplification and achieve platoon stability.

Energy efficiency of an electric boiler with indirect surface resistive heating of the heat carrier

Introduction. The share of energy for heating of households makes up to 80 % of the total energy consumption. Works on increase of energy efficiency of HVAC equipment make the biggest contribution to reduction of manmade impact on the environment. Power-to-Heat technology — electric boilers used for heating with water systems with radiators and low-temperature heating devices of the “warm floor” type. The research of energy efficiency of the wall mounted electric boiler equipped with the heat generator of indirect surface resistive heating of the heat carrier is presented.&#x0D; &#x0D; Materials and methods. The object of the research is an electric boiler ARDERIA E24, with a nominal capacity of 24 kWh, equipped with a circulation pump, an expansion tank with a volume of 6 L, a group of hydraulic safety and heat carrier recharge. Control of the capacity of the boiler is carried out on semistors with cooling radiators located on the reverse line of the circulation circuit. The boiler is equipped with an electric heat generator with indirect resistor surface heating of the heat carrier.&#x0D; &#x0D; Results. The studied electric heat generators have high specific volumetric power equal to 9.3 kWh/dm3. The average specific power of tubular electric heaters is 25.1 watts/cm2. The coefficient of energy efficiency of the boiler is 0.986. The hydraulic resistance of the unit is 1.25 meters of water column at a flow rate of 1.0 m3/h.&#x0D; &#x0D; Conclusions. The application of the electric heat generator design consisting of a cast aluminum block with tubular heating elements placed inside and a spiral coolant circulation pipe showed high energy efficiency with coefficients of 0.98–0.986 in the modulation range of heat output. The heat output modulation factor of the electric boiler is 12 (2–24 kW). The energy intensity of the heat generator design is 9.3 kWh/dm3, which is significantly higher than traditional heat generation units with “wet” heating elements. The boiler’s heat output control system eliminates the possibility of the temperature rising above 88 °C on the inner heating medium circulation pipe surface.

Experimental study on interlayer interference effect of CBM commingled production in a multi-pressure system under output control mode

This research adopted the self-developed test device to conduct tests to understand the interlayer interference in a multi-pressure system under output control mode. It analyzed the reservoir response and gas production characteristics in coalbed methane (CBM)'s commingled production and discussed the interlayer interference mechanism. The results revealed that the CBM's commingled production at the initial stage would generate interlayer interference under the output control mode, causing the cross-fluids of interlayer fluids. The interlayer interference would form a gas-production state. That is, the gas production of reservoirs with high fluid energy would inhibit that of the reservoirs with low fluid energy. When the gas production of reservoirs with high fluid energy is attenuated, that of reservoirs with low fluid energy would start recovering to maintain stable production. The reservoir pressure gradients positively influence interlayer interference. The more significant the difference between the reservoir's fluid energies aggravates, the more severe this interlayer interference. The output control values negatively affect the interlayer interference, as their increase would weaken the severity of interlayer interference. Therefore, the output control design should appropriately increase the output value or rationally select the reservoirs with a slighter difference in fluid energies. The gas model can be divided into three: conventional type, inhibitory type, and reverse-flow type, and their production stage can be divided into five different phases: gas rise, gas inhibition, reverse flow, gas recovery, and gas attenuation.

Model reference adaptive disturbance rejection control using partial-state feedback

In this paper, we propose a partial-state feedback model reference adaptive control strategy for uncertain linear time-invariant systems with unmatched disturbances. The new control design is based on parametrization and observer technique. The control structure and output matching of nominal partial-state feedback disturbance rejection are presented. The adaptive partial-state feedback disturbance rejection scheme guarantees closed-loop system stability and asymptotic output tracking. A simulation example indicates the effectiveness of the presented adaptive partial-state feedback control design.

ARX/NARX modeling and PID controller in a UV/H2O2 tubular photoreactor for aqueous PVA degradation

Water-soluble polymers are widely employed as additives in many different industries. The need to treat sewage contaminated with water-soluble polymers is essential to prevent persistent pollutants from entering our environment. The advanced oxidation process (AOP), UV/H2O2 process, is used in this study to degrade polyvinyl alcohol (PVA) in aqueous solutions. However, a suitable modeling approach and a control scheme are required to remove the PVA polymer and reduce hydrogen peroxide (H2O2) residual in the treated effluent within a safe level to prevent adverse effects on the aquatic system as well as subsequent biological processes. This study presents black-box modeling for identifying the dynamics of polyvinyl alcohol (PVA) degradation in a series of UV/H2O2 photo-reactors, where the process input and response variables are inlet hydrogen peroxide concentrations and effluent pH, respectively. Data processing, model development, and process simulation are performed using MATLAB R2019b software. In this study, the linear AutoRegressive with eXogenous input (ARX), non-linear ARX (NARX), and Hammerstein-Wiener models are considered as base system models, where the sigmoid-network-based NARX produced the best representation with 82.24% of the trainset and 76.28% of the validation-set of the process dynamics. The design of PID controllers tuned using ARX and sigmoid-network-based NARX models are discussed, and the controller performance is analyzed for set-point tracking and disturbance rejection through simulation studies. The closed-loop response of ARX-PID and NARX-PID are deemed adequate. In fact, the NARX-PID performs much better for the studied process achieving an integrated absolute error (IAE) of 0.6211 with a settling time of 4.63 h, whereas the ARX-PID has lower IAE (0.4238) and produces a more aggressive controlled output response robust in disturbance rejection. Thus, ARX-PID is adequate for frequent process disturbances but less suitable for process set-point tracking.

Electromagnetically induced transparency via localized surface plasmon mode-assisted hybrid cavity QED

In recent years, most studies have focused on the perfect absorption and high-efficiency quantum memory of the one-sided system, ignoring the characteristics of its optical switching contrast. Thus, the performance of all-optical switching and optical transistors is limited. Herein, we propose a localized surface plasmon (LSP) mode-assisted cavity QED system which consists of a Λ-shaped three-level quantum emitter (QE), a metal nanoparticle and a one-sided optical cavity with a fully reflected mirror. In this system, the QE coherently couples to the cavity and LSP mode respectively, which is manipulated by the control field. As a result, considerably high and stable switch contrast of 90% can be achievable due to the strong confined field of the LSP mode and perfect absorption of the optical medium. In addition, we obtain a power dependent effect between the control field and the transmitted frequency as a result of the converted dark state. We employ the Heisenberg–Langevin equation and numerical master equation formalisms to explain high switching, controllable output light and the dark state. Our system introduces an effective method to improve the performance of optical switches based on the one-sided system in quantum information storage and quantum communication.

Coordinated Control Design for Ethical Maneuvering of Autonomous Vehicles

This paper proposes a coordinated control design method, with which the autonomous vehicle is able to perform ethical maneuvers. The starting point of the provided method is a thorough analysis on the ethical concepts for autonomous vehicle control design methods. Using the results of the analysis, an own concept is provided based on some principles of Protestant ethics. The concept focuses on improving trust in vehicle control through clear rules and predictable vehicle motion, and it is in line with the state-of-the-art ethical vehicle control methods. Moreover, an optimal Model Predictive Control (MPC) design method is formed, in which the provided ethical concept is incorporated. The outputs of the optimal control are steering angle and velocity profile, with which the ethical maneuvering can be achieved. The contribution of the paper is a coordinated control design method, which is able to involve ethical principles. Moreover, the application of Protestant ethics in this context is also a novel achievement in the paper. The effectiveness of the method through different simulation scenarios is illustrated.

Mechanical and tribological assessment of AA7075 reinforced Si3N4/TaC/Ti hybrid metal matrix composites processed through stir casting process

ABSTRACT In the present research work, microstructural, mechanical and tribological aspects of Aluminium alloy (AA) 7075 reinforced with Titanium (Ti), Tantalum Carbide (TaC), and Silicon Nitride (Si3N4) ceramic particles were explored by utilising stir casting. Mechanical attributes like compression, tensile, hardness and flexural were evaluated. Dry sliding wear experiments at both room (30°C) and elevated atmospheric (60°C & 120°C) conditions were conducted to investigate the wear performances. Microstructural analyses reveal homogeneous distribution of reinforcements in the matrix along with good interfacial bonding with negligible amount of agglomeration. Considering the effect of hard ceramic materials in the matrix alloy tensile, compression, flexural and hardness of the developed MMCs found to be improved when compared with base alloy. Finer grains restrict the dislocation movement due to the Orowan strengthening mechanism of the developed hybrid MMCs. As the force enhances from 20 N to 40 N, the rate of wear for AA7075 reinforced with 0.75 wt% TaC, 6 wt% Si3N4, and1 wt% Ti was found to be minimum. Taguchi and Analysis of Variance (ANOVA) were performed to acquire the optimum process and dominating parameters. Regression analysis showed the relationship between the output and input control factors.

A Method and an Algorithm for Implementing Relay Protection of 6(20)/0.4 kV Step-down Transformer Substations

The article discusses a method and an algorithm for implementing the protection system for a 6(20)/0.4 kV transformer substation, using which its reliable operation is secured regardless of the grid configuration and operation mode and the operation parameters of higher-level electrical installations. The proposed method makes it possible to clear any fault in the 0.4 kV network with minimal time delays. To this end, it is necessary to supplement the 0.4 kV network with current transformers (if they are not available) and forward the algorithm control output to the circuit breaker tripping coils. To ensure short-range backup protection, the circuit breakers protective functions remain in operation. Based on the existing electrical network, the approximate pickup parameters of the proposed method are pointed out, and recommendations for their optimization are given. Various contingencies in the 0.4 kV electrical network are considered to verify the correct functioning of the proposed relay protection method and algorithm.

Part B: Steering and control of an autonomous vehicle in emergency lane change maneuvers based on skilled driver’s performance

This paper considers the vehicle control process in emergency lane change (ELC). The control method is divided into two parts: before crossing the obstacle and after crossing it. The first part is done by a feed-forward controller inspired by the driver’s behavior pattern in the ELC maneuver. This controller is compensated by a neural network system and two proportional-integral (PI) and proportional-derivative (PD) controllers, which correct the output of the feed-forward controller to follow the path more accurately. The second part consists of two PD controllers responsible for controlling and steering the vehicle in the main path after crossing the obstacle. The main novelty of the proposed method is that the computational burden is low because of using a feed-forward controller, which is the main source of the calculation’s burden. So as a result, the controller system can cover the ELC maneuver in under 2 seconds in various lateral displacements to bypass the obstacle and prevent collisions. The co-simulations are performed in CarSim software and MATLAB/Simulink, which shows that the control system can appropriately steer the vehicle and follow the desired at different speeds, in the presence of road friction and parameter uncertainty.

A new scheme of plasma control system based on real-time Linux cluster for HL-2M

HL-2M is a medium-sized tokamak constructed by the Southwestern Institute of Physics (SWIP) in China. A new plasma control system (PCS) based on the software framework of DIII-D PCS for HL-2M has been proposed to replace the original loose system. The new hardware system proposed in this paper consists of three computer nodes and peripheral equipment. Data acquisition is completed by a standing server and a reflective memory network that passes back data. The software architecture of DIII-D PCS is generally retained, but some interfaces are added to adapt to the existing system. In addition, the Linux operating system has also been upgraded and optimized so that real-time tasks can achieve better performance. The initial system involves some basic control algorithms satisfying early experiments. The new PCS has been preliminarily verified through simulation and can output control commands as expected in the integrated environment. This paper focuses on two aspects of DIII-D PCS on a new device, i.e., performance and interface adaptation. More efforts will be made to add more algorithms and use the system in real experiments.

Course keeping control for very large ship using hyperbolic tangent function based on nonlinear decoration technique

To solve the problems of difficult course keeping, high energy output, and large wear of very large ships under different sea conditions, a robust controller combining the closed-loop gain shaping algorithm and nonlinear decoration is proposed in this paper. Firstly, a linear controller is designed by using the third-order closed-loop gain shaping algorithm and takes the hyperbolic tangent function as the nonlinear decoration of the controller output, and the robustness of the system is proved by H∞ robust control theory. Secondly, taking ‘Vale Brasil’, an ore carrier with a displacement of 400,000 tons, as the test plant. The nonlinear Nomoto model and nonlinear Norrbin model were established, which were compared with the control effect from the existing controller. Thirdly, simulation experiments were carried out under normal sea state and heavy sea state to prove the effectiveness. The results indicate that the proposed control strategy can achieve the required course faster, and enhances the smoothness of rudder angle actuation compared with the existing controller. It can maintain good control ability under different sea conditions. The proposed controller has the advantages of simple parameter adjustment, better robustness, less energy consumption, and reduced rudder angle. It is more in line with engineering practice and increases ship operation benefits.

Harmonic and synchronous compound control of a dual-valve controlled single-rod electro-hydraulic actuator

This article presents a novel harmonic and synchronous compound control scheme based on the dual-valve parallel structure for controlling a single-rod electro-hydraulic actuator with high-precision control and large-flow requirements. Harmonic and synchronous compound control consists of an adaptive robust control layer and a control law allocation layer. In adaptive robust control layer, an adaptive robust control algorithm is designed to deal with the system nonlinearities and uncertainties via backstepping method. Meanwhile, dynamic surface control technique and “lumped flow” are introduced to solve the differential explosion problem and the multiple input-single output control problem. In control law allocation layer, the harmonic and synchronous compound strategy allocates the control law to two valves reasonably based on system flow and valve frequency characteristics. Furthermore, since the effect of the proportional valve dead-zone can be compensated effectively by combining the estimation of the dead-zone flow by adaptive term, the estimation error compensation by robust term, and the allocation method of control law allocation layer, improved tracking performance can be achieved. Finally, both simulations and experiments are demonstrated to illustrate the advantages of the proposed control scheme.

Mixed H∞ and passive resilient control for discrete-time systems with Round-Robin protocol and deception attacks

This paper focuses on the mixed [Formula: see text] and passive resilient control problem for uncertain discrete-time networked control systems subject to time delays. The measurement output is considered to be quantized by the dynamic quantizer before transmission through an unreliable communication channel, where the deception attacks may occur randomly. To further reduce the communication burden, the Round-Robin (RR) protocol is adopted to schedule sensors in a predetermined transmission order. Meanwhile, a new performance index is developed to solve restriction of the same dimension of control output and the exogenous disturbance. The S-procedure combined with a two-step uncertainties elimination method is adopted to deal with the nonlinear product terms involving multiple uncertainties. Furthermore, a decoupling method is introduced for static output feedback controller design. Sufficient conditions of the resilient controller and the dynamic quantizer are provided, which can improve the robustness of resulting closed-loop system and guarantee its stochastic stability and the specified mixed [Formula: see text] and passivity performance index. Finally, an example is given to illustrate the feasibility of the theoretical results.

Hybrid bidirectional multilevel inverter structures for induction motor drive

AbstractMultilevel inverters performance enhancement is a major topic, which has attracted the attention of most of the researchers, to evolve with newer topologies and modulation strategies. In this manuscript, two novel hybrid bidirectional multilevel inverter structures, which are suitable for bidirectional loads, are proposed. An enhancement in the voltage levels and reduction of the component count are achieved for these newly introduced structures. Modular expansion and series cascading are suggested systems for extension of the voltage levels. The prime requirement in most of the industrial drives is a controlled output. VSI fed induction motor drive satisfies this requirement. The Multicarrier PWM technique has been applied to the basic bidirectional seven level models and nine level model and its performance with induction motor as load has been analyzed for various modulation indices. The simulated results of the proposed structures are verified using MATLAB/SIMULINK platform. The characteristics such as stator current, rotor current speed and torque plots achieved as above model affirm that its performance is good. By then, the tracking time of the proposed work during reference speed change, load change and constant reference change is 0.185, 1.094 and 1.5 s. The tracking time of the VSI during reference speed change, load change and constant reference change is 0.5 s, 3.8 and 3.5 s. The tracking time of the MLI during reference speed change, load change and constant reference change is 0.2 s, 1.8 and 2 s.

DC Voltage Output Control of a Hybrid Synchronous Generator-based Wind Turbine

This article discusses regulating a Wind Turbine (WT) that uses a Hybrid Excitation Synchronous Generator (HESG) to power an isolated load via a diode bridge rectifier. The HESG acts as a DC generator and supplies power to the DC load. The primary objective of the suggested control strategy is to maintain a steady DC voltage output, even when there are changes in rotor speed and/or load. The entire system is simulated and modelled in Matlab/Simulink, and the simulation results prove the effectiveness of the proposed method in delivering power to an isolated location.

High power Ho:Y2O3 ceramic laser with controllable output intensity profile at 2.1 µm.

We report on a high-power Ho:Y2O3 ceramic laser at 2.1 µm with controllable output beam profile ranging from LG01 donut, flat-top to TEM00 mode using a simple two-mirror resonator. In-band pumped at 1943nm using a Tm fiber laser beam shaped via a coupling optics comprising a capillary fiber and lens-combination to achieve distributed pump absorption in Ho:Y2O3 and hence selective excitation of the target mode, the laser yields 29.7 W of LG01 donut, 28.0 W of crater-like, 27.7 W of flat-top and 33.5 W of TEM00 mode output for absorbed pump power of 53.5 W, 56.2 W, 57.3 W and 58.2 W, respectively, corresponding to a slope efficiency of 58.5%, 54.3%, 53.8% and 61.2%. This is, to the best of our knowledge, the first demonstration of laser generation with continuously tunable output intensity profile at ∼2 µm wavelength region.

Research on multi-objective collaborative control of complex product development in equipment manufacturing industry

Abstract Equipment manufacturing involves the integration of multiple technologies and is a complex product system. In the independent innovation of complex product systems, product development is the most important way. Multi-objective cooperative control has been applied to various industries with remarkable results. In this paper, high quality research and development of complex products in equipment manufacturing industry is the main goal. Inspired by the dimensional parameters of the key structures of the product and the structure of the endocrine regulation network, a multi-objective collaborative controller consisting of a speed and position coordinator, a module consisting of a speed and position coordinator, a hormone discriminator, a hormone optimizer, and a controller is designed. The data from the cooperative control study shows that when the controller parameters [3, 1, 2] are used, the velocity parameter is 0.7, the differential parameter is 0.04, and the controller output parameter is 0.8. The force control parameter is 2, the differential parameter is 0.05, and the controller output parameter is 0.7. In the multi-objective cooperative control experiment, the navigator makes a uniform circular or uniform linear motion with [v 1, w 1] T = [0.06,0.09] T . The vector forms r 2 d = [0.4,0.4] T, r 3 d =[−0.1,0.2] T ,. Both the red curve and the blue curve of the follower appear jittered. The experimental curves and control trajectories illustrate that the controller has good control over the vibration and shock phenomena that occur during the position and speed as well as force control of the product. And exhibits good tracking performance. It shows that the multi-objective collaborative controller plays a role in improving the quality of the development of complex products in the equipment manufacturing industry.

Research on a Three-Dimensional Fuzzy Active Disturbance Rejection Controller for the Mechanical Arm of an Iron Roughneck

In the position control of the mechanical arm of an iron roughneck (MAIR), a controller with high responsiveness, high accuracy, and high anti-interference capability is necessary. An MAIR consists of two proportional-valve-controlled single-extension (PVCSE) hydraulic cylinders, and a traditional proportional–integral–derivative (PID) controller cannot easily achieve the accuracy and robustness requirements of the hydraulic cylinders. In this paper, a three-dimensional fuzzy active disturbance rejection controller (TF-ADRC) is proposed for an MAIR, which adds a three-dimensional fuzzy module to a classical active disturbance rejection controller (ADRC) to adjust the controller output according to the tracking of differential deviation, deviation change rate, and deviation change acceleration rate. Firstly, the trajectory planning of the MAIR was carried out using the quintic polynomial interpolation method to improve the smoothness of the target trajectory. Then, the reliability of the established model was verified by experiments. Finally, the comprehensive performance of a PID controller, fuzzy PID controller, ADRC, and TF-ADRC were compared based on the AMESim-Simulink model. The system with the TF-ADRC exhibits higher position control accuracy and better anti-interference capability than the system with a PID or Fuzzy PID controller, and accuracy is higher compared with the common ADRC.

Synthesis of Dynamic Output Feedback Controller Using Functions of Matrix Root-Clustering in D-Regions

This article considers an algorithm for the synthesis of dynamic output controller, where the eigenvalues of a closed control system should be located in a given region (D-region) of the complex plane. The main direction of the research is to synthesize dynamic controllers of minimal order when there is no complete controllability at the output. For this purpose, a brief excursion into the external Grassmann algebra is made with the purpose of determining the external product of vectors, on the basis of which the operation of the bialternate product of matrices is explained. The use of the bialternate product of matrices made it possible to introduce the functions of matrix root-clustering of complex eigenvalues located in separate transformable D-regions. For the usual product of matrices, the functions of matrix root-clustering of real eigenvalues located in separate transformable D-domains are introduced. The functions of matrix root-clustering are transforming, respectively, complex or real points of a given bounded or unbounded D-region of the complex plane into a left half-plane. The article considers the main D-domains most widely used in practice (disk, cone, stability margin), presents their matrix root-clustering and functions of matrix root-clustering of real and complex modes. An algorithm for parametric optimization of dynamic output feedback controller over D-domains has been developed. Practical examples of synthesis are considered. For a fourth-order object (a two-mass weakly damped system with two integrators and parametric uncertainty), a secondorder dynamic controller providing robust quality has been synthesized.