Integral Control Method Research Articles

Model based smooth super-twisting control of cancer chemotherapy treatment

Chemotherapy is one of the most efficient methods for treating cancer patients. Chemotherapy aims to eliminate cancer cells as thoroughly as possible. Delivering medications to patients’ bodies through various methods, either oral or intravenous is part of the chemotherapy process. Different cell-kill hypotheses take into account the interactions of the expansion of the tumor volume, external drugs, and the rate of their eradication. For the control of drug usage and tumor volume, a model based smooth super-twisting control (MBSSTC) is proposed in this paper. Firstly, three nonlinear cell-kill mathematical models are considered in this work, including the log-kill, Norton-Simon, and Emax hypotheses subject to parametric uncertainties and exogenous perturbations. In accordance with clinical recommendations, the tumor volume follows a predefined trajectory after chemotherapy. Secondly, the MBSSTC is applied for the three cell-kill models to attain accurate trajectory tracking even in the presence of uncertainties and disturbances. Compared to conventional super-twisting control (STC), the non-smooth term is introduced in the proposed control to enhance the anti-disturbance capability. Finally, simulation comparisons are performed across the proposed MBSSTC, conventional STC, and proportional–integral (PI) control methods to show the effectiveness and merits of our designed control method.

Noise-Suppressing Newton Algorithm for Kinematic Control of Robots

In this paper, armed with the integral control method, a new noise-suppressing Newton (NSN) algorithm is proposed for the redundancy resolution of redundant robot manipulators efficiently. For practical hardware implementation, the discrete-time noise-suppressing Newton (abbreviated as DTNSN) algorithm is discretized from the continues NSN algorithm. Specifically, the distinguishing feature of the proposed DTNSN algorithm is that it can rigorously converge with inherent tolerance to noises induced by communication jamming and computational systematical errors. In contrast, considerable traditional algorithms often dispose of noises with the high-degree filter from the viewpoint of signal processing, which requires a complex system structure and further results in a heavy computational burden. Note that theoretical analyses are provided to elaborate the convergent property of the DTNSN algorithm polluted with constant bias, time-dependent linear noises and bounded random noises. Besides, by the proposed DTNSN algorithm, the end effector of both serial and parallel redundant robot manipulators complete the allocated motion planning and are impervious to the noisy simulated environment.

Comprehensive Analysis and Solution of Voltage Build-Up Failure in Aircraft PM-Assisted Reluctance Starter/Generator System

Permanent magnet assisted reluctance (PMAREL) machine possesses the potential as the aircraft starter/generator (S/G) for its high power density, high efficiency and tolerance to short-circuit faults. For aircraft S/G systems, the voltage build-up is a prerequisite for power generation. However, the voltage build-up of the PMAREL S/G system may fail if the initial DC-link voltage is low and the control is fast-response. In this paper, the mechanism of the voltage build-up failure is clarified. The conduction feature of power devices in the power electronic converter when the DC-link voltage is clamped at 0 V are explored. Conditions for clamping the DC-link voltage at 0 V all the time is determined. An integrated control method is proposed to cope with the voltage build-up failure as well as improve the dynamic performance of the S/G system. Based on a prototype of PMAREL S/G system, the correctness of the analysis and the effectiveness of the proposed method are verified through experiments.

A Cascaded Multilevel Battery Energy Storage Based Parallel Dynamic Voltage Compensator for Medium Voltage Industrial Distribution Systems

This paper proposes a cascaded multilevel battery energy storage based parallel dynamic voltage compensator (DVC) for medium voltage industrial distribution systems. In this parallel DVC, fast switch is series-connected for voltage sag detection, and cascaded multilevel battery energy storage is parallel-connected for voltage support during the voltage sag period. According to the grid-side voltage sags or not, corresponding circuits and three-layer control strategies are developed. While the feedforward proportional–integral (PI) control method is adopted in the outer layer to track the ideal compensation voltage when the grid-side voltage sags, the ideal compensation current when the grid-side voltage does not sag is obtained through battery charging current as well as reactive power, harmonics, and negative sequence load current components. In order to cope with parameter differences in cascaded multilevel battery energy storage, the middle layer interphase and the inner layer intermodular state of charge (SOC) equalization control are adopted in two scenarios. Furthermore, the parallel DVC is quantitatively compared with series DVC in the aspect of required battery capacity, and their advantages and disadvantages are systematically analyzed. Case studies are performed to verify the effectiveness and superiority of the proposed methodology on voltage support.

Chemical components of different solvent extracts of Asclepias curassavica L. and antibacterial effect of the extracts on tomato pathogens

The use of environmentally friendly and sustainable agricultural methods in the control of diseases and pests is of great importance. In both conventional and organic agricultural production systems, the utilization of various plant extracts as part of integrated pest management has gained significance in recent years. The chemical constituents of various solutions derived from the flowers, leaves, and roots of the Asclepias curassavica L. plant were investigated, along with the possibilities of utilizing these solutions in the control of tomato plant pathogenic bacteria. As a result of the analysis, acetic acid in 60% and 80% ethanol solutions, as well as acetic acid methy ester in 60% and 80% methanol solutions, were detected in the flowers, leaves, and roots. The effects of A. curassavica flower, leaf, and root extracts, prepared using three different solvents (water, methanol, and ethanol), were investigated on eight different pathogenic bacteria (Agrobacterium tumefaciens, Clavibacter michiganensis, Dickeya zeae, Pectobacterium caratovorum, Pseudomonas phaseolicola, Pseudomonas tomato, Pseudomonas viridiflava, and Xanthomonas euvesicatoria) that cause diseases in plants. Several main compounds such as acetic acid, acetic acid. methyl ester, Furfural, 2-Furanmethanol, 4H-Pyran-4-one. 2.3-dihydro-3.5-dihydroxy-6-methyl-, Glycerin, Benzo furan. 2.3-dihydro- and 5-Hydroxy methyl furfural were identified as analyzed by GC-MS with different concentrations of ethanol and methanol solutions used for the flower, leaves and root of A. curassavica plants. The flower extract prepared with 80% ethanol exhibited a higher inhibition zone (ranging from 1.5 mm to 5.3 mm) in all pathogens, compared to other applications. The successful suppression effect of A. curassavica flower extracts on this disease is promising, especially in organic farming areas. Additionally, since it is environmentally friendly and sustainable, it can be included in integrated control methods to prevent the loss of productivity caused by diseases.

Chassis Global Dynamics Optimization for Automated Vehicles: A Multiactuator Integrated Control Method

Chassis Global Dynamics Optimization for Automated Vehicles: A Multiactuator Integrated Control Method

DEVELOPMENT OF METHANE CARBON ISOTOPE BASED ON MID-INFRARED ABSORPTION SPECTRUM TECHNOLOGY APPLIED IN LOGGING PLATFORM

To meet the requirements of rapid measurement of oil and gas methane isotopes in offshore logging platforms, a methane carbon isotope measurement system based on mid-infrared TDLAS technology was proposed in this paper. The measuring system adopted a mid-infrared compact-linear optical structure, including an interband cascade laser (central wavelength at 2963.25 cm-1), long optical path multi-pass cell (effective optical path is 24 m) and mercury cadmium telluride detector (response wavelength is from 2 μm to 5 μm). Combining two 13CH4/12CH4 absorption lines, 2963.25 cm-1 and 2963.34 cm-1, with a high precision temperature control system using an integral separation PID control method, a temperature fluctuation within 100 mK can be achieved. In the experiment, CH4 gases with five different concentrations were configured to calibrate the measurement system, and the response linearity was more than 99%. When the integration time is 121s, the precision of isotope measurement was as low as 0.83 ‰. The average isotopic abundance of methane gas measured by the system was -10.2 ‰, and the error fluctuation was about ±0.5 ‰. It was verified that the system can rapidly measure oil and gas methane isotopes.

An Improved Data-Driven Integral Sliding-Mode Control and Its Automation Application

Circulating fluidized bed (CFB) boilers are widely used in industrial production due to their high combustion efficiency, low pollutant emissions and wide load-adjustment range. However, the water-level-control system of a CFB boiler exhibits time-varying behavior and nonlinearity, which affect the control performance of the industrial system. This paper proposes a novel data-driven adaptive integral sliding-mode control (ISMC) method for the CFB control system with external disturbances. Firstly, the scheme designs a discrete ISMC law based on the full-format dynamic linearization (FFDL) data model, which is equivalent to a nonlinear system. Furthermore, a new reaching law is proposed to quickly drive the system state onto the sliding-mode surface. The improved ISMC control scheme only utilizes the input–output data during the design process and does not require model information. After theoretically verifying the stability of the method proposed in this paper, it is further applied in MIMO systems. Finally, the control and practical effects of this method are evaluated by using the DHX25-1.25 CFB boiler installed in the special-equipment testing center. The experimental results show that, compared with the traditional sliding-mode control (SMC) and model-free adaptive-control (MFAC) methods, the improved control method can quickly track the given signal and exhibit resistance to noise interference. Furthermore, it can rapidly respond to changes in the working conditions of the CFB system.

Research on the Hybrid Wind–Solar–Energy Storage AC/DC Microgrid System and Its Stability during Smooth State Transitions

The hybrid AC/DC microgrid is an independent and controllable energy system that connects various types of distributed power sources, energy storage, and loads. It offers advantages such as a high power quality, flexibility, and cost effectiveness. The operation states of the microgrid primarily include grid-connected and islanded modes. The smooth switching between these two states is a key technology for ensuring the flexible and efficient operation of the microgrid. In this paper, the typical structure of an AC–DC hybrid microgrid and its coordination control strategy are introduced, and an improved microgrid model is proposed. Secondly, an adaptive current–voltage–frequency integrated control method based on signal compensation is proposed to solve the impulse current and voltage generated during the switching between a grid-connected state and an off-grid state. Finally, in response to unplanned grid-connected scenarios, an improved pre-synchronization control strategy based on BP neural networks is introduced to rapidly restore stable operation. The proposed control strategies enhanced the steady-state and transient stability of the hybrid wind–solar–energy storage AC/DC microgrid, achieving seamless grid-connected and islanded transitions without disturbances. The simulation and experimental results validated the correctness and effectiveness of the proposed theories.

An integration planning and control method of intelligent vehicles based on the iterative linear quadratic regulator

This paper proposes an integrated strategy of planning and control to address the poor quality of the generated trajectory by intelligent vehicles. The trajectory planner is designed based on the iterative linear quadratic regulator (ILQR) theory, taking into account the nonlinear dynamics of the vehicle in the trajectory planning layer. The planner directly outputs the control commands that act on the actuator, achieving the integration of planning and control. To improve the control performance of the trajectory planner under extreme operating conditions, a stability controller is developed using the sliding mode control method (SMC). Additionally, a torque distributor is designed to coordinate the control requirements of the trajectory planner and the stability controller, with the optimization goal of minimizing the tire loading rate. Finally, complex scenario tests are carried out under various working conditions to evaluate the performance of the integrated strategy. The results indicate that the integrated strategy outperforms the decoupled strategy in terms of control performance and exhibits better adaptability across various working conditions and scenarios. Even if the reference trajectory is unreasonable, the vehicle can still perform smooth, efficient, and comfortable obstacle avoidance and lane-changing maneuvers. By working in tandem, the stability controller and the trajectory planner can expand the planning and control boundaries of the system, thereby significantly enhancing the system's ability to respond to extreme working conditions.

Comparative gene expression analysis of differentiated terminal and lateral haustoria of the obligate root parasitic plant Phelipanche ramosa (Orobanchaceae)

Societal Impact StatementsThe parasitic weed Phelipanche ramosa thrives on a broad spectrum of cash crops over the Northern Hemisphere. Unfortunately, current management practices are inefficient in controlling its devastating impacts and spread. Here, valuable insights are provided on an understudied aspect of its biology, the formation of a feeding organ network on the rudimentary roots of the parasite tubercle, which will help refine our general knowledge of how parasitic plants develop on their hosts. This research sets the path for a thorough understanding of the biology of parasitic plants, which in the long run will help design integrated control methods.

Integrated Control of the Manufacturing System

In this paper, we propose a method to control the entire production process, starting with customer enquiry up to product delivery, for the make-to-order (MTO) manufacturing system. Method for integrated control of the job shop type manufacturing system proposed in this paper aims to facilitate the connection between the two departments and to achieve integrated control of job shop type manufacturing system on the basis of Earning Power (EP) evaluation. It gives a more accurate picture of a firm's profitability than gross income. The purpose of this paper is to demonstrate the ability of the proposed method on a real case and to illustrate the applicability of mathematical models that were proposed. The main problems for a MTO company manager, i.e. problems related to order acceptance and machine control are solved by the new integrated control method, which is included in this paper.

Digital-Power-Communication Concept for Energy Coordination in PV-Battery-Charging DC Microgrid

A new digital-power-communication (DPC) concept is proposed to better realize information interaction and energy coordination in the PV-battery-charging DC microgrid, which uses the DPC auxiliary power supply as carrier. The DPC auxiliary power supply can be used to replace other communication modules as a common carrier for auxiliary power supply and information interaction of microgrid interface converter. Then, the implementation conditions of DPC are indicated that this communication concept requires active power consumption and an adjustable resonant network. Meanwhile, an appropriate circuit topology of the DPC auxiliary power supply is evolved. Furthermore, an integrated control method of optimal-admittance information regulation & power supply is further proposed for the DPC auxiliary power supply, and the implementation mechanism of this method is analyzed in detail by establishing the admittance model. More importantly, based on this method, the contradiction between power supply quality and signal intensity can be solved in the transmit mode, and the received signal intensity of the communicating node can be significantly enhanced in the receive mode. Finally, the PVbattery-charging DC microgrid platform is developed, and the experiment result verify the feasibility of the DPC concept and the effectiveness of the proposed control method.

Model-free fast integral terminal sliding-mode control method based on improved fast terminal sliding-mode observer for PMSM with unknown disturbances

This paper presents a novel model-free fast integral terminal sliding-mode control (MFFITSMC) method based on an improved fast terminal sliding-mode observer (IFTSMO) for permanent magnet synchronous motor (PMSM) drive system, which can effectively eliminate the impact caused by unknown disturbances, such as parameter perturbations and external disturbances. The PMSM mathematical model with unknown disturbances is first established, and the ultra-local model (ULM) of the PMSM speed loop is constructed. Next, the model-free fast integral terminal sliding-mode controller is designed in the speed loop based on the ULM. Then, the IFTSMO is designed to precisely estimate the unknown term of the ULM, and the estimated unknown term is fed back to the MFFITSMC controller to perform compensation for unknown disturbances in real time. Finally, compared with the proportional–integral (PI) control method and the conventional model-free sliding-mode control (MFSMC) method, the results of simulations and experiments demonstrate that the presented MFFITSMC method reduces the dependence on the precise model and achieves the purpose of anti-disturbance control of the PMSM drive system.

Frequency Stability Enhancement Using Differential-Evolution- and Genetic-Algorithm-Optimized Intelligent Controllers in Multiple Virtual Synchronous Machine Systems

In this paper, multiple virtual synchronous machines (VISMAs) with fuzzy proportional integral derivative (FPID) controllers optimized by differential evolution (DE) are proposed to maintain frequency stability in the grid in the presence of renewable penetration, such as wind and solar photovoltaic (PV) systems, residential loads, and industrial loads, by reducing the area control error in the objective function. Simulations are conducted using MATLAB/Simulink, and in the optimization process, the integral of the time-weighted absolute error (ITAE) is used as the objective function. In the work to obtain optimized values of renewable energy sources (RESs), fuzzy membership functions, controller gain parameters, and loads for system modeling, differential evolution and genetic algorithm (GA) methods are applied and the results were compared. It was shown that better results were achieved while FPID controllers were optimized by DE in the presence of multiple VISMAs than DE in the presence of single VISMAs and GA in multiple VISMAs. Moreover, the study is compared to integral control methods in which, compared to all controllers, the proposed controller reduces undershoot by 0.0674 Hz more than a single VISMAs, in which it is improved approximately by 97.82%. Similarly, the proposed controller improves the system settling time, rise time, and overshoot by more than 99.5% compared to the classical integral controller. To examine the robust operation of the system under the proposed controller, the system was run under a wide range of disturbances and uncertainties using random load perturbation of ± 20%, in which the proposed controller retains the system frequency by reducing or damping the system oscillation.

Anti-Disturbance Integrated Control Method and Energy Consumption Analysis of Central Heating Systems Based on Resistance–Capacitance Reactance

Under the dual carbon strategy, with the frequent occurrence of extreme weather and the further increase in uncertainty of multi-user behavior, it is urgent to improve the stability of the heating systems and reduce heating energy consumption. Aiming at the problem of fault-disturbance control of the multi-user heating network in an integrated energy system, this paper proposes a novel analysis method of resistance–capacitance reactance based on the circuit principle to construct a dynamic thermal-power-flow model of the whole link of the multi-user heating network and analyze the fault-disturbance propagation characteristics of the heating network by this model. It shows that the difference in disturbance characteristics of different users in a multi-user heating network mainly depends on the characteristics of the heating pipeline between the heat user and the heat source, which provides a necessary basis for formulating intelligent control strategies against fault disturbance. Finally, taking a typical daily outdoor temperature in Beijing in winter as an example, this paper compares two different heating strategies and the blocker installation methods of the multi-user heating network to obtain a better heating strategy under actual conditions. Considering the heating fault disturbance, this paper proposes a novel intelligent heating strategy whose heating temperature will decrease during the fault-disturbance time, with an energy saving of about 16.5% compared with the heating strategy under actual conditions during the same period.

Integrated Control and Performance Analysis of High-Speed Medium-Voltage Drive Using Modular Multilevel Converter

The modular multilevel converter (MMC) is highly attractive to develop high-speed medium-voltage variable frequency drives (MV VFDs) due to its cascaded design, high-quality output, and strong reliability. However, high-speed MV VFDs have demanding requirements in capacitor voltage stabilization, current regulation, dynamic response, etc. The instability and distorted voltage/current could easily occur if MMCs are used as high-speed MV VFDs. This paper presents a high-speed VFD with SiC-based MMC feeding a permanent magnet synchronous machine. A new integrated control method is specifically proposed to address the aforementioned issues covering the low-/middle-/high-speed range. Performance analysis is conducted in terms of efficiency, power density, output current quality, and speed range. Steady-state and dynamic conditions are evaluated by a full-scale simulation model and a high-power SiC-based MMC testbed. Results show that the proposed method effectively removes the large capacitor voltage fluctuations, resonant circulating current, and saturated output voltage from zero to the highest speed. Compared with existing MMC VFDs of limited speed (< 4000 rpm), the SiC-based MMC VFD has three times higher speed (15000 rpm), improved efficiency (99.43%), high power density, and low current harmonic distortions.

Numerical simulations of submarine self-propulsion flows near the free surface

Submarine needs to complete more tasks near the free-surface area in modern war. When sailing near the free surface, the self-propelled characteristics of the submarine and its nearby flow field will be affected by the free surface. This paper presents the research on the self-propulsion submarine near the free surface with computational fluid dynamics (CFD) method. We take the generic Joubert BB2 submarine and Marine 7371R propeller models as the research objects. The RANS method and SST k-ω turbulence model are selected to solve the turbulent flows. The volume of fluid (VOF) method is used to capture the free surface. Grid convergence study is performed based on three sets of grids with different resolution. Numerical simulations are performed under the self-propulsion cases with different submergence depths and velocities. The proportional integral (PI) controller method is proposed to obtain the self-propulsion point. The results are more accurate compared with the traditional one. It is found that with the decrease of the submergence depths, the rotating speed of the self-propelled point and the corresponding thrust increase. The study also explores the free surface effect on flow field characteristics, wave-making characteristics and vortex structures. The scientific findings provide some useful results for the self-propulsion submarines near the free surface and support the further research in the future.

Path Following and Lateral-Yaw-Roll Stability Integrated Control Method for Autonomous Distributed Drive Electric Buses

Path Following and Lateral-Yaw-Roll Stability Integrated Control Method for Autonomous Distributed Drive Electric Buses

A speed loop control method of a laser tracing measurement control system

In a laser tracking control system, a motor drives the load to achieve continuous forward and reverse rotation speed control, and the magnitude of the load changes periodically during the motor rotation to realize tracking. Based on these characteristics, we propose an integral-separated improved variable universe fuzzy proportional-integral (PI) control method with torque feedforward compensation method in this study. The proposed method achieves the control performances of fast response, high steady-state accuracy, and strong anti-interference. The conventional fuzzy PI control method achieves good performance only in the unidirectional acceleration of a motor; therefore, we have improved its fuzzy rules, and designed a novel universe contraction–expansion factor. Additionally, a load torque observer is introduced to observe and compensate for the external load and to further improve the anti-interference performance of the tracking control system. The experimental results demonstrate that the integral-separated improved variable-universe fuzzy PI control method achieves better performance in the forward and reverse speed regulation processes of the motor. The overshoot is 92% less than that of the conventional PI control when the target speed is set to ±500 rpm. The Luenberger observer is introduced to observe and compensate for the load torque. After the stabilizing the speed and applying an external load of 0.2 N m to the motor, the maximum speed reduction is observed to be 59% less than that obtained using the conventional PI control. The improved PI control method satisfies the speed loop control requirements of the laser tracking control system and can improve the steady-state tracking accuracy and robustness of the system.