Coordination Control Research Articles

Reducing the impact of wind load on the operation of information-measuring and control systems of tricopters

The article deals with the issues of reducing the influence of wind load on the information-measuring and control systems of tricopters. A feature of the work is the development of a general mathematical model of a tricopter, taking into account the specific characteristics of the elements: adjustable electric drives, parameter sensors (barometers, accelerometers, rangefinders, etc.). The type and parameters of the controllers of tricopter coordinate control systems are determined. A variant of reducing the influence of wind load on the information-measuring and control systems of tricopters by organizing control loops for the speeds of electric motors is considered.

Robust Hierarchical Pinning Control for Nonlinear Heterogeneous Multiagent System With Uncertainties and Disturbances

This paper investigates the coordination control problem for a special nonlinear heterogeneous multi-agent system consisting of tail-sitter unmanned aerial vehicles and unmanned ground vehicles with uncertainties and disturbances. A robust hierarchical pinning control scheme is proposed for the heterogeneous multi-agent system to restrain the uncertainties and disturbances and achieve coordination scenarios. The heterogeneous multi-agent system can realize coordination tasks by selecting proper pinning nodes and estimating coupling strength. The robustness of the whole system is proven utilizing the Lyapunov stability theorem. The effectiveness of the robust hierarchical pining control method is validated by simulation scenarios.

Modeling of coordination control system for supercritical unit under wet state operating condition

The coordination control system model of supercritical unit under wet state operating condition is established in this paper. Based on the huge historical operating data of a unit, the static parameters and dynamic parameters of the model are solved by data statistics and regression and genetic algorithm and particle swarm optimization algorithm, respectively. Steady-state operating condition points verification, open-loop step response verification, and historical operation data closed-loop verification are conducted. The results show that the model is accurate and can be used for control system designing. For steady-state condition point verification, the relative error between the model output results and the actual data is less than 3.5%. The open-loop step disturbance test can objectively reflect the response characteristics of the unit. As to the closed-loop verification, the relative error between the model output results and the actual data is within 3%.

A Hybrid Control Strategy for Multimode Switched Reluctance Motors

A hybrid control strategy based on the principle of dynamic coordination control is proposed for switched reluctance motors (SRMs) in this article. The proposed controller can obtain a small torque ripple in a wide speed range. An SRM with 12/10 poles is considered as a multimode SRM as it can be used as a six-phase or a three-phase motor. In the three-phase mode, direct instantaneous torque control based on the torque sharing function is applied, which can achieve a small torque ripple and a large instantaneous torque. In the six-phase mode, the torque ripple of the multiphase SRM is small, but the system stability is insufficient. Angle position control based on active disturbance rejection control is applied to improve the stability of torque output. In order to reduce the energy loss and torque ripple caused by the switching process of the two modes, an improved dynamic coordination principle is designed to control the switching between different modes. The effectiveness of the control method is confirmed by both experiment and simulation results.

Multi-energy coordination control method of power system connected to microgrid of combined cooling, heating and power

The problems of energy shortage and ecological destruction are becoming increasingly serious. As a comprehensive energy utilization system, cogeneration system has gradually become a research hotspot. In order to improve the basic frequency stability and reduce the operation cost, this paper presents a multi-energy coordinated control method for CHP micro-grid. Firstly, the topology of CCHP system is analyzed. On this basis, this paper constructs a CCHP power system including micro turbine (MT) and air conditioning (AC). Secondly, a multi-component composite energy storage method for power system is proposed. Different types of energy storage devices than a single way of energy storage has better performance, to achieve multi-complementary. Finally, in the construction of power system collaborative control model, this paper constructs power system collaborative control model based on load storage optimization idea of source network. Experimental results show that the proposed control method has strong fundamental frequency stability and low operating cost, and has certain application value.

Perfectly Encoding π‐Conjugated Anions in the RE5(C3N3O3)(OH)12 (RE=Y, Yb, Lu) Family with Strong Second Harmonic Generation Response and Balanced Birefringence

AbstractNonlinear optical (NLO) crystal, which simultaneously exhibits strong second‐harmonic‐generation (SHG) response and desired optical anisotropy, is a core optical material accessible to the modern optoelectronics. Accompanied by strong SHG effect in a NLO crystal, a contradictory problem of overlarge birefringence is ignored, leading to low frequency doubling efficiency and poor beam quality. Herein, a series of rare earth cyanurates RE5(C3N3O3)(OH)12 (RE=Y, Yb, Lu) were successfully characterized by 3D electron diffraction technique. Based on a “three birds with one stone” strategy, they enable the simultaneous fulfillment of strong SHG responses (2.5–4.2× KH2PO4), short UV cutoff (ca. 220 nm) and applicable birefringence (ca. 0.15 at 800 nm) by the introduction of rare earth coordination control of π‐conjugated (C3N3O3)3− anions. These findings provide high‐performance short‐wavelength NLO materials and highlight the exploration of cyanurates as a new research area.

Perfectly Encoding π-Conjugated Anions in the RE5 (C3 N3 O3 )(OH)12 (RE=Y, Yb, Lu) Family with Strong Second Harmonic Generation Response and Balanced Birefringence.

Nonlinear optical (NLO) crystal, which simultaneously exhibits strong second-harmonic-generation (SHG) response and desired optical anisotropy, is a core optical material accessible to the modern optoelectronics. Accompanied by strong SHG effect in a NLO crystal, a contradictory problem of overlarge birefringence is ignored, leading to low frequency doubling efficiency and poor beam quality. Herein, a series of rare earth cyanurates RE5 (C3 N3 O3 )(OH)12 (RE=Y, Yb, Lu) were successfully characterized by 3D electron diffraction technique. Based on a "three birds with one stone" strategy, they enable the simultaneous fulfillment of strong SHG responses (2.5-4.2× KH2 PO4 ), short UV cutoff (ca. 220 nm) and applicable birefringence (ca. 0.15 at 800 nm) by the introduction of rare earth coordination control of π-conjugated (C3 N3 O3 )3- anions. These findings provide high-performance short-wavelength NLO materials and highlight the exploration of cyanurates as a new research area.

A Multimodal Analysis of Physical Factors that Influence Adolescents’ Motor Competence

ABSTRACT This study analyzed the factorial structure of motor competence tests designed to evaluate motor development among adolescents, focusing on the two main dimensions of coordination and motor control. To this end, we randomly sampled 1,026 adolescents (45.3% males; 45.7% females, age 13.75 years, SD = 1.28). Participants completed the Multidimensional Sportcomp Motor Battery, which features ten motor competence tests. Results indicate that two factors grouped seven of the ten sub-tests related to upper body strength and skill related-fitness. The factorial structure remained stable across age and sex groups, with the exception of manual grip (grip strength) and 7 Meters with Feet Together (jumping) which may relate to a sex-specific evolutionary pattern for upper body force. The Flexibility, Equilibrium and Lateral Jumps tests were not grouped by this factor analysis on any established dimension. These results underscore the multidimensionality of physical factors that influence motor competence among adolescents.

Rule-Based Time-Optimal Engine-Start Coordination Control With a Predesigned Vehicle Acceleration Trajectory in P2 Hybrid Electric Vehicles

Abstract Removing the integrated starter generator (ISG) in P2 hybrid electric vehicles (HEVs) reduces the overall cost of the powertrain, yet it comes with an additional control complexity of the engine-start process. An appropriate coordination control strategy between the internal combustion engine (ICE), drive motor, and clutch is necessary to reduce the time for the engine-start while constraining the vehicle jerk. A time-optimal coordination control strategy with a predesigned vehicle acceleration trajectory is proposed from results of nonlinear model predictive control (NMPC), which can reduce the time for the engine-start process and obtain a small vehicle jerk. A dynamic model for the engine-start process is first built. In this model, a cylinder-by-cylinder engine model (CCEM) is derived to describe the ICE dynamics. A Karnopp and Stribeck combined wet clutch model is proposed to handle effects of speed difference on the torque, and calculation problem of frequent switches when crossing zero speed point. Subsequently, the optimal control problem is formulated with selected states and solved with NMPC. Finally, a rule-based control strategy is extracted from results of NMPC. Simulation results show that the engine-start process can finish within 260 ms, 13.3% less than the previous study, with a predesigned vehicle acceleration to ensure the vehicle jerk within 10 m/s3 and the peak to peak vehicle acceleration within 0.2 m/s2 in the case study under investigation.

A Dynamics Coordinated Control System for 4WD-4WS Electric Vehicles

With the aggravation of the energy crisis and environmental problems, the new energy electric vehicle industry has ushered in vigorous development. However, with the continuous increase in car ownership, traffic accidents and other issues have gradually attracted widespread attention. Some existing stability coordination control systems often have problems, such as single stability judgment method and strong coupling between different subsystems. Therefore, based on previous research, it is necessary to further optimize the method of judging the vehicle’s stability state, establish clear coordination rules, and reasonably solve the coupling problem between subsystems. This is of great significance for promoting the further development of the electric vehicle industry. Due to four-wheel-distributed driving and four-wheel-distributed steering electric vehicles having the characteristics of integrated driving, flexible steering, and easy fault-tolerant control, it has unique advantages in improving vehicle stability and is a good carrier for designing and constructing the stability coordination control system. In this paper, four-wheel-distributed driving and four-wheel-distributed steering (4WD-4WS) electric vehicles are taken as the research object, and a coordinated control strategy of four-wheel steering and four-wheel drive is proposed. Firstly, in order to realize the accurate judgment of vehicle stability, based on the vehicle two-degree-of-freedom two-track model and magic tire model, this paper uses the phase plane law to divide the phase plane stability region of the vehicle and introduces the stability quantification index PPS-region for the evaluation of vehicle stability. Secondly, a fuzzy variable parameter active rear-wheel steering controller and a compensated yaw moment controller are designed. Then, for the coupling problem between the two controllers, a coordination rule is proposed based on the stability index PPS-region of the phase plane stability region. Finally, a hardware-in-the-loop testbed is built to verify the feasibility of the coordination control strategy proposed in this paper. Experimental results show that: When the vehicle is in different stable states, according to the divided steady state, the control strategy can be correctly switched to the corresponding control strategy, and the work of each subsystem can be reasonably coordinated. Under the continuous gain sine condition, the control algorithm can reduce the maximum amplitude of the yaw rate error response curve by 73% and the side slip angle error response curve by 85%. Compared with a single stability control system, the coordinated stability control algorithm can improve the control effect of yaw rate and side slip angle by 20% and 62.5%. In the case of double lane-change, the control algorithm can reduce the maximum amplitude of the yaw rate error response curve by 68.5% and the side slip angle error response curve by 57.4%. Compared with a single stability control system, the coordinated stability control algorithm can improve the control effect of yaw rate and side slip angle by 40.6% and 44.7%.

Policy coordination and selective corruption control in China

AbstractIn autocracies facing widespread corruption, the allocation of the scant attention available for fighting corruption strongly affects corruption control. Although research has found that authoritarian regimes tend to fight corruption selectively, it is unknown whether and how autocracies allocate attention across different policy areas to combat corruption. We propose that single‐party authoritarian regimes can steer anticorruption attention to the policy domains prioritized by the central authority through the mechanism of cross‐organizational policy coordination. Using original datasets compiled from Chinese governmental and procuratorial policy papers from 1998 to 2016, we demonstrate that Chinese prosecutors direct anticorruption attention to the policy domains accentuated in the central government's major reforms. Our field interviews support this finding and reveal possible disruption of anticorruption efforts in policy domains falling off the central government's top list. Thus, we extend the research on political influence over anticorruption agencies and show that single‐party regimes can instrumentalize anticorruption to serve the government's policy agenda, driving the allocation of limited anticorruption attention across policy areas.

A novel virtual admittance droop based inertial coordination control for medium-voltage direct current ship with hybrid energy storage

In the Medium-Voltage DC (MVDC) ships, pulse load will cause great disturbance to DC bus voltage. Hybrid energy storage (HESS) including Supercapacitor, Lithium batteries and Flywheel will bring significant improvement to the energy regulation ability of the ship integrated power system (IPS). A novel virtual admittance droop control based on the traditional virtual resistor and capacitor droop (VRCD) control is proposed. Through the design of specific virtual admittance structure and parameters, the generator and the HESS can bear the high, medium and low frequency part of the transient power fluctuation according to their own characteristics. Moreover, the State of Charge (SOC) recovery control of energy storage does not depend on the secondary controller, which simplifies the control structure. Simulation and experiment verify the effectiveness of the proposed control strategy.

A novel coordinated control strategy of regenerative braking and anti-lock system for electric vehicles

Regenerative braking is one of the core technologies to improve the economy of pure electric vehicles. To realize the improvement of the energy recovery effect under conventional braking conditions and the coordinated control between regenerative braking and anti-lock system under emergency braking conditions of pure electric vehicles, this paper studies a front and rear axle braking force distribution method with the actual road adhesion coefficient and braking strength as the premise, while using fuzzy control to distribute the front axle electromechanical braking force. The sliding mode controller with double power convergence law is designed to enhance the stability of the anti-lock system. Finally, the braking coordination control strategy is proposed by combining the designed regenerative braking and anti-lock control. Through simulations and experiment, it has been proved that the control strategy is effective and can effectively improve the economy of pure electric vehicles.

Multi-agent deep reinforcement learning-based coordination control for grid-aware multi-buildings

In commercial buildings, Heat, Ventilation, and Air Conditioning (HVAC) systems account for about 40–50 % of total electricity usage, contributing to an economic burden on building operators. Furthermore, increasing amounts of distributed generation can bring challenges and opportunities for voltage regulation in low voltage distribution networks. In this paper, we tend to develop intelligent management to save the electricity bills of HVAC systems in multiple multi-zone buildings while relieving the stress of voltage regulation across the network. However, it is challenging to achieve the above aims due to the existence of parameter uncertainties (e.g., electricity load, outdoor temperature, photovoltaic generation, etc.), a sizeable continuous decision space, unknown thermal dynamics model, and distribution network topology, and a non-convex multi-objective function. In this context, a novel model-free multi-agent deep reinforcement learning (MADRL)-based multi-building control algorithm is proposed to achieve building-side and grid-level objectives. The proposed method adopts a centralized training and decentralized execution framework while integrating an attention mechanism to ease training and preserve privacy. This also enables the agent to achieve control purposes based only on local measurements, reducing communication cost. Simulation results based on real-world data verify that the proposed method can achieve real-time physical-model-free control of multi-buildings to tackle fast fluctuations of voltage and temperature caused by the uncertain external factors while being advantageous over other two MADRL methods. Additionally, comparison analysis on untouched datasets illustrates that the proposed method achieves similar results and better computation performance with the perfect physical-model-based approach.

Simulation study on ramp inflow for hybrid autonomous driving

In view of the complexity of the ramp traffic system on the expressway and the diversity of hybrid automatic driving, the safety distance of vehicles and the corresponding car following model are analyzed based on the combination of driver’s personality characteristics and the characteristics of different automatic driving levels of the vehicle–road​ coordination system, and the risk model is established to screen the potentially dangerous vehicles in the ramp merging process. Based on game theory, this paper constructs a ramp coordination and merging control model suitable for hybrid automatic driving. The model takes the safety benefit and efficiency benefit as the objective function, predicts the benefit value under different strategies and makes the optimal strategy under the current conditions. The proposed model is verified by the joint simulation of Python and sumo. the simulation results show that the average number of combined vehicles is 1.91 times higher, the combined position is 50.11% earlier and the average driving time is 28.35% less than that without control strategy and there is obvious advantage when the density is high compared with vehicles without control strategy.

Coordinate control strategy of VSC-MTDC based on model predictive control

Coordinate control strategy of VSC-MTDC based on model predictive control

Game-based coordination control of multi-agent systems

In this paper, we are interested in how agents interact with each other in multi-agent systems. First, we model the interactions among agents in multi-agent systems as a multi-player game. The topology of the interactions among agents is a directed graph. We design cost functions for the game and assume that each agent in the systems tends to minimize its own cost. Then, the unique Nash equilibrium solution to the proposed multi-player game is obtained as the next state of the agent. A necessary and sufficient condition for achieving multi-agent consensus is established using the system transformation method and graph theory. Furthermore, we extend the result to the problem of containment control in the presence of leaders. The criterion for solving the containment control is also given in this paper. Finally, several simulation examples are given to verify the effectiveness of the theoretical results.

Coordination Control Strategy for Human-Machine Cooperative Steering of Intelligent Vehicles: A Reinforcement Learning Approach

This paper proposes a novel coordination control strategy through reinforcement learning approach for human-machine cooperative steering of intelligent vehicles, so as to realize a more flexible and efficient way for the human driver and the automated driving system to jointly complete the path-following. Firstly, the human-machine cooperative steering is modeled by the optimal preview driver model with adaptive preview time and the MPC lateral tracking model with adaptive prediction horizon and step, as well as the steering system with a realistic dual-motor steering-by-wire structure is also built into the human-machine cooperative steering system. Then, the human-machine coordination control strategy is designed and trained based on two reinforcement learning agents to further optimize the allocation of cooperative steering weights. Finally, the strategy is fully verified in lane departure simulation scenarios and also in real-world Steering-in-the-Loop experiments with real-time controller, which shows that both agents can effectively keep the vehicle with the small lateral and yaw errors in the simulation scenarios, and also can be successfully applied in the realistic human-machine cooperative system to maintain the lateral and yaw errors within a safe range during path-following.

An active power coordination control strategy for hybrid doubly-fed DC system based on actual project

A coordinated control strategy for parallel hybrid doubly-fed DC power transmission system based on the actual project is proposed, which makes full use of the unique advantage of continuous power transmission of LCC-HVDC and VSC-HVDC. This project includes Longquan conventional DC converter station, Yichang back-to-back flexible DC converter station in Hubei province of China and their near AC gird. The control requirements of frequency recovery, damping oscillation and reducing excision of generator sets after the fault are realized by means of VSC/LCC emergency power control, power modulation and frequency modulation. The proposed control strategy is simulated and analyzed in PSCAD/EMTDC, and the effectiveness of that is verified.

Modeling and Control Strategy of Wind-Solar Hydrogen Storage Coupled Power Generation System

Hydrogen production by wind and solar hybrid power generation is an important means to solve the strong randomness and high volatility of wind and solar power generation. In this paper, the permanent magnet direct-drive wind turbine, photovoltaic power generation unit, battery pack, and electrolyzer are assembled in the AC bus, and the mathematical model of the wind-solar hydrogen storage coupled power generation system and the simulation model in PSCAD/EMTDC are established. An energy coordination control strategy is designed. After simulation, the proposed control strategy can effectively reduce the rate of curtailment of wind and solar power, and stabilize the fluctuation of wind and solar power generation. It verifies that the established model is correct and the control strategy is effective and feasible.